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

This paper describes a new control algorithm which can enhance the dynamics of a sensorless control system and gives a precise sensorless control performance. Instead of the conventional sinusoidal-type voltage injection, a square-wave-type voltage injection incorporated with the associated signal processing method is proposed in this paper. As a result, the error signal can be calculated without low-pass filters and time delays, and the position estimation performance can be enhanced. Using the proposed method, the performance of the sensorless control can be enhanced; the bandwidth of the current controller was enhanced up to 250 Hz, and that of the speed controller was up to 50 Hz.

High-Bandwidth Sensorless Algorithm for AC Machines Based on Square-Wave-Type Voltage Injection

A planar touch control is used to provide input to a computer and haptic feedback is provided thereto. A touch control includes a touch input device with a planar touch surface that inputs a position signal to a processor associated with the computer based on a location of user implemented contact on the touch surface. The computer can position or modify a cursor or image in a displayed graphical environment based at least in part on the position signal, or perform a different function. At least one actuator is also coupled to the touch input device and outputs a force to provide a haptic sensation to the user via the touch surface.

Haptic feedback for button and scrolling action simulation in touch input devices

In this paper, an analysis of control structures for the electrical drive system with elastic joint is carried out. The synthesis of the control structure with proportional-integral controller supported by different additional feedbacks is presented. The classical pole-placement method is applied. Analytical equations, which allow for calculating the control structure parameters, are given. The limitation of the design due to the number of degrees of freedom of the considered drive systems is shown. In order to damp the torsional vibration effectively, the application of the feedback from one selected state variable is necessary. In the literature, a large number of possible feedbacks have been reported. However, in this paper, it is shown that all systems with one additional feedback can be divided into three different groups, according to their dynamical characteristics. In addition, the system with two additional feedbacks is investigated. The comparison between considered structures is carried out. The simulation results are confirmed experimentally in the laboratory setup

Vibration Suppression in a Two-Mass Drive System Using PI Speed Controller and Additional Feedbacks—Comparative Study

An electric traction vehicle is described herein which may be used to provide power to off-board electric power-consuming systems or devices. The electric traction vehicle may provide 250 kilowatts or more of three phase AC power to an off-board electric power consuming system. The electric traction vehicle may also include an electrical power storage device which can be selectively discharged to allow the vehicle to be serviced.

Control system and method for electric vehicle

A new speed measurement system, which is suitable for microprocessor-based motor drive, and its application to speed regulator are explained.

A Microprocessor-Controlled High-Accuracy Wide-Range Speed Regulator for Motor Drives

The object of the present invention is to provide an electric drive system which ensures effective generation of torque from the start to the maximum speed, and extended cruising distance and upgraded running performances. The drive system according to the present invention is characterized in that, in a electric vehicle to be driven by the wheels which are driven by the rotary output of two or more motors, said two or more motors comprise at least two different types of motors, and the system is provided with the control means to adjust the share of the vehicle driving force to be generated by each of said motors in conformity to the running state of said vehicle. These two or more motors comprise a combination of a low speed drive motor and high speed drive motor, and a highly efficient motor is used as said low speed motor, while a motor having a greater capacity and greater base speed than said low speed drive motor is used as the high speed drive motor. The share of the driving force of said vehicle is controlled by the control means such that up to the maximum torque is generated by said low speed drive motor, with the remaining torque generated by said high speed drive motor.

Electric vehicle drive system and drive method

An electric vehicle control system for driving a battery powered motor with use of power inverters. First and second inverters are connected with the respective three-phase primary windings of an induction motor. If one of the inverters fails, failure detection circuits detect it, and a control unit stops the failed inverter and allows the other normal inverter to drive the induction motor to move the electric vehicle. Driving the single motor with a plurality of power inverters allows the electric vehicle to move and run even if one of the power inverters fails.

Electric vehicle control system

A method for estimating instantaneous speed, suited for a microprocessor-based speed regulator for motor drives, and the characteristics of the speed control system are described. Features of the proposed method include the estimation of instantaneous speed at a real-time point using values of average speed detected by counting for a certain time the output pulses of an encoder as well as the estimated value as the speed feedback signal for the speed regulator. Since this method allows compensation to be made for the lag time of the feedback signal caused by detection of the mean value, it contributes to improved stability of the speed regulator. In particular, this provides a significant suppression of the vibrations that are generated in motor-driven machinery. >

A microprocessor-controlled speed regulator with instantaneous speed estimation for motor drives

A new control method is described in which a microprocessor is used to regulate the speed of a dc motor driven by antiparallel-connected three-phase dual thyristor converters. A distinct feature of this speed regulating system is that speed response is improved by using a fast-response current controller for the internal loop. A fast-response current controller is obtained by employing a nonlinear compensation subloop and a proportional plus integral compensation subloop. The nonlinear compensation subloop is used to linearize the nonlinear load characteristics of the thyristor converter, which are encountered under discontinuous conduction states of current. The proportional plus integral compensation subloop reduces the deviation of detected current from the current reference. With these two current-control subloops a fast motor speed response is achieved under discontinuous as well as continuous conduction states; hence the steady-state accuracy of speed is improved. A speed regulator using a microprocessor was trial manufactured and tested with a 20-kW dc motor. It was found that an extremely fast controlled current response can be obtained even with a relatively long sampling period. Further, normal action was confirmed in four-quadrant operation.

Tsutomu Ohmae

Papers

A Microprocessor-Controlled High-Accuracy Wide-Range Speed Regulator for Motor Drives

Electric vehicle drive system and drive method

Electric vehicle control system

A microprocessor-controlled speed regulator with instantaneous speed estimation for motor drives

A Microprocessor-Controlled Fast-Response Speed Regulator with Dual Mode Current Loop for DCM Drives