Method and apparatus for output saturation avoidance in preview-based vehicle system control
AssigneeClearMotion, Inc.
InventorsYu Jiang, Marco Giovanardi
Life of this patent
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Abstract
Methods related to the control of vehicle systems while a vehicle is traveling along a road surface are disclosed. In some implementations, data related to the road surface ahead of the vehicle is separated into first and second frequency ranges. Commands for a vehicle system may then be determined for the different frequency ranges and the vehicle system may be controlled based at least in part on the separate commands for the separate frequency ranges. This may include determining a combined system command based at least in part on the separate commands for the separate frequency ranges in some implementations.
Claims38
A method of operating a system onboard a vehicle while the vehicle is travelling along a road surface, the method comprising:
- receiving, at a microprocessor in the vehicle, road surface profile data associated with the road surface ahead of the vehicle;
- filtering the road surface profile data with a lower frequency band pass filter to produce a first filtered output, wherein the lower frequency band pass filter has a first lower frequency limit equal to a first frequency and a first upper frequency limit equal to a second frequency;
- supplying the first filtered output to a lower frequency transfer function to produce a lower frequency command signal;
- filtering the road surface profile data with a higher frequency band pass filter to produce a second filtered output, wherein the higher frequency band pass filter has second lower frequency limit equal to the second frequency and a second upper frequency limit equal to a third frequency, wherein the higher frequency band filter operates in parallel with the lower frequency band pass filter;
- supplying the second filtered output to a higher frequency transfer function to produce a higher frequency command signal;
- determining a total command signal based on the lower frequency command signal and the higher frequency command signal;
- and
- operating the system based at least partly on the total command signal.
A method of operating a vehicle while travelling along a road surface, the method comprising:
- (a) after a start of a first period of a given duration, operating a vehicle system according to a first motion plan, with a controller that includes a microprocessor operating at a first cycle time, wherein the motion plan is prepared, prior to the start of the first period, with a motion planner microprocessor operating at a second cycle time;
- (b) during step (a), collecting data associated with a motion of the vehicle with at least one sensor onboard the vehicle;
- and
- (c) prior to an end of the first time period, operating the vehicle system with the controller, according to a second motion plan prepared by the motion planner;
- wherein the value of at least one vehicle system parameter during the transition from the first plan to the second plan is determined, at least partially, based on the data collected during step (b).
A method of operating a vehicle while travelling along a road surface wherein the vehicle includes a vertical motion planner and a vertical motion controller, the method comprising:
- receiving, at the vertical motion planner, road surface profile data for a road segment ahead of the vehicle;
- based on the road surface profile and for a range of frequencies above a first frequency, using the vertical motion planner to develop a first vertical force profile for at least one actuator of an active suspension system, wherein the first vertical force profile is configured to isolate at least a portion of the vehicle from road surface disturbances, while the vehicle is traveling along the road segment;
- based on the road surface profile and for a range of frequencies below the first frequency, using the vertical motion planner to develop a second vertical force profile for the at least one actuator of the active suspension system, wherein the second vertical force profile is configured to cause the motion of at least the portion of the vehicle to track the road surface profile, while the vehicle is traveling along the road segment;
- providing an overall force profile to the controller, wherein the overall force profile is a combination of the first force profile and the second force profile;
- and
- operating the at least one actuator to apply a force on at least the portion of the vehicle according to the overall force profile while the vehicle is traveling along the road segment.
A controller system of an actuator of an active suspension system, comprising:
- a microprocessor-based vertical motion planner configured to develop a first optimal motion plan for a vehicle for frequencies in a range below a first frequency and a second optimal motion plan, different than the first optimal motion plan, for frequencies above the first frequency, wherein the first and second optimal motion plan are at least partially based on a road motion profile for a segment of the road ahead of the vehicle;
- and,
- a microprocessor-based controller, wherein the controller is configured to control a vertical motion of a vehicle with an active suspension controller based on the first optimal plan and the second optimal plan.
A method of operating a system onboard a vehicle while the vehicle is travelling along a road surface, the method comprising:
- receiving a preview of a road surface profile of a segment of the road ahead of the vehicle;
- separating a road profile into a first component including a range of frequencies below a first frequency and a second component including a range of frequencies above the first frequency;
- applying a first transfer function to the first component and a second transfer function, different than the first transfer function, to the second component;
- and
- controlling the system with a microprocessor-based controller based on the sum of the first component and the second component.
Dependencies are inferred from the claim text.