Jtekt Europe

Andre Michelis

Pierre Pilaz

Julien Barthomeuf

Pascal Moulaire

Christophe Ravier

Stephane Cassar

Serge Gaudin

Jocelyn Delarche

Guillaume Lengrais

Francois Gassmann

The invention relates to a method to assist with turning a vehicle power assisted steering wheel, during which method a return setpoint (final return setpoint) quantifying a return force intended to be applied to said steering wheel in order to assist with returning said steering wheel to a predetermined central position is formulated, said method involving at least one step (a) of determining longitudinal acceleration during which step the instantaneous longitudinal acceleration of the vehicle is evaluated, followed by a step (b) of adapting the return setpoint during which step the steering wheel return setpoint is adjusted according to said instantaneous longitudinal acceleration so as to increase the intensity of the return force if said longitudinal acceleration increases, and thus notably compensate for the lessening of the natural centring effect that is caused by the lightening of the steering under acceleration conditions.

Method for centering the steering wheel of a motor vehicle power-assisted steering

The invention relates to a power steering system in which the set value for torque or force at the steering wheel is predetermined on the basis of various parameters and information so as to provide the most driving comfort in all conditions of driving the vehicle. The torque or force set value is predetermined on the basis of the sideways acceleration of the vehicle, the acceleration in turn being predetermined mainly from an estimate of the force exerted on the rack, and preferably also predetermined by other methods, with the estimate being weighted among all of the obtained values. Said method is particularly useful for vehicles provided with electrical power steering.

Method for determining a torque set value for a steering wheel for a power steering system of a motor vehicle

The invention relates to a method for calculating the understeering ratio of automobiles provided with electric power steering (EPS) including an electric assistance motor () driven by an onboard electronic computer (), a sensor () providing a first piece of information on a real angular position of the steering wheel (), a wheel anti-lock braking system (ABS) providing a second piece of information on the speed of the wheels () of the vehicle, characterised in that the onboard computer () of the EPS processes the second piece of information for estimating a theoretical angular position of the steering wheel (), which is further compared to the real angular position of the steering wheel () in order to derive the understeering ratio (&#x3c4;) of the vehicle.

Method for determining the understeering ratio of a vehicle provided with electric power steering and for optionally correcting the power steering

A method for securing the assistance torque () supplied by an electric assistance motor () in a motor vehicle power steering system includes the steps of: estimating the force on the steering system rack from the torque exerted by the driver on the steering wheel (), from the assistance torque (), and optionally from other parameters such as the speed of the electric assistance motor; comparing a target assistance torque with an authorized assistance range, defined with respect to the estimated rack force () at any moment, and in the event the target assistance torque is maintained above predefined limits for a predefined duration, correcting and optionally interrupting the power steering.

Securing the assistance torque by means of an estimator of the force on the rack

The method consists in: determining in which actually sector the booster motor is located, a sector of the booster motor being defied by two successive poles; determining a relative angle position of the steering wheel in relation to the booster motor; identifying a sector, known as neutral, in which the booster motor is located when the rotation speeds of the rear wheels, i.e. right and left of the vehicle, are equal; determining an angle offset of the steering wheel corresponding to a neutral angle position of the steering wheel; determining an absolute angle position of the steering wheel which is equal to the difference between the relative angle position of the steering wheel and the offset angle thereof.

Growing community of inventors

Grigny, France

Andre Michelis