A gearbox assembly for power take off from an electric motor of an electric power assisted steering apparatus comprises a gearbox housing which houses a worm shaft and a gear wheel. The worm shaft incorporates one or more external helical worm teeth. A main bearing assembly supports the worm shaft at an end closest to the motor. A tail bearing assembly supports the worm shaft at an end furthest from the motor. At least the tail bearing assembly is free to move relative to the housing through a limited range of motion that enables the worm shaft to move radially away from an axis of the wheel gear. A piston is slidingly received within a bore in an end of the wormshaft and has a has a head at an end facing the motor which connects with an output shaft of the motor. An interface between the recess of the piston and the protrusion of motor shaft defines a pivot axis of the worm shaft. A spring located within the bore in the end of the worm shaft and is compressed between the worm shaft. The piston has a tapered shoulder located within the bore that increases in diameter from an end furthest from the motor towards an end nearest the motor. The gearbox assembly further includes an annular o-ring that sits on the tapered shoulder, the spring acting on the piston through the o-ring whereby movement of the wormshaft towards the motor shaft compresses the spring which in turn drives the o-ring along the tapered shoulder until the o-ring becomes wedged between the piston and the inner wall of the bore of the wormshaft.

A gearbox assembly for power take off from an electric motor of an electric power assisted steering apparatus comprising a gearbox housing which houses a worm shaft and a gear wheel, is disclosed. The worm shaft incorporates one or more external helical worm teeth. A main bearing assembly supports the worm shaft at an end closest to the motor. A tail bearing assembly supports the worm shaft at an end furthest from the motor, in which at least the tail bearing assembly is free to move relative to the housing through a limited range of motion that enables the worm shaft to move radially away from the axis of the wheel gear. The gearbox assembly further comprises a flexible coupler which connects the worm shaft at the main bearing end to a power take off from the motor so as to transfer torque from the motor to the worm shaft. The flexible coupler comprises a first hub part providing a connection to the worm shaft, a second hub part providing a connection to the power take off from the motor, and a flexible membrane that connects the first hub part to the second hub part. The flexible membrane provides a primary path for the transfer of torque from the first hub part to the second hub part.

A shock damper is disposed between a vehicle body side and a wheel side. A suspension control device calculates a damping force of the shock damper on the basis of vehicle height information and controls the damping force. A steering system includes an electric motor and a steering control device that controls the electric motor, and assists steering effort of the driver through the electric motor. The suspension control device calculates the vibration generated in a steering on the basis of a detected value of a vehicle height sensor and creates a signal for generating steering torque that reduces the generated vibration. The suspension control device outputs the created signal to the steering control device. Steering torque for cancelling steering vibration is accordingly outputted from the electric motor of the steering system.

A steering control device includes a control unit configured to perform a calculation based on angle information and to control the operation of a turning section based on a turning control amount. The angle information is obtained by relating the turning control amount for operating the turning section to a steering angle that is an angle by which a steering wheel is steered. The control unit includes a speed increase ratio calculation unit configured to calculate a speed increase ratio based on state variables, and an angle information calculation unit configured to calculate the angle information by converting the steering angle using the speed increase ratio obtained by the speed increase ratio calculation unit.

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.

A cart may include: a driving wheel; a motor configured to rotate the driving wheel; a motor drive circuit configured to control electric power supply to the motor; a motor control device configured to control the motor via the motor drive circuit; a switching element arranged on an electric power supply path to the motor drive circuit; a switch circuit arranged separately from the motor control device and configured to switch the switching element between a conduction state and a non-conduction state; and an operation member arranged on the cart and configured to be operated by a user. The cart may operate in a manual mode in which the motor is driven when the operation member is on and the motor is stopped when the operation member is off, and in an automatic mode in which the motor is driven regardless of whether the operation member is on or off.

A vehicle system, including: a steering system; and a longitudinal-force application system including longitudinal-force application actuators configured to apply longitudinal forces respectively to one or more left-side wheels and one or more right-side wheels and a longitudinal-force controller configured to control the longitudinal-force application actuators to control the longitudinal forces applied respectively to the one or more left-side wheels and the one or more right-side wheels;, and an onboard power source device including a main power source and a secondary power source. When the main power source fails to supply electric power to the longitudinal-force application system and the steering system, the longitudinal-force controller controls the longitudinal-force application actuators to control a difference between the longitudinal force applied to the one or more left-side wheels and the longitudinal force applied to the one or more right-side wheels, thereby turning the vehicle.

A steer-by-wire control system adapted for use with a material handling vehicle such as a forklift includes a controller programmed to receive input indicative of a desired direction of travel of the material handling vehicle and to control an actuator coupled with the steered wheels of the material handling vehicle to change the direction of travel of the vehicle.

In a steer-by-wire steering system for a vehicle, a control unit (16) controls an operation of a steering actuator to cause the steered angle of wheels to be in a prescribed relationship to a steering angle, and an operation of the reaction force actuator (15) including a pair of reaction force motors (14) to cause the reaction force to be a value (Tt) corresponding to a steered state of the wheels, wherein the control unit is provided with a failure detection unit (36) configured to detect failures of the reaction force motors, and upon detecting a failure of one of the reaction force motors, progressively reduce an output (Tta) of the other reaction motor to a prescribed limit value (TL).

In a control device to control a motor in an electric power steering apparatus including the motor, processor executes, according to a program calculation of a target assist torque by performing proportional integral (PI) control based on a target steering wheel angle and a steering angle, and control of the motor based on the target assist torque. A gain of an integrator used for integral (I) control of the PI control is variable.