A torque compensation apparatus for an electric power steering system may include: a temperature sensor configured to sense the initial temperature around the electric power steering system when a vehicle is started; a motor position sensor configured to sense a motor angle of the electric power steering system; a timer configured to detect an operation time of the started vehicle; and a controller configured to calculate a compensation gain when the initial temperature corresponds to a preset low-temperature state, the compensation gain reflects the increasing ambient temperature, and is based on the motor angles accumulated during steering and the accumulative operation time detected through the timer after the start of the vehicle; and the controller outputs the compensation gain to compensate for a motor output torque of the electric power steering system.

A capacitor current estimating unit estimates a capacitor current based on phase currents. A capacitor temperature estimating unit estimates a capacitor temperature based on the capacitor current. A motor controller can accurately estimate not only a temperature of a switching element but also the capacitor temperature based on the phase currents. As a result, the capacitor does not need to have excessive heat characteristics. Further, a current limiting unit limits a current flowing from a battery to an inverter based on the capacitor temperature. Therefore, an amount of temperature change is not over-estimated due to overheating of the capacitor. As a result, excessive current limitation can be avoided and the performance of the motor can be demonstrated.

[Problem] An object of the present invention is to provide an electric power steering apparatus that enables more precise estimation of a coil temperature for a poly-phase motor by considering a heat transfer phenomenon between a control substrate and a coil in addition to a heat transfer phenomenon between the coils.

[Means for solving the problem] An electric power steering apparatus that comprises a control substrate that controls a poly-phase motor having two-system motor windings, comprises a temperature sensor that detects a substrate temperature of the control substrate, and a coil temperature estimating section that estimates all coil temperatures by all motor currents of the poly-phase motor and the substrate temperature based on a heat transfer phenomenon between all coils that is caused by a difference in temperature between the all coils and a heat transfer phenomenon between the coil and the control substrate.

A route generation device includes: a steering loaded state input unit to which a steering loaded state of a vehicle is inputted; a parking slot position input unit to which a position of a parking slot near the vehicle is inputted; a vehicle position input unit to which a position of the vehicle is inputted; a number-of-times-of-static-steering upper limit calculation unit configured to calculate, on the basis of the steering loaded state, a number-of-times-of-static-steering upper limit value up to which static steering of the vehicle can be performed between the position of the vehicle and the position of the parking slot; and a guidance route generation unit configured to generate a guidance route for guiding the vehicle to the parking slot, on the basis of the position of the vehicle, the position of the parking slot, and the number-of-times-of-static-steering upper limit value.

A main power supply having a large capacity and a backup power supply having a small capacity are switchable by a power supply switching determination unit in a system. A motor control device drives a motor by the main power supply or the backup power supply. A drive control unit outputs a drive signal, calculated by feedback control of the current detection value with respect to the current command value, to an inverter circuit. When the power supply switching determination unit switches from the main power supply to the backup power supply, the drive control unit moves from a normal control using the main power supply to a backup control that restricts an electric power consumption and prevents the backup power supply from stopping.

Disclosed are an apparatus and method for controlling a motor. An exemplary embodiment of the present disclosure provides an apparatus for controlling an operation of a motor, the apparatus including: a first motor control unit connected to a first winding part of the motor and configured to control the operation of the motor; and a second motor control unit connected to a second winding part of the motor and configured to control the operation of the motor, in which the first motor control unit turns on or off current paths formed between the first motor control unit and the motor by controlling switches included in the first motor control unit, and the second motor control unit turns on or off current paths formed between the second motor control unit and the motor by controlling switches included in the second motor control unit.

Techniques for limiting electrical current provided to a motor for an electric power steering system are provided. A first estimated temperature of the motor is determined for a first time step. The first estimated temperature of the motor is filtered to produce a first filtered estimated temperature of the motor. A second estimated temperature of the motor is determined for a second time step subsequent to the first time step. The first filtered estimated temperature is compared with the second estimated temperature to determine whether the motor is heating or cooling. The filter is adjusted in response to determining whether the motor is heating or cooling. The second estimated temperature of the motor is filtered with the adjusted filter to produce a second filtered estimated temperature of the motor. A limit on electrical current provided to the motor is set using the second filtered estimated temperature.

A steering apparatus and method for a vehicle. Steering controllers are connected via an internal communications network. Each of the steering controllers monitors the operating state of another steering controller using the internal communications network, so that, if one of the steering controllers currently controlling the steering motor operates abnormally, the steering motor is controlled by at least one steering controller of the remaining steering controllers.

In an electric power steering system, a motor outputs, based on an AC voltage controlled by switching elements using a power-supply voltage from a power source, assist torque for assisting a driver's turning effort of a steering member. A voltage monitor monitors the power-supply voltage, and a determiner determines whether the power-supply voltage is lower than an assistive voltage. The assistive voltage is defined as a voltage that enables the motor to output the assist torque. A temperature detector detects a temperature of each switching element. A motor control unit determines whether the temperature of each switching element is lower than a heat-resistant temperature of the corresponding switching element. The motor control unit controls a motor current when it is determined that the power-supply voltage is lower than the assistive voltage, and the temperature of at least one switching element is lower than the heat-resistant temperature.

A steering system steers wheels of a vehicle through a shift of a steering shaft. The steering system includes: an electric motor; transmission device that transmits an output of the electric motor to the steering shaft; and a malfunction detector that detects a malfunction of the transmission device based on a rotational angle of the electric motor and a shift distance of the steering shaft.