Source: http://www.google.com/patents/US7878510?dq=4316055
Timestamp: 2017-04-25 17:52:47
Document Index: 40833514

Matched Legal Cases: ['§120', 'Application No. 2008100881175', 'Application No. 04100619', 'Application No. 200810081175', 'Application No. 2004', 'Application No. 2001', 'Application No. 200810081174', 'Application No. 2004']

Patent US7878510 - Surface vehicle vertical trajectory planning - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inPatentsAn active suspension system for a vehicle including elements for developing and executing a trajectory plan responsive to the path on which the vehicle is traveling. The system may include a location system for locating the vehicle, and a system for retrieving a road profile corresponding to the vehicle...http://www.google.com/patents/US7878510?utm_source=gb-gplus-sharePatent US7878510 - Surface vehicle vertical trajectory planningAdvanced Patent SearchTry the new Google Patents, with machine-classified Google Scholar results, and Japanese and South Korean patents.Publication numberUS7878510 B2Publication typeGrantApplication numberUS 11/670,849Publication dateFeb 1, 2011Filing dateFeb 2, 2007Priority dateMar 27, 2000Fee statusPaidAlso published asCN1524719A, EP1449688A2, EP1449688A3, EP1449688B1, EP2351658A2, EP2351658A3, US7195250, US7434816, US8517395, US8948968, US9417075, US20040251643, US20070096405, US20070168092, US20110160959, US20140012467, US20150160021Publication number11670849, 670849, US 7878510 B2, US 7878510B2, US-B2-7878510, US7878510 B2, US7878510B2InventorsLawrence D. Knox, Neal M. Lackritz, James A. Parison, William R. ShortOriginal AssigneeBose CorporationExport CitationBiBTeX, EndNote, RefManPatent Citations (42), Non-Patent Citations (7), Referenced by (8), Classifications (28), Legal Events (2) External Links: USPTO, USPTO Assignment, EspacenetSurface vehicle vertical trajectory planning
US 7878510 B2Abstract
1. Apparatus for a surface vehicle for operating on a path, said path comprising vertical disturbances, said apparatus comprising:
a controllable suspension for applying a force between a payload compartment and a surface engaging device; and
a trajectory developing system operatively coupled to said controllable suspension, said trajectory developing system for developing a trajectory plan responsive to data specifically representative of said vertical disturbances.
2. Apparatus in accordance with claim 1, wherein said data is expressed as one of force, velocity, and acceleration.
3. Apparatus in accordance with claim 1, said trajectory developing system comprising a device for smoothing said data to develop said trajectory plan.
4. Apparatus in accordance with claim 3, said smoothing device comprising a low pass filter.
5. Apparatus in accordance with claim 3 said smoothing device comprising a bi-directional low pass filter.
6. Apparatus in accordance with claim 1, said controllable suspension comprising a linear actuator.
7. Apparatus in accordance with claim 1, wherein said data comprises positive and negative values.
a profile storage device for storing said data.
9. Apparatus in accordance with claim 8 wherein said profile storage device is located remotely from said surface vehicle.
10. Apparatus in accordance with claim 8, wherein said trajectory plan developing system is located remotely from said surface vehicle.
11. A method for operating an active vehicle suspension system in a surface vehicle on a surface having vertical disturbances comprising:
determining the location of said surface vehicle; and
determining if there is a vertical trajectory plan corresponding to said location, said trajectory plan corresponding to data specifically representative of said vertical disturbances.
12. A method for operating an active vehicle suspension in accordance with claim 11 and further comprising,
recording input signals from sensors; and
modifying said vertical trajectory plan in response to the performance sensor input signals.
13. A method for operating an active suspension in accordance with claim 11, wherein said determining the location of said surface vehicle includes using a global positioning satellite.
14. A method for operation an active suspension in accordance with claim 11, wherein said determining the location of said surface vehicle comprises pattern matching.
15. A method for operating an active suspension in accordance with claim 11, further comprising:
in the event that there is no vertical trajectory plan corresponding to said location, operating the active vehicle suspension as a reactionary suspension, and
developing a trajectory plan signals responsive to the operating the active vehicle suspension as a reactionary suspension.
16. Apparatus for a surface vehicle comprising:
an active suspension;
a locator system for determining the location of said surface vehicle;
a trajectory plan storage device, for storing trajectory plans corresponding to locations, said trajectory plans corresponding to data specifically representative of vertical disturbances on a surface on which said surface vehicle is traveling; and
a trajectory plan microprocessor for determining if said trajectory plans contain a trajectory plan corresponding to said determined location.
17. An active suspension in accordance with claim 16, wherein said locator system comprises a global positioning system device.
18. An active suspension in accordance with claim 16, wherein said locator system comprises a pattern matching system.
This application is a continuation and claims priority under 35 USC §120 to U.S. patent application Ser. No. 10/629,243, filed on Jul. 28, 2003 now U.S. Pat. No. 7,195,250, which is a continuation-in-part of U.S. patent application Ser. No. 10/368,187, filed on Feb. 18, 2003 now abandoned, which is a continuation-in-part of U.S. patent application Ser. No. 09/535,849, filed on Mar. 27, 2000, now abandoned, and the entire contents of which are hereby incorporated by reference.
In another aspect of the invention, a method for developing a trajectory plan for use with a vehicle that includes a vehicle suspension system that includes a trajectory planning system for developing a trajectory plan, and a controllable suspension element for urging a point on the vehicle to follow the trajectory plan, includes recording a profile that includes data points, the data points representing positive and negative vertical deflections of a travel path; smoothing data of the profile, the smoothing providing positive and negative values; and recording the smoothed data as the trajectory plan.
In another aspect of the invention, a method for developing a trajectory plan for use by a vehicle including a payload compartment, a wheel, a plurality of sensors for measuring a corresponding plurality of states of the vehicle, and a controllable suspension element for exerting force between the wheel and the payload compartment, includes recording a profile including data points measured by the sensors, the data points representing positive and negative vertical values; and storing the profile as one of a series of commands causing the controllable suspension element to exert a force, and a series of states of the vehicle as measured by at least one of the sensors.
In another aspect of the invention, a vehicle includes a payload compartment and a front surface engaging device and a rear surface engaging device. The vehicle further includes a suspension system. The suspension system includes a front controllable suspension element for exerting a force between the front surface engaging device and the payload compartment to modify the distance between the front surface engaging device and the payload compartment. The front controllable suspension element has a centered position. The front controllable suspension element includes a centering subsystem for urging the front controllable suspension element toward the centered position. The suspension system further includes a rear controllable suspension element for exerting a force between the rear surface engaging device and the payload compartment to modify the distance between the rear surface engaging device and the payload compartment. The rear controllable suspension element has a centered position. The rear controllable suspension element includes a controllable centering subsystem for urging the rear controllable suspension element toward the centered position. A method for operating the vehicle includes operating the vehicle on a road segment including disturbances so that the front surface engaging device encounters the disturbances before the rear surface engaging device and so that the front controllable suspension element exerts forces responsive to the disturbances; determining the amplitude of one of the road disturbances, and responsive to a determining that the amplitude of the one of the disturbances is less than a first threshold amount, disabling the rear suspension element centering subsystem.
In another aspect of the invention, a surface vehicle includes a payload compartment; a front surface engaging device; a rear surface engaging device; and a suspension system including a front controllable suspension element for exerting a force between the front surface engaging device and the payload compartment to modify the distance between the front surface engaging device and the payload compartment, the front controllable suspension element having a centered position, the front controllable suspension element including a centering subsystem for urging the front controllable suspension element toward the centered position, the front controllable suspension element further including a measuring system to measure the amplitude of a road disturbance encountered by the front surface engaging device; and a rear controllable suspension element for exerting a force between the rear surface engaging device and the payload compartment to modify the distance between the rear surface engaging device and the payload compartment, the rear controllable suspension element having a centered position, the rear controllable suspension element including a controllable centering subsystem for urging the rear controllable suspension element toward the centered position; and controlling circuitry, responsive to the measuring system, for disabling the rear suspension element centering subsystem.
In another aspect of the invention a vehicle includes a payload compartment and a first surface engaging device and a second surface engaging device. The vehicle further includes a suspension system. The suspension system includes a first controllable suspension element for exerting a force between the first surface engaging device and the payload compartment to modify the distance between the first surface engaging device and the payload compartment. The suspension system further includes a second controllable suspension element for exerting a force between the second surface engaging device and the payload compartment to modify the distance between the second surface engaging device and the payload compartment. Each of the first controllable suspension element and the second suspension element include associated sensors to measure at least one of vertical acceleration, vertical velocity, vertical road deflection, suspension displacement, and force applied by the controllable suspension. A method for operating the vehicle includes operating the vehicle on a road segment having disturbances so that the first surface engaging device encounters the disturbances before the second surface engaging device; measuring, by the sensors associated with the first controllable suspension element, the disturbances; based on the measuring, causing the second controllable suspension element to exert a force related to the disturbance before the second surface engaging device encounters the disturbance.
In another aspect of the invention, a vehicle includes a payload compartment and a first surface engaging device and a second surface engaging device. The vehicle further includes a suspension system. The suspension system includes a first controllable suspension element for exerting a force between the first surface engaging device and the payload compartment to modify the distance between the first surface engaging device and the payload compartment. The suspension system further includes a second controllable suspension element for exerting a force between the second surface engaging device and the payload compartment to modify the distance between the second surface engaging device and the payload compartment. Each of the first controllable suspension element and the second suspension element includes associated sensors to measure at least one of vertical acceleration, vertical velocity, vertical road deflection, suspension displacement, and force applied by the controllable suspension. A method for operating the vehicle includes operating the vehicle on a road segment having disturbances so that the first engaging device encounters the disturbances before the second surface engaging device; measuring, by the sensors associated with the first controllable suspension element, the disturbances; and based on the measuring, causing the second controllable suspension element to exert a force related to the disturbance before the second surface engaging device encounters the disturbance.
In still another aspect of the invention, a method for operating a vehicle including a payload compartment and a surface engaging device the vehicle further including a suspension system, the suspension system including a controllable suspension element for exerting a force between a surface engaging device and the payload compartment to modify the distance between the surface engaging device and the payload compartment, the surface controllable suspension element having a centered position, the controllable suspension element including a reactionary operating mode and a trajectory plan operating mode, the method includes driving the vehicle on a road segment having vertical disturbances; determining the amplitude of the disturbances; responsive to a determining that an amplitude of a one of the disturbances is less than a first threshold amount, operating the controllable suspension element in the reactionary mode; responsive to a determining that the amplitude of the one of the disturbances is greater than the first threshold amount and less than a second threshold amount, disabling the centering system; and responsive to a determining that the amplitude of the one of the disturbances if greater than the second threshold amount, causing the controllable suspension to exert a force related to the one of the disturbances before the surface engaging device encounters the disturbance.
FIG. 2 a is a partially block diagram, partially diagrammatic representation of a controllable suspension according to the invention;
FIG. 2 b is a partially block diagram, partially diagrammatic representation of a controllable suspension according to the invention;
FIGS. 4 a-4 c are diagrammatic views of the operation of an active suspension according to the invention;
FIGS. 6 a, 6 b, and 6 c are flow diagrams illustrating the operation of a suspension system according to the invention;
FIGS. 10 a, 10 b, and 10 c are diagrams of a vehicle operating on a road surface in accordance with the invention; and
FIGS. 11 a-11 c diagrams illustrating the operation of a vehicle operating on a road surface in accordance with the invention.
Controllable suspension elements 18 may be components of a conventional active suspension system, in which the controllable suspension elements can respond to the control signals by varying the vertical displacement between the passenger compartment 16 and wheel 14 by applying a force. Suitable active suspension systems are described in U.S. Pat. Nos. 4,960,290 and 4,981,309 incorporated by reference herein. The force may be transmitted through some element such as a linear or rotary actuator, ball screw, pneumatic system, or hydraulic system, and may include intervening elements between the wheel and the force producing element. The controllable active suspension may also comprise an adaptive active vehicle suspension such as described in U.S. Pat. No. 5,432,700, in which signals may be used to modify adaptive parameters and gains. Controllable suspension elements 18 may also be components of a conventional suspension system, which apply forces between passenger compartment 16 and wheel 14 reactively, in response to vertical forces resulting from wheel 14 passing over uneven surfaces. In conventional suspension systems, the controllable suspension elements may respond to the control signals by extending or compressing a spring, by changing a damping rate, or in other ways. By way of example, the invention will be described in an embodiment in which the controllable suspension element is an active suspension element. Referring now to FIG. 2 a, there is shown a block diagram of a suspension according to the invention. Controllable suspension element 18 is coupled to a microprocessor 20 which is in turn coupled to profile storage device 22 and optional locator system 24. The suspension system further includes sensors 11, 13, and 15 associated with payload compartment 16, controllable suspension elements 18, and wheels 14, respectively. Sensors, 11, 13, and 15 are coupled to microprocessor 20. Locator system 24 may receive signals from an external source, such as a positioning satellite 23. For convenience, only one of the controllable suspension elements 18 is shown. The remaining wheels 14, controllable suspension elements 18, and the respective sensors 11, 13, and 15 are coupled to microprocessor 20 substantially as shown in FIG. 2 a. Microprocessor 20 may be a single microprocessor as shown. Alternatively, the functions performed by microprocessor 20 may be performed by a number of microprocessors or equivalent devices, some of which can be located remotely from vehicle 10, and may wirelessly communicate with components of the suspension system, which are located on vehicle 10.
A suspension system incorporating the invention may also include a trajectory planning subsystem, which includes (referring to FIG. 2 a) microprocessor 20, profile storage device 22, and locator system 24.
Locator system 24 detects the location of the vehicle, and microprocessor 20 retrieves a copy of the profile of the road, if available, from a plurality of profiles stored in profile storage device 22. Microprocessor 20 calculates or retrieves a trajectory plan responsive to the road profile, and issues control signals to controllable suspension element 18 to execute the trajectory plan. The profile retrieval, trajectory calculation, and suspension control may be performed by a single microprocessor as shown, or may be done by separate microprocessors if desired. The trajectory plan development process is described more fully in connection with FIGS. 6 a and 6 b. If controllable suspension element 18 is an active suspension acting reactively to road forces, microprocessor 20 may issue an adjusted control signal to controllable suspension element 18 based in part on the road profile.
A trajectory plan is a pre-determined path in space of a point or set of points on the payload compartment. To control the pitch of the vehicle, the trajectory may represent at least two points, respectively forward and rearward on the payload compartment. To control the roll of the vehicle, the trajectory plan may represent at least two points, one on each side of the vehicle. In a four wheeled vehicle, it may be convenient to use for trajectory plan development four points on the payload compartment, one near each wheel. Pairs of the points could be averaged (such as averaging the two points on each side of the vehicle to consider roll in the development of the trajectory plan, or averaging the two points in the front and the rear, respectively, to consider pitch in the development of the trajectory plan). For simplicity of explanation, the invention will be described in terms of a single point. The microprocessor issues control signals to controllable suspension element 18 to cause the vehicle to follow the trajectory plan. More detail on trajectory plans and the execution of trajectory plans are set forth in the examples that follow.
The trajectory plan may take a number of factors into account, for example matching the pitch or roll of the vehicle to the pitch or roll expected by the passengers; minimizing the vertical acceleration of the payload compartment; maximizing the stroke of the suspension available to absorb bumps or dips, (hereinafter “disturbances”) in the road; minimizing the amplitude or occurrence of accelerations of an undesirable frequency, such as frequencies around 0.1 Hz, which tends to induce nausea; maximizing tire traction; or others. The trajectory plan may also include “anticipating” a disturbance in the road and reacting to it before it is encountered, as will be described below in the discussion of FIG. 5. Further, particularly if the suspension system includes a conventional spring to support the weight of the car and the operation of the active suspension element extends or compresses the conventional spring, the trajectory plan may take power consumption into account.
Referring now to FIG. 2 b, there is shown another embodiment of the invention incorporating a trajectory plan storage device 25. Elements of FIG. 2 b are similar to elements of FIG. 2 a, except profile device 22 of FIG. 2 a is replaced by a trajectory plan storage device 25. Trajectory plan storage device 25 may be any one of a number of types of writable memory storage, such as RAM, or mass storage devices such as a magnetic or writable optical disk. Trajectory plan storage device 25 may be included in the vehicle as shown, or may be at some remote location, with a broadcasting system for wirelessly communicating path profile data to the vehicle.
Operation of the embodiment of FIG. 2 b is similar to the operation of the embodiment of FIG. 2 a, except that microprocessor 20 retrieves and calculates trajectory plans that are associated with locations rather than being associated with profiles.
Another embodiment of the invention includes both the profile storage device of FIG. 2 a and the trajectory plan storage device of FIG. 2 b. In an embodiment including both profile storage device 22 and trajectory plan storage device 25, the storage devices may be separate devices or may be different portions of a single memory device. Operation of embodiments including trajectory plan storage device 25 are described further in the discussion of FIG. 6 c. FIG. 3 shows an example of the operation of a conventional active suspension without a trajectory planning subsystem. In FIG. 3, when front wheel 14 f′ encounters sloped section 41, the distance between payload compartment 16′ and front wheel 14 f′ is shortened. When the rise r due to the slope approaches the maximum displacement of the suspension element, suspension element 18 f′ is “nosed in” to slope 41, and in extreme cases may reach or approach a “bottomed out” condition, such that there is little or no suspension travel left to accommodate bumps in the rising surface.
Referring now to FIGS. 4 a-4 c, there is shown an example of the operation of an active suspension according to the invention. Microprocessor 20 of FIG. 2 a furnishes a computed trajectory plan 47, which closely matches the road surface, including sloped section 41, and issues appropriate control signals to controllable suspension elements 18 f and 18 r to follow the trajectory plan. In this example, the trajectory plan can be followed by exerting no force to shorten or lengthen the distance between wheels 14 f and 14 r and payload compartment 16, or if the suspension system includes a conventional spring, the trajectory plan can be followed by exerting only enough force to counteract acceleration resulting from force exerted by the spring. In FIG. 4 b, when the vehicle has reached the same position in the road as in FIG. 3, payload compartment 16 is tilted slightly. In FIG. 4 c, the payload compartment is tilted at an angle φ which matches the tilt θ of the road. The gradual tilt of the payload compartment to match the tilt of the road matches rider expectations. An additional advantage is that if there is a disturbance, such as a bump 49 or depression 51 in the road, the full stroke of the suspension is available to absorb the disturbance.
The example of FIGS. 4 a-4 c illustrates the principle that following the trajectory plan may occur with little or no net force being applied by the controllable suspension element 18 and that execution of the trajectory planning subsystem may affect the normal operation of an active suspension. In FIGS. 4 b and 4 c, the vehicle is experiencing upward acceleration, and the normal reactionary operation of the active suspension would shorten the distance between wheel 14 f and the payload compartment 16 as shown in FIG. 3. With a suspension according to the invention, operating with a trajectory plan, the active suspension could remain in a centered position, so that the vehicle payload compartment follows trajectory plan 47. Alternatively, the operational example of FIGS. 4 b-4 c could be combined with the operational example of FIG. 5 below so that the vehicle payload compartment follows trajectory plan 47.
FIG. 5 shows another example of the operation of an active suspension with a trajectory planning subsystem. Road profile 50 includes a large bump 52. Microprocessor 20 (of FIG. 2 a or 2 b) furnishes a computed trajectory plan 54 appropriate for road profile 50. At point 56, before wheel 14 has encountered bump 52, controllable suspension element 18 exerts a force to gradually lengthen the distance between wheel 14 and payload compartment 16. As wheel 14 travels over bump 52, the normal operation of the controllable suspension element 18 causes controllable suspension element 18 to exert a force, which shortens the distance between payload compartment 16 and wheel 14. When wheel 14 reaches the crown 57 of bump 52, controllable suspension element 18 begins to exert a force, which lengthens the distance between payload compartment 16 and wheel 14. After wheel 14 has passed the end of bump 52, controllable suspension element 18 exerts a force shortening the distance between payload compartment 16 and wheel 14. The example of FIG. 5 illustrates the principle that the trajectory planning subsystem may cause the controllable suspension element 18 to exert a force to lengthen or shorten the distance between wheel 14 and payload compartment 16 even on a level road and further illustrates the principle that the trajectory plan may cause the controllable suspension element to react to a disturbance in the road before the disturbance is encountered.
The trajectory plan may take perceptual thresholds of vehicle occupants into account. For example, in FIG. 5 even less vertical acceleration would be encountered by the occupants of the vehicle if the trajectory plan began rising before point 56 and returned the vehicle to the equilibrium position after point 58. However, the difference in vertical acceleration may not be enough to be perceived by the vehicle occupants, so the active suspension need not react before point 56 or continue to react past point 58. Additionally, if the vehicle includes a conventional suspension spring, the force applied by the active suspension between points 56 and 57 may need to exert a force to extend the spring in addition to a force to lift the vehicle, so not beginning the rise of the trajectory plan until point 56 may consume less power than beginning the rise earlier.
Referring now to FIG. 6 a, there is shown a method for developing, executing, and modifying a trajectory plan by a system without optional locator system 24. At step 55, sensors 11, 13, 15 collect road profile information and transmit the information to microprocessor 20 which records the road profile in profile storage device 22. At step 157, the profile microprocessor compares the road profile information with road profiles that have been previously stored in profile storage device 22. The comparison may be accomplished using a pattern matching system as described below. If the road profile information matches a road profile that has previously been stored, at step 62 a, the profile is retrieved, and microprocessor 20 calculates a trajectory plan appropriate for that profile. Concurrently, at step 62 b, sensors 11, 13, 15 furnish signal representations of the road profile that may be used to modify, if necessary, the profile stored in profile storage device 22.
If it is determined at step 157 that there is no previously stored road profile that matches the road profile information collected in step 55, at step 64 controllable suspension element 18 acts in a reactionary mode.
Referring now to FIG. 6 b, there is shown a method for developing, modifying, and executing a trajectory plan by a system that includes optional locator system 24. At step 70, locator system 24 determines the location and direction of the vehicle. At step 72 trajectory plan microprocessor 20 examines stored profiles in profile storage device 22 to see if there is a profile associated with that location. If there is a profile associated with that location, a step 74 a microprocessor 20 retrieves the profile and calculates or retrieves a trajectory plan. Depending on how the data is stored and processed, step 72 may also consider direction of travel in addition to location in determining whether there is an associated profile. Concurrently, at step 74 b, sensors 11, 13, 15 provide signals representative of the road profile that may be used to modify, if necessary, the profile stored in profile storage device 22.
Referring now to FIG. 6 c, there is shown a method for developing, modifying, and executing a trajectory plan in an embodiment of the invention as shown in FIG. 2 b and having some device to locate the vehicle, such as the locator system 24, or the profile storage device 22 of FIG. 2 a. At step 70, locator system 24 determines the location and direction of the vehicle. At step 172 trajectory plan microprocessor 20 examines trajectory plans in trajectory plan storage device 25 to see if there is a trajectory plan associated with that location. If there is a trajectory plan associated with that location, at step 174 a microprocessor 20 retrieves the trajectory plan and transmits the information to controllable suspension element 18, which executes the trajectory plan. Depending on how the data is stored and processed, step 172 may also consider direction of travel in addition to location in determining whether there is an associated profile. Concurrently, at step 174 b, signals from sensors 11, 13, 15 representative of the actual profile may be recorded so that the trajectory plan associated with the location can later be modified to provide a smoother or more comfortable ride.
The methods of FIGS. 6 a, 6 b, and 6 c illustrate one of the learning features of the invention. Each time the vehicle is driven over a portion of road, the profile or trajectory plan, or both, may be modified, so that the trajectory plan furnished by microprocessor 20 may be used to provide for a smoother ride for the occupants of the vehicle during subsequent rides over the same portion of road. Additionally, the vehicle suspension system may employ an optimization process shown below in FIG. 9.
It is desirable to determine the location of the vehicle accurately, ideally within one meter, though an active suspension with a locator system having a lesser degree of precision performs better than conventional active suspensions. One method of attaining a high degree of precision is to include in locator system 24 of FIG. 2 a incorporating a high precision GPS system, such as a differential system accurate to within centimeters. Another method is to include in locator system 24 of FIG. 2 a a GPS system having a lower degree of precision (such as a non-differential system accurate to within about 50 meters or some other locator system not incorporating GPS) and a supplementary pattern matching system.
This form of pattern matching can be usefully applied to a trajectory planning active suspension by recording a pattern of z-axis deflections from a base point and using the pattern of z-axis deflections as the search string. Pattern matching can then be used in at least two ways. In one application, the GPS system is used to get an approximate (within 30 meters) location of the vehicle, and pattern matching is then used to locate the vehicle more precisely, by using for the target string, the previously recorded pattern of z-axis deflections stored in profile storage device 22 of FIG. 2 a. In a second application, pattern matching is used to compare the pattern of z-axis deflections as measured by sensors 11, 13, and 15 of FIG. 2 a with patterns of z-axis deflections stored in profile storage device 22 to determine if there is a profile stored in memory.
Referring now to FIG. 7, there is shown a diagrammatic view of an automobile and a road surface, illustrating the development of a trajectory plan. Line 80 represents the road profile as stored by profile device 22 of FIG. 2 a. Line 82 represents the road profile 80 which has been bidirectionally low-pass filtered using a break frequency in the range of 1 Hz, and is used as the trajectory plan; the bidirectional filtering eliminates phase lag inaccuracies that may be present with single directional filtering. When the automobile 84 passes over the road surface represented by line 80, controllable suspension element 18 of FIG. 2 a urges the payload compartment of automobile 84 to follow the trajectory plan represented by line 82. The high frequency, low amplitude disturbances in the road are easily handled by the normal operation of the active suspension. Developing of a trajectory plan by low pass filtering is very useful in dealing with the situation as described in FIGS. 3 and 4 a-4 c. Processing the road profile data in the time domain to develop trajectory plans is advantageous when the velocity of the vehicle is constant; that is, each trip across the road segment is at the same velocity.
As stated above, the data is expressed in positive and negative terms; for example a bump may be treated as a positive value and a depression (or “pothole”) treated as a negative value. The data smoothing maintains positive and negative values. Maintaining positive and negative values in the data enables the trajectory plan to urge the controllable suspension element to apply a force in either direction, for example, to shorten the distance between the wheel and the passenger compartment in the case of a bump and to lengthen the distance between the wheel and the passenger compartment in the case of a depression. Maintaining positive and negative data values is not required for active suspension systems that modify controller parameters such as gain, and therefore expressing the data in a form that is always positive, such as root-mean-square, is sufficient. Active suspension systems that control gain control how the suspension will exert a force to shorten or lengthen the distance between the wheel and the passenger compartment responsive to a road disturbance only when the road disturbance is encountered; whether the disturbance is positive or negative can be determined when the disturbance is encountered. An active suspension system according to the invention exerts a force to lengthen or shorten the distance between the wheel and the passenger compartment before the disturbance is encountered; therefore it is desirable that data for a suspension system according to the invention retain positive and negative values.
FIGS. 3, 4 a-4 c, and 5 and the corresponding portions of the disclosure illustrated the principle that the execution of the trajectory planning subsystem may affect the normal reactionary operation of an active suspension. In FIG. 3, a normal reactionary operation of the suspension element may cause the vehicle to “nose in” to a hill. In FIGS. 4 a-4 c, the controllable suspension using a trajectory plan causes the vehicle to follow a pre-determined path in space (that is, the trajectory plan) and pitch, rather than “nosing in” to a hill. The trajectory plan may cause the controllable suspension to exert no force even if there is a road disturbance. The trajectory plan may cause the controllable suspension to exert a force related to a road disturbance before encountering the disturbance. The trajectory plan may cause the controllable suspension to continue to exert a force related to a road disturbance even after the disturbance has been traversed.
FIGS. 10 a-10 c each show diagrammatic views of a vehicle and a road surface, illustrating the application of the invention to the front and rear wheels. The “front to rear” feature is especially useful when a vehicle is traversing a portion of road for the first time, and for which no road profile is available. The vehicles of FIGS. 10 a and 10 b use information from sensors associated with a front wheel to develop a trajectory plan for the rear wheel. This feature of the invention is illustrated by showing the trajectory of a point 114 in the passenger compartment above a front wheel 14 f, and the trajectory of a point 116 in the passenger compartment above a rear wheel 14 r. Front and rear wheels 14 f and 14 r are mechanically coupled to payload compartment 16 by corresponding controllable suspension elements 18 f and 18 r, respectively. The vehicle is operating on a road that has a disturbance 112 a that has a height h1, which is greater than the available suspension stroke with the suspension in a centered position, and which is smaller than total combined suspension stroke (that is the combined available upwards and downwards suspension travel with the suspension element in a centered position). When front wheel 14 f encounters disturbance 112 a, the suspension reacts to keep the trajectory of point 114 flat. As the suspension bottoms out, or approaches bottoming out, for example at point 118, the upward force caused by the road disturbance is transferred to point 114, so that point 114 follows a path 120. As described above, many suspension systems have centering systems for preventing the suspension from bottoming out and for maintaining available suspension stroke; the action of these systems also results in an upward acceleration of point 114 and a path similar to path 120.
As the front wheel travels the section s of the road, the microprocessor may record the profile of the road and smooth the profile data to provide a trajectory plan for execution by the rear wheel controllable suspension element 18 r. When the rear wheel approaches the beginning of section s at point 122, prior to engaging disturbance 112 a, controllable suspension element 18 r exerts a force to lengthen the distance between wheel 14 r and passenger compartment 16, urging point 116 gradually upward. When wheel 14 f engages disturbance 112 a, the normal reactionary mode action of the controllable suspension element 18 r is to exert a force to cause point 116 to follow the trajectory plan 124. Since the controllable suspension element has lengthened the distance between the wheel and the passenger compartment more suspension stroke is available, and the controllable suspension element can absorb disturbance 112 a without reaching or approaching a bottomed out situation. A trajectory such as trajectory 124 is more comfortable for passengers in the vehicle because it avoids rapid vertical accelerations and velocities.
Another feature of the invention is illustrated in FIG. 10 b. A vehicle similar to the vehicle of FIG. 10 a has a centering system for maintaining available suspension stroke and preventing the suspension element from bottoming out. If the suspension element approaches a bottomed out or topped out condition, the centering system urges the suspension element system toward a centered position, which preserves suspension travel but allows some vertical acceleration of the passenger compartment. Road disturbance 112 b has a height h2 that is slightly less than the available suspension stroke with the suspension element in a centered position. When front wheel 14 f engages disturbance 112 b, the controllable suspension element 18 f acts to keep the passenger compartment level and to prevent vertical acceleration of the passenger compartment. As the suspension element approaches a bottomed out condition, for example at point 126, the centering system acts to prevent the suspension element from bottoming out by allowing some vertical movement of the passenger compartment as indicated at point 126 of path 128. As the front wheel traverses disturbance 112 b, the sensors record the height h2 of the disturbance. Since the height of the disturbance 112 b is less than the available suspension travel, the controllable suspension disables the centering system for the rear wheel. When the rear wheel 14 r traverses the disturbance 112 b, there is no vertical movement of the passenger compartment, as indicated by path 130.
A variation of the example of FIG. 10 b is shown in FIG. 10 c. In the example of FIG. 10 c, when the passenger compartment begins to move vertically when the front wheel is at point 126 and rear wheel is at point 126′, the rear control suspension element exerts a force so that the path of 130 of rear point 116 follows the same trajectory as the front point 114. This lessens the amount of pitch experienced by the passengers. When the rear wheel encounters disturbance 112 b, the rear suspension element may operate as in FIG. 10 b. Referring to FIGS. 11 a and 11 b, there is shown another feature of the invention. In FIG. 11 a, when the front wheel 14 f encounters the beginning 136 of long upslope 138 on a road for which the controllable suspension element does not have a profile, front controllable suspension element 18 f acts to keep the passenger compartment level. The leveling action of the front controllable suspension element continues until point 132 in which the front controllable suspension element 18 f is “nosed in” and approaches bottoming out as discussed above in the discussion of FIG. 3. When the front controllable suspension element reaches or approaches a bottomed out condition, a centering subsystem urges the front controllable suspension element 18 f toward a centered position, at, for example, point 134. In the interval between points 132 and 134, the occupants of the vehicle, particularly the front seat passengers experience a “nosed in” sensation, and experience the upward acceleration after the wheel has encountered the hill, that is after they expect it. This can be disconcerting to the occupants. Additionally the passengers experience vertical acceleration that is greater than the passengers would have experienced if the front suspension element had remained in a centered position and not acted to keep the car level. The vertical acceleration, suspension displacement, and other measurements are recorded by the microprocessor, which then develops a response for the rear suspension element.
In FIG. 11 b, when rear wheel 14 r encounters the beginning 136 of long upslope 138, the microprocessor issues a command to the rear suspension element to remain in a centered position and not to react to the upslope. The result is that the rear point 116 follows a path that is similar to the upslope of the road, and which causes the occupants of the vehicle, especially the occupants of the back seat, to experience less vertical acceleration and velocity when the rear wheel encounters the upslope than when the front wheel encounters the upslope. Additionally, they experience the amount of upward acceleration that they expect, and experience the upward acceleration when they expect it.
The example of FIGS. 11 a and 11 b illustrates the feature that a controllable suspension according to the invention may react to some road stimuli less than a conventional reactive suspension. In an actual implementation, the operational example of FIG. 11 b may be combined with the operational example of FIG. 10 a to lessen the upward acceleration at point 136 of FIG. 11 a-11 b so that the actual trajectory spread the upward acceleration over a longer horizontal distance, such as in trajectory 130A of FIG. 11 c. Vehicle suspension systems not using information from a front suspension element to affect the operation of a rear wheel suspension element cannot perform the ride-improving actions shown in FIGS. 10 a, 10 b, and 11 b. Vehicle suspensions that use information from a front suspension element to change characteristics of a control system of a rear suspension element cannot cause the rear suspension element to apply a force before a disturbance is encountered.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS4518169Mar 18, 1983May 21, 1985Nissan Motor Company, LimitedAutomatic vehicle height-adjusting systemUS4618156Oct 26, 1984Oct 21, 1986Nippondenso Co., Ltd.Vehicle height control systemUS4647068Dec 31, 1985Mar 3, 1987Toyota Jidosha Kabushiki KaishaRear suspension controllerUS4685689May 28, 1985Aug 11, 1987Mitsubishi Jidosha Kogyo Kabushiki KaishaVehicle suspension responsive to vertical acceleration and change in heightUS4960290May 10, 1989Oct 2, 1990Bose CorporationWheel assembly suspendingUS4981309Aug 31, 1989Jan 1, 1991Bose CorporationElectromechanical transducing along a pathUS5013067Jan 12, 1990May 7, 1991Fuji Jukogyo Kabushiki KaishaMethod and apparatus for controlling vehicle heightUS5287277Jun 9, 1993Feb 15, 1994Fuji Jukogyo Kabushiki KaishaMethod and apparatus for controlling height of a vehicleUS5311173Aug 28, 1991May 10, 1994Hitachi, Ltd.Navigation system and method using map dataUS5432700Dec 21, 1992Jul 11, 1995Ford Motor CompanyAdaptive active vehicle suspension systemUS5748476Jun 5, 1995May 5, 1998Honda Giken Kogyo Kabushiki KaishaVehicle control systemUS5899288Nov 12, 1997May 4, 1999Case CorporationActive suspension system for a work vehicleUS5944153Sep 29, 1997Aug 31, 1999Tokico Ltd.Suspension control systemUS5987378Oct 24, 1996Nov 16, 1999Trimble Navigation LimitedVehicle tracker mileage-time monitor and calibratorUS6000703Nov 12, 1997Dec 14, 1999Case CorporationActive suspension system for a work vehicle having adjustable performance parametersUS6268825Mar 25, 1999Jul 31, 2001Toyota Jidosha Kabushiki KaishaNavigation device for vehicle and preparation of road shape data used thereforUS7195250Jul 28, 2003Mar 27, 2007Bose CorporationSurface vehicle vertical trajectory planningDE3439000A1Oct 25, 1984Apr 30, 1986Teldix GmbhIntegrated-navigation deviceDE10028911A1Jun 10, 2000Dec 20, 2001Bosch Gmbh RobertIntelligent predictive system (IPS) for predicting vehicle behavior and controlling component, e.g. lights, gears, brakes, behavior according to forthcoming road path and gradientDE19600734A1Jan 11, 1996Jul 17, 1997Zahnradfabrik FriedrichshafenMotor vehicle system control method w.r.t. external conditions, location etc.EP0217356A2Sep 30, 1986Apr 8, 1987Toyota Jidosha Kabushiki KaishaSuspension controllerEP0534892A1Sep 24, 1992Mar 31, 1993Nessim Igal LevyPosition-locating methodEP0662602A1Dec 20, 1994Jul 12, 1995SOCIETE D'APPLICATIONS GENERALES D'ELECTRICITE ET DE MECANIQUE SAGEM Société anonyme françaiseProcedure for terrestrial navigationEP0819912A2Jul 11, 1997Jan 21, 1998Toyota Jidosha Kabushiki KaishaVehicle driving condition prediction device and warning device using the prediction deviceEP1138530A2Feb 13, 2001Oct 4, 2001Bose CorporationSurface vehicle vertical trajectory planningGB2353872A Title not availableJP2589461B2 Title not availableJP2000275051A Title not availableJP2000318634A Title not availableJP2000338865A Title not availableJPH0911723A Title not availableJPH1191550A Title not availableJPH04331615A Title not availableJPH06171333A Title not availableJPH08271272A Title not availableJPH09304083A Title not availableJPH10109513A Title not availableJPH10300480A Title not availableJPH11304663A Title not availableJPS60255519A Title not availableJPS62289422A Title not availableWO1998023918A1Nov 25, 1997Jun 4, 1998Toyota Jidosha Kabushiki KaishaNavigation device for vehicle and preparation of road shape data used thereforNon-Patent CitationsReference1Chinese Second Office Action in counterpart Application No. 2008100881175.4 dated Mar. 18, 2010, 10 pages.2European Patent Office Examination Report in counterpart Application No. 04100619.8-1264 dated May 19, 2010, 6 pages.3Granted Patent, Chinese Patent Application in counterpart Application No. 200810081175.4 dated Jul. 16, 2010, 3 pages.4Japanese Final Office Action in counterpart Application No. 2004-034527 dated Jun. 1, 2010, 5 pages.5Japanese Office Action in counterpart Application No. 2001-090037 dated Jun. 1, 2010, 9 pages.6Office Action and Translation in corresponding Chinese Patent Application No. 200810081174.X dated Aug. 21, 2009, 6 pages.7Office Action and Translation in corresponding Japanese Patent Application No. 2004-034527 dated Jul. 6, 2009, 6 pages.Referenced byCiting PatentFiling datePublication dateApplicantTitleUS8938333 *Jun 27, 2012Jan 20, 2015Bose CorporationActive wheel dampingUS8948968 *Jun 20, 2013Feb 3, 2015Bose CorporationSurface vehicle vertical trajectory planningUS9109913Sep 30, 2013Aug 18, 2015Ford Global Technologies, LlcRoadway-induced ride quality reconnaissance and route planningUS9417075 *Nov 17, 2014Aug 16, 2016Bose CorporationSurface vehicle vertical trajectory planningUS9440508Nov 25, 2014Sep 13, 2016Seth M. LACHICAActive vehicle suspension system and method for managing drive energyUS20140005888 *Jun 27, 2012Jan 2, 2014Amar G. BoseActive wheel dampingUS20140012467 *Jun 20, 2013Jan 9, 2014Bose CorporationSurface Vehicle Vertical Trajectory PlanningUS20150160021 *Nov 17, 2014Jun 11, 2015Bose CorporationSurface Vehicle Vertical Trajectory Planning* Cited by examinerClassifications U.S. Classification280/5.518, 180/168, 180/167, 701/38, 701/37International ClassificationB60G17/015, G01C21/26, B60G17/0165Cooperative ClassificationG01C21/26, B60G17/0165, B60G2800/912, B60G2500/20, B60G2400/824, B60G2600/604, B60G2800/915, B60G2800/0192, B60G2400/821, B60G2600/182, B60G2800/24, B60G2800/014, B60G2401/16, B60G2600/1879, B60G2600/1877, B60G2600/1876, B60G17/0195European ClassificationB60G17/0165, B60G17/0195, G01C21/26Legal EventsDateCodeEventDescriptionFeb 8, 2007ASAssignmentOwner name: BOSE CORPORATION, MASSACHUSETTSFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KNOX, LAWRENCE D.;LACKRITZ, NEAL M.;PARISON, JAMES A.;AND OTHERS;REEL/FRAME:018870/0319;SIGNING DATES FROM 20040128 TO 20040129Owner name: BOSE CORPORATION, MASSACHUSETTSFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KNOX, LAWRENCE D.;LACKRITZ, NEAL M.;PARISON, JAMES A.;AND OTHERS;SIGNING DATES FROM 20040128 TO 20040129;REEL/FRAME:018870/0319Aug 1, 2014FPAYFee paymentYear of fee payment: 4RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services