Brushless direct-current motor rotation speed detection device adopting charge coupled device (CCD) camera and method

Abstract

The invention discloses a brushless direct-current motor rotation speed detection device adopting a charge coupled device (CCD) camera and a method. The device comprises a CCD camera and a main computer, wherein the CCD camera also comprises a preprocessing circuit and an analog / digital (A / D) conversion unit. The method comprises the following steps of setting a mark line on a rotating shaft; installing the CCD camera; and detecting a rotation speed of a motor. Due to the adoption of the device and the method, a position sensor does not need to be arranged inside the brushless direct-current motor, so that the structure of the motor main body is prevented from being changed, and the running reliability of the motor is improved. Due to the adoption of the CCD camera video detection method, the noncontact measurement of the motor speed can be realized, the system can response as long as a motor rotor produces one pixel displacement, and the measurement precision is high.

Description

technical field [0001] The invention relates to a brushless direct current motor speed detection device and method, in particular to a brushless direct current motor speed detection device and method using a CCD camera. Background technique [0002] Brushless DC motors generally adopt a 120° conduction type three-phase six-state square wave drive control method. By detecting the position of the permanent magnet rotor, the drive signals of six power tubes in one control cycle are given to ensure the correct commutation of each phase. And through the effective voltage applied to the motor to adjust its speed. The detection of the speed of the brushless DC motor is usually realized by installing Hall sensors and photoelectric encoders inside the motor. However, the existence of the rotor position sensor built into the motor increases the number of connecting elements between the motor and the control circuit, and the immunity to interference deteriorates. Aiming at the variou...

AI Technical Summary

Problems solved by technology

However, when the brushless DC motor is static or the speed is low, it is difficult to obtain accurate rotor position and motor speed by these methods. It is necessary to start the motor to a certain speed before using the corresponding detection method, which limits the use of the detection method to a large extent. Promotion and Application of Brushed DC Motor

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