Patent ID: 6219604
Filing Date: 2001-04-17
Classification: B62D

Abstract:
A steer-by-wire steering system for a motorized vehicle, said vehicle including a front axle, a plurality of steerable wheels connected to said axle, an electronically controlled steering positioner, a steering gear, and a steering wheel, said system comprising:a steering wheel sensor for sensing a driver's selected direction from the steering wheel;a feedback actuator connected to the steering wheel for providing road feedback to a driver, said actuator including a steering wheel positioner and steering wheel regulator;a torque sensor and a current sensor, both said torque sensor and current sensor connected to said steering wheel regulator for determining aligning torques and aligning currents;a steering regulator connected to said steering positioner;a nominal value generator connected to said steering regulator, said steering regulator and nominal value generator modifying a driver's selected direction as a function of a moving vehicle's handling dynamics and generating a nominal value for the steering positioner, said steering regulator determining a nominal manual torque for a driver as a function of simulated aligning torques derived from one of aligning torques and aligning currents, from signals measured by said steering wheel sensor and from operational status signals of said vehicle including driving speed, the co-efficient of friction between the road and vehicle, and wherein the nominal manual torque is used as the basis of the manual torque transferred to the steering wheel through the steering wheel positioner.