Patent Publication Number: US-2017361672-A1

Title: Electro-dynamically controlled leveling system

Description:
CROSS REFERENCE OF RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. §119(e) of the filing date of provisional patent application Ser. No. 62/352,228 filed Jun. 20, 2016, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     This disclosure relates to an electronically controlled dynamic leveling system that improves roll stability, ride comfort, and road holding of a vehicle using a pneumatic air suspension system. 
     BACKGROUND 
     Pneumatic air suspension systems commonly include an air tank that supplies air to air springs (also referred to as air suspension bags or air bags) that are installed at the axles, in between the vehicle frame or body. The air tank is connected to the air springs through a series of hoses and connectors that transfer air from the air tank to the air springs. In some cases, check valves and regulators are incorporated in line with air hoses in order to provide the necessary protection to prevent over-inflating the air springs or depleting the air tank in case of air spring failure. The pneumatic suspension commonly incorporates a load-leveling valve that can adjust the pressure in the air spring based on the wheel load or the vehicle load. 
     Most common air suspensions in vehicles including, but not limited to, heavy trucks use a mechanical load leveling valve that adjusts the air pressure within the air suspension in response to the load placed on the suspension. When the vehicle is loaded, the air pressure is increased for higher suspension stiffness and better supporting the added weight (load) placed on top of the suspension. Conversely, when load is removed, the air pressure is decreased to provide a softer suspension and prevent the vehicle frame from jacking up. The end result is a vehicle that rides “level,” meaning it rides at the same ride height independent of its loading condition. The load leveling is accomplished through the aforementioned mechanical leveling valve, commonly referred to as “load leveling valve,” or “ride height control valve.” 
     Once the truck body is leveled to a set ride height, the valve remains predominantly closed, in the sense that the valve does not remove or add any air to the suspension air springs. When, however, the vehicle body is raised or lowered, the valve adds or removes air from the suspension to return the body back to the set ride height. For suspensions with one leveling valve, such adjustment happens in response to the side of the vehicle to which the valve is connected. On the other hand, for suspensions with two load leveling valves, the air in each side is adjusted independent of the other side, allowing for better static and dynamic leveling of the body. For instance, when the vehicle is unleveled side-to-side, one side is raised while the other side is lowered. In such a case, the leveling valve on the lower side adds air to the suspension, whereas the valve on the other side does the opposite by removing air from the suspension. Thereby, the leveling valves on the two sides preform diametrically opposite of each other: one releasing air to lower the body relative to the axle while the other one adding more air to raise the body. One leveling valve increases the suspension stiffness while the other reduces it. 
     In either a single valve suspension system or a double valve suspension system, load leveling valves of the prior art are actuated by a mechanical means that typically includes an arm connected to a linkage, hereinafter referred to as “control rod,” which attaches to the bottom or axle side of the suspension system. The connection of the control rod between the load leveling valve arm and the bottom of the suspension system transmits movement from the air springs in the vertical direction to the valve arm in a rotational direction. Accordingly, the movement of the suspension system triggers the load leveling valve to supply or exhaust air to and from the air springs, thereby the ride height of the vehicle is controlled completely in response to the movement of the suspension system. 
     However, while in motion, a vehicle often experiences dynamic, side-to-side or front-to-back weight shifts that cause the vehicle to roll or pitch at a sudden movement. Such weight shifts occur as a result of the vehicle traveling on a curved roadway, or during acceleration and deceleration. Roll implies the angular motion of the vehicle body relative to its longitudinal axis, i.e., the axis that extends from the back of the vehicle to front. Such motions predominantly occur when the vehicle is subjected to lateral forces during steering maneuvers; for instance, when the vehicle is negotiating a curved pathway or turn. Pitch is the angular motion of the vehicle about its lateral axis, the axis extending from one side to the opposite side of the vehicle. Pitch occurs when the vehicle is subjected to longitudinal forces, for instance while accelerating and braking. Because load leveling valves of the prior art are predominantly intended to provide body leveling in a static sense, they are slow to respond to dynamics, such as side-to-side or front-to-back weight shifts of the vehicle. Consequently, conventional pneumatic air suspension systems tend to respond too late to an impulsive weight shift of a moving vehicle, ultimately proving to be ineffective in preventing body roll and pitch. In extreme cases, such body movements can result in rollovers in places such as sharp turns. Such rollovers are often disastrous. 
     Accordingly, there is a need for a pneumatic air suspension system that can respond quickly to a dynamic weight shift in a moving vehicle to reduce the possibility of the vehicle overturning at a sudden change of movement, such as a sharp turn. Furthermore, there is a need for a pneumatic air suspension system that controls the supply and exhaust of air to and from the air springs based on the vehicle operating condition and total body movement, beyond the movement of the suspension system, in a manner that the ride height of the vehicle is controlled, proactively and dynamically, through sensing and predicting the dynamic conditions of the vehicle. 
     SUMMARY 
     The present invention provides an electro-dynamically controlled leveling system for a vehicle, in which the electro-dynamically controlled leveling system includes a plurality of air springs mounted on at least one axle of the vehicle for supporting the weight of the vehicle; one or more electro-pneumatic valves configured to adjust the air pressure of the plurality of air springs by supplying air to the plurality of air springs from an air source or removing air from the plurality of air springs; one or more sensors configured to monitor one or more characteristics of the vehicle and transmit the one or more characteristics as a sensory input; and a central control module (CCM) in electrical communication with the one or more sensors and the one or more electro-pneumatic valves. The CCM is configured to receive the sensory input from the one or more sensors, calculate a dynamic condition of the vehicle based on the sensory input, determine a desired air pressure for each air spring based on the calculated dynamic conditions of the vehicle, and transmit a command to the one or more electro-pneumatic valves to adjust the air pressure of each air spring to the desired air pressure. 
     The one or more characteristics monitored by the sensors may include a steering angle, vehicle lateral acceleration, vehicle longitudinal acceleration, roll angle of the vehicle, roll rate of the vehicle, pitch angle of the vehicle, pitch rate of the vehicle, yaw rate of the vehicle, air pressure of the plurality of air springs, vehicle speed, suspension displacement, suspension velocity, accelerator position, or brake pressure. The dynamic condition calculated by the CCM may include the vehicle&#39;s body roll, the vehicle&#39;s body pitch, or both the vehicle&#39;s body roll and body pitch. In one configuration, the dynamic condition may include the vehicle&#39;s body roll and the one or more characteristics of the vehicle may include the vehicle lateral acceleration, the roll angle, and the roll rate. In another configuration, the dynamic condition may include the vehicle&#39;s body roll and the one or more characteristics of the vehicle may include suspension displacement and suspension velocity. In another configuration, the dynamic condition may include vehicle&#39;s body pitch and the one or more characteristics of the vehicle may include a forward speed of the vehicle, an accelerator position of the vehicle, and a brake pressure. 
     The electro-pneumatic valves may include a valve body having one or more airflow passages in pneumatic communication with an air source, the atmosphere, and at least one of the air springs, and an actuator mechanism configured to open or close the airflow passages of the valve body, wherein the CCM is configured to trigger the actuator mechanism by electrical communication to open or close the airflow passages of the valve body. In one configuration, the valve body includes a chamber connected to the one or more flow passages and a disk configured to rotate between one or more angular positions within a chamber of the valve body to alter pneumatic communication between the flow passages, and the actuator mechanism includes a stepper motor configured to induce rotation of the rotary disk to the one or more angular positions. In another configuration, the valve body includes a manifold having a spring port, a supply port, an exhaust port, and a chamber connected with the spring port, supply port, and exhaust port, and the actuator mechanism includes a solenoid and a poppet received in the chamber of the manifold. The poppet is configured to slide between a first and second position to alter pneumatic communication between the spring port, the supply port, and the exhaust port, and the CCM is configured to control movement of the poppet by triggering the solenoid via electrical communication. 
     Other features and characteristics of the subject matter of this disclosure, as well as the methods of operation, functions of related elements of structure and the combination of parts, and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments of the subject matter of this disclosure. In the drawings, like reference numbers indicate identical or functionally similar elements. 
         FIGS. 1A and 1B  are schematic views of a pneumatic suspension system of the prior art. 
         FIGS. 2A, 2B, and 2C  are schematic views of electro-dynamic controlled leveling systems according to configurations of the present invention. 
         FIG. 3A  is a top view of an electro-pneumatic valve according to a configuration of the present invention.  FIG. 3B  is a cross-sectional view of an electro-pneumatic valve according to a configuration of the present invention. 
         FIGS. 4A and 4B  are cross-sectional views of an electro-pneumatic valve according to a configuration of the present invention. 
         FIGS. 5A, 5B, and 5C  are wiring diagrams of electrodynamic controlled leveling systems according to configurations of the present invention. 
         FIG. 6  is a control loop of an electro-dynamic controlled leveling system according to a configuration of the present invention. 
         FIG. 7  is a flow diagram of an operation procedure for a CCM according to a configuration of the present invention. 
         FIG. 8  is a block diagram of the sensory inputs for a CCM according to a configuration of the present invention. 
         FIG. 9  is a schematic force body diagram of a vehicle having a pneumatic suspension system. 
         FIGS. 10-12  are block diagrams of methods of calculating a body roll according to a configuration of the present invention. 
         FIG. 13  is a block diagram of an overall method of calculating a body roll according to a configuration of the present invention. 
         FIGS. 14 and 15  are block diagrams of methods of calculating a body pitch according to a configuration of the present invention. 
         FIG. 16  is a block diagram of an overall method of calculating a body pitch according to a configuration of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     While aspects of the subject matter of the present disclosure may be embodied in a variety of forms, the following description and accompanying drawings are merely intended to disclose some of these forms as specific examples of the subject matter. Accordingly, the subject matter of this disclosure is not intended to be limited to the forms or embodiments so described and illustrated. 
     The disclosure relates to an electro-dynamically controlled (EDC) leveling system for controlling the static and dynamic ride height of a vehicle through a mechanism that can be controlled in real time, such as, but not limited to, one or more electro-pneumatic dynamic (EPD) valves, in which each EPD valve is capable of supplying or removing air from a set of air springs mounted on a vehicle axle. As will be discussed further herein below, the EDC leveling system includes one or more EPD valves interfacing with a CCM that provides the requisite input based on the characteristics and dynamics of the vehicle for any actions executed by the electro-pneumatic valve, such as adding air to or removing air from the air springs. The EDC leveling system further implements an integration of devices, such as, but not limited to, embedded analog/digital controllers, sensors, and data already available on a vehicle through a Controller Area Network (CAN) Bus or other such means. The CCM interacts with the integration of devices so that the CCM may sense and determine the vehicle&#39;s dynamics, the vehicle operator&#39;s commands, and the suspension response. Accordingly, the EDC leveling system may manage the internal air pressure of each air spring based on various inputs, ultimately providing proactive control of the suspension system. 
       FIG. 2A  illustrates a pneumatic suspension system  10  of a vehicle incorporating an EDC leveling system  100  according to the general inventive concept. The pneumatic suspension system  10  includes an air source, such as a supply tank  12 , for supplying air to two pneumatic circuits  14   a,    14   b.  Each pneumatic circuit  14  includes a set of air springs  16  positioned on a respective side of a vehicle (not shown) and is connected to the supply tank  12  by an EPD valve ( 120   a  or  120   b ) and a series of air hoses  18   a - c.  The series of air hoses  18   a - c  include a supply hose  18   a  connecting the supply tank  12  to a respective EPD valve ( 120   a  or  120   b ). Each supply hose  18   a  is further provided with a pressure protection valve  13 . A valve hose  18   b  extends between the EPD valve ( 120   a  or  120   b ) and a respective air fitting  19 . Furthermore, the series of air hoses  18   a - c  include two pairs of spring hoses  18   c,  in which each spring hose  18   c  extends between a respective air fitting  19  and a respective air spring  16 . The pneumatic suspension system may include other air fittings (not shown) to connect the air hoses to each other, and other components of the pneumatic suspensions system, as well. The types of air fittings may include elbows, T-connectors, adaptors, etc. 
     As shown in  FIG. 2A , the EDC leveling system  100  for the pneumatic suspension system  10  includes a central control module  110  in electrical communication with two EPD valves  120   a,    120   b  through electrical wiring  112   a,    112   b,  in which each EPD valve is implemented with a respective pneumatic circuit. However, other forms of communication may be provided to establish electrical communication between the CCM  110  and the EPD valves  120   a,    120   b,  such as wireless communication or digital connection, without departing from spirit and scope of the present invention. Referring to  FIG. 2A , each EPD valve controls the air pressure of springs on a respective side of the vehicle. In alternative configuration shown in  FIG. 2B , the EDC leveling system  100  for the pneumatic suspension system  10  includes only one EPD valve  120   a  in electrical communication with the CCM  110  through electrical wiring  112   a.  Rather than controlling the air pressure of the air springs on one side of the vehicle, the EPD valve  120   a  shown in  FIG. 2B  controls the air pressure of the air springs on both sides of the vehicle. The two pneumatic circuits  14   a,    14   b  of  FIG. 2B  are linked together by the EPD valve and only one supply air hose  18   a  connecting the EPD valve to the supply tank  12 . 
     In another configuration shown in  FIG. 2C , the EDC leveling system  100  includes four EPD valves  120   a - d,  each corresponding to an individual air spring  16 , so that each EPD valve only controls the air pressure of an individual air spring  16 . For each configuration described above, the CCM  110  receives inputs regarding the vehicle&#39;s dynamics, the vehicle operator&#39;s commands, and the suspension response, and the CCM  110  outputs commands to the one or more EPD valves  120   a - d  so that each air spring  16  is set to a desired air pressure that promotes roll stability, ride comfort, and road holding for the vehicle. 
     Referring to  FIGS. 2A-C , the supply tank  12  serves as the reservoir for supplying air to the pneumatic circuits  14   a  and  14   b.  In one configuration, the supply tank  12  is made of a sufficiently strong material to hold pressurized air. The supply tank  12  is configured to provide sufficient air to the air springs  16  during repeated cycles of purging and supplying air. To ensure that the supply tank  12  is configured to provide sufficient air to the air springs  16 , the air pressure of the tank is regulated to a nominal pressure. When the air pressure of the supply tank  12  falls below the nominal pressure, the supply tank  12  is replenished with air from a compressor (not shown). Once the air pressure of the supply tank  12  reaches a set maximum limit, the compressor cuts out and no additional air is provided to the supply tank  12 . 
     As shown in  FIGS. 2A-C , the series of air hoses  18   a - c  connect and establish pneumatic communication between various components of the pneumatic suspension system  10 . In one configuration, the air hoses  18   a - c  are made of a polymer that is flexible enough for routing around the vehicle, yet strong enough for sustaining high pressure air. The air hoses  18   a - c  may be made from various classes of polymers, plastics, or similar synthetic materials. The air hoses  18   a - c  may also be reinforced with cords to increase their ability to sustain high-pressure air. To simplify the installation process, the air hoses  18   a - c  may be made in various colors to ease the identification of a particular air hose and provide better visual instruction during the installation process. 
     Referring to  FIGS. 2A-C , the air springs  16  are placed in between the vehicle axle and chassis or frame (not shown) to provide compliance for the pneumatic suspension system. In one configuration, each air spring  16  is a canister-like element having rubber sidewalls that inflate or deflate in the primary direction of suspension travel, most commonly in the vertical direction. A change in the internal pressure of the air springs  16  alters the separation distance between the vehicle body and axle, thereby raising or lowering the vehicle body relative to the axle. When air is added to the air springs  16 , the internal air pressure of the air springs  16  increases and raises the vehicle body from the axle. In contrast, when air is removed from the air springs  16 , the internal air pressure of the air springs decreases and lowers the vehicle body toward the axle. In addition, adding or removing air from the air springs  16  increases or decreases the suspension stiffness, respectively. Managing the internal air pressure of the air springs  16  allows control of the height of each vehicle side relative to the ground and the compliance of the suspensions. Changes between the heights of each vehicle side affect the vehicle body roll angle and stability. Compliance of the suspensions affects the vehicle ride comfort. Accordingly, the ECD system  100  controls both the roll stability and ride quality of the vehicle by controlling the air pressure of each individual air spring  16  through the EPD valve. 
     As shown in  FIGS. 2A-C , each supply hose  18   a  is provided with a pressure protection valve  13 . The pressure protection valve  13  is adapted to prevent a complete loss of pressure within the supply tank  12 , in case of a failure of the pneumatic suspension system  10 , such as a punctured air spring or hose or a failed connector. Similar to the operation of a check valve, the pressure protection valve  13  is held in an open state if the pressure in the supply tank  12  is above a minimum pressure threshold, thereby permitting air flow from the supply tank  12  to the air springs  16 . However, if the internal pressure of the supply tank  12  falls below the minimum pressure threshold, the pressure protection valve  13  switches to a closed state, thereby preventing air flow from the supply tank  12  to the air springs  16 . Accordingly, the supply tank  12  becomes isolated from the air springs  16  during a failure in the pneumatic suspension system, which prevents the supply tank  12  from being completely depleted of air. 
     The supplying and discharging of air into and out of the air springs  16  of the pneumatic system  10  shown in  FIGS. 2A-C  are controlled by the one or more EPD valves  120 . The one or more EPD valves  120  generally include a valve body connected to and operated by an actuating mechanism (e.g., a solenoid, stepper motor, or the like). The valve body includes one or more airflow passages pneumatically linked to the supply tank  12 , the air springs  16 , and the atmosphere. The valve body is configured to shuttle air flow between the supply tank  12  and the air springs  16  shown in  FIGS. 2A-C . The one or more EPD valves  120  control the air flow between the supply tank  12  and the air springs  16  by the supply of an electrical current or voltage that triggers the actuation mechanism (e.g., a solenoid, stepper motor, or the like) to open or close airflow passages within the valve body. 
     According to one configuration of the EPD valve  120  shown in  FIGS. 3A and 3B , the EPD valve  120  includes a valve body  130  and an actuation mechanism such as a stepper motor  140 . Referring to  FIG. 3B , the valve body  130  is formed by an upper housing  131  mounted on a lower housing  132 , wherein a chamber  133  is defined between the upper housing  131  and the lower housing  132 . The lower housing  132  includes a supply port  136   a,  an exhaust port  136   b,  and one or more spring ports  136   c.  The ports  136   a - c  are pneumatically linked to the chamber  133  by airflow passages  137  formed in the lower housing  132  of the valve body  130 , in which each port  136   a - c  is connected to the chamber  133  by a respective airflow passage  137 . The electro-pneumatic dynamic valve  120  further includes a rotary disk  134  received in the chamber  133  of the valve body  130 . The rotary disk  134  is configured to rotate freely within the chamber  133  about a shaft  135 , which extends through the upper housing  131  to the stepper motor  140 . As shown in  FIGS. 3A and 3B , the stepper motor  140  is connected to the rotary disk  134  by the shaft  135  such that the stepper motor  140  induces rotation of the rotary disk  134 , which shuttles air between the supply port  136   a,  the exhaust port  136   b,  and the one or more spring ports  136   c.  The rotary disk  134  is configured to rotate between a plurality of angular positions to alter the pneumatic communication between the ports  136   a - c  of the valve body  130 . 
     In operation, the stepper motor  140  positions the rotary disk  134  to a desired location within the chamber  133  of the valve body  130  to direct airflow from the supply tank  12  to the one or more air springs  16 . In addition, when necessary, the rotary disk  134  purges air from the air springs  16  to the atmosphere. The stepper motor  140  may rotate the rotary disk  134  to a base position, in which spring ports  136   c  pneumatically communicate neither with the supply port  136   a  nor the exhaust port  136   b.  The stepper motor  140  may rotate the rotary disk  134  to first and second angular positions, in which the supply port  136   a  pneumatically communicates with one of the spring ports  136   c  and the exhaust port  136   b  communicates with the other one of the spring ports  136   c . Accordingly, air is supplied to one of the spring ports  136   c,  while air is purged from the other one of the spring ports  136   c.  Moreover, the air flow through one spring port versus the other port can be asymmetric, in which one of the spring ports  136   c  can receive more or less air flow than the other one of the spring ports  136   c.  Thus, the supplying and purging of the air for two air springs  16  is independent of each other so that one side of a vehicle may be raised and the other side of the vehicle be lowered simultaneously. The EPD valve  120  shown in  FIGS. 3A and 3B  may be used with either EDC leveling system  100  shown in  FIGS. 2A and 2B . 
       FIGS. 4A and 4B  illustrate another configuration of the EPD valve  120  incorporated into the EDC leveling system  100  shown in  FIG. 2C , in which the EPD valve  120  is configured to control the air pressure of an individual air spring  16 . Rather than controlling the air pressure of multiple air springs through the use of one actuator mechanism as shown in  FIGS. 3A and 3B , the EPD valve  120  shown in  FIGS. 4A and 4B  uses one actuator mechanism (e.g., a solenoid, a stepper motor, or the like) to control the air pressure of only one individual air spring  16  independent of the other air springs  16  installed on the vehicle. Accordingly, the air pressure and the force of one air spring  16  are controlled independent of the air pressure and forces of other air springs  16 , thereby providing enhanced dynamic control for the vehicle body and axle. 
     As shown in  FIGS. 4A and 4B , the EPD valve  120  includes a valve body  150  and an actuation mechanism such as a solenoid  160 . The valve body  150  includes a manifold  151  defining a chamber  151   a.  The valve body  150  further includes a supply port  152 , a spring port  153 , and an exhaust port  154  connected with the manifold  151  and pneumatically linked with the chamber  151   a  of the manifold  151 . The supply port  152  is pneumatically linked to the supply tank  12 , and the exhaust port  154  is open to the atmosphere. The spring port  153  is pneumatically linked to an individual air spring  16  and is configured to attach directly to an individual air spring  16  of the pneumatic suspension system  10 . The valve body  150  further includes a poppet  155  received in the chamber  151   a  of the manifold  151 , in which the poppet  155  is configured to alter communication between the supply port  152 , the spring port  153 , and the exhaust port  154  by sliding between a first position and a second position. Referring to  FIG. 4A , the poppet  155  is biased by linear spring  156  in the first position, wherein the spring port  153  is in pneumatic communication with the supply port  152  but not in pneumatic communication with the exhaust port. The solenoid  160  is received in the chamber  151   a  of the manifold  151  and is connected to the poppet  155  by a plunger  162 , which is configured to slide in a direction parallel to the linear spring  156  between an extended position and a retracted position. As shown in  FIG. 4A , the plunger  162  of the solenoid  160  is in a retracted position so that the linear spring  156  biases the poppet  155  to the first position. Referring to  FIG. 4B , the plunger  162  of the solenoid  160  slides to the extended position overcoming the bias of the linear spring  156  so that the poppet  155  slides forward to the second position, wherein the spring port  153  is in pneumatic communication with the exhaust port  154  but not in pneumatic communication with the supply port  152 . 
     In operation, the solenoid  160  may switch between different states, including an inactivated state and an activated state. When the solenoid  160  is set to the inactivated state, the plunger  162  is set to the retracted position shown in  FIG. 4A . Accordingly, the spring port  153  is in pneumatic communication with the supply port  152  so that the air spring  16  receives air from the supply tank  12 . When electrical power is supplied to the solenoid  160  so that the solenoid  160  switches to the activated state, the plunger  162  slides to the extended position, thereby forcing the poppet  155  to move to the second position shown in  FIG. 4B . Accordingly, the spring port  153  is in pneumatic communication with the exhaust port  154  to reduce the air pressure of the air spring  16 . In both the supply and purge configurations ( FIGS. 4A and 4B ), the EPD valve  120  manages the air flow such that the proper rate is achieved for dynamic control of the body and axle. Although the EPD valve  120  shown in  FIGS. 4A and 4B  is incorporated into the EDC leveling system  100  shown in  FIG. 2C , the EPD valve  120  of  FIGS. 4A and 4B  may also be used in the EDC leveling system  100  shown in  FIGS. 2A and 2B . 
     The EDC leveling system further includes a series of sensors (not shown) such as, but not limited to, pressure sensors, roll rate sensor, yaw rate sensor, pitch rate sensor, accelerometers, gyros, velocity and displacement sensors (such as haul effect sensors or linear voltage differential transformers (LVDT)), steering wheel angle sensor, steering column sensors, and height sensors. The sensors may also obtain information through vehicle to infrastructure (V2I), vehicle to vehicle (V2V), and Vehicle to other communication networks, which are collectively known as V2X. The sensors are arranged along the vehicle so that conditions and road input measured at the vehicle&#39;s front end may be inputted to anticipate conditions for suspensions disposed on the vehicle&#39;s axles. In one configuration, sensors may be located at vehicle&#39;s center of gravity, positions of air springs, and vehicle&#39;s axles. The roll rate sensors and pitch rate sensors may monitor roll conditions of the vehicle according to a measured height of one or more points on the vehicle relative to the ground surface. Collectively, the sensors are adapted for measuring the vehicle dynamic response, operator input, autonomous system commands, and any other input or response that is critical for successfully and safely determining the suspension forces so that the vehicle may maneuver and interact with the environment in an optimal fashion. 
     As shown in  FIGS. 5A-C ,  6 , and  8 , the CCM  110  receives information from the sensors as sensory input  124  and output commands to the EPD valves  120   a - d  of the EDC leveling system  100  as electrical signals transmitted along the wiring  112   a - d.  To generate commands to the EPD valves  120   a - d,  the CCM  110  analyzes the sensor input according to a control methodology that integrates the sensory inputs into mathematical formulations, which determines the most suitable response for the EPD valve in terms of adjusting the internal pressure of the air springs through the removal or supply of air. The CCM  110  includes software, which embodies the control strategy and mathematical formulations, and memory, such as volatile and/or nonvolatile memory, to store all the necessary software. The CCM  110  further includes one or more (micro)processors linked to the memory by a bus, in which the one or more (micro)processors are adapted to execute the software embodying the control strategy and mathematical formulations. The CCM  110  also includes one or more connectors, receivers, transmitters, and transceivers linked to all the sensors, the one or more EPD valves  120   a - d,  and the V2X, thereby establishing electrical communication, either wired or wireless, between the one or more (micro)processors of the CCM  110  and all the components of the EDC leveling system  100 . Accordingly, the CCM  110  is adapted to receive all the necessary input to calculate a desired air pressure for each air spring  16  of the pneumatic suspension system  10  and convey commands in terms of supplying or purging air to all EPD valves  120   a - d.    
     Referring to  FIG. 8 , examples of sensory inputs for the EDC leveling system  100  include steering input, speed, direction of driving, driver steering and acceleration/braking input, body response, suspension response, suspension displacement, vehicle yaw and any and all dynamics that are critical to measuring and predicting the vehicle roll stability, and pitch dynamics during acceleration and braking. In particular, types of acceleration include lateral, longitudinal, and vertical acceleration at various strategic locations along the vehicle, such as the vehicle&#39;s center of gravity and the positions along the vehicle frame or axle that are adjacent to the air springs  16 . The EDC leveling system  100  further includes one or more pressure sensors, in which each sensor is configured to monitor the internal pressure of a respective air spring. The EDC leveling system  100  is configured to operate congruently with active safety systems such as Roll Stability Control (RSC), Electronic Stability Control (ESC), Antilock Brake System (ABS), Positive Traction Control (PTC), Automated Emergency Braking (AEB), collision avoidance systems, and all other such systems. Any and all sensory inputs used for active safety systems, collision avoidance systems, driver-assisted systems, semi-autonomous vehicles, and autonomous vehicles serve as sensory input for EDC leveling system  100 . In addition to the list of sensory inputs shown in  FIG. 8 , the sensory input to the EDCP controller can include other information on the vehicle&#39;s CAN bus or other similar communication protocols. The CAN bus is a vehicle bus standard designed to allow microcontrollers and devices to communicate with each other in applications without a host computer. 
     Referring to  FIG. 6 , the EDC leveling system  100  operates as a closed-loop control system to maintain desired air pressures for each air spring  16  of the pneumatic suspensions system  10 . As shown in  FIG. 7 , the CCM first receives information from the operator input, the sensory input, and the vehicle&#39;s safety systems or V2X input. The CCM then determines the desired air pressure for each individual air spring of the pneumatic suspension system based on the operator input, the sensory input, and the vehicle&#39;s safety systems or V2X input. In determining the desired air pressure for each individual air spring, the CCM first calculates or estimates the vehicle&#39;s dynamic conditions as a function of the sensory input. The calculated vehicle&#39;s dynamic conditions may include the vehicle roll stability and pitch dynamics while the vehicle is accelerating and breaking. The sensory input used to calculate the vehicle&#39;s dynamic conditions may include the lateral, longitudinal, and vertical acceleration at strategic locations along the vehicle, vehicle yaw input, steering input, vehicle speed, and suspension displacement and velocity. By determining the dynamic conditions of the vehicle, the CCM may then determine the suspension forces necessary to maintain the vehicle at a leveled position. Accordingly, the CCM determines an air pressure for each air spring that satisfies a condition, in which the suspension forces provide a net moment that counters lateral or longitudinal forces against the vehicle&#39;s center of gravity. Once determining the desired air pressure for each air spring, the CCM outputs commands to each EPD valve to alter the internal pressure of the air springs accordingly. The new state of the vehicle body is re-evaluated by the sensors and the CCM&#39;s actions are repeated, as shown by the closing loop in  FIG. 7 . 
     As shown in  FIG. 6 , the CCM may receive feedback from the plurality of sensors to ensure the air springs are adjusted to a desired air pressure or any other mechanical property. For example, the CCM may receive feedback from pressure sensors to determine the adjusted air pressure of the air springs. Alternatively, the CCM may receive feedback from the displacement sensors to determine the adjusted displacement of the suspension system. The CCM may further adjust the air pressure of the air springs based on the feedback from the plurality of sensors, thereby ensuring the vehicle is maintained at a leveled height. 
       FIG. 9  illustrates one scenario when the vehicle experiences a dynamic weight shift, such as negotiating a turn, and how the pressure is adjusted amongst the air springs. The dynamic weight shift causes one set of air springs to compress and the other set of air springs to extend away from the vehicle axle. In response, the EDC leveling system  100  increases the air pressure of the compressed air springs and decreases the air pressure of the extended air springs in order to generate suspension forces that are conducive to leveling the vehicle in case of roll or pitch. The suspension force on one side increases while suspension force on the other side reduces. The force differential between the first and second sides of the vehicles results in a net moment that counters the moment caused by the lateral or longitudinal forces against the vehicle&#39;s center of gravity. To ensure that the suspension system provides the necessary force, the CCM may determine the required air pressure for each air spring based on a calculated/estimated body roll of the vehicle. The EDC leveling system may calculate the body roll based on various available sensory inputs, as described in detail below. 
     As shown in  FIG. 10 , the CCM may calculate the vehicle&#39;s body roll based on the vehicle&#39;s lateral acceleration, vehicle&#39;s roll angle and rate, and input activation from the vehicle&#39;s ESC, ABS, and AEB. Maneuvers that cause the vehicle body to roll side to side, such as the scenario described above, result in lateral accelerations at the vehicle&#39;s center of gravity. Accordingly, the vehicle&#39;s body rolls against the suspension at a roll angle and a roll rate that is directly proportional to the lateral accelerations. Sensors of the EDC leveling system  100 , such as a lateral acceleration sensor, roll rate sensor, or a gyro, are configured to measure the lateral acceleration, roll angle, and roll rate of the vehicle and input these values to the CCM. In addition, the vehicle&#39;s active safety devices, such as the ABS, ESC, AEB, the Lane Departure Warning System, and the Collision Warning System, may activate to maintain the directional stability and overall safety of the vehicle. If the vehicle&#39;s active safety devices are activated, the CCM is configured to receive input values from the vehicle&#39;s active safety devices via the vehicle&#39;s CAN bus. After receiving sensory input that includes the vehicle&#39;s lateral acceleration, roll angle, and roll rate and input from the vehicle&#39;s active safety devices, the CCM estimates the vehicle&#39;s body roll. Based on the estimated body roll value, the CCM determines the suspension force required by each air spring to provide a net moment that counters the moment caused by the lateral or longitudinal forces against the vehicle&#39;s center of gravity. The CCM then determines the required air pressure for each air spring of the pneumatic suspension system to provide the suspension force necessary to keep the vehicle in a level position. After determining the desired air pressure for each air spring, the CCM commands the EPD valves to adjust the internal pressure of the air springs accordingly in terms of adding or removing air. 
       FIGS. 11 and 12  show alternative methods to calculate the vehicle&#39;s body roll based on different inputs. Referring to  FIG. 11 , input from the vehicle&#39;s safety devices is not available, along with the lateral acceleration of the vehicle. The CCM receives sensory input that only includes roll angle and roll angle rate. Although the CCM only receives the roll angle and roll rate as inputs, it may still calculate the vehicle&#39;s body roll based on mathematical algorithms embedded in software that is stored in the memory of the CCM. Accordingly, the CCM determines a desired air pressure for each air spring based on the vehicle&#39;s body roll and commands the EPD valves to adjust the internal pressure of the air springs accordingly. 
       FIG. 12  shows a method of calculating the vehicle&#39;s body roll based on the suspension displacement and suspension velocity. Sensors of the ECD suspension system  100 , such as a height sensor, are configured to measure the suspension displacement on each side of the vehicle and the rate of change of displacement across the suspension (i.e., suspension velocity). The sensors input these values to the central control module, which allows the CCM to calculate how rapidly the vehicle&#39;s body roll is changing. The CCM may then determine a desired air pressure for each air spring based on how the vehicle&#39;s body roll is changing and output commands to the EPD valves in terms of adding or removing air from the air springs. Accordingly, the ECD suspension system not only reacts to the body roll but also anticipates how the body roll is changing, ultimately making the pneumatic suspension system more effective in stabilizing the vehicle. 
       FIG. 13  shows an overall arrangement for implementing a multitude of sensors onboard a vehicle to directly calculate or estimate a vehicle&#39;s body roll. The CCM may directly calculate the vehicle&#39;s body roll depending on data, such as suspension travel, lateral acceleration, or roll angle. In comparison, the CCM may estimate the vehicle&#39;s body roll depending on data, such as steering angle, accelerator position, and brake pressure. The collection of the data shown in  FIG. 13  allows a determination of the required suspension forces based on a more sophisticated and complete assessment of the vehicle&#39;s body roll. 
     Rather than determining the air pressure for each air spring based on the vehicle&#39;s body roll, the CCM may determine air pressure for each air spring based on the body pitch as the dynamic condition of the vehicle. The body pitch may be calculated during dynamic events, such as acceleration and deceleration of the vehicle. Referring to  FIG. 14 , sensor inputs for the CCM include the vehicle&#39;s forward speed, accelerator position, and brake pressure. In addition, the central control module  110  may receive input from vehicle&#39;s safety devices, such as ESC, ABS, AEB activation. Accordingly, the CCM estimates the longitudinally dynamics of the vehicle when the vehicle is accelerating and braking. The required suspension forces for preventing the vehicle from excessive pitch are then calculated based on the longitudinal dynamics of the vehicle, in the sense of “dive” during braking or “squad” during acceleration. Referring to  FIG. 15 , the body pitch may be calculated by inputting the pitch angle and the pitch angle rate to the central control module  110 . The control arrangement of  FIG. 15  may be implemented as an alternative to or be used in conjunction with the arrangement shown in  FIG. 14 . 
       FIG. 16  shows an overall arrangement for implementing a multitude of sensors onboard a vehicle to directly calculate or estimate a vehicle&#39;s body pitch. The CCM may directly calculate the vehicle&#39;s body pitch depending on data, such as the pitch angle and the pitch angle rate. Alternatively, the CCM may estimate the vehicle&#39;s body pitch depending on data, such as vehicle&#39;s forward speed, accelerator position, and brake pressure. Similar to the arrangement shown in  FIG. 13  for determining the vehicle&#39;s body roll, the arrangement shown in  FIG. 16  allows a determination of the required suspension forces based on a more sophisticated and complete assessment of the vehicle&#39;s body pitch. The CCM may further determine the desired air pressure for each air spring based on both the calculated or estimated body roll, as shown in  FIG. 13 , and the calculated or estimated body pitch, as shown in  FIG. 15 . For any and all system configurations shown in  FIGS. 8 , and  10 - 16 , the new state of the vehicle is re-evaluated by the sensors and control process repeated, in a closed-loop formation. 
     According to each configuration described above, the ECD suspension system is configured to control proactively the air pressures of each individual air spring to provide a suspension force that satisfies a condition, in which the suspension force creates a net moment that counters the moment caused by vehicle&#39;s dynamic conditions that act against the vehicle&#39;s center of gravity. Consequently, the ECD suspension system enables the vehicle to maneuver and interact with the environment in an optimal fashion. 
     As used herein, the term “body roll” refers to the angular motion of the vehicle body relative to its longitudinal axis, i.e., the axis that extends from the back of the vehicle to front. 
     As used herein, the term “body pitch” refers to the angular motion of the vehicle about its lateral axis, the axis extending from one side to the opposite side of the vehicle 
     While the subject matter of this disclosure has been described and shown in considerable detail with reference to certain illustrative embodiments, including various combinations and sub-combinations of features, those skilled in the art will readily appreciate other embodiments and variations and modifications thereof as encompassed within the scope of the present disclosure. Moreover, the descriptions of such embodiments, combinations, and sub-combinations is not intended to convey that the claimed subject matter requires features or combinations of features other than those expressly recited in the claims. Accordingly, the scope of this disclosure is intended to include all modifications and variations encompassed within the spirit and scope of the following appended claims.