A damping control method of steering system may include determining, by a controller, a basic damping value based on a vehicle velocity, a steering angular velocity, and an output value of a steering motor when it is determined that steering for restoring a steering wheel to a steering angle neutral position is to be performed; determining, by the controller, whether a driver is in a hand-off state in which the driver takes its hands off the steering wheel according to signals reflecting a steering state and a behavior of a vehicle; compensating, by the controller, for the basic damping value so that the basic damping value is increased and determining a final damping value when it is determined that the driver is in the hand-off state; and controlling, by the controller, the steering motor with the final damping value obtained by the compensation, and restoring and steering the steering wheel.

A control method of a motor driven power steering (MDPS) for a vehicle may include determining a steering angle of a steering wheel of the vehicle; determining a steering torque variation rate of the vehicle; counting an exceeding number of times that the steering torque variation rate exceeds a predetermined value to store the counted number of times in an MDPS system; and deleting the number of times stored in the MDPS system when the exceeding number of times is less than a predetermined number of times, and applying a reverse phase compensation torque to a steering motor when the exceeding number of times is equal to or larger than the predetermined number of times.

An electric power steering apparatus that includes a function to perform a handle-returning control being consistent with an intention of a driver by using, for a calculation of a target steering angular velocity, only a steering input due to the intention of the driver which is included in a steering torque and the assist current or only vehicle motion characteristics based on the steering input, in the handle-returning control which performs a PID-control depending on a deviation between the target steering angular velocity and a steering angular velocity.

A vehicle includes a vehicle frame, a steering swivel unit supported on a head pipe of the vehicle frame and angularly movable about a steering axis, a front wheel angularly movable in unison with the steering swivel unit, and a steering handle mounted on the steering swivel unit. The vehicle has a steering handle turning mechanism that makes the steering handle angularly movable about the steering axis relatively to the steering swivel unit. The steering handle turning mechanism includes a handle turning motor for angularly moving the steering handle about the steering axis.

An apparatus for compensating a torque of a motor-driven power steering system includes a column torque sensor detecting a column torque applied to a steering shaft; a vehicle speed sensor detecting a vehicle speed; a steering angle sensor detecting a steering angle velocity of a steering wheel; and a control unit suitable for calculating a high frequency assist gain for controlling a high frequency region of the column torque by receiving the column torque and the vehicle speed, determining whether a steering state is a steering reversal state, based on the steering angle velocity received from the steering angle sensor and motor current applied from an MDPS motor, compensating the high frequency assist gain depending on a result of determination, and compensating a high frequency characteristic of an assist torque calculated from the column torque and the vehicle speed, by using the compensated high frequency assist gain.

In a steering control apparatus, a basic assistance torque calculating unit calculates a basic assistance torque. A return control unit calculates a return control amount to assist in returning a steering wheel to a neutral position, as a correction torque to be added to the basic assistance torque. In the return control unit, a target steering speed calculating unit calculates a target steering speed being that is a target value for a steering speed. A return control amount calculating unit calculates the return control amount such that the steering speed follows the target steering speed. A returning state determining unit determines whether the steering wheel is turning or returning. The target steering speed calculating unit gradually increases an absolute value of the target steering speed from an absolute value of the steering speed when the steering wheel is returning.

A servo controller calculates a base assist torque so that a steering torque follows a target steering torque. A convergence control calculation unit provided as a correction control calculation unit calculates a correction control value in accordance with a steering speed which is a steering state value. A torque converter outputs a torque limit value determined by converting a current limit value into a torque to a servo limit value calculation unit. The servo limit value calculation unit calculates the servo limit value so that an absolute value of the servo limit value to be larger than an absolute value of the torque limit value in at least a part of a region of the steering speed or the correction control value.

A method for determining a neutral position of a MDPS (Motor Driven Power Steering) system may include: determining, by a controller, whether a vehicle is driving; determining, by the controller, whether a steering torque is smaller than a preset break point on a boost curve, when the vehicle is driving; and determining, by the controller, that the vehicle is in a neutral state, when the steering torque is smaller than the preset break point on the boost curve.

There is provided an electric power steering device, including: a reverse steering detection unit configured to determine start of reverse steering when a magnitude of a rotational speed of a motor is equal to or smaller than a set speed, a rotational acceleration of the motor is in a direction of causing the rotational speed of the motor to become 0, and a magnitude of the rotational acceleration of the motor is equal to or larger than a set acceleration; and a current command control unit configured to output a current command for the motor based on the steering torque or the rotational speed of the motor, in which the current command control unit is configured to increase a transfer gain from input to output by the current command control unit when the reverse steering detection unit determines start of the reverse steering.

A system includes a computer programmed to specify, while a vehicle is turning, a feedback torque based on a steering torque applied to a steering rack and a difference between a desired angle and an actual angle of vehicle steerable wheels. The computer is further programmed to actuate feedback torque to a vehicle steering wheel.