Patent ID: 9008910
Filing Date: 2015-04-14
Classification: B62D

Abstract:
1. An electrical power-steering system for a motor vehicle, comprising: a steering-rack actuator and a sensor measuring torque applied by a driver to a steering wheel, the actuator and sensor being located on a steering column between the steering wheel and the steering rack, and between the actuator and the steering wheel respectively; an elaboration unit configured to produce a final assist torque for electrical power-steering using a transfer function representative of an identical location of the steering-rack actuator and of the torque measurement sensor on the steering column, such that at two main mechanical resonant frequencies of the system the phase of a Bode diagram representing the system operation is approximately zero, the elaboration unit includes a first filtering unit configured to filter the initial assist torque as a function of the assist gain and a second filtering unit configured to filter a measurement of the torque applied by the driver to the steering wheel; and an estimation unit configured to estimate a predetermined initial assist torque and a predetermined assist gain, depending on the measurement of the torque applied by the driver to the steering wheel.