System And Method For Reducing Steering Wheel Vibration In Electronic Power Steering Systems

Abstract

Methods and apparatus are provided for reducing steering wheel vibrations in electronic power steering systems. The apparatus includes a processor and performs a method that estimates an average angular wheel speed of at least one wheel of the vehicle; determines an average wheel angle from the average angular wheel speed; generates sine and cosine functions of the average angular wheel angle; processes the sine and cosine functions with a steering wheel torque signal received from a torque sensor to extract amplitude components of at least one of the sine and cosine functions; reconstructs the sine and cosine functions using the steering wheel torque signal; combines the sine and cosine functions to provide a control signal, and controls the EPS system via the control signal to attenuate smooth road shake vibrations in a steering wheel of the vehicle.

Description

technical field

[0001] The technical field relates generally to electric power steering (EPS) systems, and more particularly, to techniques for reducing periodic steering wheel vibrations that occur in EPS systems. Background technique

[0002] Electric power steering (EPS) systems use an electric motor that can be coupled directly to a steering gear or steering column to reduce driver effort in steering the vehicle. During vehicle operation, the driver applies force to the steering wheel in an effort to steer the vehicle. This results in "driver torque" being applied to the shaft coupled to the steering wheel. The torque sensor detects the torque applied to the steering column by the driver and transmits this information to the electronic control unit. The electronic control unit generates motor control signals that are applied to the electric motor, causing the electric motor to produce "motor assist torque" that is combined with driver torque. This combined torque is t...

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