Nissan Motor Company Limited

Yu Wun Chai

Kazuhiro Igarashi

Takaaki Eguchi

Yukinobu Matsushita

Taku Suzuki

A control computing unit allocates the current axial force and the transverse-G axial force at the predetermined allocation ratio to calculate a feedback axial force which is the steering-rack axial force. Then, the control computing unit drives the reaction force motor on the basis of the calculated feedback axial force. Additionally, the allocation ratio of the transverse-G axial force is set to be greater than the allocation ratio of the current axial force.

Steering control apparatus and steering control method

A control computing unit blends a feedforward axial force and a feedback axial force at an allocation ratio, based on an axial force difference, a lateral acceleration, a vehicle velocity, a steering angle, and a steering angular velocity so as to set a final axial force. Then, the control computing unit applies a steering reaction force based on the final axial force that has been set.

Steering control device

A vehicle steering control device and a vehicle steering control method achieve an ideal steering feeling. A turning controller is configured to set as a target turning angle of a turning wheel an addition value obtained by adding a steady steer control amount that is a control amount depending on a steering angle and a differential steer control amount that is a control amount depending on a steering angular velocity. In this situation, when a driver is increasingly turning a steering wheel, the differential steer control amount is computed to be smaller than the differential steer control amount when the driver is not increasingly turning the steering wheel. Accordingly, the phase of the turning angle with respect to the steering angle in the steering returning operation can be delayed as compared to the phase in the steering increasing operation.

Vehicle steering control device and vehicle steering control method

A control computing unit calculates current axial force of a steering rack based on a turning current. Moreover, the control computing unit calculates lateral axial force of the steering rack based on a lateral acceleration. Then, the control computing unit calculates steering reaction force based on the current axial force at a time of a steering increasing operation of a steering wheel, and calculates the steering reaction force based on the current axial force and the lateral axial force at a time of a steering returning operation of the steering wheel.

A control computing unit allocates a feedback axial force and a feedforward axial force at an allocation ratio based on an axial force difference which is a difference between the feedback axial force and the feedforward axial force to set a final axial force as a steering-rack axial force. The control computing unit drives a reaction force motor on the basis of the set final axial force.

A vehicle steering controller produces a steering system friction value and a tire lateral force value. A steering reactive force having a magnitude based on the tire lateral force value and the steering system friction value is generated for application to a steering wheel of the vehicle. By reflecting both the tire lateral force and the steering system friction in the steering reactive force, a good steering sensation can be realized in a steer-by-wire system.

Growing community of inventors

Isehara, Japan

Yu Wun Chai