Abstract: A method of detecting the angle of rotation of a DC motor includes the steps of: driving the DC motor with a predetermined torque for a predetermined period of time which is selected so that the angular acceleration of the DC motor is substantially constant during the above period of time; and calculating the angle of rotation of the DC motor from the driving time period and the voltage generated by the DC motor after the driving of the DC motor is stopped. This method makes it possible to accurately detect the angle of rotation and the load torque using an apparatus having a simple structure.

Abstract: A motor for a motor-assisted power steering device is controlled with a control value which is obtained by detecting an error between an actual steering torque which has undergone phase lead compensation and a target steering torque, and by summing a proportional value, an integration value and a differentiation value of the error, or with a control value which is obtained by detecting an error between actual steering torque and a target torque; obtaining a proportional value, an integration value and a differentiation value of the error; clipping the lower limit value of the integration value with a first clipping circuit, and clipping the upper and lower limit values of motor-controlling quantity obtained by summing the proportional value, the integration value and the differentiation value by using a second clipping circuit.

Abstract: A power steering system for a motor vehicle comprises a speed sensor 11, a steering torque sensor 12, a current calculating/driving circuit 21 for outputting a motor current command value on the basis of the vehicle speed and the steering torque, an assist torque generating electric motor 10 coupled to the steering system through an electromagnetic clutch 9, a clutch control circuit 50 for controlling a coupling effort of the electromagnetic clutch, an abnormal torque decision calculating circuit 31 for arithmetically determining an abnormal torque and a vehicle speed corresponding to the abnormal torque for a predetermined reference temporal duration to thereby output both an abnormal torque decision value indicating an abnormal torque corresponding to the vehicle speed detected by the vehicle speed sensor and the reference temporal duration, a load torque arithmetic circuit 33 for arithmetically determining both a load torque value indicating a sum of the steering torque detected by the steering torque sens

Abstract: A motor-driven power steering control system of a motor vehicle for assisting a driver in manipulating a steering wheel by making use of an assist torque generated by a reversible motor which is operatively coupled to a steering mechanism of the motor vehicle includes an electric reversible motor mechanically coupled to a steering system of the motor vehicle through an electromagnetic clutch, a motor drive circuit, an H-bridge switching driver circuit for driving the electric reversible motor in forward or reverse direction under the control of the motor drive circuit, and a clutch control circuit for controlling the electromagnetic clutch.

Abstract: A motor for a motor-assisted power steering device is controlled with a control value which is obtained by detecting an error between an actual steering torque which has undergone phase lead compensation and a target steering torque, and by summing a proportional value, an integration value and a differentiation value of the error, or with a control value which is obtained by detecting an error between actual steering torque and a target torque; obtaining a proportional value, an integration value and a differentiation value of the error; clipping the lower limit value of the integration value with a first clipping circuit, and clipping the upper and lower limit values of motor-controlling quantity obtained by summing the proportional value, the integration value and the differentiation value by using a second clipping circuit.

Abstract: An electric locker apparatus with a plurality of locker boxes each having an electric lock device including a latch member normally maintained by a stopper member in a lock position in engagement with the door of the box, and biased toward an unlock position wherein the door can be opened, and an actuator responsive to electric command signal, with an output member movable into an operative position for allowing the latch member to be released from the stopper member and moved into the unlock position. The apparatus further includes an emergency unlocking device for forcibly moving the output member of the actuator into the operative position without requiring input of the command signal. The unlocking device has an emergent key cylinder into which an emergent key can be inserted from outside. The angular motion of the key is converted into a linear motion of the output member of the actuator toward the operative position.