Feed-forward active brake control
First Claim
1. A vehicle active brake control having sensors for detecting vehicle speed and a driver steering input, wherein the control differentially brakes the vehicle wheels to impart a commanded yaw to the vehicle, the improvement wherein the commanded yaw is determined according to a method comprising the steps of:
- determining a desired yaw rate as a function of the detected vehicle speed and driver steering input;
determining a first yaw command component in proportion to the desired yaw rate when such desired yaw rate is outside a first predefined dead-band window, said first yaw command component being limited to a first saturation threshold outside said first dead-band window;
determining a second yaw command component in proportion to a rate of change of said desired yaw rate when such rate of change is outside a second predefined dead-band window, said second yaw command component being limited to a second saturation threshold outside said second dead-band window;
summing said first and second yaw command components to form said commanded yaw.
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Accused Products
Abstract
An improved active brake control in which differential braking is used in a feed-forward control to develop vehicle yaw in response to a desired yaw value determined as a function of steering wheel position and vehicle speed. The desired yaw rate value is used to develop a derivative yaw component and a proportional yaw component, which are summed to form a feed-forward yaw command for differential braking. Both proportional and derivative components have limited control authority determined by dead-band and saturation thresholds, and the proportional term is subjected to a diminishing integrator which reduces the yaw command as the desired yaw rate value approaches steady-state.
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Citations
11 Claims
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1. A vehicle active brake control having sensors for detecting vehicle speed and a driver steering input, wherein the control differentially brakes the vehicle wheels to impart a commanded yaw to the vehicle, the improvement wherein the commanded yaw is determined according to a method comprising the steps of:
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determining a desired yaw rate as a function of the detected vehicle speed and driver steering input; determining a first yaw command component in proportion to the desired yaw rate when such desired yaw rate is outside a first predefined dead-band window, said first yaw command component being limited to a first saturation threshold outside said first dead-band window; determining a second yaw command component in proportion to a rate of change of said desired yaw rate when such rate of change is outside a second predefined dead-band window, said second yaw command component being limited to a second saturation threshold outside said second dead-band window; summing said first and second yaw command components to form said commanded yaw. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A vehicle active brake control having sensors for detecting vehicle speed and a driver steering input, wherein the control differentially brakes the vehicle wheels to impart a commanded yaw to the vehicle, the improvement wherein the commanded yaw is determined according to a method comprising the steps of:
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determining a desired yaw rate as a function of the detected vehicle speed and driver steering input; determining a first yaw command component in proportion to the desired yaw rate if such first yaw command component is outside a first predefined dead-band window; limiting said first yaw command component to a first saturation threshold outside said first dead-band window; determining a second yaw command component in proportion to a rate of change of said desired yaw rate if such second yaw command component is outside a second predefined dead-band window; limiting said second yaw command component to a second saturation threshold outside said second dead-band window; summing said first and second yaw command components to form said commanded yaw.
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10. A vehicle active brake control having sensors for detecting vehicle speed and a driver steering rate, wherein the control differentially brakes the vehicle wheels to impart a commanded yaw to the vehicle, the improvement wherein the commanded yaw is determined according to a method comprising the steps of:
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integrating the detected driver steering rate to estimate a driver steering angle; determining a desired yaw rate as a function of the detected vehicle speed and said estimated driver steering angle; determining a first yaw command component in proportion to the desired yaw rate when such desired yaw rate is outside a first predefined dead-band window, said first yaw command component being limited to a first saturation threshold outside said first dead-band window; determining a desired rate of change of yaw rate based on the detected vehicle speed and driver steering rate; determining a second yaw command component in proportion to the desired rate of change of yaw rate when such rate of change is outside a second predefined dead-band window, said second yaw command component being limited to a second saturation threshold outside said second dead-band window; and summing said first and second yaw command components to form said commanded yaw. - View Dependent Claims (11)
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Specification