Control device for electric power steering device

Abstract

An object of the present invention is to provide a control unit for an electric power steering apparatus that constitutes a model following control that an output of a controlled object follows-up toan output of a reference model, eliminates or reduces the occurrences of a noisy sound and a shock force at an end hitting without giving any uncomfortable steering feeling, takes a safety countermeasure against the model following control and suppresses the variation of the control output in a case that the safety countermeasure is excessively operated. A control unit for an electric apparatus that calculates a current command value based on at least a steering torque and performs an assist-control of a steering system by driving a motor based on the current command value, comprising: a configuration of a model following control including a viscoelastic model as a reference model within a predetermined angle at front of a rack end, wherein shift correction is performed against displacement information which is used in the model following control; and wherein rack end hitting is suppressed by limiting a range of a control amount in the model following control by using a limit value which is set based on at least steering velocity.

Description

technical field [0001] The present invention relates to a control device for an electric power steering apparatus, which calculates a current command value based on at least a steering torque, and drives a motor by the current command value to apply assist force to a steering system of a vehicle. More particularly, the present invention relates to a control device of an electric power steering apparatus, which sets a viscoelastic model as a reference model, and reduces assist torque by limiting a current command value near the end of a rack so that the rack The momentum at the time of the end collision is attenuated and the collision energy is reduced, thereby suppressing the collision noise (abnormal sound) that makes the driver feel uncomfortable, and also improving the steering feeling. Background technique [0002] Electric Power Steering (EPS) uses the rotational force of an electric motor to impart assist force to the steering system of a vehicle, which transmits the d...

AI Technical Summary

Problems solved by technology

[0007] In such an electric power steering device, when a large assist torque is applied by the electric motor near the maximum steering angle (rack end) of the steering system, when the steering system reaches the maximum steering angle, a Large impact, and also produces impact noise (abnormal sound), so it may make the driver feel uncomfortable

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