Electric power steering device

Abstract

[Problem] To provide an electric power steering device that: constitutes a control system on the basis of a physical model; constitutes model-following control whereby output (distance to a rack end) of a control target follows a reference model; suppresses the occurrence of noise at end contact, without providing any unusual steering sensation to a driver; suppresses impact force; reduces unpleasant vibration; does not give a sense of discomfort to the driver; and enables smooth steering. [Solution] An electric power steering device that performs assist control of a steering system by calculating a current command value 1 on the basis of at least steering torque and driving a motor on the basis of the current command value 1, said electric power steering device: constituting model-following control having a viscoelastic model as a reference model within a prescribed angle range just before the rack end. The model-following control configuration comprises a feedback control unit. The model-following control has a noise reduction function and suppresses impact force at rack end end contact.

Description

technical field [0001] The present invention relates to an electric power steering apparatus that 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. In particular, the present invention relates to an electric power steering apparatus in which the viscoelastic model is set as a normative model, and by limiting the current command value (current command value を twist る) near the end of the rack so as to reduce the assist torque and make the end collide Momentum attenuation and reduced impact energy, thereby suppressing the impact noise (abnormal sound) that makes the driver uncomfortable and improving steering feel. Background technique [0002] Electric Power Steering (EPS) uses the rotational force of the electric motor to apply assist force to the steering system of the vehicle, which assists the steering shaft or the rack shaft by passing the drivin...

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, a large torque will be generated when the steering system reaches the maximum steering angle. Hit and produce bump noise (abnormal sound), so it may make the driver feel uncomfortable

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