An electric power-steering device has a speed-reducing mechanism (17) for reducing the speed of an output shaft (16) of an electric motor (15). The speed-reducing mechanism (17) has an internal gear (39) engaged and rotated with the output shaft (16) and an external gear (40) with which the internal gear (39) internally meshes. A drive pulley (41) rotatable together with the external gear (40) and a driven pulley (42) provided so as to surround a steering shaft are connected by an endless belt (43). Speed reduction is obtained by the internal gear (39) and the external gear (40), and the speed-reducing mechanism (17) as a whole achieves a high reduction ratio without greatly reducing the diameter of the drive pulley (41).

Electric power-steering device

An electric power steering control system in which the steering "feel" is improved, having a steering force detector an electric motor for producing an auxiliary steering force, a motor current detector and a control unit for deciding the motor current value and rotational direction at least in accordance with the detected steering force. The motor current is limited in accordance with the detected steering force and motor current values.

Electric power steering control system

An electric power steering apparatus has a steering mechanism SM having universal joints 4, 6 in a torque transmitting system, a steering toque detecting unit 14, a steering angle detecting, unit 18, a torque fluctuation detecting unit 43 for detecting a torque fluctuation due to the crossing angle α in the universal joints 4, 6 on the basis of the steering angle θ detected by the steering angle detecting unit 18 and any one of the steering torque T detected by the steering torque detecting unit, a current command value It and self-aligning torque SAT; and a current command value correcting unit 44 for correcting the current command value on the basis of the torque fluctuation detected by the torque fluctuation detecting unit 43 and the steering angle θ detected by the steering angle detecting unit 18.

Electric Power Steering Apparatus

An electric power steering apparatus being provided with: a torque sensor 10 for detecting a steering torque applied to a steering wheel (not shown); and a steering assisting motor 24 driven by a drive circuit 13 to which the voltage of a mounted battery P is applied, in which the drive circuit 13 rotates the motor 24 in accordance with a motor current instruction value determined based on the steering torque detected by the torque sensor 10, is further provided with: judging means 12 for judging whether the motor current instruction value is higher than a first threshold value or not; boosting instruction outputting means 12 for, when the judging means 12 judges that the motor current instruction value is higher, outputting a boosting instruction for boosting the voltage of the mounted battery P; and a boosting circuit 8d for boosting the voltage of the mounted battery in response to the outputted boosting instruction Even when the voltage of the mounted battery P fluctuates, a voltage from which a stable steering assisting force is always obtained can be supplied to the steering assisting motor, so that the steering assisting motor can be reduced in size

Electric power steering apparatus

An apparatus including a controller, a workpiece transport in communication with the controller having a movable portion and a transport path, and a multi-dimensional position measurement device including at least one field generating platen attached to the movable portion and at least one sensor group positioned along the transport path and in communication with the controller, the field generating platen is configured for position measurement and propelling the movable portion, each sensor in the at least one sensor group is configured to provide but one output signal along a single axis corresponding to a sensed field generated by the at least one field generating platen and the controller is configured calculate a multi-dimensional position of the movable portion based on the but one output signal of at least one of the sensors in the at least one sensor group, the multi-dimensional position including a planar position and a gap measurement.

Multiple dimension position sensor

A generator generates two voltage outputs which have different voltage levels. One voltage output from the generator is used for operating a power steering apparatus. Another voltage output from the generator is used for charging a battery which supplies current to other loads.

Motor-driven power steering apparatus

An electric power steering control system includes an electric motor for producing an assisting torque for the vehicle steering system through a reduction gear, a steering torque sensor fitted on the steering shaft, a controller for controlling the input to the motor in accordance with the torque sensor output, a battery for supplying power to the controller, and a voltage step-up circuit connected to the battery for driving the motor at a voltage higher than the battery voltage. The controller drives the motor at a high voltage.

A permanent-magnetic motor employs a skew structure in an armature iron core and an equal gap structure. A center line of a permanent magnet field pole is disposed to be shifted against a mechanical center line of the motor or a center line of the iron core. The magnet field pole is made to have an unequal pitch. A cogging torque generated at both end extending portions in the magnets is cancelled out. The cogging torque of the permanent-magnetic motor in power steering assistance such as for the automobile yields a smooth steering feeling sensitivity during the operation of the automobile.

Permanent-magnetic motor having anti-cogging structure

An electric power steering apparatus for a vehicle comprises a steering shaft, an electric motor operable to generate an auxiliary steering force having a magnitude corresponding to a value of electric current supplied thereto, a steering toque sensor for detecting a steering torque applied to the steering shaft, a vehicle weight sensor for detecting a vehicle weight, and a control device. The control device is constituted to increase and decrease the value of electric current to be supplied to the electric motor in accordance with not only the increase and decrease of the value detected by the steering torque sensor but also the increase and decrease of the value detected by the vehicle weight sensor.

Hisatugu Ishikura

Papers

Motor-driven power steering apparatus

Electric power steering control system

Permanent-magnetic motor having anti-cogging structure

Electric power steering apparatus for vehicle

Elektrisches servolenkungs-regelsystem