Patent ID: 8135516
Filing Date: 2012-03-13
Classification: B62D

Abstract:
1. A method for controlling a steering device with steering power support means for a motor vehicle with at least one steerable road wheel, wherein the steering device includes a steering shaft with a first end to adopt a steering wheel, a control device controlling said power support means, sensing means detecting steering shaft torque introduced in said steering shaft, and means to determine a hands-off situation in which the driver does not introduce a torque into said steering shaft, wherein the steering power support means support the driver on the basis of a driver demand introduced into the steering shaft, the method comprising: determining a steering wheel torque on basis of the steering shaft torque; determining a time derivative of the detected steering wheel torque; if the absolute value of the steering wheel torque is lower than a threshold torque limit and if the absolute value of the derivative of steering wheel torque is lower than a threshold derivative torque limit, increasing a counter by one count; if the absolute value of the steering wheel torque is higher or equal than a threshold torque limit, or/and if the absolute value of the derivative of steering wheel torque is higher or equal than a threshold derivative torque limit, decreasing said counter by one count; and if said counter has a value equal to or higher than a threshold count limit, determining the hands-off state.