A vehicle power steering system comprises first actuator 14 engaged with a steering rack 34 and a second actuator 16 engaged with a steering column 22, and an operation mode of each is determined. The operation mode of an actuator 14, 16 is adjusted upon detecting a failure in the other actuator 16, 14, so that at least one of rack 34 and column 22 is actuated based on the operation mode. In an angle control mode, a predetermined steering angle is provided to actuators 14, 16 to adjust rack 34 according to the steering angle. In a torque control mode, a steering column torque from a torsion sensor disposed on column 22 is provided to actuators 14 16 to adjust rack 34 according to the steering column torque. Suitably, the torque control mode may be used if first actuator 14 fails, and the angle control mode may be used if second actuator 16 is used or if the steering is operated in a fully autonomous mode.
Enhanced steering operation
2018-03-14
Patent
Electronic Resource
English
IPC: | B62D MOTOR VEHICLES , Motorfahrzeuge |