Adaptive compensation of rear-wheel steering control using vehicle dynamics parameter estimation
First Claim
1. A control system for providing active rear-wheel steering for a vehicle, said system comprising:
- a vehicle dynamics parameter estimation sub-system responsive to input signals, said vehicle dynamics parameter estimation sub-system employing a parameter estimation algorithm for estimating vehicle parameters based on the input signals, said vehicle dynamics parameter estimation sub-system comparing the estimated vehicle parameters with nominal vehicle parameters and generating difference signals indicative of the change between the estimated vehicle dynamics parameters and the nominal vehicle dynamic parameters;
an open-loop control sub-system for generating an open-loop steering control signal, said open-loop control sub-system being responsive to a vehicle speed signal, a front-wheel steering angle signal and the difference signals, said open-loop control sub-system including an open-loop look-up table for generating a nominal open-loop steering signal based on the vehicle speed signal and the front-wheel steering angle signal, said open-loop sub-system further including an open-loop adaptive compensation sub-system for generating a corrected open-loop steering angle signal based on the front-wheel steering angle signal, the open-loop steering angle signal and the difference signal, said open-loop steering control signal being a combination of the nominal open-loop steering angle signal and the corrected open-loop steering angle signal; and
a closed-loop control sub-system being responsive to the vehicle speed signal, the front-wheel steering angle signal and the input signals applied to the vehicle dynamics parameter estimation sub-system, said closed-loop sub-system including at least one look-up table providing a nominal closed-loop steering angle signal and at least one closed-loop adaptive compensation process sub-system providing a corrected closed-loop steering angle signal, wherein the closed-loop steering control signal is a combination of the nominal closed-loop steering angle signal and the corrected closed-loop steering angle signal, and wherein the open-loop steering control signal and the closed-loop steering control signal are combined to provide a wheel steering signal.
13 Assignments
0 Petitions
Accused Products
Abstract
An active rear-wheel vehicle steering control system that employs both open-loop and closed-loop control, where the open-loop and closed-loop control include adaptive compensation sub-systems that compensate for changes in vehicle dynamic parameters. The control system includes a dynamic parameter estimation sub-system that provides an estimated front-wheel cornering compliance and rear-wheel cornering compliance based on a front-wheel steering angle signal, a rear-wheel steering angle signal, a vehicle lateral acceleration signal, a vehicle yaw rate signal and a vehicle speed signal. The closed-loop control includes active gain for each of vehicle yaw rate, vehicle yaw rate acceleration, side-slip velocity and side-slip velocity rate, all based on the vehicle speed and vehicle dynamic parameter changes.
24 Citations
23 Claims
-
1. A control system for providing active rear-wheel steering for a vehicle, said system comprising:
-
a vehicle dynamics parameter estimation sub-system responsive to input signals, said vehicle dynamics parameter estimation sub-system employing a parameter estimation algorithm for estimating vehicle parameters based on the input signals, said vehicle dynamics parameter estimation sub-system comparing the estimated vehicle parameters with nominal vehicle parameters and generating difference signals indicative of the change between the estimated vehicle dynamics parameters and the nominal vehicle dynamic parameters; an open-loop control sub-system for generating an open-loop steering control signal, said open-loop control sub-system being responsive to a vehicle speed signal, a front-wheel steering angle signal and the difference signals, said open-loop control sub-system including an open-loop look-up table for generating a nominal open-loop steering signal based on the vehicle speed signal and the front-wheel steering angle signal, said open-loop sub-system further including an open-loop adaptive compensation sub-system for generating a corrected open-loop steering angle signal based on the front-wheel steering angle signal, the open-loop steering angle signal and the difference signal, said open-loop steering control signal being a combination of the nominal open-loop steering angle signal and the corrected open-loop steering angle signal; and a closed-loop control sub-system being responsive to the vehicle speed signal, the front-wheel steering angle signal and the input signals applied to the vehicle dynamics parameter estimation sub-system, said closed-loop sub-system including at least one look-up table providing a nominal closed-loop steering angle signal and at least one closed-loop adaptive compensation process sub-system providing a corrected closed-loop steering angle signal, wherein the closed-loop steering control signal is a combination of the nominal closed-loop steering angle signal and the corrected closed-loop steering angle signal, and wherein the open-loop steering control signal and the closed-loop steering control signal are combined to provide a wheel steering signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A control system for providing active rear-wheel steering for a vehicle, said system comprising:
-
a vehicle dynamics parameter estimation sub-system responsive to input signals, said vehicle dynamics parameter estimation sub-system employing a parameter estimation algorithm for estimating vehicle parameters based on the input signals, said vehicle dynamics parameter estimation sub-system comparing the estimated vehicle parameters with nominal vehicle parameters and generating difference signals indicative of the change between the estimated vehicle dynamics parameters and the nominal vehicle dynamic parameters; and an open-loop control sub-system for generating an open-loop steering control signal, said open-loop control sub-system being responsive to a vehicle speed signal, a front-wheel steering angle signal and the difference signals, said open-loop control sub-system including an open-loop look-up table for generating a nominal open-loop steering signal based on the vehicle speed signal and the front-wheel steering angle signal, said open-loop sub-system further including an open-loop adaptive compensation sub-system for generating a corrected open-loop steering angle signal based on the front-wheel steering angle signal, the open-loop steering angle signal and the difference signal, said open-loop steering control signal being a combination of the nominal open-loop steering angle signal and the corrected open-loop steering angle signal and provide at least part of a wheel steering signal. - View Dependent Claims (13, 14, 15, 16, 17)
-
-
18. A control system for providing active rear-wheel steering for a vehicle, said system comprising:
-
a vehicle dynamics parameter estimation sub-system responsive to input signals including a front-wheel steering angle signal, a rear-wheel steering angle signal, a vehicle lateral acceleration signal, a vehicle yaw rate signal and the vehicle speed signal, said vehicle dynamics parameter estimation sub-system employing a linear parameter estimation algorithm for estimating vehicle parameters based on the input signals, said vehicle dynamics parameter estimation system comparing the estimated vehicle parameters with nominal vehicle parameters and generating difference signals indicative of the change between the estimated vehicle dynamics parameters and the nominal vehicle dynamic parameters; an open-loop control sub-system for generating an open-loop steering control signal, said open-loop control sub-system being responsive to a vehicle speed signal, a front-wheel steering angle signal and the difference signals, said open-loop controller including an open-loop look-up table for generating a nominal open-loop steering signal based on the vehicle speed signal and the front-wheel steering angle signal, said open-loop sub-system further including an open-loop adaptive compensation sub-system for generating a corrected open-loop steering angle signal based on the front-wheel steering angle signal, the open-loop steering angle signal and the difference signal, said open-loop steering control signal being a combination of the nominal open-loop steering angle signal and the corrected open-loop steering angle signal; and a closed-loop control sub-system being responsive to the vehicle speed signal, the front-wheel steering angle signal and the input signals applied to the vehicle dynamics parameter estimation sub-system, said closed-loop sub-system including include a yaw rate feedback look-up table and a yaw rate feedback adaptive compensation sub-system, said yaw rate feedback look-up table providing an original yaw rate feedback angle signal and said yaw rate feedback adaptive compensation sub-system providing a corrected yaw rate feedback angle signal based on the estimated vehicle dynamics parameters, said closed-loop sub-system further including a yaw rate acceleration feedback look-up table and a yaw rate acceleration feedback adaptive compensation sub-system, said yaw rate acceleration feedback look-up table providing an original yaw rate acceleration feedback angle signal and said yaw rate acceleration feedback adaptive compensation sub-system providing a corrected yaw rate acceleration feedback angle signal based on the estimated vehicle dynamics parameters, said closed-loop sub-system further including a side-slip feedback look-up table and a side-slip feedback adaptive compensation sub-system, said side-slip feedback look-up table providing an original side-slip feedback angle signal and said side-slip feedback adaptive compensation sub-system providing a corrected side-slip feedback angle signal based on the estimated vehicle dynamics parameters and said closed-loop sub-system further including a side-slip rate feedback look-up table and a side-slip rate feedback adaptive compensation sub-system, said side-slip rate feedback look-up table providing an original side-slip rate feedback angle signal and said side-slip rate feedback adaptive compensation sub-system providing a corrected side-slip rate feedback angle signal based on the estimated vehicle dynamics parameters, wherein the original yaw rate feedback angle signal, the corrected yaw rate feedback angle signal, the original yaw rate acceleration feedback angle signal, the corrected yaw rate acceleration feedback angle signal, the original side-slip feedback angle signal, the corrected side-slip feedback angle signal, the original side-slip rate feedback angle signal, and the corrected side-slip rate feedback angle signal are combined to be a closed-loop steering control signal, and wherein the open-loop steering control signal and the closed-loop steering control signal are combined to provide a rear-wheel steering signal. - View Dependent Claims (19, 20, 21, 22, 23)
-
Specification