T-method motor speed measurement method of four-way parallel sampling

Abstract

The invention relates to the technical field of motor speed measurement by a four-way parallel sampling T-method motor speed measurement method, and specifically relates to a method for obtaining the rotational speed of an incremental photoelectric encoder applied to a servo system at low speed operation. First, the incremental photoelectric encoder Output the square wave signals of phase A and phase B to the signal processing controller, set the trigger signals of the four timers as: rising edge of phase A, falling edge of phase A, rising edge of phase B, falling edge of phase B, and then timing The timer starts counting the high-frequency clock pulse signal with a cycle of T, when the timer encounters the same A and B phase change edges again, it records the number of high-frequency clock pulse signals, and at the same time clears the counter and starts the next count cycle, and then calculate the motor speed according to the number M of high-frequency clock pulse signals, and update the speed every time the timer finishes counting the high-frequency clock pulse signals, thus completing the speed measurement of the motor. The speed measuring method of the invention has high speed measuring precision when measuring the low speed of the motor, low dynamic speed measuring error and high dynamic response speed.

Description

[technical field] [0001] The invention relates to the technical field of motor speed measurement, in particular to a method for acquiring the rotational speed of an incremental photoelectric encoder applied to a servo system during low-speed operation. [Background technique] [0002] The performance of the servo motor running at low speed is one of the performance indicators of the servo drive. The accuracy and rapidity of the speed feedback data at low speed operation affect the control performance of the servo system. [0003] The motor speed is indirectly obtained by detecting the output pulse number of the incremental photoelectric encoder coaxially connected with the motor. According to the detected incremental photoelectric encoder pulse frequency and pulse timing, the motor speed is calculated and the motor rotation is judged. direction. [0004] The methods of motor speed measurement mainly include: measuring cycle method (T method), measuring frequency method (M me...

AI Technical Summary

Problems solved by technology

Due to the manufacturing process, the A phase and B phase output by the incremental photoelectric encoder are not orthogonal to each other, which makes the output square wave signal phase shifted, resulting in two adjacent pulses of the quadrupled frequency signal. The deviation of the distance between them will reduce the speed measurement accuracy

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