Abstract: A steering system is configured such that electric power is supplied to a steering actuator and a turning actuator from a first power supply when a power state of a vehicle is an on state and supply of the electric power from the first power supply is cut off when the power state is an off state. The steering system includes a rotation curbing unit configured to operate such that rotation of the steering wheel is curbed in at least a part of a first power-off period from when the power state becomes an off state until when the power state becomes the on state next, as an operating period, and a second power supply configured to supply, to the rotation curbing unit, the electric power required for operation of the rotation curbing unit in the operating period, the second power supply being different from the first power supply.

Abstract: A steer-by-wire steering system for a vehicle, including: an operating member operable by a driver; a dual-system steering device including two systems each of which includes an electric motor as a drive source, the steering device being configured to steer a wheel; and a controller configured to control a current to be supplied to each of the electric motors of the respective two systems so as to cause the steering device to steer the wheel in accordance with an operation of the operating member, wherein the controller is configured to prohibit the current greater than an upper limit value from being supplied to the electric motors of the respective two systems, and wherein, when the wheel is steered only by only one of the two systems, the controller raises the upper limit value of the current to be supplied to the electric motor of the one of the two systems.

Abstract: A steer-by-wire steering system, including a steering device including a dual-system steering motor including a main system and a sub system, wherein a power supply to the main system is conducted selectively by a main power source and a backup power source, and a power supply to the sub system is conducted by only the main power source, wherein, in a normal power-supply situation in which the power supply to the main system and to the sub system is conducted by the main power source, a controller controls the sub system to operate in accordance with the main system, and wherein, in a backup power-supply situation in which the power supply to the main system is conducted by the backup power source, the controller controls the main system not to operate or to operate while limiting the power supply to the main system and controls the sub system independently.

Abstract: 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.

Abstract: 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.

Abstract: A power supply system includes a system control unit, an auxiliary power supply, and an auxiliary-power-supply control unit. The system control unit and the auxiliary-power-supply control unit are configured such that information of at least one control unit of the system control unit and the auxiliary-power-supply control unit is able to be output to another control unit of the system control unit and the auxiliary-power-supply control unit. The at least one control unit is configured to output information indicating that an operation of the at least one control unit is stopped to the other control unit when the at least one control unit stops the operation of the at least one control unit.

Abstract: An electric power source device includes an auxiliary electric power source for a main electric power source that supplies electric power to electric power supply targets, including an electric circuit of a control system for controlling a specific control target and an electric circuit of a power system that requires larger electric power than the electric circuit of the control system; and a selection circuit configured to supply the electric power from one electric power source having a higher voltage, out of the main electric power source and the auxiliary electric power source, to at least the electric circuit of the control system among the electric power supply targets.