Toyoda Koki Kabushiki Kaisha

Jtekt Corporation

Hiroshi Kuroyanagi

Shoji Asai

Toshihiro Takahashi

Shoji Ogawa

Shinji Takeuchi

Eiichi Ono

Yoshiyuki Shibata

Minekazu Momiyama

In a steer-by-wire system, a first steering reaction force made-up value (Hc) is determined in dependence on a road reaction force (W), and a second steering reaction force made-up value (Hc) is determined in dependence on a steering position (X) of a steering handleor steerable wheels. A steering reaction force command value (H) is generated from both of the first steering reaction force made-up value (Hc) and the second steering reaction force made-up value (Hc) the weightings on which are adjusted by respective weighting gains (G, G), and the ratio of the weighting gains is properly altered in dependence on the state of a road surface. Thus, it can be realized to provide the steer-by-wire systemcapable of adjusting the steering reaction force to be sensitive or insensitive to the state of the road surface.

Steer-by-wire-system

The present invention relates to a steering control apparatus for maintaining operating characteristics which do not change from when conditions are normal and when an impairment occurs. The apparatus includes a plurality of motors for driving a steered wheel and a plurality of ECUs, each associated with one of the motors. When the steering control apparatus is operating normally, a torque command representing torque required to turn the steered wheel is generated. The torque command is divided in accordance with the number of motors. Each of the ECUs control the associated motors in accordance with a corresponding one of the distributed torques.

Vehicle steering control apparatus

A controller of a steer-by-wire steering apparatus determines whether voltage applied to a steering motor in accordance with a current command value has reached a predetermined voltage. Based on the result, the controller selects one of the value of an actual current through the steering motor and a current command value. Based on the selected current value, an axial force applied to a steering rod is estimated. Based on the estimated axial force, a counter torque motor is controlled. Therefore, An error or oscillation occurring in the estimated steering axial force is prevented, and the driver is suppressed from further turning the steering wheel when the voltage applied to the steering motor is saturated.

Vehicle steering apparatus and method for controlling the same

A steer-by-wire steering apparatus for a vehicle includes an elastic member couples a reaction force actuator to a steering wheel. With respect to the elastic member, a side closer to the steering wheel is referred to as a primary side, and a side closer to the reaction force actuator is referred to as a secondary side. A steering wheel position detector is located at the secondary side. Therefore, the apparatus is capable of giving a feel of a steering reaction force equivalent to an ordinary mechanically connected steering apparatus to an operator and secures stability of a control system.

Vehicle steering apparatus

A power steering apparatus is provided to generate an assistant force corresponding to a change of viscous friction in the steering unit or the like, without losing information on reaction force from a road surface. An external force calculation portion calculates an external force, that is, a force other than a force for steering (i.e. a steering force) among forces (action forces) acting on the steering unit of a vehicle. The external force is assumed to be composed of an outside force received from the road surface, such as an SAT (self-aligning torque), and an internal drag resulting from a viscous friction generated in the steering unit, and the like and these two forces are separated in an outside force and internal drag calculation portion. In separating these two forces, under the assumption that the outside force is a function of a side slip angle and an internal drag is a function of a steering angular velocity, and coefficients of functions are obtained. On the basis of the thus calculated internal drag, a motor control portion controls a motor so as to generate an adequate assistant force.

Growing community of inventors

Nagoya, Japan

Hiroshi Kuroyanagi