Electric power-steering device

Abstract

The invention provides a safe electric power-steering device that produces a good steering feel, has the ability to disengage steering-wander suppression or steering-pull suppression, and produces an increased driver-burden reduction effect during steering wander or steering pull. [Solution] A motor-current correction-value computation unit that uses a motor-current correction value based on a motor correction signal to correct a current command value comprises the following: a straight-line-movement determination unit (110, 120) that determines whether a vehicle is moving in a straight line; an adaptive calculation unit that calculates the aforementioned motor correction signal (SG4) in accordance with the result of the straight-line-movement determination, a steering angle (theta), and an applied force (SAT estimate), at least, and outputs said motor correction signal (SG4); a vehicle-speed-sensitive gain unit (133) that outputs a vehicle-speed gain (Ga) that depends on the speed (V) of the vehicle; and an output calculation unit (105, 106) that multiples the motor correction signal (SG4) by the vehicle-speed gain (Ga) and outputs a motor-current correction value (Imc). The motor-current correction-value computation unit also has the ability to set thresholds for the motor correction signal and steering information and disengage steering-wander suppression or steering-pull suppression depending on the result of a condition determination performed on said motor correction signal and steering information and said thresholds.

Description

technical field [0001] The present invention relates to an electric power steering device, which applies an assist force generated by an electric motor to a steering mechanism of a vehicle by using a current command value calculated based on at least the steering torque, and in particular relates to an electric power steering device that is safe and has a good steering feel. A power steering device having a function of suppressing lateral deviation or lateral deviation based on a correction value of a motor current, and also having a function of suppressing departure from lateral deviation or suppression of lateral deviation, thereby enabling better reduction of lateral deviation Effect of driver load on offset or lateral offset. Background technique [0002] Electric Power Steering (EPS) applies the steering assist force (assist force) to the steering mechanism of the vehicle using the rotational force of the electric motor, which transfers the driving force of the electric...

AI Technical Summary

Problems solved by technology

Also, due to age-related changes in the vehicle (for example, age-related deterioration of elastic elements such as rubber bushes in the suspension structure, time-dependent changes in the vehicle body, etc.), collisions with curb stones, etc., resulting in There is a problem with wheel alignment. If the driver does not hold the steering wheel hard to maintain the direction, the vehicle will not be able to drive straight (lateral offset or lateral offset, also known as vehicle deviation) )

In such a driving process, I am afraid that it will cause a great burden on the driver.

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