Electric power steering apparatus
AssigneeJtekt Corporation
InventorAkihiko Nishimura
Life of this patent
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Abstract
A microcomputer is provided with an extracting section capable of extracting a specific frequency component from an input signal. The extracting section extracts, from a pinion angle corresponding to a signal indicating the state of a steering system, a frequency component corresponding to a vibration that increases generation of a rattling noise in a speed reducing mechanism. The extracting section outputs an effective value of the extracted frequency component as a power spectrum. If the power spectrum output from the extracting section is equal to or more than a predetermined threshold value, the microcomputer outputs a motor control signal to reduce the assist force generated by the EPS actuator.
Claims21
An electric power steering apparatus applied to a steering system that transmits a steering operation of a driver to a steerable wheel, the apparatus comprising:
- a steering force assist device provided with a motor as a driving source, the steering force assist device applying an assist force for assisting the steering operation to the steering system by rotating a steering shaft that couples a steering wheel operated by the driver to the steerable wheel using the motor;
- control means controlling actuation of the steering force assist device by feeding a driving power to the motor;
- and
- a speed reducing mechanism provided with first and second gears meshed with each other,
- wherein the motor is drivingly coupled to the steering shaft via the speed reducing mechanism, and
- wherein the control means controls the actuation of the steering force assist device to suppress rattling noise generated in the meshed part of the first and second gears based on a frequency analysis of a vibration generated in the steering system.
Dependencies are inferred from the claim text.