Jtekt Europe

Nicolas Baudouin

Pascal Moulaire

Alain Guilemond

Tahar Slama

Pierre Larminy

Sébastien Bourdrez

Serge Gaudin

Dimitri Barthes

Arnaud Thiery

Method for compensating for a friction between at least two parts, the method being based on a friction model (M), a speed (v) between at least one part and at least one other part of the at least two parts, the speed being measured, or estimated from a measurement, the speed (v) being input data of the model (M), the model (M) being based on an internal state (z) of friction, a time derivative (ż) of the internal state (z) being a function of said internal state and of the speed (v) and of a first gain (σ), the method comprising a step of saturation of the speed v at the input of the friction model, so that an absolute value |v| of the speed (v) remains lower than a saturation value, the saturation value being a function of the speed, of the first gain and of a second gain.

Method for compensating for friction in a power steering system

A method for estimating a value of a friction force exerted on a part of a power steering system of a vehicle, the part of the power steering system including at least one motor exerting a motor torque, the value of the friction force making it possible to modify the motor torque, by means of a mathematical model.

Method for estimating a value of a friction force exerted on a part of a power steering system by means of a mathematical model

Method for determining a friction to be adjusted in a power steering system or for modifying a hysteresis of a steering wheel torque applied to a steering wheel of the power steering system, the method including the following steps of: determining a speed, from a measurement of a speed of a part of the power steering system and/or a measurement of the steering wheel torque; determining the friction to be adjusted on the basis of a modified LuGre model, said modified LuGre model determining the friction to be adjusted as a function of a state of the system, a time derivative of the state being determined as a function of said state of the system, the speed, a first gain, and a coulomb friction, according to an equation of the form:

Method for estimating and adjusting friction to be adjusted, and controlling hysteresis of a steering wheel torque, and corresponding power steering system

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 managing a power steering system assist motor, includes defining, over the functional length of the actuator member, at least one reduced assist area separate from a normal assist area by an end-of-travel virtual threshold, a step of assessing an instantaneous position and a direction of the movement of the actuator member on the functional length, a step of applying an input resistance set point value to the assist motor when the actuator member crosses the end-of-travel virtual threshold in such a way as to move from the normal assist area into the reduced assist area. After the step of applying an input resistance set point value, an output resistance set point value is applied when the actuator member is in the reduced assist area and the direction of the movement of the actuator member is directed from the reduced assist area towards the normal assist area.

Differentiation of a resisting torque according to direction of movement of a steering rack for improving feel of driver at the approach to an end-of-travel virtual stop

Growing community of inventors

Lyons, France

Nicolas Baudouin