The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 18, 1992
Filed:
Jul. 05, 1990
Koichi Nakazawa, Amagasaki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A motor control system is disclosed which includes an encoder for generating pulses in proportion to the rotational amount of the motor. A speed instructing unit provides a speed instruction for the desired rotational speed of the motor. A speed control unit calculates (1) the actual rotational speed of the motor based on the pulse signal from the encoder and (2) a voltage to be applied to the motor and outputs a PWM signal which represents the actual motor speed. The PWM signal is identical with the voltage to be applied to the motor. This arrangement ensures that the motor speed will follow the speed instruction. A driver unit supplies electric power to the motor by amplifying the PWM signal. The speed of the motor is controlled by (i) adding the PWM signal which has been calculated by the speed control unit with a compensation value depending upon the rotational speed of the motor or alternatively (ii) adding the PWM signal which has been calculated by the speed control unit with a first compensation value when the motor is servo-locked and adding the PWM signal which has been calculated by the speed control unit with a second compensation value depending upon the rotational speed of the motor when the motor is rotated. This achieves nonlinearity compensation for the motor and motor control without causing oscillations when the motor is servo-locked and is stopped and without causing a time lag with respect to a speed instruction when the motor is started-up.