Electric power steering device

Abstract

The present invention provides an electric power steering device capable of easily achieving a desired steering torque with respect to a steering angle. The electric power steering device is providedwith a torsion bar that is mounted on a column shaft of a steering wheel of a vehicle. A motor connected to the column shaft is driven on the basis of a current command value so as to assist in controlling a steering system. The electric power steering device is provided with a target steering torque generation unit that generates a target steering torque on the basis of at least one EPS / vehicle information, a conversion unit and a torsion angle control unit, wherein the conversion unit converts the target steering torque into a target torsion angle, and the torsion angle control unit calculates the current command value on the basis of the target torsion angle, the steering angle, the torsion angle of the torsion bar, and the motor angular velocity. Moreover the electric power steering device of the present invention performs control, so that the torsion angle follows the target torsion angle.

Description

technical field [0001] The present invention relates to a high-performance electric power steering device, which is controlled so that the torsion angle of the torsion bar "mounted on the column shaft (steering shaft or steering wheel shaft)" follows the steering angle. Corresponding value, so that the desired steering torque can be realized, and it will not be affected by the state of the road surface, nor will it be affected by the change of mechanism system characteristics (friction, motor output characteristics, etc.) over the years. Background technique [0002] As a device equipped with a motor control device, there is, for example, an electric power steering device (EPS). The electric power steering device uses the rotational force of the electric motor to impart assist force (steering assist force) to the steering system of the vehicle, which transmits the driving force of the electric motor controlled by the electric power supplied by the inverter through the transm...

AI Technical Summary

Problems solved by technology

However, in this method, "steering torque sometimes varies depending on the steering angle" due to different road surface conditions (for example, different road surface inclinations)

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