Control method for motor driving shield door and provided with position sensor

Abstract

The invention provides a control method for a motor driving a shield door and provided with a position sensor. The control method comprises the steps that a, when the motor drives the shield door, a digital signal processor carries out speed closed-loop PID control over the motor; b, if the digital processor can not obtain a position change signal detected by the position sensor, the digital signal processor compares currents of the motor with a preset threshold value, and when the currents are larger than the set threshold value, the motor is controlled to stop rotating or reversely rotate to an initial state; when the currents are not larger than the set threshold value, then whether the digital signal processor has already recorded a time and duty ratio curve of the whole door opening and closing process is judged, if no, the motor is controlled to rotate at a constant speed, and if yes, according to the recorded time and duty ratio curve, the motor is controlled according to a door opening and closing speed curve. According to the control method, when the position sensor in the motor fails, the motor can still be controlled safely to drive the shield door to be opened or closed normally.

Description

technical field [0001] The invention relates to a motor control method with a position sensor, in particular to a brushed DC motor control method for driving a screen door. Background technique [0002] The commonly used actuators in subway shielded door control systems are brushed DC motors and brushless DC motors. Compared with brushless motors, brushed motors have the advantages of low price, simple control (no commutation required), etc. In order to obtain the position of brushed motors Signal, usually a photoelectric code sensor is embedded inside the motor as a position sensor. The motor controller obtains the displacement change △s through the change of the sensor input signal, and records the time △t used for the displacement change at the same time, and then calculates the running speed of the motor v=△s / △t. The controller takes the speed as the target PID (Proportional Integral Derivative) control. The built-in position sensor of the brushed DC motor is prone to ...

AI Technical Summary

Problems solved by technology

The built-in position sensor of the brushed DC motor is prone to failure due to reasons such as connectors or poor use environment, and the controller can accurately calculate the speed of the motor only by obtaining the position signal. If the built-in sensor fails, the position signal cannot be obtained correctly, and the controller The calculated speed will not match the actual speed of the motor, which may cause safety accidents, such as pinching passengers, improper closing, etc. Even if the motor stops safely, it will affect the normal operation of the subway

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