An embodiment of a control system includes a current command module configured to receive a torque command and output a current command for controlling a direct current (DC) motor, and a current capability limiting module configured to receive the current command and a current limit indicating a maximum motor current, limit the current command based on the current limit, and actively further limit the current command based on a capability limit value.

An electric power steering system includes a vehicle speed sensor configured to detect a vehicle speed, a motor driving circuit configured to supply power to an electric motor, a main power supply and a capacitor that can supply power to a driving circuit, a charging circuit configured to charge the capacitor based on the main power supply, and an ECU for power source control that controls the charging circuit. The ECU for power source control drives the charging circuit to charge the capacitor only when the vehicle speed is lower than a first predetermined value and an inter-terminal voltage of the capacitor is lower than a second predetermined value.

In an electric power steering system, an offset correction value setting unit corrects second offset correction values in a state where 100% of current command values is distributed to a first control unit, and 0% of the current command values is distributed to a second control unit. The offset correction value setting unit corrects first offset correction values in a state where 100% of the current command values is distributed to the second control unit, and 0% of the current command values is distributed to the first control unit.

A system for control of a steering system of a vehicle, mechanically coupled to the wheels and including an actuator for applying a force or a torque to the steering system. A force or torque can be superimposed on a force or torque originating from the wheels. The system includes a detection unit disposed on the vehicle and configured for anticipatorily detecting at least one surface condition of a surface section located ahead of the vehicle in the direction of vehicle travel and subsequently driven on by the vehicle. The system including a data processing unit disposed on the vehicle and connected to and communicating with the detection unit. The data processing unit configured for generating control signals for controlling an actuator of the steering system based on the detected surface condition.

The present application discloses a control apparatus for electric power steering, including: a gain determination portion configured to determine a first assist gain in correspondence to a steering torque acting on a steering shaft when a driver rotates a steering wheel; and a gain adjuster which adjusts the first assist gain in response to a change in a rotation direction of the steering wheel to generate a second assist gain. The gain adjuster generates the second assist gain so as to reduce a difference between a first torque, which is required of the driver rotating the steering wheel to a predetermined rotation position, and a second torque, which is required of the driver holding the steering wheel at the rotation position.

The present application discloses a control apparatus for electric power steering, including: a gain determination potion configured to determine a first assist gain in correspondence to a steering torque acting on a steering shaft when a driver rotates a steering wheel; and a gain adjuster which adjusts the first assist gain in response to a change in a rotation direction of the steering wheel to generate a second assist gain. The gain adjuster generates the second assist gain so as to adjust a difference between a first torque, which is required of the driver rotating the steering wheel to a predetermined rotation position, and a second torque, which is required of the driver holding the steering wheel at the rotation position.

An electronic power steering apparatus for a vehicle having a steering mechanism to generate a steering assisting force includes: a steering angle sensor; a steering torque sensor; a target steering torque setting unit for setting a target steering torque based on the detected steering angle; a torque deviation computing unit for computing a torque deviation between the target steering torque and the detected steering torque; a first target current value computing unit for computing a first target current value for generating a steering assisting force by the motor based on the computed torque deviation; and a vehicle speed sensitivity adjusting unit that adjusts the first target current value, at least corresponding to a detected vehicle speed, and outputs the adjusted first current value as a second target current value. The motor control unit controls the motor to generate the steering assisting force based on the second target current value.

The present invention relates to a drive control apparatus for an electric motor and a control method thereof. In the present invention, the generation of electric brake is suppressed while protecting a semiconductor relay from excessive surge voltage. The drive control apparatus is configured to include: a drive circuit for controlling the drive of the electric motor; a semiconductor relay arranged on a drive line between the drive circuit and the electric motor to cut off current supply from the drive circuit to the electric motor; and an active clamp circuit for turning on the semiconductor relay when a potential difference between the drive circuit side and the electric motor side of the semiconductor relay is greater than or equal to a predetermined value.

A device for controlling a steering wheel and a method for controlling a steering wheel using the same that includes: a detecting bar which is rotated in conjunction with a steering shaft of an industrial vehicle's steering wheel; a sensor at one side of the detecting bar so as to detect a steering angle of the steering wheel by means of the detecting bar; and a controller which controls the steering wheel based on a sensing signal of the sensor so as to position the steering wheel in a neutral position during a time when electric power is applied to the industrial vehicle and the industrial vehicle is initialized. When an operator turns on a power source of the electric forklift, the steering wheel is positioned in the neutral position to enable an operator to immediately drive the electric forklift without confirming a position of the steering wheel.

A method of controlling a motor of a power steering system is provided. The method generates a direct-axis voltage command and a quadrature-axis voltage command based on a current measurement signal received from the motor. The method transforms the direct-axis voltage command and the quadrature-axis voltage command into an alpha voltage command and a beta voltage command. The method determines an offset error in the phase current measurement based on the alpha and beta voltage commands.