Angle self-correction method and system based on multi-frequency excitation

Abstract

The invention discloses an angle self-correction method and system based on multi-frequency excitation. The system includes a multi-frequency signal generation module, which is used to generate an excitation signal containing multiple frequencies, and inject the excitation signal into a coil to generate a magnetic field; a high-speed ADC module , used to sample the output signal generated by electromagnetic induction with equal time difference; and convert the sampled output signal into a digital signal; the microprocessor module is used to control the sampling timing of the high-speed ADC module; and use the Fourier transform method to The phase of the digital signal is extracted to obtain the angle function of the measured rotating object at each frequency; the self-correction module is used to self-extract the error parameter of the angle function, and correct the angular displacement sensor according to the error parameter. The invention has low cost and high practicability, and can be widely used in the technical field of displacement measurement.

Description

technical field [0001] The invention relates to the technical field of displacement measurement, in particular to an angle self-correction method and system based on multi-frequency excitation. Background technique [0002] Electromagnetic encoder usually includes two parts: magnetic pole and reading head. The reading head injects a single high-frequency excitation signal, then modulates the angular displacement to realize angular displacement measurement, and then cooperates with the space equalization technology to reasonably and evenly distribute the magnetic poles to achieve better The purpose of high-precision displacement measurement. According to the way the magnetic field is generated, magnetic encoders can be divided into electromagnetic encoders and permanent magnet encoders that rely on alternating current excitation coils for electromagnetic induction. When the electromagnetic encoder modulates the signal, it contains the repeated conversion process of "electric...

AI Technical Summary

Problems solved by technology

The Chinese patent (application number 201710720507.8) describes a method for optimizing the layout of the reading head for self-calibration. This patent is used to improve the installation of the reading head in the EDA method and expand the application of the EDA method, but it still needs to install multiple Readhead, no hardware cost reduction

However, this method obviously has the following shortcomings: 1. The installation accuracy of multiple reading heads is limited by the structural size of the encoder; 2. For encoders with too small diameter, when the number of reading heads is greater than 3, there will be serious installation errors; 3. It is impossible to install the reading head in infinite equal parts on a circle, and the position of each reading head needs to ensure a high degree of consistency, so that the effect of the EDA method is obvious

The performance is as follows: (1) The EDA method needs to install multiple reading heads, which has high installation requirements and increases the application cost; (2) the traditional correction method needs to collect a large amount of position data at equal intervals throughout the week, and the process is cumbersome and responsible, time-consuming and laborious ; (3) Existing methods all need to rely on external instruments, or construct multiple reading heads by physical methods

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