A method for operating an electric power steering system of a motor vehicle, wherein a steering wheel angle is specified by a steering handle as a measurement for a desired wheel steering angle for at least one steerable wheel of the motor vehicle, wherein an electric servo drive having an electric motor provides steering assistance, and wherein an additional restoring force is provided to compensate for increased internal friction in the power steering system based upon temperature, wherein the additional restoring force is reduced based upon a desired steering direction that is detected at the steering handle. Also disclosed is an associated electric power steering system, an associated computer program, and an associated control unit.

A electric power steering control device equipped with a motor having a resolver detection unit includes: an ambient temperature detector for detecting ambient temperature around a portion generating heat by current flow; a motor temperature detector for, based on a signal from the resolver detection unit of the motor, estimating the temperature of the portion generating heat; and an abnormality determiner for comparing the temperature detected by the ambient temperature detector with the temperature detected by the motor temperature detector and determining that the ambient temperature detector is abnormal.

An apparatus for temperature-dependent control of an electric motor includes a control device for adjusting the power output of the electric motor, and means for detecting the temperature of a component of the electric motor, wherein the control device reduces the power of the electric motor in the case of a component temperature above a temperature threshold, and wherein the temperature detection means distinguish between self-heating and external heating, wherein the control device counteracts only the self-heating by reducing the power.

A rotary electrical machine control apparatus is provided which controls drive of a rotary electrical machine having a plurality of winding sets. The apparatus includes inverters that are provided so as to respectively correspond to the winding sets, a temperature detection element that detects a base element that is used as a base for estimation of inverter temperatures, which are temperatures of the inverters, and a control section that has a temperature estimation section that estimates the inverter temperatures based on the base temperature and a temperature change amount generated due to current application to the inverters. On-resistance of the switching elements of the first inverter is smaller than on-resistance of the switching elements of the second inverter. The temperature detection element is disposed in an area, a distance between the area and the first inverter being shorter than a distance between the area and the second inverter.

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.

[Problem] An object of the present invention is to provide a motor control unit that the heat generation of FETs is not concentrated in one FET and the heat generation is distributed to the plural FETs by operating the duties of all three-phases in a case that the driving of the motor is stopped. [Means for Solving the Problem] The present invention is the motor control unit comprising a current detector; an upper-stage maximum heat generation-phase specifying means to calculate respective heat generation amounts of upper-stage FETs and specify an upper-stage maximum heat generation phase; a lower-stage maximum heat generation-phase specifying means to calculate respective heat generation amounts of lower-stage FETs and specify a lower-stage maximum heat generation phase; an upper-stage selecting means to select an upper-stage selecting duty and an upper-stage selecting phase current based on the upper-stage maximum heat generation phase; a lower-stage selecting means to select a lower-stage selecting duty and a lower-stage selecting phase current based on the lower-stage maximum heat generation phase; a duty operating amount calculating section to calculate a duty operating amount; and a duty operating section to operate the respective phase duties based on the duty operating amount.

An electric power steering system includes an electric motor configured to provide power to a steering mechanism of a vehicle. A controller operates the electric motor in response to an input. A flash memory device is in communication with the controller. A temperature sensor provides an output indicative of a temperature of a part of the electric power steering system. The controller is configured to power down or prevent power up of the flash memory device if the temperature of the electric power steering system is outside of a predetermined temperature range. A method of operating an electric power steering system includes measuring a temperature of the electric power assisted steering system and switching off a flash memory device of the electric power steering system if the temperature of the electric power steering system is outside of a predetermined temperature range.

A steering control device and a steering control method are disclosed. Particularly, a steering control device according to the disclosure comprises: a command current calculation unit for calculating a first command current on the basis of detected steering wheel steering information; a resistance calculation unit for calculating internal resistance on the basis of a detected internal temperature; a supply current estimation unit for estimating the supply current of a battery on the basis of an input supply voltage of the battery, the first command current and the internal resistance; and a command current applying unit for comparing the supply current and a preset reference current and, if the supply current is greater than the reference current, changing the first command current to a second command current and applying the second command current to a steering motor.

A method controls a power-steering assistance of a motor vehicle internal combustion engine that includes an automatic engine stop/restart system and an electric or electrohydraulic power-assisted steering system. The method includes providing, during an automatic engine-stopping phase of the automatic stop/restart system, a steering assistance torque less than an assistance saturation value which is less than a nominal steering assistance value, and maintaining the steering assistance torque during an automatic engine-restart phase.

The present embodiments relate to an electronic power steering device, and relates to a technology for reducing a torque rise resulting from an increase in frictional force in a low-temperature situation of the electronic power steering device. According to the present embodiments, a viscous friction compensation current is calculated using a viscous gain, which has been determined according to a damping coefficient estimated from a temperature sensed in a low-temperature situation of the electronic power steering device, and a steering angular velocity, a Coulomb friction compensation current is calculated using the sensed temperature and the mount of accumulated steering angles, and the calculated viscous friction compensation current and the Coulomb friction compensation current are added to the motor driving current and then supplied such that the driver can have the same feeling of driving, even in the low-temperature situation, as that in the room-temperature situation.