Multi-magnetic track sector positioning off-axis absolute value encoder

Abstract

The invention discloses a multi-magnetic track sector positioning off-axis absolute value encoder, comprising an outer ring main magnetic track and an inner ring auxiliary magnetic track, and the outer ring main magnetic track is provided with a plurality of magnetic pole pairs magnetized according to a sine law and a magnetoresistive sensor; a plurality of Hall switches are arranged in the innerring auxiliary magnetic track, one Hall switch corresponds to the magnetic pole width of one auxiliary magnetic track, and the inner ring auxiliary magnetic track adopts square wave magnetization; therelative positions of the Hall switches and the magnetoresistive sensor are fixed, and the Hall switches perform circular motion around the circle center of the encoder. According to the absolute value encoder provided by the invention, the difficulty of a magnetizing process is reduced by improving the magnetizing law of the auxiliary magnetic track, for example a square wave magnetizing technology and the number of magnetic poles are adopted, for example the number of auxiliary magnetic track magnetic poles is half of the number of main magnetic track magnetic poles. And meanwhile, the auxiliary magnetic track adopts square wave magnetization, and the auxiliary magnetic track sensor can adopt a single-stage digital Hall sensor with extremely strong anti-interference capability, so thatthe interference of an external strong electromagnetic field is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of encoders, in particular to a multi-track sector positioning off-axis absolute value encoder. Background technique [0002] At present, the off-axis absolute value magnetic encoder has two schemes: the single-track mode with the precision stripe magnetic pole width varying in density and the multi-track mode with the uniform magnetic pole width. [0003] The single-track encoder with different widths of precision stripe magnetic poles is difficult to magnetize because the magnetic poles are too precise, the structure of the sensor is complicated, and the cost is high. [0004] The multi-track (generally two or three tracks) encoder with uniform magnetic pole width uses one more magnetic pole pair in the main track than the auxiliary track, and the principle of sinusoidal magnetization is adopted, so the sensor of the main and auxiliary tracks The collected signal value has a unique phase difference value ...

AI Technical Summary

Problems solved by technology

[0005] The present invention provides a multi-track sector positioning off-axis absolute value encoder. For the traditional multi-track encoder, the phase difference of the periodic signal of the main and auxiliary tracks is used to calculate the absolute position. The magnetic field recognized by the sensor is an analog signal, and the amplitude error is very large. Sensitive, the traditional method is particularly unstable, on the basis of the traditional multi-track encoder, the auxiliary track structure with specific digital encoding rules is designed to represent the sector number of each magnetic pole pair of the main track, and the magnetoresistive sensor is combined on the main track. Collect and calculate the relative position value, you can get the absolute position value data in the circle to prepare to reflect the specific absolute position value and improve the application of multi-track encoder

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