摘要:
A vehicle-trailer back-up control system that employs an active front steer sub-system. The system includes a smart hitch controller that receives a vehicle speed signal and a hand-wheel angle signal, and calculates a hitch angle command signal. The system further includes a hitch angle sensor that measures the hitch angle between the vehicle and the trailer that is compared to the hitch angle command signal to generate a hitch angle error signal. A PID control unit receives the hitch angle error signal, and generates a corrected road wheel angle signal based on proportional and derivative gains. The corrected road wheel angle signal is used to generate a motor angle signal that is applied to a steering actuator to be combined with the steering angle signal to generate the front wheel steering signal during a back-up maneuver.
摘要:
A vehicle steering control system for a vehicle/trailer combination that provides rear-wheel steering assist to improve the vehicle/trailer combination stability and handling performance. The control system provides an open-loop feed-forward control signal based on hand-wheel angle and vehicle speed. The control system includes a vehicle yaw rate command interpreter that provides a vehicle closed-loop feedback control signal based on the yaw rate of the vehicle, a trailer yaw rate command interpreter that provides a trailer closed-loop feedback control signal based on the yaw rate of the trailer, and a vehicle lateral acceleration command interpreter that provides a closed-loop feedback control signal based on the lateral acceleration of the vehicle. The closed-loop feedback signals are added together and then combined with the open-loop feed-forward control signal to provide the rear-wheel steering assist.
摘要:
A vehicle steering control system for a vehicle/trailer combination that provides rear-wheel steering assist to improve the vehicle/trailer combination stability and handling performance. The control system provides an open-loop feed-forward control signal based on hand-wheel angle and vehicle speed. The control system includes a vehicle yaw rate command interpreter that provides a vehicle closed-loop feedback control signal based on the yaw rate of the vehicle, a trailer yaw rate command interpreter that provides a trailer closed-loop feedback control signal based on the yaw rate of the trailer, and a vehicle lateral acceleration command interpreter that provides a closed-loop feedback control signal based on the lateral acceleration of the vehicle. The closed-loop feedback signals are added together and then combined with the open-loop feed-forward control signal to provide the rear-wheel steering assist.
摘要:
A method to assist steering of a vehicle equipped with an active steering system when operating in a reverse direction is provided. The method comprises monitoring vehicle operating characteristics and an operator steering input. Boundaries of a target region and a reference point are determined. A target steering angle range is calculated based upon the reference point and the target location. A controlled steering angle of the active steering system is corrected when the operator steering input is outside the target steering angle range. An aspect of the invention included determining the reference point comprising a point of intersection of a first vector and a second vector, the first vector parallel to and passing through a centerline of a rear axle of the vehicle and the second vector perpendicular to and passing through a centerline of an inside front steerable wheel of the vehicle.
摘要:
A vehicle-trailer back-up control system that employs an active front steer sub-system. The system includes a smart hitch controller that receives a vehicle speed signal and a hand-wheel angle signal, and calculates a hitch angle command signal. The system further includes a hitch angle sensor that measures the hitch angle between the vehicle and the trailer that is compared to the hitch angle command signal to generate a hitch angle error signal. A PID control unit receives the hitch angle error signal, and generates a corrected road wheel angle signal based on proportional and derivative gains. The corrected road wheel angle signal is used to generate a motor angle signal that is applied to a steering actuator to be combined with the steering angle signal to generate the front wheel steering signal during a back-up maneuver.
摘要:
There is disclosed a method for integrating a vehicle stability enhancement system and rear wheel steering. The method includes inputting a vehicle speed and measured vehicle yaw rates. Determining a front and rear wheel steer angle. Calculating a desired yaw rate. Comparing the measured yaw rate with the desired yaw rate to determine a yaw error term. Applying a braking force to a wheel of a vehicle imparting a yaw moment based upon the magnitude of the error term calculated. The rear wheel steer angle is taken into account in calculating a desired yaw rate.
摘要:
A method is disclosed for controlling the rear wheel angle in a four-wheel steering vehicle such as a pickup truck. The front wheels are steered using the conventional operator handwheel linked to the front wheels. The rear wheels are actuated with a reversible electric motor and the rear wheel angle controlled using a computer with inputs of vehicle velocity, operator handwheel position and correlated front wheel angle, and handwheel turning rate. Control of rear wheel angle starts with a correlation of ratios of rear wheel angle to front wheel angle, R/F, vs. vehicle velocity suitable, determined under steady state front steering angle and velocity conditions, to maximize the contribution of the rear wheels while avoiding side-slip of the vehicle. It is found that driver steering feel and vehicle maneuverability is improved by imposing a minimum front wheel angle requirement before rear wheel steering is permitted and by modifying the current value of R/F with gain factors base d on the hand wheel angle and rate of motion.
摘要:
A method to assist steering of a vehicle equipped with an active steering system when operating in a reverse direction is provided. The method comprises monitoring vehicle operating characteristics and an operator steering input. Boundaries of a target region and a reference point are determined. A target steering angle range is calculated based upon the reference point and the target location. A controlled steering angle of the active steering system is corrected when the operator steering input is outside the target steering angle range. An aspect of the invention included determining the reference point comprising a point of intersection of a first vector and a second vector, the first vector parallel to and passing through a centerline of a rear axle of the vehicle and the second vector perpendicular to and passing through a centerline of an inside front steerable wheel of the vehicle.
摘要:
A controller (32) for a vehicular system (10) that includes a hand-wheel (16) and an electric motor (34) includes a torque-assist function (56) responsive to a signal representing the torque applied to the hand-wheel (16) for providing a torque-assist command to the motor (34), and a steering-pull compensator (52) responsive to a signal representing a valid ignition cycle for modifying the torque-assist command to the motor (34) by an offset corresponding to a detected steering-pull condition; where the method of control includes receiving the signal indicative of the torque applied to the hand-wheel (16), providing a torque-assist command to the motor (34) in response to the received torque signal, detecting an enabling signal related to the signal representing a valid ignition cycle, quantifying a steering-pull condition in response to the received and detected signals, and modifying the torque-assist command to the motor (34) by an offset corresponding to the quantified steering-pull condition.
摘要:
A vehicle stability enhancement system for a vehicle having at least one vehicle subsystem includes at least one sensor for sensing at least one vehicle parameter, at least one vehicle control system for adjusting the at least one vehicle subsystem wherein the at least one vehicle control system includes a rear wheel steering control system, at least one memory including at least one set of gain factors, and a controller responsive to the at least one sensor and the at least one set of gain factors for controlling the at least one vehicle control system.