Jtekt Europe

Alain Guilemond

Nicolas Baudouin

Pascal Moulaire

Tahar Slama

Sébastien Bourdrez

Romain Moretti

A method for estimating a value for friction exerted on a power steering system of a vehicle, during turning resulting in the crossing of a straight line angle, the turning being achieved at a substantially uniform speed included within a predefined range, and an angle of a steering wheel included within a predefined range, including: a step (1) of acquiring a plurality of vehicle-related data items, including at least one value of a force of a power steering motor on a rack and pinion, and a value of a force of the steering wheel on the rack and pinion; a step (4) of estimating the value for friction by averaging the sum of the forces of the steering wheel and the forces of the power steering motor on the rack and pinion.

Method for estimating a value for friction

A method in which a continuous estimation of the intermediate friction rate is carried out, allowing the integration of the method into a general friction compensation method so as to continuously improve the feel on the steering wheel, particularly for speeds below a determined threshold. Also, a method for friction compensation in an electrical power steering system, characterised in that the compensation method takes into account a continuous estimation of the intermediate friction rate obtained by the estimation method.

Method for friction compensation in a power steering system and associated estimation method

A method for controlling a steering system having an electric assistance motor in view of reducing shocks against end-of-travel stop, the method including getting a distance information of the rack with respect to the end of travel stop, getting an actual rotation speed information of the steering wheel, identifying a maximum allowed acceleration for the steering wheel, the maximum allowed acceleration being such that, in view of the distance information and the actual rotation speed information, the rotation speed of the steering wheel can decrease pursuant to a target deceleration value of a target deceleration profile so as to be lower than a required maximal speed when arriving at the end-of-travel stop, determining a maximum power assistance torque from the maximum allowed acceleration for controlling the power assistance torque applied to the assistance motor so as to target the deceleration value or profile of the rotation of the steering wheel.

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Marennes, France

Alain Guilemond