A power steering apparatus and a control circuit for a power steering apparatus are provided. The power steering apparatus detects an abnormality in the power steering apparatus based on whether there is a periodic change within a predetermined frequency range with respect to the number of rotations of an electric motor, a steering velocity, or a steering torque.

A power steering apparatus and a control circuit for a power steering apparatus are provided. The power steering apparatus detects an abnormality in the power steering apparatus based on whether there is a periodic change within a predetermined frequency range with respect to the number of rotations of an electric motor, a steering velocity, or a steering torque.

Provided is a power conversion device for suppressing a variation amount of a bus current to decrease a power loss in consideration of control of detecting the bus current during operation. In control by a power conversion part in accordance with a switching signal, a voltage vector is caused to bring a mode into a power running mode at a timing of detecting the bus current when an AC rotating machine is in a power running operation state, and the voltage vector is caused to bring the mode into a regeneration mode at a timing of detecting the bus current when the AC rotating machine is in a regeneration operation state, thereby decreasing the power loss due to the variation in the bus current.

[Problem]

An object of the present invention is to provide an electric power steering apparatus capable of smoothly switching the control systems without self-steer by gradually changing a control torque of the torque control and a command value of the position/speed control upon the fade processing

[Means for solving the problem]

The present invention is the electric power steering apparatus including a torque sensor to detect a steering torque and a motor control unit to control a motor that applies an assist torque to a steering system of a vehicle, comprising: a function to switch a control system of the motor between a torque control system to control a motor output torque and a position/speed control system to control a steering angle of a steering in accordance with a predetermined switching trigger, wherein a fade processing which switches from the torque control system to the position/speed control system or vice versa.

[Problem]

An object of the present invention is to provide an electric power steering apparatus capable of smoothly switching the control systems without self-steer by gradually changing a control torque of the torque control and a command value of the position/speed control upon the fade processing

[Means for solving the problem]

The present invention is the electric power steering apparatus including a torque sensor to detect a steering torque and a motor control unit to control a motor that applies an assist torque to a steering system of a vehicle, comprising: a function to switch a control system of the motor between a torque control system to control a motor output torque and a position/speed control system to control a steering angle of a steering in accordance with a predetermined switching trigger, wherein a fade processing which switches from the torque control system to the position/speed control system or vice versa.

A motor control apparatus that calculates duty command values of respective phases for controlling currents of a motor by means of a control calculation, forms PWM-signals in correspondence to the duty command values, drives the motor by means of an inverter based on the PWM-signals, and which is provided a rotation sensor to detect a motor angle of the motor.

One embodiment provides a power steering apparatus including: a worm gear that is rotated by receiving a driving force; a bearing member that supports the worm gear so as to make the worm gear rotatable; a worm wheel that is connected to the worm gear so as to be rotatable and apply a steering assist force to a steering wheel; and a support member that supports the bearing member so as to make the bearing member slidable in a crossing direction that crosses a rotating shaft of the worm wheel. The support member has a guide surface to guide the bearing member in the crossing direction therealong. The support member also has a holding portion that holds a lubricant in a recessed portion that is recessed from the guide surface.

The disclosure provides a steering system for a vehicle. The steering system may include a steering rack and an electronic power steering (EPS) system. The EPS system may include an actuator that assists movement of the steering rack, a torque sensor; an angle sensor; and an EPS system controller. The EPS controller may be configured to determine a steering rack center point indicating a center of the steering rack between opposite maximum steering angles. The EPS controller may be configured to determine a vehicle center zero point. The EPS controller may be configured to store the vehicle center zero point in response to determining that the vehicle center zero point is within a threshold of the steering rack center point.

A method of isolating a fault in an electric power steering system includes calculating a value for fault signature components. Each of the calculated values of the fault signature components is compared to a respective threshold value, to determine if any of the calculated values of the fault signature components exceeds its respective threshold value. When at least one of the calculated values of the plurality of fault signature components exceeds its respective threshold value, the above threshold comparison results are compared to a fault table that relates pre-calculated threshold comparison results to pre-identified faults, to determine if the above threshold comparison results correspond to a pre-identified fault. Based on the fault table comparison results, a control action is automatically executed to indicate a pre-identified fault or an unknown fault in the electric power steering system.

A steering system including a plurality of steering devices respectively provided for a plurality of steerable wheels that belong to at least one of a front-wheel side and a rear-wheel side of a vehicle, wherein the plurality of steering devices respectively include a plurality of steering actuators, and wherein each of at least one of the plurality of steering actuators is disposed on an inner side of a corresponding one of side members of the vehicle.