Vehicle load monitoring for four wheel steering
AssigneeGM Global Technology Operations LLC
InventorsScott L. Williston, Kevin J. Lavigne
Life of this patent
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Abstract
Methods and apparatus are provided for automatically determining the steering system calibration of a vehicle in accordance with vehicle loading. The apparatus comprises a combination of a load monitor and a steering controller. The load monitor senses the actual loading of the vehicle and provides a corresponding feedback signal to the steering controller. The steering controller determines a steering calibration appropriate for the load represented by the feedback signal. As a result, the handling performance of the vehicle can be improved over that of a single, fixed steering calibration for a wide range of load conditions.
Claims16
A method of calibrating a four-wheel vehicle steering system based on the loading of the vehicle, comprising the steps of:
- a) receiving a vehicle load signal and a hand wheel angle;
- b) processing the vehicle load signal to establish a relationship between a rear wheel angle and a front wheel angle of the vehicle;
- c) adjusting the relationship between the rear wheel angle and the front wheel angle based upon the hand wheel angle, wherein the adjusting comprises applying a pre-determined relationship between the hand wheel angle of the vehicle and a corresponding hand wheel angle multiplier;
- and
- d) applying the adjusted relationship between the rear wheel angle and the front wheel angle to the four-wheel vehicle steering system to thereby simulate the responsiveness of two-wheel steering with the four-wheel vehicle steering system and thereby calibrate the four-wheel vehicle steering system.
A four-wheel vehicle steering system comprising:
- a load sensing device configured to generate a load feedback signal corresponding to the actual loading of the vehicle;
- and
- a steering controller configured to receive the load feedback signal from the load sensing device and to determine an appropriate four-wheel steering relationship between a rear wheel angle and a front wheel angle of the vehicle in accordance with the received load feedback signal, and to reduce the determined four-wheel steering relationship between the rear wheel angle and the front wheel angle in response to a hand wheel angle of the vehicle based upon a pre-determined relationship between the hand wheel angle of the vehicle and a corresponding hand wheel angle multiplier to thereby simulate the responsiveness of two-wheel steering with the four-wheel vehicle steering system.
A four wheel steering system for a vehicle, comprising:
- a front wheel steering mechanism;
- a load monitor configured to measure the loading of the vehicle;
- and
- a rear wheel steering system comprising a controller and a rear wheel steering device, wherein the controller is configured to select a load-related rear wheel steering calibration curve based on a measured load signal received from the load monitor and to select a hand wheel adjustment curve based upon a hand wheel angle of the vehicle, wherein the hand wheel adjustment curve provides a predetermined relationship between the hand wheel angle and a corresponding hand wheel angle multiplier, and wherein the controller is further configured to activate the rear wheel steering device in accordance with the load-related rear wheel steering calibration curve and the hand wheel angle multiplier from the hand wheel adjustment curve to thereby simulate the responsiveness of two-wheel steering with the four wheel steering system.
Dependencies are inferred from the claim text.