Real-time Lissajous Circle Eccentricity Processing Method for Encoder

Abstract

The invention relates to a real-time encoder Lissa jous circle eccentric processing method. The method comprises the following steps that an encoder is electrified and initialized and is connected to an external FRAM module, the FRAM module reads a previous (sin theta, cos theta) signal value to an RAM module in a FPGA module and calculates an initial circular eccentric value; the encoder starts and woks at a fixed frequency, the RAM module continuously updates an eccentric (sin theta, cos theta) signal value, carries out determination and eccentric value calculating, maps to an angle grid point index of a non-eccentricity Lissa jous circle so as to carry out angle grid point calculating and compares change conditions of the index; angle grid point calculating processing is performed on the eccentric (sin theta, cos theta) signal value, a newest value is used to carry out eccentric value compensation and then a cordic module calculates an accurate angle; and the FPGA module carries out voltage monitoring, and when a voltage is decreased, the (sin theta, cos theta) signal value in the RAM module is immediately written into the FRAM module. In the method, an encoder does not need to be calibrated in advance, and an eccentric value is calculated in real time and is compensated so that an error brought by an eccentricity is completely eliminated.

Description

technical field [0001] The invention relates to the technical field of encoders, in particular to a method for processing real-time Lissajous circle eccentricity of an encoder. Background technique [0002] The Lissajous circle is put to the The synthetic circle enclosed by the X-axis and the Y-axis, in which the DC term [a,b] of the cosine signal and the sine signal is the X-axis and Y-axis coordinates of the center of the Lishayu circle, and the amplitude A of the sine or cosine signal is the Lisayu The radius of the circle. Due to the existence of calculation errors in the Lisa circle, the problem of eccentricity of the Lisa circle often occurs. The current solution is to calibrate the encoder to measure a fixed and average eccentricity value and write it into the memory chip (Flash). , when calculating the angle, read this value and compensate for {sinθ, cosθ} before calculating the angle. [0003] In order to improve the resolution, the encoder usually has physical s...

AI Technical Summary

Problems solved by technology

[0004] Based on this, it is necessary to provide a real-time Lissajous circular eccentricity processing method for encoders that does not require prior calibration, the eccentricity value is real-time dynamic, and can completely eliminate the circular eccentricity error.

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