FPGA-based orthogonal signal real-time processing method

Abstract

The invention discloses an FPGA-based orthogonal signal real-time high-precision processing method. The FPGA-based orthogonal signal real-time processing method adopts an orthogonal signal processing board constructed based on an FPGA, and computer measurement software. The orthogonal signal processing board and the computer measurement software realize processed data communication between upper and lower computers by means of USB data lines. The orthogonal signal processing board mainly realizes acquisition, differential preprocessing, mean filtering, error compensation, real-time phase calculation, as well as phase subdivision and direction judgment of orthogonal signals. The computer measurement software screens orthogonal signal sampled data input by the lower computer, then calculates a signal error compensation parameter through matrix operation, controls an orthogonal signal compensation program of the lower computer to operate, displays a correction effect and a measurement result on a measurement software display interface in real time, and stores relevant data. The FPGA-based orthogonal signal real-time processing method realizes the effect of compensating for orthogonal errors, amplitude fluctuations and DC drift errors of signals of a gate type sensor and a laser interferometer in real time, and provides an engineering solution for high-precision grating signal analysis and error real-time compensation.

Description

technical field [0001] The invention relates to the field of orthogonal signal processing methods, in particular to an FPGA-based orthogonal signal real-time processing method. Background technique [0002] Grid sensors and laser interferometers are widely used in modern precision measuring instruments, CNC machine tools, photolithography machines, superfinishing and other fields, and are typical measurement equipment for modern precision testing. The output signals of grid sensors and laser interferometers are orthogonal signals. In practical applications, although such sensors are optimized in the design of sensing structures such as optical paths and photoelectric conversion circuits to reduce the influence of error factors, the actual output of orthogonal signals It is inevitable that there will be quadrature error, amplitude fluctuation, and DC drift error factors of the signal, which will eventually affect the measurement accuracy of the sensor. With the development o...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a real-time processing method for quadrature signals based on FPGA to solve the problem that the processing speed of quadrature signals in the prior art is slow and only offline analysis and compensation can be performed.

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