A method for detecting the rotational speed of a motor

Abstract

The invention relates to the technical field of motors. The invention discloses a method for detecting the rotational speed of a motor. The method is used for carrying out the alternate mode driving and control of pulse power supply and pulse power supply stop on the motor, and comprises the following steps of S1, carrying out AD (Analog-Digital) sampling on electromotive force generated by two ends of the motor during the period of the pulse power supply stop, and entering a step S2; S2, carrying out amplitude limiting wave filtration treatment on an AD sampling value obtained in the step S1, if amplitude limiting wave filtration is met, putting the AD sampling value in an array A, and otherwise, abandoning the AD sampling value; returning to the step S1 until the array A is full, and entering a step S3; S3, taking out a maximum value in the array A, putting the maximum value in an array B, discarding other numerical values of the array A, and returning to the step S1 until the array B is full, and entering a step S4; S4, carrying out median average wave filtration treatment on a numerical value in the array B to obtain a final numerical value, wherein the final numerical value is the characterization amount of the rotational speed of the motor. The method does not need an extra sensor, cannot influence an assembly space, and is low in cost, high in detection precision and quick in response speed.

Description

technical field [0001] The invention belongs to the technical field of motors, and in particular relates to a method for detecting the rotational speed of a motor. Background technique [0002] The basis of DC brush motor speed control is the detection of motor speed. At present, the commonly used motor speed detection technologies mainly include the following methods: Hall signal and photoelectric sensor are used to detect the speed. Both of these methods require additional sensors. Not only affects the assembly space, but also increases the hardware cost. Another way is to detect the working voltage and current of the motor, but because the current and voltage clutter in the working of the motor is very large, and the amount of calculation is large, it is too difficult to achieve precise control. [0003] Chinese published patent: CN101098118A, discloses a speed control method and its control circuit of a DC drive system. The disadvantage of this method is that this pate...

AI Technical Summary

Problems solved by technology

[0002] The basis of DC brush motor speed control is the detection of motor speed. At present, the commonly used motor speed detection technologies mainly include the following methods: Hall signal and photoelectric sensor are used to detect the speed. Both of these methods require additional sensors. Not only affects assembly space, but also increases hardware cost

Another way is to detect the working voltage and current of the motor, but because the current and voltage clutter in the motor work is very large, and the amount of calculation is large, it is too difficult to achieve precise control

[0003] Chinese published patent: CN101098118A, discloses a speed control method and its control circuit of a DC drive system. The disadvantage of this method is that this patent uses a hardware circuit to realize the timing control of the pulse and the voltage holder to judge and compare the electromotive force. This patent not only uses many devices, but the cost is high, and the whole scheme can only achieve a single speed. Control, can not flexibly realize a variety of speed detection and control, and the sampling accuracy of the hardware is low, the feedback of the speed change is slow, and it is difficult to achieve fast response in the control of the motor speed when the load changes

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