Multitrack Sector Positioning Off-Axis Absolute Encoder

Abstract

The invention discloses a multi-track sector positioning off-axis absolute value encoder, which comprises a main track of an outer ring and an auxiliary track of an inner ring. The main track of the outer ring is equipped with a plurality of magnetic pole pairs and magnetoresistive sensors magnetized with a sinusoidal law; a plurality of The Hall switch is configured in the auxiliary track of the inner ring, one Hall switch corresponds to the magnetic pole width of an auxiliary track, and the auxiliary track of the inner ring is magnetized with a square wave; the relative position of the Hall switch and the magnetoresistive sensor is fixed, and a circle is made around the center of the encoder sports. The absolute encoder provided by the present invention reduces the difficulty of the magnetization process by improving the magnetization law of the auxiliary track, such as adopting square wave magnetization technology and the number of magnetic poles, such as that the number of magnetic poles of the auxiliary track is half of that of the main track. At the same time, because the auxiliary track adopts square wave magnetization, the auxiliary track sensor can use a single-stage digital Hall sensor with strong anti-interference ability, thus greatly reducing the interference of external strong electromagnetic fields.

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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