Other

Gm Global Technolgoy Operations, Inc.

Delphi Technologies, Inc.

William Chin-Woei Lin

Yuen-Kwok Chin

Weiwen Deng

Youssef A Ghoneim

David M Sidlosky

David S Rule

Ashok Chandy

Yong Han Lee

Mark Philip Colosky

Hsien Heng Chen

Kathryn L Pattok

Sanket S Amberkar

Xiao He

Scott P Sherman

Paul A Grougan

Eugene A Rodden

Yixin Chen

Ke Ding

A road slope estimation system providing road grade information for vehicle automatic parking assist system includes synchronized filters for processing vehicle speed differentiation to obtain vehicle acceleration to be compared with chassis accelerometer signal. Road grade information is extracted based on the comparison of the two signals. The system includes a dynamic compensator module to minimize the chassis accelerometer signal disturbance caused by chassis dynamic response to vehicle motion. The system further includes a predictive filter to obtain the steady-state filter result during the filter transient stage.

Road slope estimation system for automatic parking assist

An electric drive system includes a motor output shaft rotating on a motor axis and a first electric motor. The system includes an epicyclical gear that includes a sun gear, a ring gear, a plurality of planet gears and a carrier. The sun gear, the ring gear and the carrier gear of the epicyclical gear all rotate on the motor axis, and the carrier gear is connected to the motor output shaft via a first flange. The system also includes a second electric motor interposed between the first electric motor and the epicyclical gear. The second motor shaft has a hollow center along the motor axis and the first motor shaft extends through the hollow center of the second motor shaft and is connected to the sun gear. The system also includes a second flange. The second flange connects the second motor shaft to the carrier. The first flange and the second flange are located at opposite sides of the epicyclical gear.

High efficiency electric motor drive system

A controller () for a vehicular system () that includes a hand-wheel () and an electric motor () includes a torque-assist function () responsive to a signal representing the torque applied to the hand-wheel () for providing a torque-assist command to the motor (), and a steering-pull compensator () responsive to a signal representing a valid ignition cycle for modifying the torque-assist command to the motor () 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 (), providing a torque-assist command to the motor () 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 () by an offset corresponding to the quantified steering-pull condition.

Robust steering-pull torque compensation

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.

Rear wheel steering control

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.

Integration of rear wheel steering with vehicle stability enhancement system

A method is disclosed for controlling a backing maneuver of an automotive vehicle and trailer combination in which the vehicle has operator-actuated front wheel steering and microprocessor-actuated, reversible electric motor driven rear wheel steering. For a given initial alignment of vehicle and trailer, the computer-executed method first determines whether the driver needs to pull forward before commencing the backing operation. The driver is then requested to turn the front wheels in a direction suitable for backing the vehicle without a trailer in the desired direction. The process then determines whether the driver needs to perform counter front wheel steering before backing. Then the process controls the steering of the rear wheels during the backing operation.

Vehicle-trailer backing-up control system with vehicle rear wheel steering

An improved vehicle yaw control that does not require a yaw sensor, wherein the validity of an estimate of vehicle yaw is determined and used to select an appropriate control methodology. The vehicle yaw is estimated based on the measured speeds of the un-driven wheels of the vehicle, and various other conditions are utilized to determine if the estimated yaw rate is valid for control purposes. When it is determined that the estimated yaw rate is valid, a closed-loop yaw rate feedback control strategy is employed, whereas in conditions under which it is determined that the estimated yaw rate is not valid, a different control strategy, such as an open-loop feed-forward control of vehicle yaw, is employed. The validity of the estimated yaw rate is judged based on a logical analysis of the measured wheel speed information, braking information, and steering wheel angle. The measured speeds of the un-driven wheels are used to compute an average un-driven wheel speed and an average un-driven wheel acceleration. The operator steering angle and the vehicle velocity are used to determine a desired yaw rate, which is compared to the yaw estimate to find a yaw rate error. Based on these variables, the control reliably determines whether the estimated yaw rate is valid, and selects an appropriate control methodology in accordance with the determination.

Vehicle yaw control based on yaw rate estimate

An improved closed-loop vehicle yaw control in which a yaw rate limit based on measured lateral acceleration is used during transient steering maneuvers to dynamically limit a desired yaw rate derived from driver steering input. A preliminary yaw rate limit is computed based on the measured lateral acceleration, and a dynamic yaw rate limit having a proper phase relationship with the desired yaw rate is developed based on the relative magnitudes of the desired yaw rate and the preliminary yaw rate limit. A two-stage process is used to develop the dynamic yaw rate limit. A first stage yaw rate limit is determined according the lower in magnitude of the desired yaw rate and the preliminary yaw rate limit, and a second stage yaw rate limit (i.e., the dynamic yaw rate limit) is determined according to the relative magnitudes of (1) the desired yaw rate and the second stage yaw rate limit, and (2) the first stage yaw rate limit and the second stage yaw rate limit. The desired yaw rate, as limited by the dynamic yaw rate limit, is then combined with the actual or estimated yaw rate to form a yaw rate error, which in turn, is used to develop a yaw rate control command for the vehicle.

Vehicle yaw rate control with yaw rate command limiting

An apparatus provides improved vehicle handling during turning maneuvers by providing control of vehicle understeer. The understeer control includes determining a desired turning radius for the vehicle, a corresponding ideal outer to inner wheel speed ratio. A closed loop torque command is determined in proportion to the difference between the ideal wheel speed ratio and the actual wheel speed ratio. The closed loop torque command is used in conjunction with an open loop torque command responsive to operator power demand to provide wheel speed control in a manner to maintain the desired vehicle understeer characteristics.

Growing community of inventors

Troy, MI, United States of America

William Chin-Woei Lin