A Position Identification Method Based on Signal Injection

Abstract

The invention discloses a position identification method based on signal injection. The method comprises the following steps: injecting the same sinusoidal voltage signals of constant frequency and equal amplitude in a stationary two-phase coordinate system, generating harmonic current containing position information; sampling current through a current sensor; separating a fundamental wave and a harmonic wave through a high-pass or band-pass filter, taking out harmonic response current [i<alpha h> i<beta h>]<T>; by the [i<alpha h> i<beta h>]<T>, calculating high-frequency voltage response current [i<xh> i<yh>]<T>, multiplying the [i<xh> i<yh>]<T> by sin(omega<h>t), further performing low-pass filtering, removing an original sin(omega<h>t) item in the signal, and obtaining [i<xh-low> i<yh-low>]<T>. In the position identification method based on signal injection, the high-frequency voltage signals are injected into the stationary two-phase coordinate system, due to a saliency effect of amotor, the harmonic current containing the position information is generated, the harmonic current is processed, thus, the position information can be extracted. The method provided by the inventioninjects the signals in the stationary coordinate system, debugging is relatively easy, complex coordinate conversion is avoided, system is relatively simple, and cost is relatively low.

Description

technical field [0001] The invention relates to the field of servo control, in particular to a position identification method based on signal injection. Background technique [0002] In the servo control system, position information is used in various stages such as positioning, speed regulation, and current vector generation, and is extremely important information. Position sensors (such as photoelectric code discs, gratings, magnetic grids, etc.) are widely used to provide feedback on the position of the mover, and the application is very mature. However, common mechanical position sensors have certain limitations: [0003] 1. The position sensor increases the complexity of the hardware. The installation of the position sensor increases the volume and quality of the system. It needs to be used in conjunction with the hardware circuit for extracting the position signal. The sensor needs to be checked and maintained frequently when it is used; [0004] 2. The accuracy of t...

AI Technical Summary

Problems solved by technology

However, common mechanical position sensors have certain limitations:

[0005] 3. The cost of the position sensor is high, occupying the system budget

However, the rotating high-frequency voltage injection method involves complex coordinate transformation, and the system is too complicated; the pulse-vibration high-frequency voltage injection method is performed under a hypothetical position, and debugging is difficult

Images