PATENT DOCUMENT

Publication Number: US-12097740-B1
Application Number: US-202217677258-A
Country: US
Kind Code: B1

Title: Control system

Abstract:
A support system includes a primary actuator that transfers force between a sprung mass and an unsprung mass. A control system operates the primary actuator to provide additional control when a damper exceeds a capacity threshold. The control system changes the capacity threshold according to the environmental condition.

Claims:
What is claimed is: 
     
       1. A vehicle comprising:
 a vehicle body; 
 a wheel; 
 a suspension system that supports the vehicle body relative to the wheel, wherein the suspension system includes a primary actuator that transfers force between the wheel and the vehicle body, the primary actuator being a ball screw actuator; 
 a sensing system for sensing an environmental condition ahead of the vehicle, learning road disturbance information from the suspension system, and obtaining real-time feedback from the suspension system; and 
 a control system that determines a road disturbance estimation based on the sensed environmental condition and the learned road disturbance information, determines a suspension output including a primary ride control and a secondary ride control based on the road disturbance estimation and the real-time feedback, and operates the suspension system according to the suspension output, 
 wherein the control system operates the primary actuator with a first suspension stiffness setting and with a second suspension stiffness setting that are determined according to the road disturbance estimation. 
 
     
     
       2. The vehicle according to  claim 1 , wherein sensing the environmental condition includes observing a road surface ahead of the vehicle and the real-time feedback from the suspension system includes a vertical wheel acceleration of the wheel. 
     
     
       3. The vehicle according to  claim 1 , wherein learning the road disturbance information includes recording vehicle information as the vehicle is operated over a section of road. 
     
     
       4. The vehicle according to  claim 1 , wherein the first suspension stiffness setting is a low stiffness and the second suspension stiffness setting is a high stiffness that is greater than the low stiffness. 
     
     
       5. The vehicle according to  claim 4 , wherein the control system operates the primary actuator with the second suspension stiffness setting when the sensed environmental condition ahead of the vehicle includes a localized road feature. 
     
     
       6. The vehicle according to  claim 5 , wherein the localized road feature is a pothole or a bump. 
     
     
       7. The vehicle according to  claim 1 , wherein the first suspension stiffness is a default setting at which the control system predominantly operates the primary actuator. 
     
     
       8. The vehicle according to  claim 1 , wherein the first suspension stiffness setting and the second suspension stiffness setting are controlled using gain scheduling. 
     
     
       9. The vehicle according to  claim 1 , wherein the primary ride control includes active damping of inputs to the wheel occurring below 10 Hz. 
     
     
       10. An active suspension system for a vehicle comprising:
 a wheel; 
 an actuator coupled to the wheel; 
 a suspension component coupled to the wheel and the actuator and configured to support the wheel; 
 a sensing system for near-field sensing of a road surface relative to the vehicle; and 
 a control system that determines a feedforward road disturbance estimation according to the near-field sensing, determines suspension output with the feedforward road disturbance estimation, and controls the actuator based on the suspension output, 
 wherein the suspension output includes one or more of primary ride control or secondary ride control, the primary ride control includes active damping of inputs to the wheel occurring below 10 Hz, and the secondary ride control is active damping at frequencies of other inputs to the wheel occurring near a natural frequency of an unsprung mass that includes the wheel. 
 
     
     
       11. The active suspension system according to  claim 10 , wherein the near-field sensing includes one or more of observing the road surface in close proximity to the vehicle or sensing vertical wheel acceleration. 
     
     
       12. The active suspension system according to  claim 11 , wherein the near-field sensing includes both of observing the road surface and sensing the vertical wheel acceleration. 
     
     
       13. The active suspension system according to  claim 10 , wherein the suspension output includes both of the primary ride control and the secondary ride control. 
     
     
       14. The active suspension system according to  claim 10 , wherein the control system further determines the suspension output according to feedback from a sensor coupled to the suspension component. 
     
     
       15. The active suspension system according to  claim 10 , wherein the control system further determines the suspension output according to feedback from a sensor configured to observe a road surface in close proximity to the vehicle. 
     
     
       16. A method for feedforward suspension control of a suspension system of a vehicle comprising:
 performing near-field sensing of a road surface proximate to the vehicle; 
 obtaining real-time feedback from the suspension system; 
 determining a feedforward road disturbance estimation according to the near-field sensing and the real-time feedback; 
 determining a suspension output according to the feedforward road disturbance estimation, the suspension output including a primary ride control and a secondary ride control; and 
 operating the suspension system according to the suspension output which includes controlling a primary actuator with a first suspension stiffness setting and a second suspension stiffness setting that has a greater stiffness than the first suspension stiffness setting. 
 
     
     
       17. The method according to  claim 16 , wherein the real-time feedback includes sensing a vertical wheel acceleration of the vehicle. 
     
     
       18. The method according to  claim 5 , wherein the first suspension stiffness setting is a default setting at which the suspension system controls the primary actuator. 
     
     
       19. The method according to  claim 16 , further comprising learning road disturbance information from the suspension system and determining the feedforward road disturbance estimation is based on the near-field sensing and the learned road disturbance information. 
     
     
       20. The method according to  claim 16 , wherein the first suspension stiffness setting and the second suspension stiffness setting are controlled using gain scheduling.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation of U.S. patent application Ser. No. 16/567,482, filed Sep. 11, 2019, which claims priority to and the benefit of U.S. Provisional Patent Application No. 62/730,058, filed Sep. 12, 2018, the entire disclosures of which are incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to support systems and operation thereof. 
     BACKGROUND 
     Support systems have been developed by which a characteristic of the support may be controlled in response to a present condition. 
     SUMMARY 
     Disclosed herein are implementations of vehicles, suspension systems, control systems, and methods of controlling the vehicles. In one implementation, a vehicle includes a vehicle body, wheels, a suspension system that supports the wheels relative to the vehicle body, a drive system operatively coupled to two or more of the wheels for driving the vehicle, a sensing system for determining a roughness of a road surface ahead of the vehicle, and a control system that determines an operating speed according to the roughness, and operates the drive system to drive the vehicle at the operating speed over the road surface. 
     In one implementation, a vehicle includes a vehicle body, a wheel, a suspension system that supports the wheel relative to the vehicle body, a sensing system for determining an environmental condition ahead of the vehicle and a control system. The suspension system includes a primary actuator that transfers force between the wheel and the vehicle body, and a wheel hop damper that includes a moving mass and that transfers force between the wheel and the moving mass independent of the vehicle body to inhibit resonance of an unsprung mass formed by the wheel and a portion of the suspension system coupled thereto. The control system operates the primary actuator to provide additional secondary ride control when the wheel hop damper exceeds a capacity threshold. The control system changes the capacity threshold according to the environmental condition. The wheel hop damper may be a reaction mass actuator or a tuned mass damper. 
     In one implementation, a vehicle includes a vehicle body, wheels, a suspension system that supports the four wheels relative to the vehicle body, a sensing system for assessing an obstacle ahead of the vehicle, and a control system that operates the suspension to raise a ride height of the vehicle according to the obstacle for the obstacle to pass below the vehicle body and between two or more of the wheels. 
     In one implementation, a vehicle includes a vehicle body, four wheels that include two front wheels and two rear wheels, a suspension system that supports the wheel relative to the vehicle body, a steering system operatively coupled to two or more of the wheels for turning the vehicle, a sensing system for determining an environmental condition ahead of the vehicle, and a control system. The suspension system includes four actuators that are each operatively coupled to one of the four wheels to control force applied between the wheel and the vehicle body. The control system, according to the environmental condition, operates the steering system to turn the vehicle, and one of in advance of or concurrent with operating the steering system to turn the vehicle, operates the suspension system to transfer weight between the four wheels. 
     In one implementation, a vehicle includes a vehicle body, four wheels, a suspension system that supports the wheel relative to the vehicle body, a drive system operatively coupled to two or more of the wheels for driving the vehicle, a steering system operatively coupled to two or more of the wheels for turning the vehicle, a sensing system for assessing a disturbance in a road surface ahead of the vehicle, and a control system that, according to the disturbance and contemporaneous with one of the wheels traveling over the disturbance, operates the suspension system to mitigate vertical acceleration of the vehicle body, and operates one or both of the drive system or the steering system to mitigate horizontal acceleration of the vehicle body. In one implementation, a vehicle includes a vehicle body, four wheels that include two front wheels and two rear wheels, a suspension system that supports the wheels relative to the vehicle body, a sensing system for assessing an elevation change ahead of the vehicle, and a control system that, according to the elevation change, operates the suspension system to change a ride height of the vehicle prior to the vehicle reaching the elevation change. 
     In one implementation, a vehicle includes a vehicle body, wheels coupled to the body, a steering system operatively coupled to two or more of the wheels for turning the vehicle, a sensing system for assessing road disturbances of a road surface ahead of the vehicle, and a control system. The control system determines a coarse route plan by which the vehicle is to travel in a lane of a road section ahead of the vehicle, determines according to the assessing of the road disturbances a fine route plan by which the vehicle is to travel at lateral locations with the lane of the road section ahead of the vehicle, and operates the steering system to turn the vehicle according to the fine route plan over the road section. 
     In one implementation, a vehicle includes a vehicle body, wheels, a suspension system that supports the wheels relative to the vehicle body, a sensing system having a first sensor for sensing an environmental condition and a second sensor having a sensing capability that is affected by the environmental condition, and a control system that according to the environmental condition changes operation of the suspension system to improve the sensing capability of the second sensor. 
     In one implementation, a vehicle includes a vehicle body, wheels, a suspension system that supports the wheels relative to the vehicle body, a sensing system, and a control system. The sensing system includes a vehicle motion sensor that measures motion of the vehicle and a suspension system sensor that measures one or more of force or displacement of a suspension actuator of the suspension system. The control system records road disturbance information for a section of road with one or more of the vehicle motion sensor or the suspension system sensor, and controls the vehicle according to the road disturbance information when later travelling over the section of road. 
     In one implementation, a vehicle includes a vehicle body, a wheel, a suspension system, and a control system. The suspension system supports the vehicle body relative to the wheel. The suspension system includes a primary actuator that transfers force between the wheel and the vehicle body and is a ball screw actuator. The sensing system determines road conditions ahead of the vehicle. The control system operates the primary actuator with a first suspension stiffness setting and with a second suspension stiffness setting that are determined according to the road conditions ahead of the vehicle. 
     The first suspension stiffness setting may be a low stiffness and the second suspension stiffness setting is a high stiffness that is greater than the low stiffness. The control system may operate the primary actuator with the second suspension stiffness setting when the road conditions include an isolated road feature. The isolated road feature may be a pothole or a bump. The first suspension stiffness may be a default setting at which the control system predominantly operates the primary actuator. The control system may operate the primary actuator with the first suspension stiffness 50% or more of time. The first suspension stiffness setting and the second suspension stiffness setting may be gains. 
     In one implementation, a vehicle includes a vehicle body, a wheel, a suspension system, a sensing system, and a control system. The suspension system supports the vehicle body relative to the wheel, and includes a primary actuator that transfers force between the wheel and the vehicle body. The sensing system performs near-field sensing of a road surface relative to the vehicle. The control system that determines a feedforward road disturbance estimation according to the near-field sensing, determines suspension output with the feedforward road disturbance estimation, and operates the suspension system to provide the suspension output. 
     The near-field sensing may include one or more of observing the road surface in close proximity to the vehicle or sensing vertical wheel acceleration. The suspension output may include one or more of primary ride control or secondary ride control. The primary ride control includes active damping of inputs to the wheel occurring below 10 Hz. The secondary ride control is active damping at frequencies of other inputs to the wheel occurring near a natural frequency of an unsprung mass that includes the wheel. The control system may further the suspension output according to feedback from the suspension system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not to-scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. 
         FIG.  1 A  is a schematic view of a vehicle. 
         FIG.  1 B  is a schematic view of the vehicle of  FIG.  1 A  on a road. 
         FIG.  2    is a partial view of a vehicle body and a suspension system of the vehicle. 
         FIG.  3    is a schematic view of a sensing system of the vehicle. 
         FIG.  4 A  is a schematic view of a hardware configuration of controller of a control system of the vehicle. 
         FIG.  4 B  is a schematic view of the vehicle. 
         FIG.  5    is a flow chart of a method for controlling a vehicle according to roughness of a road surface ahead of the vehicle. 
         FIG.  6 A  is a flow chart of a method for controlling secondary ride of the vehicle according to conditions ahead of the vehicle. 
         FIG.  6 B  is a flowchart of another method for controlling secondary ride of the vehicle. 
         FIG.  6 C  is a flowchart of another method for controlling secondary of the vehicle. 
         FIG.  7    is a flow chart of a method for controlling the vehicle for obstacle avoidance. 
         FIG.  8    is a flow chart of a method for controlling the vehicle to perform a steering maneuver. 
         FIG.  9    is a flow chart of a method for controlling the vehicle to perform a vehicle maneuver according to a disturbance ahead of the vehicle. 
         FIG.  10    is a flow chart of a method for operating the suspension system of the vehicle according to elevation changes ahead of the vehicle. 
         FIG.  11    is a flow chart of a method the vehicle according to a temperature of the suspension system and a road ahead of the vehicle. 
         FIG.  12    is a flow chart of a method the vehicle according to a coarse route plan and a fine route plan. 
         FIG.  13    is a flow chart of a method for operating the suspension system of the vehicle according to conditions affecting sensors of the vehicle. 
         FIG.  14    is a flow chart of a method for controlling a vehicle according to previously-determined road disturbance. 
         FIG.  15    is a flow chart of a method for controlling stiffness of a suspension system. 
         FIG.  16    is a flow chart of a method for feedforward suspension control according to near-field sensing of a road surface. 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed herein are vehicles having active suspension systems and other vehicle systems (e.g., drive and steering systems) that are operated according to conditions ahead of the vehicle. By accounting for conditions ahead of the vehicle, as opposed to only reacting to the road underneath the vehicle, various advantages may be afforded. One advantage may include improved ride comfort, for example, by allowing the vehicle to foresee and avoid combinations of road conditions and vehicle conditions (e.g., suspension conditions) that might otherwise induce undesirable behavior in the suspension system. Avoiding such combinations may also be advantageous by allowing the active suspension system to use more available capacity of the active suspension system (e.g., higher thresholds for suspension travel and/or force output), which as compared to a reactive suspension system may allow for greater overall capabilities and/or permit reduction in available capacity to achieve the same overall capabilities. This reduction of available capacity, such as reducing the travel, force, and/or bandwidth capabilities of suspension actuators, may be referred to as economizing. Still further advantages of accounting for conditions ahead of the vehicle include preparing the vehicle ahead of the road disturbance to better isolate the vehicle and performing maneuvers to avoid road disturbances. The vehicles, the suspension systems, and the methods disclosed herein may provide these and other advantages. 
     Referring to  FIG.  1 A , a vehicle  100  includes a vehicle body  102  and wheels  104 . The vehicle  100  also includes a drive system  110 , a steering system  120 , a braking system  130 , a suspension system  140 , a sensing system  150 , and a control system  160 , which are depicted schematically. The vehicle body  102 , for example, includes a passenger compartment. The wheels  104  may include tires coupled thereto, which engage a surface over which the vehicle  100  travels (e.g., a road surface). The vehicle  100  may, for example, include four of the wheels  104  wheels, including two wheels at a front end of the vehicle  100  (i.e., two front wheels on a left side and a right side of the vehicle  100 ) and two wheels at a rear end of the vehicle (i.e., two rear wheels on the front side and the right side of the vehicle  100 ). 
     The drive system  110  is coupled to the wheels  104  to cause rotation thereof to accelerate and/or decelerate the vehicle  100  in a fore-aft direction. The drive system  110  may, for example, include an internal combustion engine, one or more electric motors, or both (e.g., a hybrid drive system), which are operatively coupled (e.g., via drive shafts) to two or more of the wheels  104  for transferring torque thereto for driving the wheels  104 . The drive system  110  may also be referred to as a powertrain or a drivetrain. 
     The steering system  120  is operatively coupled to two or more of the wheels  104  to turn the wheels  104  (e.g., pivoting about a generally vertical axis) to cause lateral acceleration (e.g., turning left or right) of the vehicle  100 . The steering system  120  includes one or more steering actuators, such as a rack and pinion actuator (e.g., a steering rack), that applies torque to two or more of the wheels  104  to pivot the wheels  104  about generally vertical axes. The steering system  120  may be capable of turning the wheels  104  independent of each in some circumstances, such as turning one of two front wheels  104  independent of the other of the two front wheels  104 . 
     The braking system  130  is operatively coupled to the wheels  104  to decelerate the vehicle  100 . The braking system  130  may, for example, include friction braking components (e.g., brake calipers and rotors associated with each of the wheels  104 ) that apply torque to the wheels  104  to hinder rotation thereof. Braking may also be provided by the drive system  110 , for example, by the electric motor applying a counter torque to the wheels  104  (e.g., during regenerative braking). 
     The suspension system  140  is operatively coupled to each of the wheels  104  and to the vehicle body  102  to support the vehicle body  102  and the wheels  104  relative to each other (e.g., to control generally vertical displacement therebetween). The suspension system  140  is an active suspension system, which may be controlled in various manners to maintain contact between the wheels  104  and the ground (e.g., the road surface) for traction and/or to provide ride comfort to passengers of the vehicle  100 . The suspension system  140  may also be referred to as a suspension and is discussed in further detail below. The term “active suspension,” as used herein, includes suspension systems that are controllable to variably absorb energy and output energy, as well as suspension systems that are controllable to variably absorb energy but not output energy. 
     The sensing system  150  includes one or more sensors to monitor conditions of the vehicle  100 , monitor conditions of the environment, and/or otherwise receive information about conditions of the environment. The sensing system  150  is discussed in further detail below. 
     The control system  160  is configured to control operation of the drive system  110 , the steering system  120 , the braking system  130  and/or the suspension system  140 , for example, according to the conditions as assessed with the sensing system  150 . 
     Referring to  FIG.  1 B , as the vehicle  100  travels along or over a road  106 , a current road portion  106   a  is that portion of the road  106  over which the vehicle  100  is currently positioned (e.g., is engaging), while a forward road portion  106   b  is that portion of the road  106  ahead of the vehicle  100  over which the vehicle  100  is expected to travel. For example, the vehicle  100  may travel over the forward road portion  106   b  according to user inputs or a motion control plan (e.g., an autonomous drive plan that does not require continual input from a user). The road  106  may also include various features, including localized disturbances  106   c  (e.g., a pothole or bump), potential hazards  106   d  (e.g., vehicles ahead, vehicles traveling in the opposite direction, pedestrians, etc.), areas with different roughness  106   e  (e.g., washboard or smooth), and areas with different surface conditions  106   f  (e.g., wet, snow, icy, or dry), among other characteristics and features. The sensing system  150  observes the forward road portion  106   b , such as with a field of view (schematically represented by forward pointing arrows) or otherwise determines information thereabout according to which the control system  160  operates the suspension system  140  and other systems of the vehicle  100 . 
     Referring to  FIG.  2   , the suspension system  140  generally includes suspension actuator assemblies  242  that are each associated with one of the wheels  104  (e.g., four suspension actuator assemblies  242  for four wheels  104 ). Each of the suspension actuator assemblies  242  controls generally vertical motion of the wheel  104  associated therewith relative to the vehicle body  102 . Each suspension actuator assembly  242  generally includes a suspension arm  244 , a primary actuator  246 , and a spring  248 . The suspension arm  244  is pivotally coupled to and extends between the vehicle body  102  and the wheel  104  to allow the wheel  104  to move in a generally vertical path relative to the vehicle body  102 . 
     The primary actuator  246  and the spring  248  are coupled to and extend between the vehicle body  102  and the suspension arm  244  to control movement of the wheel  104  in the generally vertical path. The primary actuator  246  and the spring  248  form parallel load paths between the vehicle body  102  and the suspension arm  244 . The vehicle body  102  may be considered a sprung mass, while the wheel  104 , the suspension arm  244 , and other components that move therewith (e.g., portions or components of the braking system  120 , the steering system  130 , and/or the suspension system  140 ) may be considered an unsprung mass. The primary actuator  246  may, for example, be a ball screw actuator or other linear actuator capable of providing positive displacement (e.g., extension thereof). The spring  248  may, for example, be a coil spring or other type of spring (e.g., an air spring). While depicted schematically as coaxial and part of a common strut assembly, the primary actuator  246  and the spring  248  may instead be spaced apart, be provided as separate assemblies, or may be provided in another suitable manner. The primary actuator  246  provides primary ride control, which generally refers to active damping of road disturbances over a range of frequencies, which may include natural frequencies of the sprung mass and the unsprung mass, and is capable of outputting high force at high velocity between the vehicle body  102  and the suspension arm  244 . For example, the primary ride control may operate in a low frequency range (e.g., below 10 Hz, such as 8 Hz and below, such as below a natural frequency of an unsprung mass that includes the wheel  104 , as described below). 
     The suspension system  140  may also include reaction mass actuators  250 , or other wheel hop damper, associated with each of the wheels  104  to provide secondary ride control (e.g., wheel hop control). The unsprung mass may have a natural frequency (e.g., between approximately 10 and 15 Hz) and may resonate when force is input by the road to the unsprung mass at such frequency. The natural frequency of the unsprung mass may be influenced, for example, by the mass, stiffness, and damping characteristics of the tire, the wheel  104 , the suspension arm  244 , and other components coupled thereto. Such resonance may be referred to as wheel hop and, absent damping of such forces, may result in the wheel  104  having reduced contact with the road surface. 
     The reaction mass actuator  250  provides secondary ride control, which generally refers to active damping of road inputs to an unsprung mass, which occur at frequencies near the natural frequency of the unsprung mass or that might otherwise induce resonance in the unsprung mass or wheel hop. For example, the reaction mass actuator  250  dampens the high frequency input forces from the road surface to the unsprung mass to increase contact and, thereby, maintain high friction (e.g., traction) between the wheel  104  and the road. The reaction mass actuator  250  is coupled to the unsprung mass, such as to the wheel  104  (e.g., to a wheel or steering hub), to the suspension arm  244 , or to the suspension actuator assemblies  242 . Advantageously, the reaction mass actuator  250  provides secondary ride control generally without or by reducing force transfer to the vehicle body  102 , which might otherwise be felt by passengers of the vehicle  100 . 
     The reaction mass actuator  250  includes, for example, a reaction mass  250   a , a secondary actuator  250   b  (e.g., a secondary actuator), and a spring  250   c , the secondary actuator  250   b  and the spring  250   c  being coupled to and extending between the unsprung mass and the reaction mass  250   a  to transfer force therebetween. The secondary actuator  250   b  applies force between the reaction mass  250   a  and the unsprung mass at the natural frequency to dampen force of the unsprung mass by moving the reaction mass  250   a . The reaction mass actuator  250  may have a capacity, which is the ability to dampen forces of the unsprung mass (e.g., at the natural frequency thereof) and may be a function of the mass of the reaction mass  250   a , the spring constant of the spring  250   c , and/or the force and/or stroke distance of the secondary actuator  250   b . The mass of the reaction mass  250   a  is sufficient to provide suitable damping at the natural frequency of the unsprung mass, which may be determined according to the mass of the unsprung mass among other considerations (e.g., overall vehicle mass). The reaction mass  250   a  may also be referred to as a moving mass. 
     The primary actuator  246  may also provide secondary ride control. For example, in the event or anticipation of the capacity of the reaction mass actuator  250  being exceeded, the primary actuator  246  may transfer force to the vehicle body  102 , so as to maintain contact between the wheel  104  and the road surface and/or to prevent the reaction mass actuator  250  from reaching full stroke (e.g., bumping into end stops thereof). However, such force transfer to the vehicle body  102  may be felt by passengers thereof. As described in further detail below, the secondary ride control may be divided between the reaction mass actuator  250  and the primary actuator  246  according to road conditions ahead of the vehicle  100 . 
     Instead of being configured as a reaction mass actuator  250 , the wheel hop damper may instead be configured as a tuned mass damper. The tuned mass damper may have a similar configuration as the reaction mass actuator  250  with the secondary actuator  250   b  being replaced by a damper (e.g., a linear fluid damper, such as a shock absorber), such that the tuned mass damper includes a mass  250   a  (e.g., a moving mass), a damper  250   b , and a spring  250   c . The mass  250   a , the damper  250   b , and the spring  250   c  are cooperatively configured (e.g., tuned) to damp wheel hop (e.g., movement of the unsprung mass at the natural frequency). 
     The suspension system  140  may also include spring seat actuators  252  associated with each of the wheels  104 . The spring seat actuators  252  includes a spring seat  252   a  and an actuator  252   b . The spring seat  252   a  is movably coupled to the vehicle body  102 , while the spring  248  extends between the spring seat  252   a  and the suspension arm  244  to cooperatively form a load path between the vehicle body  102  and the unsprung mass. The actuator  252   b  moves the spring seat  252   a  toward and away from the vehicle body  102 , so as to reduce or increase ride height of the vehicle  100  and to transfer loading between the vehicle body  102  and the unsprung mass. The spring seat actuator  252  may be part of the suspension actuator assembly  242  and may, for example, be a ball screw actuator, a lead screw actuator, or a hydraulic actuator, among other types of actuators. The spring seat actuator  252  is capable of outputting high force, such as to support the vehicle  100  and change the ride height thereof, at a low velocity. As described in further detail below, the spring seat actuators  252  may be controlled according to road conditions ahead of the vehicle  100 . 
     Referring to  FIG.  3   , the sensing system  150  monitors conditions of the vehicle  100 , monitors conditions of the environment of the vehicle, and/or receives, stores, or otherwise acquires condition information regarding the environment of the vehicle  100 . The sensing system  150  includes vehicle sensors  352 , which monitor conditions of the vehicle  100 . For example, the vehicle sensors  352  may include drive system sensors  352   a  that measure various conditions of the drive system  110  (e.g., speed, torque, current, temperature of the drive components, such as electric motors, and the wheels  104 ), steering system sensors  352   b  that measure various conditions of the steering system  120  (e.g., steering angle of the wheels  104 , position and/or force of the steering system components), braking system sensors  352   c  that measure various conditions of the braking system  130  (e.g., position, force, and/or temperature of the brake components), suspension system sensors  352   d  that measure various conditions of the suspension system  140  (e.g., force, motion/position, and temperature of the various actuators described above), and/or motion sensors  352   e  that measure motion and/or position information of the vehicle  100  (e.g., accelerometers, gyroscopes, magnetometers, inertial measurement unit (IMU), global positioning (GPS)). 
     The sensing system  150  also includes environment sensors  354  and environment information sources  356 , which monitor, store, and/or receive information pertaining to conditions of the environment in which the vehicle  100  is operating. More particularly, the environment sensors  354  are generally configured to monitor or observe conditions of the environment ahead of the vehicle  100 , which the vehicle  100  might encounter. The environment sensors  354  may, for example, include LIDAR sensors  354   a  (i.e., light detection and ranging sensors), radar sensors  354   b , ultrasonic sensors  354   c , infrared sensors  354   d , structured light sensors  354   e , cameras  354   f , and/or sound sensors  354   g . The environment sensors  354  may be used to detect, identify, and/or assess environment conditions using suitable methodologies and/or algorithms, such as with computer vision or object recognition techniques, that may be executed by the control system  160  (e.g., by controllers or processors thereof, as described below). 
     The environment information sources  356  may include stored information sources  356   a , such as data storage components that store generally static or learned information, and communicated information sources  356   b , such as wireless transceivers that receive transmitted environment condition information from external information sources  358  (e.g., other cars or infrastructure). 
     The environment information may include static information and dynamic information. Static information includes information that generally does not change or which changes slowly over time, such as road location, road elevation, road surface (e.g., material, roughness characterization, friction characterization), and road markers (e.g., markers, signs, stop lights, etc.). Dynamic information includes information that changes relatively quickly, such as weather conditions (e.g., snowing, raining, dry), road surface (e.g., roughness, friction), obstacles or disturbances (e.g., types, size, and/or location), traffic, and light changes. 
     Static information may be stored, received, and/or learned. For example, mapping information (e.g., road position, elevation, and surface) may be stored on the vehicle  100  (e.g., on a hard disk drive). Mapping information may be received and stored to update, supplement, and/or replace previously stored information (e.g., road additions/expansions, road information, such as road disturbances collected by the vehicle  100 , other vehicles, or a service, such with the environment sensors  354  or motion sensors  352   e ). Dynamic information may be sensed by the environment sensors  354  and/or received from the external information sources  358 , such as other vehicles (e.g., vehicle-to-vehicle communication, such as road conditions and obstacles), infrastructure (e.g., vehicle-to-infrastructure communication), and other sources (e.g., weather data information). 
     The control system  160  is in communication with and configured to control the various other systems of the vehicle  100 , such as the drive system  110 , the steering system  120 , the braking system  130 , the suspension system  140 , and/or the sensing system  150 , for example, according to the vehicle and environment conditions. Such communication is represented schematically by the dashed lines shown in  FIG.  1   . 
     Referring to  FIG.  4 A , the control system  160  may include one or more controllers  462 , which may have a hardware configuration as shown. The controller  462  generally includes a processor  462   a , a storage  462   b , a memory  462   c , and a communications interface  462   d  that are in communication via a bus  462   e . The processor  462   a  is operable to execute computer program instructions and perform operations described thereby. The processor may, for example, be a central processing unit (CPU) or other conventional processing device. The storage  462   b  is a long-term information storage device, such as a hard or solid-state drive, or other non-volatile information storage device. The storage  462   b , for example, stores the computer program instructions (e.g., software code or code segments). The memory  462   c  may be a short-term information storage device, such as a random-access memory module (RAM) or other volatile, high-speed, short-term storage device. The communications interface  462   d  is an input/output (I/O) device that provides for the receipt and/or sending of signals to and/or from the controller  462 , which may include information signals and/or instructions signals that are processed or generated by the processor  462   a  according to the computer program instructions in the storage  462   b.    
     Referring to  FIG.  4 B , the one or more controllers  4621 - m  of the control system  160  may be associated with one or more of the systems  110 ,  120 ,  130 ,  140 ,  150  described above and/or controllable components thereof (e.g., motors and/or actuators). The control system  160  is in communication with the sensor system  150  (e.g., the sensors thereof) and the various output systems (e.g., the drive, brake, steering, and suspension systems  110 ,  120 ,  130 ,  140 ). The control system  160  executes computer program instructions that generally include a condition assessment unit  470  and a vehicle control unit  480 , which may be provided as a program stored and executed by a single controller  462  or multiple different controllers  462 . The condition assessment unit  470  may generally receive sensing signals from the sensing system  150  (e.g., the vehicle sensors  352 , the environment sensors  354 , and the information sources  356 ), process the sensing signals, and output a condition variable or signal. The vehicle control unit  480  may generally receive the condition signal or variable, process the condition signal or variable to determine vehicle control instructions, and operate the various output systems and components of the vehicle  100  according to the vehicle control instructions (e.g., the suspension system  140  and the primary actuators  246  thereof). 
     Referring to  FIGS.  5 - 16   , the suspension system  140  is controlled and/or other systems of the vehicle  100  are controlled according to environmental conditions ahead of the vehicle  100  and/or according to conditions or characteristics of the suspension system  140 . The methods and various operations thereof may be performed by any suitable combination of one of more of the controllers  4621 - m  of the control system  160 , for example, by the processor(s) thereof executing software programming (e.g., code) stored thereby. 
     Referring to  FIG.  5   , the vehicle  100  is controlled according to roughness of the road ahead of the vehicle  100 . The sensing system  150  may determine the road surface ahead of the vehicle  100  to have a roughness, which may cause wheel hop (e.g., induce resonance) in the unsprung mass associated with one or more of the wheels  104 . The vehicle  100  is controlled according to the roughness, for example, to reduce occurrence of (e.g., prevent or inhibit) resonance in the unsprung mass. 
     The roughness may be defined with a general characterization (e.g., smooth, brick or cobblestone, dirt or washboard) or a specific characterization, such as a period or frequency (e.g., corresponding to the distance between cyclical road disturbances, such as with a segmented road surface (e.g., brick or cobblestone) or with otherwise textured surfaces (e.g., washboard dirt road)). The roughness may be determined with the vehicle sensors  352  (e.g., motion of front wheels  104  used to control the suspension system  140  for the rear wheels  104 ), environment sensors  354  (e.g., LIDAR, cameras) using computer vision to assess the road surface ahead of the vehicle  100 , environment information sources  356  (e.g., receiving roughness information from another vehicle traveling ahead of the vehicle  100 ), or combinations thereof (e.g., using the vehicle sensors  352  to determine a position of the vehicle (e.g., GPS coordinates), which is correlated to stored information pertaining to the roughness (e.g., mapping information learned from previous travel of the vehicle  100 , other vehicles, or other sources)). 
     In one example, the speed of the vehicle  100  may be controlled according to the roughness of the road surface. Resonance of the unsprung may be expected to be more likely to occur when the vehicle  100  is driven at certain speeds (e.g., a small range of speeds) over the road surface having a certain roughness (e.g., having a general roughness characterization or having a specific roughness characterization, as described above). At such speeds in such conditions, the wheel hop damper (e.g., the reaction mass actuator  250  or the tuned mass damper) may have insufficient capacity to dampen such road input forces arising from the roughness. Accordingly, the vehicle  100  is operated at a different speed (e.g., faster or slower) than that at which resonance of the unsprung might be expected, such that force inputs to the unsprung mass from the road surface occur at a frequency other than that natural frequency of the unsprung mass. As a result, the speed of the vehicle  100  may be controlled according to both the roughness of the road surface and the natural frequency of the unsprung mass. 
     Instead or additionally, the speed of the vehicle  100  may be controlled to prevent disturbances at other frequencies, which may be bothersome to passengers of the vehicle  100 . Such other frequencies may, for example, include other natural frequencies at which resonance might occur for other portions of the vehicle  100 , such as the sprung mass (e.g., as a whole having a lower natural frequency, such as below approximately 5 Hz), the vehicle body  102 , brake components or assemblies (e.g., brake caliper, brake rotor, or both), steering components or assemblies (e.g., a steering knuckle, a steering actuator), drive components (e.g., a motor or gearbox), suspension components (e.g., of the suspension arm  244 , the actuator assembly  242 ), and/or components or items in the vehicle body  102  (e.g., seats, passengers (e.g., to prevent head wobble), screens, controls (e.g., steering wheel or accelerator pedal). As a result, the speed of the vehicle  100  may be controlled according to both the roughness of the road surface and the natural frequency of the sprung mass, the vehicle body, or other components or assemblies of the vehicle  100 . 
     As shown in  FIG.  5   , a method  500  is provided for controlling a vehicle  100  according to roughness of the road surface ahead of the vehicle  100 . The method  500  includes a first operation  510  of determining an intended speed of the vehicle  100 , a second operation  520  of determining a roughness of a road surface ahead of the vehicle, a third operation  530  of determining an operating speed according to the roughness and characteristics of the vehicle  100 , such as the suspension system  140 , and a fourth operation  540  of operating the vehicle  100  at the operating speed. 
     The first operation  510  of determining an intended speed of the vehicle  100  may, for example, be performed by the control system  160 . The intended speed may be based on an input from the user or be a speed of a motion control plan (e.g., an autonomous drive plan), for example, based on the speed limit of the road ahead. 
     The second operation  520  of determining roughness of a road surface may be performed by the control system  160  in conjunction with the sensing system  150 . For example, the roughness may be determined by using the environment sensors  354  observing the road surface (e.g., identifying, measuring, or otherwise detecting disturbances in the road surface) and/or behavior of other vehicles ahead of the vehicle  100 . Roughness may instead or additionally be determined by using the vehicle sensors  352  in conjunction with stored information sources  356   a  (e.g., correlating GPS coordinates to mapping information that includes road surface roughness information). The roughness may be defined by a general characterization based on the type of road surface (e.g., a category, such as smooth, washboard, brick, cobblestone, segmented) or a specific characterization based on observed characteristics of the road surface (e.g., the period of cyclical disturbances in the road surface). 
     The third operation  530  of determining an operating speed may be performed by the control system  160 . The operating speed is determined according to roughness of the road surface (i.e., as determined in the second operation  520 ) and characteristics of the vehicle  100 , such as a natural frequency of the suspension system  140  (e.g., of the unsprung mass formed thereby). The operating speed may instead or additionally be determined according to other characteristics of the vehicle  100  (e.g., natural frequencies of various other components or assemblies, such as the sprung mass, the vehicle body  102 , and/or other components or assemblies). For example, certain combinations of vehicle speed and roughness may be expected to induce undesirable suspension conditions, such as resonance or wheel hop in the unsprung masses (e.g., that include one or more of the wheels  104 ). The operating speed is determined to be a speed at which such undesirable suspension conditions are not expected to occur as a result of the roughness. 
     The operating speed may, for example, be determined according to the intended speed and the roughness with a lookup table that accounts for the suspension characteristics. The operating speed may be the intended speed (e.g., if the undesirable suspension conditions are not likely to occur), or a different speed (e.g., higher or lower to achieve a different input frequency from the road surface to the unsprung mass). Alternatively, the operating speed may be determined according to formulae that account for the suspension characteristics and that use the intended speed and the roughness as inputs. Thus, whether using a lookup table or formulae, the operating speed is determined according to the roughness of the road ahead of the vehicle  100  and characteristics of the suspension system  140 . 
     The third operation  530  may instead be divided into a first suboperation of determining whether the undesirable suspension conditions are likely to occur at the intended speed, and a second suboperation of determining the operating speed to be different than the intended speed if undesirable suspension conditions are first determined to be expected or likely at the intended speed. 
     The fourth operation  540  of operating the vehicle  100  at the operating speed is performed by the drive system  110 . For example, the control system  160  causes the drive system  110  to drive the vehicle  100  at the second speed over the road surface determined to have the roughness. 
     Referring to  FIG.  6 A , the primary actuator  246  is controlled according to characteristics of the wheel hop damper (e.g., the reaction mass actuator  250  or the tuned mass damper) and conditions ahead of the vehicle  100 . As described above, the reaction mass actuator  250  or the tuned mass damper provides secondary ride control, for example, to prevent wheel hop. As referenced above, the secondary ride control (i.e., dampening of high frequency road inputs to prevent resonance or wheel hop) may be allocated to (e.g., actively provided by) the reaction mass actuator  250 , which dampens road inputs by transferring force to the reaction mass  250   a , and to the primary actuator  246 , which dampens high frequency road inputs by transferring force to the vehicle body  102 . Based on the conditions ahead of the vehicle  100 , the secondary ride control may be allocated to the primary actuator  246  earlier (e.g., at a lower threshold) or later (e.g., at higher threshold) than in other conditions. As described above, the tuned mass damper may instead passively damp wheel hop (i.e., resonance of the unsprung mass). In such case, based on the conditions ahead of the vehicle  100 , the secondary ride control may be allocated to the primary actuator  246  earlier (e.g., at a lower threshold) or later (e.g., at higher threshold) than in other conditions. By providing the secondary ride control with the primary actuator  246  at a lower threshold, the tuned mass damper may be prevented from reaching its damping capacity. 
     For example, in typical operation, secondary ride control may be provided by the reaction mass actuator  250 , or the tuned mass damper may passively damp movement of the unsprung mass at the natural frequency thereof. When a capacity threshold is exceeded by the reaction mass actuator  250  or the tuned mass damper, additional secondary ride control is provided the primary actuator  246  (e.g., concurrent with the secondary ride control being provided by the reaction mass actuator  250 , or the tuned mass damper providing passive damping). The capacity threshold may, for example, be a percentage of the overall capacity of the reaction mass actuator  250 , such as a percentage of the stroke distance of the reaction mass actuator  250 , or other suitable parameter (e.g., force, frequency, and/or stroke distance). The capacity threshold may function to reserve capacity of the reaction mass actuator  250 , for example, if further damping is required to maintain traction and/or to limit circumstances in which the full capacity of the reaction mass actuator  250  is utilized. Reaching full capacity of the reaction mass actuator  250  may be undesirable, because when the reaction mass  250   a  reaches travel limits (e.g., impacting end stops thereof), sharp forces may be transferred to the unsprung mass and, ultimately, to the vehicle body  102 . Similarly, the capacity threshold of the tuned mass damper may be a percentage of the overall capacity of the tuned mass damper, such as a percentage of a stroke distance of the mass or other suitable parameter (e.g., acceleration of the mass). Reaching full capacity of the tuned mass damper may be undesirable, because when the mass reaches travel limits (e.g., impacting end stops thereof), sharp forces may be transferred to the unsprung mass and, ultimately, to the vehicle body  102 . 
     Based on environmental conditions, secondary ride control may instead be provided by the primary actuator  246  later than during typical operation, for example, by changing (i.e., increasing) the capacity threshold of the wheel hop damper (e.g., the reaction mass actuator, or the tuned mass damper). The capacity threshold may be increased, for example, when high traction for turning or braking is less likely to be required (e.g., on a straight road and/or few potential obstacles). By increasing the capacity threshold, the primary actuator  246  may be used to provide secondary ride control in fewer instances and/or with lower force transfer to the vehicle body  102 , such that ride quality is improved and passengers of the vehicle  100  are less disturbed by such force transfer. In other circumstances, the capacity threshold may be decreased, such that the primary actuator  246  provides secondary ride control in more instances and/or with more force transfer. 
     As referenced above, the capacity threshold may be increased when environmental conditions ahead of the vehicle  100  are less likely to require high traction and/or acceleration (e.g., deceleration and/or lateral acceleration) of the vehicle  100 . Such conditions may, for example, include road direction (e.g., presence and/or severity of curves ahead), presence of potential obstacles (e.g., number and/or distance to surrounding vehicles), road friction conditions (e.g., dry, wet, or snow covered), and/or confidence in such conditions (e.g., ability to observe the environment ahead and/or whether stored or received information is available for the environment ahead). In specific examples, the capacity threshold may be increased when the road ahead is determined to be straight and/or when potential obstacles (e.g., people or objects, such as vehicles, that are or may become obstacles in a path of the vehicle  100 ) are not present. 
     As shown in  FIG.  6 A , a method  600  is provided for controlling secondary ride with the primary actuator  246  according to environmental conditions ahead of the vehicle. The method  600  includes a first operation  610  of providing secondary ride control with a wheel hop damper (e.g., actively with a reaction mass actuator, or passively with a tuned mass damper), a second operation  620  of providing additional secondary ride control with a primary actuator when a capacity threshold is exceeded by the wheel hop damper, a third operation  630  of changing the capacity threshold according to environmental conditions ahead of the vehicle  100 , and a fourth operation  640  of providing additional secondary ride control with the primary actuator when the changed capacity threshold is exceeded by the reaction mass actuator. 
     The first operation  610  of providing secondary ride control is performed by the wheel hop damper (e.g., actively by the reaction mass actuator  250  as operated by the control system  160 , or passively by the tuned mass damper) associated with one or more of the wheels  104 . With reaction mass actuator  250 , the secondary actuator  250   b  applies force between the reaction mass  250   a  and the unsprung mass (e.g., formed by the wheel  104  and the suspension arm  244 ) to counter high frequency road inputs to the unsprung mass, which might otherwise induce resonance of the unsprung mass or wheel hop. With the tuned mass damper, force is transferred passively between the mass  250   a  by the damper and the spring. 
     The second operation  620  of providing additional secondary ride control is performed with the primary actuator  246  and may be operated by the control system  160  and the suspension system sensors  352   d  (e.g., measuring displacement and/or acceleration of the moving mass of the wheel hop damper). For example, the control system  160  may determine that the capacity threshold (e.g., a first capacity threshold, such as a percentage of a stroke distance, acceleration, or force value) is exceeded by the reaction mass actuator  250  or the tuned mass damper associated with the wheel  104 . If exceeded, the control system  160  may, accordingly, cause the primary actuator  246  apply force between the unsprung mass and vehicle body  102  to further counter high frequency road inputs to the unsprung mass, which might other otherwise induce resonance of the unsprung mass or wheel hop. The initial capacity threshold may, for example, be a default value normally used by the vehicle  100 . 
     The third operation  630  of changing the capacity threshold according to environmental conditions ahead of the vehicle  100  is performed using the sensing system  150  and the control system  160 . For example, the sensing system  150  may observe or otherwise determine environmental conditions ahead of the vehicle  100 , which may include road direction, presence of potential obstacles, and/or road friction conditions. Obstacles, such as surrounding vehicles, may be observed with the environment sensors  354  (e.g., LIDAR, radar, and/or cameras) or be determined with external sources (e.g., other vehicles). Road direction and/or road friction conditions may be observed with the environment sensors  354  (e.g., LIDAR, radar, and/or cameras). Road direction and/or road friction conditions may be observed with the environment sensors  354  and/or be determined by stored or received mapping information that is correlated with the position of the vehicle  100  determined with the motion sensor  352   e  (e.g., GPS coordinates). 
     Upon detecting environmental conditions that are less likely to require high traction for accelerating the vehicle  100  (e.g., straight road, no presence or limited number of potential obstacles, and/or high friction road surface), the capacity threshold is changed from the initial capacity threshold to a higher capacity threshold. Conversely, when detecting environmental conditions that are more likely to require high traction for acceleration the vehicle (e.g., curvy road, many potential obstacles, and/or low friction road surface), the capacity threshold may be changed from the initial capacity threshold to a lower capacity threshold. 
     For example, the capacity threshold may be changed in a binary manner upon detection such conditions (e.g., moving from 80% to 90%), or may be changed according to a lookup table according to the environmental condition. 
     The third operation  630  of changing the capacity threshold according to environmental conditions may be performed in multiple suboperations, for example, including first determining whether environmental conditions exist that warrant a change of the capacity threshold, and subsequently determining a changed capacity threshold only upon detecting environmental conditions that warrant such a change. 
     The fourth operation  640  of providing additional secondary ride control is performed with the primary actuator  246  as operated, for example, by the control system  160  and the suspension system sensors  352   d . For example, the control system  160  may determine that the changed capacity threshold is exceeded (e.g., a second capacity threshold) by measuring displacement and/or acceleration of the moving mass with the suspension system sensors  352   d  for comparison with the changed capacity threshold, and accordingly provide the additional secondary ride control with the primary actuator  246 . 
     It should be noted that the first operation  610  of providing secondary ride control with the reaction mass actuator  250  may be performed simultaneous with each of the second, third, and fourth operations  620 ,  630 ,  640 . 
     Furthermore, the method  600  may be performed in conjunction with the method  500 . For example, the speed of the vehicle  100  may be changed according to roughness of the road ahead of the vehicle  100 , while the capacity threshold may be changed according to whether environmental conditions are more likely to require accelerating the vehicle  100 . 
     Referring to  FIG.  6 B , instead of or in addition to adjusting the capacity threshold of the reaction mass actuator  250  or tuned mass damper, the secondary ride control provided by the primary actuator  246  may be increased (e.g., preemptively) according to a condition of the environment ahead (e.g., a bump, pothole, or other large input), irrespective of the capacity threshold of the reaction mass actuator  250  or the tuned mass damper. For example, based on the condition ahead (e.g., rough road expected to induce wheel hop), the secondary ride control provided by the primary actuator  246  may be increased, thereby reducing the eventual damping demand on the reaction mass actuator  250  or the tuned mass damper, regardless of whether the capacity threshold thereof (adjusted or not according to the method  600 ) is exceeded. Providing secondary ride control with the primary actuator  246  irrespective of whether the capacity threshold is exceeded by the reaction mass actuator  250  or the tuned mass damper may provide a particular benefit for environmental conditions (e.g., road conditions) that are isolated and/or have large force transfer to the wheel  104  (e.g., the localized disturbance  106   c , such as a pothole or large bump). Other or additional benefit may be achieved more predictably and/or gradually increasing force transfer from the primary actuator  246  to the vehicle body  102  to provide the secondary ride control in direct response to the environmental condition ahead as opposed to, possibly suddenly, beginning such force transfer when exceeding the capacity threshold of the reaction mass actuator  250  or the tuned mass damper. 
     As shown, a method  601  is a variation of the method  600  and provides for increasing the secondary ride control of the primary actuator  246  according to the condition of the environment ahead. The method  601  generally includes the first operation  610  (described above), and a second operation  611  of providing additional secondary ride control with a primary actuator according to environmental conditions ahead of the vehicle  100 . The second operation  611  is performed generally as described above with respect to the operation  630  (e.g., using the sensing system  150 ), but rather than changing the capacity threshold according to which the secondary ride control may or may not be provided by the primary actuator  246 , secondary ride control is provided by the primary actuator  246  according to the environmental condition irrespective of whether the capacity threshold is met. As referenced above, the environmental condition may be an isolated, high magnitude road feature (e.g., a pothole or bump) as opposed to continuous, repeated, and/or low magnitude feature (e.g., a washboard road). For example, the secondary ride control may be provided by the primary actuator  246  in advance of predicted to either require high force output or power consumption from the reaction mass actuator or to cause the tuned mass damper reach its actual capacity, regardless of the capacity threshold. 
     The method  601  may be performed in conjunction with the method  600 , for example, with the second operation  611  being performed in parallel to the second operation  620  of providing the secondary ride control with the primary actuator  246  when the capacity threshold is met. In such an arrangement, the secondary ride control may be provided by the primary actuator  246  based either directly on the environmental condition ahead (i.e., the method  601 ) or the capacity threshold (adjusted or not) being exceeded (i.e., the method  600 ). Referring to  FIG.  6 C , instead of or in addition to changing the capacity threshold of the reaction mass actuator  250  or the tuned mass damper or increasing the secondary ride control provided by the primary actuator  246 , an overall level of secondary ride control to be achieved is adjusted according to the environmental condition ahead of the vehicle  100 . This overall level of secondary ride control, which is provided individually or cooperatively by the reaction mass actuator  250 , the tuned mass damper, and/or the primary actuator  246 , is referred to herein as a secondary ride control target and may be adjusted to different target levels. The secondary ride control target may be a damping ratio. For those environmental conditions in which greater traction may be required (e.g., twisting road, gravel road, twisting gravel road, and/or high traffic), the secondary ride control target may be increased (e.g., at a high level). For those environmental conditions in which lesser traction may be required (e.g., straight road, paved road, and/or low traffic), the secondary ride control target may be lowered (e.g., at a low level as compared to the high level). One benefit of adjusting the secondary ride control target is that energy consumption of the suspension system  140  may be reduced when providing secondary ride control at lower levels. 
     As shown in  FIG.  6 C , a method  602  is provided for adjusting secondary ride control target according to the environment ahead of the vehicle  100 . The method  602  includes a first operation  612  of establishing a secondary ride control target at a first target level, a second operation  622  of providing secondary ride control to achieve the first target, a third operation  632  of adjusting the secondary ride control target to a second target level according to environmental conditions ahead of the vehicle, and a fourth operation  642  of providing the secondary ride control to achieve the second target level. 
     The first operation  612  of establishing the secondary ride control target at the first target level includes establishing (e.g., setting or prescribing) a target amount of secondary ride control that is to be achieved (e.g., targeted or reached). The secondary ride control target may be a damping ratio for one or more of the mass-spring systems formed of one of the wheels  104  and portions of the suspension assembly  242  (e.g., also including the reaction mass actuator  250 ). In one example, the first target level provides a high level of traction (e.g., for maximum traction with the wheel  104 ) and may be adjusted downward (e.g., only downward) if reduced levels of traction are desired. In another example, the first target level provides middle level of traction and may be adjusted upward or downward if higher or lower levels of traction are desired. 
     The second operation  622  of providing the secondary ride control to achieve the first target level is performed by providing all or a portion of the secondary ride control with the reaction mass actuator  250  or the tuned mass damper and additionally (if necessary) with the primary actuator  246 . For example, the primary actuator  246  may provide additional secondary ride control if the capacity threshold for the reaction mass actuator  250  or the tuned mass damper is exceeded. 
     The third operation  632  of adjusting the secondary ride control target to a second target level according to the environmental conditions is performed similar to the first operation  630  described previously for changing the capacity threshold in the method  600 . For example, the sensing system  150  may observe or otherwise determine environmental conditions ahead of the vehicle  100 , which may include road direction, presence of potential obstacles, and/or road friction conditions. Upon detecting environmental conditions that are less likely to require high traction for accelerating the vehicle  100  (e.g., straight road, no presence or limited number of potential obstacles, and/or high friction road surface), the secondary ride control target is changed to a second target level that is lower than the first target level (e.g., the damping ratio is decreased). Conversely, when detecting environmental conditions that are more likely to require high traction for acceleration the vehicle (e.g., curvy road, many potential obstacles, and/or low friction road surface), the secondary ride control target is changed to a second target level that is higher than the first target level (e.g., the damping ratio is increased). 
     The fourth operation  642  of providing the secondary ride control to achieve the second target level is performed by providing all or a portion of the secondary ride control with the reaction mass actuator  250  or the tuned mass damper and additionally (if necessary) with the primary actuator  246 . For example, the primary actuator  246  may provide additional secondary ride control if the capacity threshold for the reaction mass actuator  250  or the tuned mass damper is exceeded. 
     The method  602  may be performed in conjunction with the method  600 , such that the capacity threshold used in one or both the second operation  622  and the fourth operation  642  may be adjusted according to the environmental conditions ahead of the vehicle  100 . The method  602  may, instead or additionally, be performed in conjunction with the method  601 . 
     Referring to  FIG.  7   , the suspension system  140  may be operated according to assessment of an obstacle ahead of the vehicle  100 . The vehicle  100  may detect the obstacle in the road ahead and both raise the vehicle  100  (e.g., increase a ride height of the vehicle  100 ) and steer the vehicle  100 , such that the vehicle  100  straddles the obstacle between the wheels  104  thereof. 
     The vehicle  100  may observe the road ahead with the environment sensors  354  to assess (e.g., detect and/or characterize). For example, LIDAR, radar, and/or cameras may be used in conjunction with the control system  160  to identify an obstacle and assess an obstacle, for example, by characterizing a size of the obstacle (e.g., by height, width, and/or predicted motion). Based on the assessment of the obstacle, the vehicle  100  determines an appropriate maneuver to avoid the obstacle, which may be referred to as an obstacle avoidance maneuver. The obstacle avoidance maneuver may include steering and increasing a ride height of the vehicle  100  for the obstacle to pass under the vehicle body  102  and between two or more wheels  104  of the vehicle  100 , which may be referred to as a straddle maneuver. The obstacle avoidance maneuver may instead include steering the vehicle  100  around the obstacle and/or stopping the vehicle  100  before the obstacle, which may be referred to as a swerving maneuver and a stopping maneuver, respectively. 
     As shown in  FIG.  7   , a method  700  is provided for obstacle avoidance. The method  700  includes a first operation  710  of assessing an obstacle ahead of the vehicle, a second operation  720  of determining whether to perform a straddle maneuver, a third operation  730  of determining suspension instructions and steering instructions of the straddle maneuver, and a fourth operation  740  of operating the suspension system  140  according to the suspension instruction and the steering system  120  according to the steering instruction to straddle the obstacle with the vehicle  100 . 
     The first operation  710  of assessing an obstacle may be performed with the sensing system  150  (e.g., the environment sensors  354  and/or the environment information sources  356 ), for example, in conjunction with the control system  160 . The sensing system  150 , with the environment sensors  354 , may observe the environment ahead of the vehicle  100  (e.g., the road ahead of the vehicle), such as with one or more of LIDAR, radar, sonar, and/or cameras, which are in communication with the control system  160 . The environment information sources  356  may include another vehicle, which previously identified an obstacle, or another source (e.g., mapping data). 
     In assessing an obstacle, obstacle characteristics are determined by which a suitable obstacle avoidance maneuver may be determined. The obstacle characteristics include information suitable to determine whether the vehicle  100  is capable of performing the straddle maneuver to avoid the obstacle, which may include characterizing a size of the obstacle (e.g., a height and a width of the obstacle) or other suitable characteristics (e.g., characterizing the obstacle by size category, such as small, large, short, long, narrow, and/or wide). The obstacle characteristics may further include predicting motion of the obstacle such that a predicted location of the obstacle may be determined. 
     The second operation  720  of determining whether to perform the straddle maneuver is performed, for example, by the control system  160 . The control system  160  may, for example, compare the obstacle characteristics to vehicle characteristics (e.g., fixed and/or dynamic characteristics) to determine whether the straddle maneuver may be performed. For example, the obstacle characteristics (e.g., height, width, size, and/or motion) may be compared to thresholds that correspond to fixed characteristics of the vehicle  100  (e.g., distance between wheels  104  and maximum ride height of the vehicle  100 ) and/or to dynamic characteristics of the vehicle  100  (e.g., maximum available ride height achievable at given speed of the vehicle  100  and suspension requirements). 
     Determining whether to perform the straddle maneuver may also include assessing other obstacle avoidance maneuvers, such as whether the swerving maneuver and/or the braking maneuver may be performed to avoid the obstacle (e.g., based on braking distance, cornering ability, presence of other obstacles, such as other vehicles). For example, the straddle maneuver may be preferable over the swerve maneuver if less disturbance to passengers of the vehicle  100  or to surrounding vehicles is expected. 
     The third operation  730  of determining the straddle maneuver includes determining maneuver instructions, including determining a suspension instruction (e.g., to raise the vehicle body  102  to pass above the obstacle) and determining a steering instruction (e.g., sequence of steering angles) according to a predicted position of the obstacle (e.g., to steer the vehicle  100  for the obstacle to pass between the wheels  104  on left and right sides thereof). Maneuver instructions may also include braking instructions, for example, to slow the vehicle  100  sufficiently to allow the suspension height and/or steering inputs to be achieved prior to the vehicle  100  reaching the obstacle. 
     The fourth operation  740  of operating the suspension system and the steering system is, for example, controlled by the control system  160  according to the suspension instruction and the steering instruction. For example, for one or more wheels  104  (e.g., all four wheels  104 ), the primary actuator  246  and/or the spring seat actuator  252  may raise the vehicle body  102  relative to the road surface. The steering system  120  may also change the steering angle of the wheels  104  to guide the obstacle between two or more of the wheels  104  and/or the braking system  130  may slow rotation of the wheels  104 . 
     Referring to  FIG.  8   , the suspension system  140  is controlled according to environmental conditions ahead of the vehicle  100  to assist a steering maneuver. Based on conditions ahead of the vehicle  100 , a steering maneuver may be determined by which the steering system  120  is operated to turn the vehicle  100  and the suspension system  140  transfers load between the wheels  104  to assist turning of the vehicle  100 . For example, the environmental condition may be presence of an obstacle, which may be assessed by observing the road ahead of the vehicle  100  and/or by correlating a position of the vehicle  100  to stored information (e.g., mapping data that includes environmental information, including obstacle information, such as obstacle locations). In case of an obstacle being present, the steering maneuver may be to steer around the obstacle. In one example, the steering maneuver is an oversteer maneuver in which the vehicle  100  turns by a greater amount than would be expected of the vehicle  100  at low speed with the same steering angles of the wheels  104 . In advance of and/or concurrent with turning the wheels  104  with the steering system  120 , the suspension system  140  is operated to transfer weight from the rear wheels  104  to the front wheels  104 , which in combination with turning the wheels  104  (e.g., the front wheels) with the steering system  120 , induces oversteer. For example, the suspension system  140  may pitch the vehicle  100  forward, such as by operating the primary actuators  246  to accelerate a rear of the vehicle  100  upward (e.g., by increasing force between the rear wheels  104  and the vehicle body  102 ) and/or a front of the vehicle  100  downward (e.g., by decreasing force between the front wheels  104  and the vehicle body  102 ). In another example, weight may be transferred between the front wheels  104  (e.g., left to right) and the rear wheels  104  in an opposite direction (e.g., right to left) to induce warp. 
     As shown in  FIG.  8   , a method  800  is provided for assisting a steering maneuver with the suspension system  140 . The method  800  includes a first operation  810  of assessing the environment ahead of the vehicle  100 , a second operation  820  determining a vehicle maneuver according to the environment ahead of the vehicle  100 , a third operation  830  operating the suspension system  140  according to the suspension instruction of the vehicle maneuver, and a fourth operation  840  operating the steering system  120  according to the steering instruction of the vehicle maneuver subsequent to or concurrent with operating the suspension system  140 . 
     The first operation  810  of assessing the environment ahead of the vehicle  100  may be performed by the sensing system  150  in conjunction with the control system  160 . For example, the sensing system  150  may observe the environment ahead of the vehicle  100  with the environment sensors  354  thereof, such as by observing the road (e.g., changes in direction and/or elevation) and/or potential obstacles. Instead or additionally, the environment may be assessed using stored environment information (e.g., map data correlated with a position and path of the vehicle  100  determined with the motion sensors  352   e ) or received information (e.g., from vehicles ahead). 
     The second operation  820  of determining a vehicle maneuver according to the environment ahead of the vehicle is performed, for example, with the control system  160 . The vehicle maneuver may, for example, include following the road ahead (e.g., according to an autonomous drive plan) or avoiding an obstacle. The vehicle maneuver includes a suspension instruction and a steering instruction. For example, the vehicle maneuver may be an oversteer maneuver in which the suspension instruction includes operating the primary actuators  246  to transfer weight to the front wheels  104 , while the steering instruction includes turning the front wheels  104  by an amount less than normally required (e.g., in slow speed conditions) to achieve the desired amount of steering. The facilitate the oversteer maneuver, the suspension instruction may be configured to pitch the vehicle body  102  forward, for example, by operating the primary actuators  246  coupled to the rear wheels  104  to upwardly accelerate the rear of the vehicle  100  and/or by operating the primary actuators  246  coupled to the front wheels  104  to downwardly accelerate the front of the vehicle  100 . 
     The third operation  830  of operating the suspension system  140  is controlled, for example, by the control system  160  according to the suspension instruction of the vehicle maneuver determined in the second operation  820 . For example, the control system  160  may operate the suspension system  140  according to the suspension instruction to transfer weight between the wheels  104 , such as to increase the load of the front wheels  104 , in the manners described above. 
     The fourth operation  840  of operating the steering system  120  is controlled, for example, by the control system  160  according to the steering instruction of the vehicle maneuver determined in the second operation  820 . The fourth operation  840  may be performed subsequent to and/or concurrent with the third operation  830  of operating the suspension system  140 , such that the front wheels  104  experience increased loading (e.g., increased force between the wheels  104  and the road surface) while the front wheels  104  are turned according to the steering instruction to turn the vehicle  100 . 
     Referring to  FIG.  9   , the suspension system  140  and one or more of the drive system  110  or the steering system  120  are controlled according to a disturbance ahead of the vehicle  100  to mitigate vertical and/or horizontal acceleration of the vehicle  100 , or to mitigate other disturbances to the vehicle  100 . The vehicle  100  identifies disturbances in the road surface ahead of the vehicle  100 , and determines a vehicle maneuver by which the suspension system  140  is operated in conjunction with one or more of the drive system  110  and/or the steering system  120  to mitigate force transfer from the disturbance to the vehicle body  102 . Acceleration of the vehicle body  102  is thereby mitigated, so as to improve ride comfort of passengers. Acceleration of the vehicle body  102  may be at a center of gravity of the vehicle  100 , a center of volume of the vehicle  100 , or at another point of the vehicle  100  (e.g., under one or more passengers thereof). Vehicle body disturbances other than acceleration of the vehicle body  102  may be mitigated instead of or in addition to acceleration, such as jerk (i.e., the derivative of the acceleration), the root mean square of acceleration (RMS), or other vehicle body disturbance. 
     When the vehicle  100  travels over a disturbance in a road surface, such as a pothole, the disturbance applies force to the wheels  104 , which includes both a vertical component and horizontal components (e.g., in fore-aft and inboard-outboard directions). The vehicle maneuver operates the suspension system  140  to reduce net vertical force that might otherwise be transferred from the disturbance to the vehicle body  102  and, thereby, reduce net vertical acceleration of the vehicle body  102  and contemporaneously operates one or more of the drive system  110  and/or the steering system  120  to reduce net horizontal force transfer from the disturbance to the vehicle body  102  and, thereby, reduce net horizontal acceleration of the vehicle body  102 . The suspension system  140  and the drive system  110  and/or the steering system  120  may instead be operated contemporaneously to mitigate the other vehicle body disturbances identified above (e.g., jerk, or the root mean square of acceleration). 
     The vehicle maneuver includes applying a force to the wheel  104  with the primary actuator  246 , as the wheel  104  passes over the disturbance, which may be upward or downward. It should be noted that all of the wheels  104  may or may not pass over the disturbance. For example, in case of the disturbance being a pothole, the wheels  104  on only one side of the vehicle may pass over the disturbance in succession front to back in which case an upward force is applied to the wheels  104  on the side of the vehicle  100  of the disturbance. In case of the disturbance being a speed bump, all of the wheels  104  may pass over the disturbance in succession front to back in which case an upward force is applied to all of the wheels  104 . By applying an upward force to the wheel  104  contemporaneous with passing over the disturbance (e.g., immediately prior to, during, and/or immediately after), a net vertical force applied to the wheel  104  by the disturbance is mitigated, such that vertical force transferred to and, thereby, vertical acceleration of the vehicle body  102  is mitigated. 
     The vehicle maneuver may also include turning one or more of the wheels  104  with the steering system  120  toward the disturbance as one or more of the wheels  104  pass over the disturbance. By turning the wheel  104  into the disturbance contemporaneous with passing over the disturbance, a net lateral force applied to the wheel  104  is mitigated, such that lateral force transferred to and, thereby, lateral acceleration of the vehicle body  102  is mitigated. The wheel  104  may be turned independent of the other wheels  104 . Alternatively, other wheels  104  may instead or additionally be turned toward the disturbance contemporaneous with the wheel  104  passing over the disturbance. 
     The vehicle maneuver may also include accelerating one or more of the wheels  104  with the drive system  110  in a forward direction as one or more of the wheels  104  pass over the disturbance. For example, in case of the disturbance impacting the wheels  104  on one side of the vehicle  100 , one or more of the wheels  104  on the side of the disturbance may be accelerated in the forward direction by the drive system  110  contemporaneous with one or more of the wheels  104  passing over the disturbance. Instead or additionally, one or more wheels  104  on both sides of the vehicle  100  may be accelerated in the forward direction by the drive system  110 . By accelerating one or more of the wheels  104  in the forward direction contemporaneous with passing over the disturbance, a net fore-aft force applied to the wheel  104  is mitigated, such that fore-aft force transferred by the wheel  104  to and, thereby, fore-aft acceleration of the vehicle body  102  is mitigated. Accelerating the one or more wheels  104  with the drive system  110  may be performed by electric motors of the drive system  110 , which may be more responsive than a gasoline engine. 
     As noted above, the suspension system  140  and the drive system  110  and/or the steering system  120  may instead be operated contemporaneously to mitigate the other vehicle body disturbances identified above (e.g., jerk, or the root mean square of acceleration). 
     As shown in  FIG.  9   , a method  900  is provided for a vehicle maneuver that mitigates vertical and horizontal force transfer to a vehicle body from a road disturbance. The vehicle maneuver may instead mitigate another vehicle body disturbance (e.g., jerk, RMS). The method  900  includes a first operation  910  of identifying and assessing a road disturbance, a second operation  920  of determining a vehicle maneuver according to the road disturbance, a third operation  930  of operating the suspension system  140  according to the vehicle maneuver contemporaneous with the wheel  104  of the vehicle  100  passing over the disturbance, and a fourth operation  940  of operating the drive system  110  and/or the steering system  120  according to the vehicle maneuver contemporaneous with the wheel  104  passing over the disturbance. 
     The first operation  910  of identifying a disturbance is performed by the sensing system  150 , for example, in conjunction with the control system  160 . The environment sensors  354  may observe the road surface ahead of the vehicle  100  to identify a road disturbance, such as a pothole. Instead or additionally, the environment sensors  354  may observe behavior of another vehicle ahead of the vehicle  100  and/or be identified using stored information (e.g., by correlating a position of the vehicle  100  determined by GPS with stored mapping information). 
     The second operation  920  of determining a vehicle maneuver is performed by the control system  160 . The vehicle maneuver includes a suspension instruction and one or more of a drive instruction or a steering instruction. The suspension instructions include instructions to operate the suspension system  140  to apply an upward force to the wheel  104  passing over the disturbance. The drive instruction includes instructions to operate the drive system  110  to accelerate one or more of the wheels  104  contemporaneous with the wheel  104  or the other wheels  104  passing over the disturbance. The drive instruction may include accelerating one or more of the wheels  104  on a side of the vehicle  100  passing over the disturbance. The steering instructions includes operating the steering system  120  to turn the wheel  104  into the disturbance (e.g., to point the wheel  104  toward the disturbance) contemporaneous with the wheel  104  passing over the disturbance and/or turning others of the wheels  104  toward the disturbance contemporaneous with the wheel  104  passing over the disturbance. 
     The third operation  930  of operating the suspension system  140  is controlled, for example, by the control system  160  according to the suspension instruction. The control system  160  causes the suspension system  140  to force with the primary actuator  246  to the wheel  104  as the wheel  104  passes over the disturbance, which may be upward or downward. For example, by applying an upward force with the primary actuator  246  to the wheel  104 , vertical force applied by the disturbance to the wheel  104  is mitigated, such that net vertical force applied to and acceleration of the vehicle body  102  (or other vehicle body disturbance) is mitigated. Applying a downward force may be advantageous, for example, resulting in reduced net force applied to the vehicle body  102 . 
     The fourth operation  940  of operating the drive system  110  and/or the steering system  120  is controlled, for example, by the control system  160  according to the drive instruction and/or the steering instruction, respectively. The control system  160  may cause the drive system  110  to accelerate the one or more of the wheels  104  in the forward direction contemporaneous with the wheel  104  passing over the disturbance. As described above, by accelerating the wheel  104  forward, net fore-aft force applied by the disturbance to the wheel  104  is mitigated, such that net fore-aft force applied to and acceleration of the vehicle body  102  (or other vehicle body disturbance) is mitigated. 
     Referring to  FIG.  10   , the suspension system  140  is operated according to an elevation change ahead of the vehicle  100 . The vehicle  100  identifies an elevation change ahead of the vehicle  100 , such as an incline or a decline, and operates the suspension system  140  in advance of and concurrent with travelling through the elevation change. For example, the vehicle  100  may determine an upward hill in the road ahead of the vehicle  100 , such that the road changes from a low slope (e.g., a horizontal) to an increased slope (e.g., an inclined slope). To reduce upward acceleration of the vehicle  100  when transitioning from the low slope to the increased slope, the suspension system  140  may be operated to increase a ride height of the vehicle  100  prior to reaching the increased slope. As the vehicle  100  travels from the low slope to the increased slope, the suspension system  140  may, in sequence, lower the ride height at a front of the vehicle  100  and subsequently lower the ride height at a rear of the vehicle  100 . By raising the ride height prior to reaching the increased slope, the suspension system  140  provides more available downward suspension travel (i.e., downward movement of the vehicle body  102  relative to the wheels  104 ) and, thereby, more time over which the vertical velocity of the vehicle  100  changes (i.e., the vehicle  100  accelerates vertically) from the low slope to the increased slope. Thereby, lower vertical acceleration will be experienced by the vehicle body  102  and, thereby, passengers therein. 
     Conversely, the vehicle  100  may determine a downward hill in the road ahead of the vehicle  100 , such that the road changes from a high slow (e.g., horizontal) to a decreased slope (e.g., a declined slope). To reduce downward acceleration of the vehicle  100  when transitioning from the high slope to the decreased slope, the suspension system  140  may be operated to decrease a ride height of the vehicle  100  prior to reaching the decreased slope, thereby providing more available upward suspension travel (i.e., upward movement of the vehicle body  102  relative to the wheels  104 ). 
     The suspension system  140  may be operated to lower or raise the ride height at a front of the vehicle  100  and at a rear of the vehicle  100  simultaneously, by the same or varying degrees, to heave the vehicle  100  (i.e., cause vertical motion) as opposed to pitch the vehicle  100  (i.e., tilt forward or rearward). In some circumstances, such as in the case of a short hill (e.g., less than a few lengths of the vehicle  100 , such as when transitioning between public roadways and parking lots or private driveways), heaving the vehicle  100  may be preferable to pitching the vehicle  100  depending on sensitivities of occupants of the vehicle  100  (e.g., persons more sensitive to pitch than heave). 
     The elevation change may be determined with the sensing system  150  by observing the road ahead of the vehicle and/or by correlating a position of the vehicle  100  to mapping information that includes road elevation information. Notably, for decreased slopes, the sensing system  150  may be unable to directly observe elevation changes beyond a crest (e.g., peak) of a road surface. For example, the road elevation beyond such a crest may be a sustained downward slope (e.g., a hill) or an unsustained downward slope before (e.g., a dip). In such circumstances, the mapping information or other stored information (e.g., learned information or information received from other vehicles) or observing behavior of other vehicles may be more informative as to the changed slope according to which the ride height of the vehicle  100  may be lowered to provide more downward suspension travel. 
     As shown in  FIG.  10   , a method  1000  is provided for operating the suspension system  140  according to elevation changes ahead of the vehicle  100 . The method  1000  includes a first operation  1010  of assessing an elevation change of a road ahead of the vehicle  100 , a second operation  1020  of changing a ride height of the vehicle  100  according to the elevation change prior to the vehicle  100  reaching the elevation change, a third operation  1030  of changing a front ride height of the vehicle  100  as the front wheels  104  transition from a first slope to a second slope, and a fourth operation  1040  of changing a rear ride height of the vehicle  100  as the rear wheels  104  transition from the first slope to the second slope. 
     The first operation  1010  of assessing elevation changes of ahead of the vehicle  100  are performed by the sensing system  150 . The sensing system  150  may observe the road ahead of the vehicle  100  with the environment sensors  354  to determine elevation changes and/or may correlate a position of the vehicle  100  to stored elevation information (e.g., mapping information). As referenced above, assessing negative elevation changes may advantageously be performed by correlating a position of the vehicle  100  to stored elevation information. 
     The second operation  1020  of changing a ride height of the vehicle  100  is performed by the suspension system  140 , for example, as operated by the control system  160 . In case of an increased slope being determined, the suspension system  140  increases a ride height of the vehicle  100 , for example, by operating the primary actuator  246  and/or the spring seat actuators  252  associated with each of the wheels  104 , which increases available downward suspension travel. In case of a decreased slope being determined, the suspension system decreases a ride height of the vehicle  100 , for example, by operating the primary actuator  246  and/or the spring seat actuators  252  associated with each of the wheels  104 , which increases available upward suspension travel. As noted above, the ride height is changed prior to the vehicle reaching the changed slope. 
     The third operation  1030  of changing a front ride height of the vehicle  100  is performed by the primary actuators  246  and/or the spring seat actuators  252  associated with the rear wheels  104  of the vehicle  100 . The front ride height is decreased or increased as the front wheels  104  initially travel over the increased slope or the decreased slope, respectively. 
     The fourth operation  1040  of changing a rear ride height of the vehicle  100  is performed by the primary actuators  246  and/or the spring seat actuators  252  associated with the rear wheels  104  of the vehicle  100 . The rear ride height is decreased or increased as the rear wheels  104  initially travel over the increased slope or the decreased slope, respectively. 
     Referring to  FIG.  11   , the vehicle  100  is controlled according to a temperature of the suspension system  140 , such as the primary actuator  246 , and conditions ahead of the vehicle  100 . For example, the primary actuator  246  may have a reduced capacity (e.g., force output) at high temperatures or other temperature-related considerations may make operating at a reduced capacity advantageous (e.g., preserve durability). Conditions ahead of the vehicle  100  may, however, under a normal control methodology, require that the suspension system  140  to operate above such thresholds. By knowing the conditions ahead of the vehicle  100 , the vehicle  100  may operate according to an alternative control methodology to reduce demand of the suspension system  140  (e.g., of the primary actuator  246 ). For example, if the road ahead is known to have a high quantity and/or magnitude of road disturbances, the vehicle  100  may be operated at a different speed, such as a slower speed resulting in lower force transfer from road disturbances to the unsprung mass, or in a different path known to have fewer and/or lower magnitude of road disturbances, such as in an adjacent lane or on another street. In another, example, the suspension system  140  may instead or additionally be operated in different manners. Depending on whether the road ahead is known to have high quantity and/or magnitude disturbances (i.e., requiring greater loading of the suspension system  140 ) or low quantity and/or magnitude disturbances, the suspension system  140  may be operated to reduce demand of the primary actuator  246 . For example, the suspension system  140  may be operated for the spring  248  to transfer more force from the unsprung mass to the vehicle body  102  (e.g., by allowing more suspension travel to be utilized, such as by reducing damping force provided by the primary actuator  246 ), thereby reducing loading of the primary actuator  246 . 
     As shown in  FIG.  11   , a method  1100  is provided for operating the vehicle  100  according to changes in temperature of the suspension system  140 , such as of one or more of the primary actuators  246  thereof. The method  1100  includes a first operation  1110  of determining a first vehicle control plan, a second operation  1120  of assessing a road ahead for suspension demand of the vehicle  100 , a third operation  1130  of assessing a temperature of the suspension system  140 , a fourth operation  1140  of determining a second vehicle control plan, and a fifth operation  1150  of operating the vehicle  100  according to the second vehicle control plan. 
     The first operation  1110  of determining a vehicle control plan may, for example, be performed by the control system  160 . The first operation  1110  includes determining a route plan of the vehicle  100  and a suspension setting of the suspension system  140 . The route plan of the vehicle  100 , for example, includes a direction (e.g., a road and/or lane) and a speed of the vehicle  100  that the vehicle  100  is to travel. The suspension setting of the suspension system  140 , for example, is a setting according to which the suspension system  140  (e.g., the primary actuator  246 ) controls force transfer from road disturbances between the unsprung mass and the vehicle body  102 , such as a damping setting. 
     The second operation  1120  of assessing the road ahead of the vehicle  100  for suspension demand may be performed by the control system  160  in conjunction with the sensing system  150 . The first operation, for example, includes assessing a number (e.g., frequency) and/or a magnitude of road disturbances ahead of the vehicle  100 , or otherwise quantifying the road surface and/or assessing possible suspension demand. The road ahead of the vehicle  100  may be assessed by the sensing system  150  observing the road ahead with the environment sensors (e.g., identifying, measuring, or otherwise detecting disturbances in the road surface) and/or behavior of other vehicles ahead of the vehicle  100 . The road ahead of the vehicle  100  may instead or additionally be assessed for suspension demand with the vehicle sensors  352  in conjunction with stored information sources  356   a  (e.g., correlating GPS position to mapping information with road surface information, such as road disturbance information). 
     The third operation  1130  of assessing the temperature of the suspension system  140  may be performed by the control system  160  in conjunction with the sensing system  150  and, in particular, the suspension system sensors  352   d  (i.e., the temperature sensors) that may measure temperature of the one or more primary actuators  246 . 
     The fourth operation  1140  of determining a second vehicle control plan may be performed by the control system  160  according to the assessment of the road ahead and the assessment of the temperature of the suspension system  140 . For example, if the temperature of the suspension system  140  exceeds a threshold, the fourth operation  1140  includes determining the second vehicle control plan to have one or more of a different route plan or a different suspension setting than the first vehicle control plan. The different vehicle route plan may include having a different route (e.g., road and/or lane) and/or a different speed at which the vehicle is to travel, which would be expected to have lesser suspension demand (e.g., by having fewer and/or lower magnitude road disturbances). The different suspension setting may include transferring a lesser amount of force with the primary actuator  246  or allowing greater suspension travel for a given disturbance (e.g., by changing damping settings). 
     The fifth operation  1150  of operating the vehicle  100  according to the different vehicle control plan may be performed by the control system  160  in conjunction with the various output systems of the vehicle  100 , such as the drive system  110 , the steering system  130 , and/or the suspension system  140 . 
     Referring to  FIG.  12   , the vehicle  100  is controlled according to road disturbances ahead of the vehicle  100  and, in particular, is controlled according to a route plan having a coarse route plan and a fine route plan. Different sections of a road may have different road disturbances at different lateral locations within a lane, which may be regular disturbances or irregular disturbances. Regular disturbances are disturbances having a regular pattern (e.g., intentional pattern), such as rumble strips on one side of a lane that, while under construction, has shifted to a shoulder of the road. Irregular disturbances are disturbances having no regular pattern, such as bumps or undulations that develop in a road surface over time (e.g., cracks, potholes, and/or waviness, which may have developed from traffic and/or thermal expansion/contraction). 
     By knowing the lateral locations of the road disturbances ahead of the vehicle  100 , the vehicle  100  may be guided to lateral locations within a lane to reduce the cumulative effect of road disturbances to the suspension system  140  (e.g., the magnitude, quantity, and/or other cumulative measure) and/or lateral acceleration to avoid such road disturbances, for example, to improve ride comfort or other considerations. For example, the vehicle  100  may determine a coarse route plan by which the vehicle  100  is routed over a lane of a road, and further determine a fine route plan by which the vehicle  100  is routed within the lane of a road to reduce road disturbances (e.g., as compared to traveling through a center of the lane). 
     The fine route plan is to be distinguished from avoiding a single obstacle or avoiding multiple obstacles in sequence in that the fine route plan accounts for multiple different road disturbances at different forward locations and allows the vehicle  100  to travel at different lateral locations within a lane for sustained period of time. This allows the vehicle  100  to avoid impacting road disturbances that are spaced apart in a forward direction, while also reducing steering inputs and lateral acceleration therebetween, which might otherwise detract from ride comfort. For example, road disturbances (e.g., potholes) may be detected on a right side of the lane (e.g., to impact the right wheels  104  of the vehicle  100  if centered in the lane) and 25 yards apart. The fine route plan may include the vehicle  100  traveling in a straight path in the lane to the left of the two disturbances, rather than steering back toward the center of the lane between the disturbances. 
     The fine route plan may be determined, for example, by sensing the road ahead (e.g., with the environment sensors) or according to the stored information sources  356  (e.g., mapping information). Sensing the road ahead may include assessing the quantity and/or magnitude of road disturbances at lateral locations in the lane ahead). The stored information sources  356  may include information from the vehicle  100  or other vehicles having travelled through different lateral portions (e.g., paths) of the lane to assess the road disturbances at lateral locations within a lane, for example, by recording movement of the vehicle  100  and/or the suspension system  140 . The vehicle  100  or another vehicle may first assess road disturbances when traveling through one lateral region (e.g., path) of a lane over one section of road, and later assess the road disturbances when again travelling through another lateral region (e.g. another path) of the same lane over the same section of road. 
     As shown in  FIG.  12   , a method  1200  is provided for operating the vehicle  100  according to a coarse route plan and a fine route plan. The method  1200  includes a first operation  1210  of determining a coarse route plan, a second operation  1220  of assessing the lane of the coarse route plan, a third operation  1230  of determining a fine route plan, and a fourth operation  1240  of operating the vehicle  100  according to both the coarse route plan and the fine route plan. 
     The first operation  1210  of determining a coarse vehicle route plan may be performed by the control system  160 . The first operation  1210  includes determining the coarse route plan to include a road and a lane of a road ahead of the vehicle  100  over which the vehicle  100  is to travel. 
     The second operation  1220  of assessing the lane of the coarse route plan may be performed by the control system  160  in conjunction with the sensing system  150 . For example, the environment sensors may be used to assess quantity and/or magnitude of road disturbances at lateral locations within the lane over which the wheels  104  of the vehicle  100  may travel. Instead or additionally, the lane of the coarse route plan may be assessed according to stored information, such as mapping information or information previously gathered by the vehicle  100  or another vehicle when travelling through the lane previously at one or more different lateral positions. 
     The third operation  1230  of determining the fine route plan may be performed by the control system  160 . The fine route plan includes lateral locations (e.g., a path) of the vehicle  100  within the lane of the coarse route plan. The fine route plan is determined according to the assessing of the lane of the course route plan to reduce disturbance to the vehicle  100 , for example, as compared the vehicle  100  being centered in the lane. For example, the fine route plan may be determined to reduce the quantity, magnitude, and/or other cumulative measure of road disturbances over a forward section that will be impacted by the wheels  104  as the vehicle  100  travels through the lane. Instead or additionally, the fine route plan may be determined to be one of multiple previous paths that the vehicle  100  or another vehicle has travelled through the lane and was determined to reduce the quantity, magnitude, and/or other cumulative measure of road disturbances over the forward section of road as compared to the other of the multiple previous paths. 
     The fourth operation  1240  of operating the vehicle  100  according to the fine route plan may be performed by the control system  160  in conjunction with the steering system  130 , which steers the vehicle  100  within the lane at the lateral locations of the fine route plan. 
     Referring to  FIG.  13   , the suspension system  140  is controlled according to a characteristic of the sensing system  150 . For example, the sensing system  150  may include cameras having image sensors, which require longer exposure times in darker conditions to obtain equivalent quality images as during light conditions. However, more movement, of the sensors  354  relative to the object or the object relative to the sensors  354 , may occur during the longer exposure times, which may create image blur. The suspension system  150  may, however, be utilized to stabilize the sensors  354  to obtain improved image quality, for example, by softening the suspension system to reduce quick movement of the sensors  354  in dark conditions. 
     As shown in  FIG.  13   , a method  1300  is provided for operating the suspension system  140  according to a condition affecting the sensing system  160 . The method  1300  includes a first operation  1310  of sensing a condition affecting a sensor, a second operation  1320  of changing a setting of the suspension system  150  according to the condition impacting the sensor, and a third operation  1330  of operating the suspension system  150  according to the changed suspension setting, while using the affected sensor (e.g., capturing images). 
     The first operation  1310  of sensing a condition impacting the sensing system  160  may be performed with the control system  160  in conjunction with the sensing system  150 . The affected part of the sensing system may, for example, be cameras or another light sensitive sensor. The condition sensed may be light level determined by an ambient light sensor or a time of day (e.g., correlated to sunrise and sunset times for the given day). 
     The second operation  1320  of determining a changed suspension setting may be performed with the control system  160 . For example, while the environment is determined to be bright, the suspension system  140  may operate according to a first setting by which force is transferred quickly to the vehicle body  102  to which the sensors are coupled, which may result in the sensors moving abruptly. This may be acceptable for cameras  354   f , which require low exposure times in high light conditions. When the environment is determined to be dark, the suspension system  140  may operate according to a second setting by which force is transferred more slowly to the vehicle body  102  to which the various sensors (e.g., environment sensors, such as the camera  354   f ), which may result in the such sensors moving less abruptly (e.g., more slowly). This reduces amount of movement of the cameras  354   f  during exposure times relative to the environment being sensed, so as to improve sensing capabilities. 
     The third operation  1330  of operating the suspension system  150  may be controlled by the control system  160 . 
     Referring to  FIG.  14   , the vehicle  100  is configured to learn (e.g., sense and record) road disturbance information for later use. As the vehicle  100  travels over different roads and road sections, the vehicle body  102  and the suspension system  140  experience different movements and different forces, which may be sensed and recorded by the vehicle  100  or other vehicles for later use by the vehicle  100  or the other vehicles. For example, the vehicle  100  may detect road disturbances, such as roughness, localized disturbances, and/or elevation changes. Such road disturbances may be determined, for example, with the motion sensors  352   e  of the vehicle  100  (e.g., measuring acceleration of the vehicle body  102 ) and/or the suspension system sensors  352   d  (e.g., measuring displacement and/or force of the primary actuators  246 ). The learned road disturbance information may be used in the methods above (e.g., controlling the vehicle  100  according to the roughness), spatially locating the vehicle  100  when GPS is unavailable (e.g., based on signature for a particular location, such as railroad tracks), for determining the fine route plan within a lane (e.g., by travelling different paths through sections of roads and comparing road disturbance information), and/or for other uses (e.g., communicating road conditions for infrastructure uses, such as identifying required repairs and/or providing public alerts pertaining to the road disturbances). 
     As shown in  FIG.  14   , a method  1400  is provided for learning road disturbance information with the suspension system  140 . The method  1400  generally includes a first operation  1410  of operating the vehicle  100  over a section of road, a second operation  1420  of recording vehicle information pertaining to road disturbances of the section of road, a third operation  1430  of determining road disturbance information from the vehicle information, and a fourth operation  1440  of using the road disturbance information. 
     The first operation  1410  of operating the vehicle  100  over a section of road is controlled, for example, by the control system  150 , such as when transporting a passenger, between transporting passengers, or on a sensing route (e.g., dedicated purpose for gathering road disturbance information). 
     The second operation  1420  of recording vehicle information is performed with the sensing system  150 . The vehicle sensors  352 , including the suspension systems sensors  352   d  and the motion sensors  352   e , measure motion thereof, which may be recorded against a position of the vehicle  100  (e.g., determined by GPS). For example, the motions sensors  352   e  may measure acceleration of the vehicle body  102 . The suspension system sensors  352   d  may measure displacement and/or force of the primary actuator  246 . 
     The third operation  1430  of determining road disturbance information from the vehicle information may be performed by the control system  160 . For example, the vehicle information may be used to determine roughness (e.g., from repeated force inputs to the suspension system  140  for a given speed of the vehicle), local disturbances (e.g., potholes from sharp decrease and subsequent increase in force to the primary actuator  246  associated with one of the wheels  104 ), and/or elevation changes (e.g., from acceleration of the vehicle body  102  and changes in the displacement of the primary actuators  246 ). The road disturbance information is then stored by the vehicle  100  and/or transferred to another vehicle. The road disturbance information may, alternatively, be transferred to a remote system, such as an infrastructure system or a rebroadcasting system. Such an infrastructure system may be used to monitor road conditions, for example, to identify required road repairs. Such a rebroadcasting system may send the road disturbance information to other vehicles, for example, to control the output systems of the other vehicles (e.g., suspension systems thereof) and/or to provide alerts about road conditions thereto. 
     The fourth operation  1440  of using the road disturbance information is performed, for example, with the control system  160 , which controls one or more of the output systems of the vehicle  100  according to the road disturbance information (e.g., according to one of the methods described above, or another suitable method). 
     Referring to  FIG.  15   , the suspension system  140  is controlled to achieve a suspension stiffness and/or a body ride frequency according to conditions ahead of the vehicle  100 . As referenced above, the primary actuator  246  and the spring  248  form two parallel load paths by which input force is transferred from the wheel  104  (e.g., from a road disturbance) to the vehicle body  102 . For a given input force, stiffness of the suspension system  140  may be increased or decreased by controlling the primary actuator  246  to transfer, respectively, a higher or lower proportion of the given input force to the vehicle body  102 . This in turn causes the spring  248  to transfer a lower or higher proportion, respectively, of the force to the vehicle body  102  and results in the wheel  104  travelling less or more, respectively relative to the vehicle body  102 . It may be beneficial from an energy consumption standpoint to operate the suspension system  140  predominantly with a low stiffness and increase the stiffness when predicted to be needed, since the primary actuator  246  consumes more power when providing increased stiffness. The stiffness of the suspension system  140  may be increased from a low stiffness level (e.g., a default stiffness level) based on conditions ahead of the vehicle  100 , for example, to prevent the suspension system  140  from reaching full suspension travel (e.g., reaching end stops of the primary actuator  246 ) and/or to prevent low frequency movement of the vehicle body  102  that might be uncomfortable to the user (e.g., pitching and rolling). 
     The stiffness of the suspension system  140  may be changed according to the road conditions using, for example, gain scheduling. The suspension system  140  and, in particular, the primary actuator  246  may be controlled according to a suspension control logic that, for example, controls output of the primary actuator  246  (e.g., torque and/or direction) according to the suspension system sensors  352   d  (e.g., force, position, and/or motion) of the primary actuator  246 . For those road conditions for which increased stiffness is desired, the gain may be increased, such that the output of the primary actuator  246  (e.g., the torque) achieves a higher stiffness. Other inputs for gain scheduling may include, for example, speed of the vehicle  100  and/or weight of the vehicle  100  (e.g., which may vary according to occupants thereof). The stiffness of the suspension system  140  may be changed in other manners, for example, by changing target parameters of the suspension control logic (e.g., travel and/or force transfer of the primary actuator  246 ). 
     As shown in  FIG.  15   , a method  1500  is provided for controlling suspension stiffness according to road conditions ahead of the vehicle  100 . The method  1500  generally includes a first operation  1510  of determining a first suspension stiffness setting, a second operation  1520  of operating the suspension system  140  according to the first suspension stiffness setting, a third operation  1530  of determining a second suspension stiffness setting that achieves different stiffness according to conditions ahead of the vehicle  100 , a fourth operation  1540  of operating the suspension system  140  according to the second suspension stiffness setting. The operations of the method  1500  are repeated, so as to continuously change the suspension stiffness according to road conditions ahead of the vehicle  100 . 
     The first operation  1510  of the determining a first suspension stiffness setting of the suspension system  140  may, for example, include setting the first suspension setting to have a low stiffness, which may be a low stiffness setting at which the suspension system  140  is typically operated (e.g., considering other parameters, such as speed and/or weight of the vehicle  100 ). As referenced above, the first suspension stiffness setting may be a first gain value. 
     The second operation  1520  of operating the suspension system  140  according to the first suspension stiffness setting is performed by the primary actuator  246 . For example, the primary actuator  246  outputs torque according to suitable control logic that accounts for the first suspension stiffness setting (e.g., using gain scheduling). 
     The third operation  1530  of determining a second suspension stiffness setting according to the road conditions ahead is performed similar to various operations described previously (see, e.g., the operations  630 ,  632 ). For example, the sensing system  150  may observe or otherwise determine environmental (e.g., road) conditions ahead of the vehicle  100 , which may include road direction, presence of potential obstacles, road friction conditions, and/or elevation changes. Upon detecting environmental conditions that are either likely to cause the suspension system  140  to encounter full travel (e.g., of the primary actuator  246 ) or induce undesirable low frequency motion (e.g., pitching and/or rolling) at the first suspension stiffness setting, the second suspension stiffness setting is changed from the first suspension stiffness setting. If the first suspension stiffness setting is the low or default stiffness setting, or if the suspension system  140  is likely to encounter full travel, the second suspension stiffness setting is determined to provide higher stiffness. In other circumstances, the second suspension stiffness setting is determined to provide lower stiffness (e.g., if the first suspension stiffness setting is not the low or default setting and is predicted to cause the undesirable low frequency motion). The second suspension stiffness setting may be a second gain value that is different from the first gain value. 
     The fourth operation  1540  of operating the suspension system  140  according to the second suspension stiffness setting is performed by the primary actuator  246 . For example, the primary actuator  246  outputs torque according to suitable control logic that accounts for the second suspension stiffness setting (e.g., using gain scheduling). 
     The first through fourth operations  1510 ,  1520 ,  1530 ,  1540  the repeated, so as to continually adjust the suspension stiffness setting. For example, if the second suspension stiffness setting is a high stiffness, the suspension stiffness setting may be changed to the low or default stiffness setting, or may be changed to an even higher stiffness setting, according to the environmental conditions. Preferably, the suspension system  140  will be operated predominantly in a low or default stiffness setting, such as more than 50%, 70%, 85%, or 90% of the time, while operating in the one or more high stiffness settings only momentarily, in short durations, or otherwise substantially less time than in the low or default stiffness setting. 
     Referring to  FIG.  16   , the suspension system  140  is controlled according to a feed-forward control system that uses near-field sensing of road disturbances as the feedforward. The feedforward may include, for example, near-field road disturbance information, which is road disturbance information obtained from sensors that observe the road surface in close proximity to the vehicle  100  (e.g., underneath the vehicle  100 , within 50, 25, 10, 5, feet or less of a front of the vehicle  100 , or 5, 3, 2, 1, or 0.5 seconds or less of travel time until the front of the of the vehicle  100  passes thereover) and/or acceleration (e.g., vertical acceleration) of the wheel  104 . The near-field road disturbance information may be determined with near-field LIDAR sensors (e.g., the LIDAR sensors  354   a ) or vertical distance sensors (e.g., laser-based, ultrasonic or other downward-facing sensors) that observe the road surface. Acceleration of the wheel  104  may be determined with one or more accelerometers coupled to steering or suspension components that are in close proximity to and move in unison with the wheel  104  (e.g., a steering knuckle or the suspension arm  244 ). Vertical acceleration of the wheel  104  is considered to include proxies thereto (e.g., vertical acceleration of the steering knuckle or the suspension arm  244 ). A road disturbance estimation is made according to the near-field road disturbance information, the vertical wheel acceleration, or both. Using both the near-field road disturbance information in combination with the vertical acceleration of the wheel  104  as feedforwards may provide a road disturbance estimation that has reduced noise as compared to the near-field road disturbance information or the vertical wheel acceleration alone. The road disturbance estimation is then provided as the feedforward to a primary ride control system (e.g., a feedback control system) by which the primary actuator  246  is operated to provide primary ride control (e.g., ride control other than at frequencies of the secondary ride control). The road disturbance estimation may, instead or additionally, be provided to a secondary ride control system (e.g., another feedback control system) by which the reaction mass actuator  250  and/or the primary actuator  246  are operated to provide secondary ride control. 
     As shown in  FIG.  16   , a method  1600  provided feedforward suspension control based on near-field road disturbance estimation. The method  1600  generally includes a first operation  1610  of near-field sensing of a road surface, a second operation  1620  of determining a feedforward road disturbance estimation according to the sensing, a third operation  1630  of determining suspension output according to the feedforward road disturbance estimation, and a fourth operation  1640  of operating the suspension system according to suspension output. The method  1600  may also include a parallel first operation  1615  of additional near-field sensing of the road surface that is performed in parallel with the first operation  1610  and may be used in the second operation  1620  of the determining of the feedforward road disturbance estimation. The third operation  1630  of the determining the suspension control may include a first suboperation  1632  of determining a primary ride control and a second suboperation  1634  of determining a secondary ride control. The fourth operation  164  of the operating of the suspension system may include a first suboperation  1642  of providing the primary ride control and a second suboperation  1644  of provide the secondary ride control. 
     The first operation  1610  of the near-field sensing of the road surface is performed, as described above, by observing the road surface proximate or below the vehicle or measuring acceleration (e.g., vertical acceleration) of the wheel. The observing of the road surface may be performed with near-field LIDAR sensors, ultrasonic sensors, laser-based sensors), as was described above (e.g., at the distances described above). The acceleration of the wheel  104  is measured with one or more accelerometers on steering or suspension components that are coupled to and move in unison with the wheel  104  (e.g., a steering knuckle or a suspension arm). 
     The parallel first operation  1615  of the near-field sensing of the road surface is performed by measuring acceleration of the wheel  104 . The parallel first operation  1615  may be performed in some but not all embodiments (as indicated by the dashed lines). If the parallel first operation  1615  is performed, the first operation  1610  is performed by observing the road surface. 
     The second operation  1620  of the determining the feed forward road disturbance estimation is performed according to one or both of the first operations  1610 ,  1615 . The feed forward road disturbance estimation may include, for example, the magnitude of a road disturbance and the timing or frequency thereof. For example, the feedforward road disturbance estimation may be quantified as a frequency and magnitude (e.g., vertical distance). 
     The third operation  1630  of the determining the suspension output is determined with the feedforward road disturbance estimation as a feedforward thereto. The third operation  1630  may be performed according to other inputs, such as with a feedback control system in which outputs (e.g., magnitude, such as stroke distance, frequency, and/or force) of the primary actuator  246 , the reaction mass actuator  250 , or the tuned mass damper are inputs according to which the suspension output is determined. 
     The suboperation  1632  includes determining primary ride control that, as described above, is provided at least at low frequencies (e.g., 10 Hz or below) that are below the natural frequency of the unsprung mass that include the wheel  104 . 
     The suboperation  1634  includes determining secondary ride control that, as described above, is active damping of road inputs to an unsprung mass, which occur at frequencies near the natural frequency of the unsprung mass or that might otherwise induce resonance in the unsprung mass or wheel hop. 
     The fourth operation  1640  operating the suspension system  140  performed according to the suspension output. The subperiod  1642  includes providing the primary ride control with the primary actuator. The suboperation  1644  includes providing the secondary ride control with the reaction mass actuator  1650  and/or the primary actuator  246  (e.g., if the capacity threshold is exceeded by the reaction mass actuator  250  or the tuned mass damper).

Metadata:
Filing Date: 20220222
Publication Date: 20240924
Grant Date: 20240924
Priority Date: 20180912
Inventors: HALL, JONATHAN L.
MILOVICH, Matisse J.
KEAS, PAUL J.
LACKRITZ, NEAL M.
Assignee: APPLE INC
CPC Classifications: [{"code": "B60G17/0165", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G2400/823", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60G2400/824", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60G17/0161", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G2400/821", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60G17/0164", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G17/021", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G2500/10", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60G17/0195", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G2401/142", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60G2401/174", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60G2400/824", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60G2400/823", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60G2400/821", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60G17/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G17/021", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G17/0165", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G17/0164", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G17/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "B60G17/0161", "inventive": true, "first": true, "tree": "[]"}, {"code": "B60G2400/824", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60G2400/823", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60G2400/821", "inventive": false, "first": false, "tree": "[]"}, {"code": "B60G17/021", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G17/0165", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G17/0164", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G17/0161", "inventive": true, "first": false, "tree": "[]"}, {"code": "B60G17/06", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 80855330