Honda Motor Co., Ltd.

Thyssenkrupp Presta Ag

Jtekt Corporation

Hayato Miyakawa

Munetsugu Hanji

Yosuke Ojima

Péter Kakas

Yoshinobu Watanabe

Imre Szepessy

Kunimichi Hatano

Hideo Kometani

Levente Pásztor

Satoshi Nakahara

Nariaki Sakamoto

Masashi Fujimoto

Agen Nishikido

Nobuyuki Taoka

Takumitsu Otani

Kristof Polmans

Imre Benyo

Miklós Arányi

Krisztián Dömötör

Takaya Yamaguchi

Laszlo Dombai

Adela Beres

Isao Shintani

Levente PÁSZTOR

Yoshiyuki Maenaka

Kei Nakate

Yoschinobu Watanabe

Provided is a steer-by-wire steering system for a vehicle that can reduce or eliminate the impact noise generated by the rack at the rack end. A control unit of the steering system is configured to determine a target steered angle (αt) according to the steering angle and drive the steering actuator so as to cause the steered angle to coincide with the target steered angle, and to determine a target reaction force (Tt) according to a steered state of the wheels and drive the reaction force actuator so as to cause the reaction force to coincide with the target reaction force. The control unit is further configured to set a maximum limit (αmC) on the target steered angle, the maximum limit being a value smaller than a physical maximum steered angle (αmP) of the wheels imposed by the steering mechanism.

Steering system for vehicle

A method for power saving in a steering system of a motor vehicle including a road wheel actuator acting on a rack to turn steerable road wheels and a controller configured or programmed to generate an operation signal for the road wheel actuator, wherein the controller includes a position controller to generate a motor torque request based on an actual and/or a measured position of the rack and a requested rack position, includes detecting a passive mode of the steering system by a passive mode detector of the controller if the motor vehicle is stopped and no steering input is provided, and if a passive mode is detected by the passive mode detector, setting the motor torque request to zero in order to save power.

Power saving mode for steering systems of a motor vehicle

To prevent a driver from feeling uncomfortable when the driver touches a steering member in a state where a driving source is stopped, a vehicle steering system () is provided in a vehicle () that travels by a driving force generated by a driving source (). The vehicle steering system () includes; a steering member () configured to accept a steering operation; and a reaction force actuator () configured to apply a reaction force to the steering member () in response to the steering operation. In a state where the driving source () is stopped, the reaction force actuator () is configured to apply the reaction force to the steering member () based on a stopped time position that is a position of the steering member () at a time when the driving source () is stopped.

Vehicle steering system

A method to control a steer-by-wire steering system of a road vehicle including a feedback actuator, a road wheel actuator, and a controller configured or programmed to control the feedback actuator and the road wheel actuator, and the method includes, upon external request to the controller, providing a garage mode of the steer-by-wire system, switching off the feedback actuator, depending on the external request, moving to a predetermined position or moving from a first end position to a second end position of the road wheel actuator or fixing a position of the road wheel actuator at a last position or a center position, and, after the garage mode is terminated, returning the road wheel actuator to an original position before the garage mode was entered into and switching on the feedback actuator.

Method for controlling a steer-by-wire steering system of a road vehicle with garage mode

A method to control a steer-by-wire steering system for a road vehicle including a steering device, a road wheel actuator to actuate road wheels, and a controller configured or programmed to generate a motor torque request for the road wheel actuator based on an actual or an estimated position and a position request, which is based on the position of the steering device, includes detecting a road wheel actuator power limit situation, modifying the position request so that it can be followed by the road wheel actuator within power limits, and using the modified position request to generate the motor torque request for the road wheel actuator.

Steer-by-wire steering system with road wheel actuator power limit handling

A steer-by-wire steering system including a feedback actuator to simulate a steering feel to a steering device and including an electric motor connected to a steering shaft to transmit a torque, and a steering lock including a latch connected to the steering shaft in a torsion-resistant manner and a lock to engage with the latch at locking positions to block a rotation of the steering shaft. If an ignition is switched-off and a movement of the steering device is detected, a position of the steering shaft and a distance between the lock and a next locking position of the latch is determined. If the distance is greater than a predefined value, a counter-torque is transmitted to the steering shaft by the feedback-actuator opposite to the movement of the steering device until the locking position reaches the lock and the lock can engage with the latch.

Method for controlling steering locking of a steer-by-wire steering system of a motor vehicle

When the driving mode of a vehicle is switched from an automatic driving mode to a manual driving mode in response to steering of the steering wheel by a driver while the vehicle is traveling in the automatic driving mode, a control device determines whether a recognized steering angle which is the steering angle of the steering wheel recognized by the driver is near a neutral position or near a one turn position according to the grip positions on the steering wheel, and when the determined recognized steering angle differs from an actual steering angle, the control device changes a ratio between the steering angle of the steering wheel and a steered angle of a wheel such that the steered angle approaches a recognized steered angle corresponding to the recognized steering angle.

Steering device for automatic driving vehicle

A steer-by-wire type steering device includes: a steering support part fixed to a vehicle body; a steering shaft rotatably supported by the steering support part; a steering wheel fixed part fixed to the steering support part; and a steering wheel rotation part connected to the steering shaft and rotatably disposed on an outer circumference of the steering wheel fixed part, wherein the steering wheel rotation part is formed in rotational symmetry with respect to a rotation axis thereof.

Steering device

A steering device includes: a steering wheel which is rotatable over an angle range exceeding 180 degrees in each of leftward and rightward directions from a neutral position; a steering mechanism that steers a wheel according to a steering angle of the steering wheel, with a ratio of the steering angle to a steered angle being changeable; and a control device that controls the ratio of the steering mechanism. The control device sets the ratio to a first value during travel of a vehicle in the manual driving mode and sets the ratio to a second value smaller than the first value during travel of the vehicle in the automatic driving mode, wherein the second value is set such that the steering angle corresponding to a maximum steered angle of the wheel specified by the steering mechanism is less than 180 degrees.

Steering device for automatic driving vehicle and automatic driving vehicle provided with same

A rack-and-pinion steering system includes a pinion shaft having pinion teeth, a rack shaft on which rack teeth are formed which mesh with the pinion teeth; and a rack bush which supports the rack shaft slidably in an axial direction thereof. An outer circumferential surface of the rack shaft includes a first area which is a concave formed on an outer circumferential surface of the rack shaft and extending in the axial direction and a second area which is an area of the outer circumferential surface excluding the first area and lies adjacent to an end portion of the first area in the axial direction. The rack teeth are formed in the first area. A chamfered portion or a rounded portion is provided on a boundary between the end portion of the first area and the second area to chamfer or round a corner portion on the boundary.

Steering system

A rack bush for supporting a rack shaft in a rack-and-pinion steering system so that the rack shaft slides in an axial direction thereof includes a teeth side support portion and a back side support portion. Rack teeth are formed in a first area of an outer circumferential surface of the rack shaft. The teeth side support portion contacts a second area of the outer circumferential surface to support the rack shaft from a teeth side where the rack teeth are formed. The second area lies adjacent to the first area in the axial direction. The back side support portion contacts a third area of the outer circumferential surface to support the rack shaft from a back side other than the teeth side. The third area is positioned out of the first area in a circumferential direction around an axis of the rack shaft.

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Wako, Japan

Hayato Miyakawa