US 6,995,679 B2 · Electronically controlled power steering system for vehicle and method and system for motor control

Abstract

A power steering device capable of obtaining a high rotary speed in the medium low torque range of an electric motor without incurring a drastic increase in manufacturing cost. The power steering device generates an auxiliary steering power by oil pressure that is generated by a pump which is driven by an electric power motor. The electric motor is a triple-phase brushless motor, with its angle of rotation being detected by the Hall sensors. The field coils are provided with the electric current from a drive circuit which is driven by a drive signal from the motor drive control part. The motor drive control part controls the electric motor by PWM control in the low medium speed rotation range and controls the electric motor by phase advance angle control, with PWM duty at 100 percent, in the medium high speed range.

Claims15

Dependent claims

A steering device for generating auxiliary steering power by means of an oil pressure generated by a pump that is driven by an electric motor, the electric motor having a conduction angle during which electrical power is provided to at least one motor phase, the steering device comprising:

a rotary angle detector that detects the rotary angle of the rotor of said electric motor,
a steering angular speed sensor for detecting a steering angular speed of a steering operating member,
a drive target value setting device that sets a drive target value of said electric motor based on an output of the steering angular speed sensor,
a drive signal generator that generates a drive signal for driving said electric motor on the basis of the drive target value which is set by the drive target value setting device, and
an angle setting device that sets a phase advance angle of said drive signal with respect to the rotary angle that is detected by said rotary angle detector in relation to the drive target value which is set by said drive target value setting device, thereby varying the conduction angle.

2 more elements

Dependencies are inferred from the claim text.

Electronically controlled power steering system for vehicle and method and system for motor control

Life of this patent

Electronically controlled power steering system for vehicle and method and system for motor control

Life of this patent

Abstract

Claims15