Vehicle steering apparatus
AssigneeJtekt Corporation
InventorsHiroaki KATO, Satoru MIKAMO
Life of this patent
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Abstract
A vehicle steering apparatus 1 includes a variable gear ratio actuator 7, an IFS ECU 8, which controls the actuator 7, an EPS actuator 17, and an EPS ECU 18, which controls the EPS actuator 17. The variable gear ratio actuator 7 varies the transmission ratio between a steering wheel and steered wheels. The EPS actuator 17 applies an assist force that assists a steering operation. A microcomputer 43 of the EPS actuator 17 increases an inertia compensation current command Iti* (Iti**), which is a compensation component based on the differential value of a steering torque, during actuation of the variable gear ratio actuator 7, that is, when an ACT angle θta is changed.
Claims9
A vehicle steering apparatus for changing an angle of a steered wheel of a steering system of a vehicle in accordance with operation of a steering wheel by a driver, the vehicle steering apparatus comprising:
- a variable transmission ratio device including a motor, the variable transmission ratio device changing the transmission ratio between the steering wheel and the steered wheel by superimposing a first steering angle of the steered wheel based on a turning angle of the steering wheel, on a second steering angle of the steered wheel based on activation of the motor;
- a steering force assist device for applying an assist force that assists steering operation to the steering system;
- and
- control means, which controls actuation of the steering force assist device,
- wherein the control means calculates a basic assist component for controlling the steering force assist device, calculates a compensation component based on a differential value of a steering torque generated in the steering system, and computes a target assist force for controlling the steering force assist device by superimposing the basic assist component and the compensation component on each other, and
- wherein the control means increases the compensation component based on the differential value of the steering torque when the variable transmission ratio device is being actuated.
Dependencies are inferred from the claim text.