Jtekt Europe

Sébastien Bourdrez

Pascal Moulaire

Christophe Ravier

Romaric Pregniard

Tahar Slama

Nicolas Baudouin

Serge Gaudin

Alain Guilemond

Kazusa Yamamoto

Loïc Bastien

Pierre Dupraz

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 estimates a track rod force which is exerted, in a power steering system with which a vehicle is equipped, on a track rod belonging to a steering mechanism which connects an actuator to a steered wheel which is orientable in the yaw direction and which bears a tyre of which the tread is in contact with the ground, the value of the estimated track rod force being corrected as a function of the longitudinal speed of the vehicle by a force component that models the release of the elastic torsion of the tyre so as to reduce, the estimated track rod force according to the longitudinal speed of the vehicle, when the vehicle transitions from a park situation in which the longitudinal speed of the vehicle is zero to a drive situation in which the longitudinal speed of the vehicle is non-zero.

Method for determining the track rod force modeling the torsional elastic release of the tyre in order to manage transitions between park and drive

A method for estimating the ageing of a steering mechanism during which the ageing of the steering mechanism is assessed by calculating a value called &#xab;ageing value&#xbb; according to an ageing function (old, old2, ene) which corresponds to the integral, over time, of an expression which is weighted by a stress indicator (T(u), T(u)) the value of which at each considered instant (u) is representative of the intensity of a stress force (T, T), such as the operating force exerted by the assist motor, which is undergone by the steering mechanism at the considered instant.

Estimation of the ageing of a power steering

The invention concerns a method for detecting a transition (') in a noisy signal, which involves submitting a noisy signal (&#x3b4;Signal) carrying an item of information used for managing the power steering, said method comprising a derivation sub-step (a), which involves evaluating the time derivative of the noisy signal (&#x3b4;Signal/&#x3b4;t), following by a selective filtering sub-step (a) which involves comparing said time derivative of the noisy signal (&#x3b4;Signal/&#x3b4;t) with a predefined variation threshold (S) in order to detect the appearance of a derivative peak (), greater than said variation threshold (Spic), evaluating the holding time (dpic) of said derivative peak, during which the time derivative of the noisy signal (&#x3b4;Signal/&#x3b4;t) is held above said variation threshold (Spic), and checking if said peak holding time (Spic) reaches or exceeds a predefined minimum time threshold (d).

Filtering method for the detection of the transitions of a power steering signal

A method for managing a power steering system, including a step (a) of detecting a reversal in the steering direction which involves acquiring a signal, referred to as a 'motor torque signal' (C), representative of the assistance force (C) delivered by the power steering motor, then evaluating the time derivative (&#x3b4;C/&#x3b4;t) of the motor torque signal, then comparing the time derivative of the motor torque signal to a predefined variation threshold (S) in order to detect a derivative peak, greater than the variation threshold (S), that indicates a reversal in the steering direction. The method next includes a friction evaluation step (b) which involves evaluating the friction from the drop, during the reversal in the steering direction, in a so-called 'actuation force signal' (C), which is representative of the total actuation force exerted together on the power steering by the driver and by the power steering motor.

Detection method of a steering reversal by monitoring of the torque provided by a steering assist motor and application of said method for evaluating the friction

The present invention concerns a method for determining the position of a movable steering member () belonging to a steering mechanism () of a vehicle that comprises at least a first movable member (), such as a shaft () of an assistance motor (M), and a second movable member (), such as a rack (), which cooperate with each other by means of at least one first link (L), said method comprising a step (a) that involves measuring the position (&#x3b8;) of the first member (), then a step (b) that involves calculating the instantaneous position (&#x3b8;) of the second member () from said position of the first member (&#x3b8;), and a correction step (d) during which the calculation of the position (&#x3b8;) of the second member () is adapted, taking into consideration the offset (&#x3b4;&#x3b8;&#x3c5;) in the position of the second member () that results from the elastic deformation of the first link (L) under the force (C) transmitted by the latter.

Method for calculating, in real time, the absolute position of a power steering member with improved accuracy

A method for evaluating the frictions in a power steering mechanism, the method including a step of acquiring a series of characterization points, during which are measured, for several different values taken successively by the assistance force during the operation of the steering mechanism, the corresponding friction values, so as to empirically obtain a series of distinct characterization points each associating a measured friction value to a measured value representative of the assistance force, then a step of constructing an empirical friction model, during which a correlation law is established between the characterization points constitutive of the series of characterization points, from the scatter chart formed by the series of the characterization points.

Modelling of frictions in a power steering system using a scatter of points

A method determines a link force within a power-steering mechanism of a vehicle, the method including a step (a) of determining an actuation force, which involves determining the actuation force that results from the assistance force exerted by the assistance motor and the driver force exerted by the driver of the vehicle on the steering mechanism; a step (b) of assessing dry friction; and a step (c) of calculating the link force, which has a summation sub-step which involves calculating an expression representing the link force, which uses the algebraic sum of the actuation force and the dry friction force, and a filtering sub-step which involves applying a low-pass filter in order to smooth the result of the expression when the expression is calculated upon a steering reversal of the steering mechanism.

Growing community of inventors

Yzeron, France

Sébastien Bourdrez