A steer-by-wire steering system for a vehicle, including: an operating member operable by a driver; a steering device including an electric motor and configured to steer a wheel by a force generated by the electric motor; a controller configured to control the steering device, wherein the controller enables the wheel to be steered in accordance with an operation of the operating member while imposing limitation on a supply current to the electric motor, and wherein the limitation imposed on the supply current is made smaller when a running speed of the vehicle is lower than a set speed and a steering motion of the wheel is a motion in a direction to decrease a steering amount than i) when the running speed of the vehicle is not lower than the set speed and ii) when the steering motion of the wheel is a motion in a direction to increase the steering amount.

A rotating electric machine control device includes a first system controller and a second system controller, an overheat protection controller and an abnormality detector. The overheat protection controller includes a temperature estimator and a restricted current calculator. The temperature estimator estimates system temperatures as well as other temperature, including a shared component temperature of a shared component that is connected to both of plural systems in a shared manner. The restricted current calculator calculates restricted current values, based on the system temperatures and the shared component temperature. At least one of the system temperatures, the shared component temperature, and/or the restricted current values is changed from an all-systems normal time, when at least one of a plurality of systems is abnormal.

A self-holding termination determination section has an overheat protection map that defines a relationship between a current value and a maximum temperature of a protected portion to which a current value is applied, and sets a limit temperature corresponding to a required current value at next start time based on the map. The self-holding termination determination section calculates, as an evaluation temperature, temperature obtained by adding a performance assurance upper limit temperature, which assures output performance of a motor at the next start time, to the sum of temperature rises. In a next time performance determination process, if the evaluation temperature for all protected portions has fallen below the limit temperature, the self-holding termination determination section determines that a performance assurance condition is met, and terminates power self-holding based on at least the fact that the performance assurance condition is met.

[Problem]

An object of the present invention is to provide a motor control apparatus that, with a high reliability, protects the motor release-switch comprising the semiconductor switching elements in small size and an electric power steering apparatus provided the same.

[Means for solving the problem]

An electric power steering apparatus that drive-controls a motor by an inverter, and a motor release-switch is connected between the inverter and the motor, comprising: a control section to detect an assist state on a driving control system and to ON/OFF-switch a control of the inverter based on a detection result; a motor rotational number detecting section to detect a rotational number of the motor; an energy calculating section to calculate an energy of a motor back-EMF and a regenerative current based on the rotational number; and a judging section to compare the energy with an area of safety operation of the motor release-switch and to OFF-switch the d motor release-switch when the energy becomes within the area of safety operation. As occasion demands, the area of safety operation is calculated with the temperature.

Using an update amount, an update amount calculating circuit manipulates a phase-control angle so as to perform feedback control such that a steering torque corresponds to a target torque. The steering torque is obtained by reducing a steering torque in magnitude by a predetermined value. The phase-control angle is used to convert a current command value to a value of a fixed coordinate system, for example. Using a guard value, a guard processing circuit performs a guard process on a current command value set by a command value setting circuit, so that the current command value becomes the current command value. The guard value is used to determine an appropriate range for a variation in the current command value in accordance with an amount by which the steering torque exceeds in magnitude the target torque.

A steering control device has a steering actuator as an operation target, the steering actuator includes a motor and a steering mechanism mechanically connected to a rotary shaft of the motor. The steering control device includes a controller configured to perform i) a low-temperature process of changing a torque of the motor when an estimated value estimated from a temperature of a lubrication target part of the steering mechanism is equal to or lower than a predetermined value with respect to when the estimated value is higher than the predetermined value and ii) an estimation process of calculating the estimated value which is set be lower than a detected value of a temperature sensor detecting a temperature of a predetermined member attached to the steering mechanism based on a heat emission parameter of the steering actuator associated with a current flow with the detected value as an input.

A vehicle system, including: an on-board device mounted on a vehicle; and a control device configured to control the on-board device such that the vehicle travels in a target traveling state, wherein the control device includes: a predicting portion that predicts a state of the on-board device when the vehicle travels in the target traveling state; and a modifying portion that modifies the target traveling state when the control device determines based on the state of the on-board device predicted by the predicting portion that an operation of the on-board device needs to be limited.

A device for determining a temperature of a semiconductor power switch with a built-in temperature-dependent gate resistor may include a non-inverting amplifier circuit comprising an operational amplifier and a feedback resistor. Inverting input of the operational amplifier may be connected to the semiconductor power switch such that a gain of the non-inverting amplifier circuit in a predefined frequency range of an input signal depends on the built-in temperature-dependent gate resistor and the feedback resistor and is a measure of the temperature of the semiconductor power switch. The feedback resistor may be disposed between a negative input and an output of the operational amplifier.

Aspects of the technology involve controlling a vehicle configured to operate in an autonomous driving mode. This includes receiving a set of environmental inputs including temperature information from different temperature sources, receiving initial steering information from a steering system of the vehicle, and obtaining an initial rack position command by a motion control module of the vehicle. The system determines, based on the environmental inputs, the initial steering information and an initial rack position, a likelihood that a steering actuator of the steering system of the vehicle is blocked or likely to become blocked. The system determines whether a threshold excitation amount has been applied to the steering system within a selected amount of time or a selected driving distance. When the threshold amount of excitation is not met, an excitation profile is applied to the steering system in order to modify the initial rack position.

An electronic unit includes a heat sink, a substrate, a heating component, a temperature sensor, a first interconnection, and a second interconnection. The heat sink includes a strut. The substrate is fixed to the strut of the heat sink. The heating component is mounted on the substrate to generate heat upon energization of the heating component. The temperature sensor is mounted on the substrate to detect temperature. The first interconnection is provided in a high-temperature region in which the heating component is mounted on the substrate, and is connected to the strut of the heat sink. The second interconnection is provided in a detection region in which the temperature sensor is mounted on the substrate, and is provided separately from the first interconnection. The second interconnection is connected to the strut of the heat sink and the temperature sensor.