The invention relates to a steer-by-wire steering system for a vehicle, comprising a steering wheel unit, a wheel unit, and a communication link between the steering wheel unit and the wheel unit, wherein the steering wheel unit has a steering wheel angle sensor for capturing a steering wheel angle of a steering wheel, a steering wheel actuator for setting a steering wheel target torque on the steering wheel, and a steering wheel controller for actuating the steering wheel actuator, and wherein the wheel unit has a steering sensor for capturing at least one actual steering value, at least one wheel actuator for setting a target steering value, and a wheel controller for actuating the wheel actuator, wherein the wheel controller is furthermore designed to calculate a virtual torsion rod torque based on the target steering value and the actual steering value, and to actuate the wheel actuator based on the calculated virtual torsion rod torque and to transfer the calculated virtual torsion rod torque to the steering wheel unit, wherein the steering wheel controller is furthermore designed to calculate the steering wheel target torque based on the transferred virtual torsion rod torque. Moreover, the invention relates to a method for operating a steer-by-wire steering system.

The vehicle control system is applied as a system of a vehicle mounted with an EPS device having an electric motor driven to control the steering angle. The vehicle control system includes a controller configured to perform steering control for controlling an energization of the electric motor to control the steering angle of the wheels. When the wheels are held after being steered by a specific steering in the steering control, the controller performs a steering return process in which the wheels are turned back and held in a direction opposite to a steering direction of the specific steering. And during a stationary steering-holding in which the steering angle is held and the vehicle is stopped, the controller performs an energization suppression process for reducing energization to the electric motor to be smaller than the energization before the stationary steering-holding.

A system includes a computer programmed to specify, while a vehicle is turning, a feedback torque based on a steering torque applied to a steering rack and a difference between a desired angle and an actual angle of vehicle steerable wheels. The computer is further programmed to actuate feedback torque to a vehicle steering wheel.

Assist torque or reaction force torque with little unnatural feeling to a driver is applied. An ECU includes: a control amount calculation section that calculates a control amount for controlling magnitude of the assist torque or the reaction force torque with reference to steering torque applied to a steering member; and a control amount correction section that corrects the control amount calculated by the control amount calculation section with reference to a lateral G of a vehicle body, a steering angle of the steering member, and a steering angle speed of the steering member.

[Problem]

An object of the present invention is to provide an electric power steering apparatus that enables suppression of a high-frequency vibration and enhancement of followability of a motor angular velocity to a motor velocity command by using a velocity control section (for example, PI-control, PID-control) and adding a motor current compensation value to a motor current command value on the basis of a steering state signal, even when a gain of the velocity control section is made large.

[Means for Solving the Problem]

A steering angle control section comprises a position control section that outputs a motor velocity command value based on a first steering state signal and a target steering angle, a velocity control section that outputs a second motor current command value based on the motor velocity command value and a second steering state signal, a stabilization compensating section that outputs a third motor current command value based on a third steering state signal, and a first adding section that inputs the second motor current command value and the third motor current command value, and outputs a first addition value, and outputs a first motor current command value based on the first addition value.

A motor electric control unit (ECU) for an electromechanical power steering mechanism, which controls current through an electric assist motor in response to sensed vehicle signals, wherein the ECU comprises an application specific integrated circuit (ASIC) design, that implements safety and platform features in hardware.

A steering device for a motor vehicle is described, the steering device comprising a steering element for steering the motor vehicle, and an actuating element by means of which wheels of the motor vehicle are adjusted as a function of an actuation of the steering element. The steering element has a steering assist unit associated with it, in particular an electronic steering assist unit for active return of the steering element, the steering assist unit comprising a motor and an open- and closed-loop control unit which drives the motor for generating an assist torque. The open- and closed-loop control unit receives data from a first sensor which directly senses the position of the actuating element, and drives the motor as a function of the position of the actuating element. Further described is a method of controlling a steering device.

A vehicle steering device includes a steering wheel, an input shaft, an output shaft coupled to the input shaft via a torsion bar, an electric motor, a torque detector that detects a torsion bar torque applied to the torsion bar, a rotational angle detector that detects a rotational angle of the electric motor, and a microcomputer. The microcomputer is configured to estimate a driver torque applied to the steering wheel using at least (i) the torsion bar torque detected by the torque detector, (ii) the rotational angle of the electric motor detected by the rotational angle detector, and (iii) a physical model that is constructed with a torsion bar viscosity and a torsion bar rigidity, and determine whether the steering wheel is operated in a hands-on state or a hands-off state based on the estimated driver torque.

An apparatus and a method for controlling a vehicle steering system, which are capable of improving a sense of unity between driver's driving input and vehicle motion and the stability of the vehicle by estimating a side slip angle and performing return control, may include an assist torque determination module for determining assist torque for steering assist, a return control module for determining steering return torque for returning the steering wheel to a neutral position, a side slip angle estimation module for estimating a side slip angle, a side slip control module for determining a return control gain value in a response to the estimated side slip angle, a correction unit of correcting the determined steering return torque in a response to the return control gain value, and a torque compensation unit of determining final assist torque by compensating the determined assist torque with the corrected steering return torque.

The microcomputer included in the steering control unit calculates a basic assist component that is a component of the assist force, on the basis of the steering torque. The microcomputer calculates a damping compensation component that suppresses a sudden change in a rotation angle, on the basis of a rotational angular velocity that is a time rate of change of the rotation angle. The microcomputer calculates, independently of the damping compensation component, a return compensation component that suppresses influence of the damping compensation component, on the basis of the rotational angular velocity. The microcomputer compensates the basic assist component by using both the damping compensation component and the return compensation component, in a situation where the steering wheel comes back to the neutral position without a steering operation that a driver performs to return the steering wheel.