Research On ARM-based Grating Subdivision Technology

The high-accuracy displacement and distance measurement techniques based on the grating Moire fringe principle have a wide range of applications in many fields.Raster subdivision technology can effectively increase the subdivision multiple of the signal without increasing the density of the grating lines.In many raster signal subdivision methods,this paper selects the method of amplitude segmentation subdivision,and tries to subdivide the amplitude division method of raster signal on ARM.The STM32F4 is used in this paper as an ARM development platform for the MCU.The ADC,DMA,LCD,and serial ports are used to implement signal input,function processing,and signal upload.The experimental results preliminarily realized the subdivision processing and output of grating signals.This article first discussed the advantages and disadvantages of the existing subdivision methods.Then the amplitude division subdivision method was chosen to subdivide the grating signal.There are various errors in the grating signal output by the sensor,including high-frequency noise,DC components,amplitude deviation,and phase deviation.This article provides a theoretical method for correcting the above errors.This method is mainly to establish a mathematical model of the sampled signal and the undesired signal components contained in it,and to solve the errors in the signal by the method of least-squares fitting.Then correct the error.This paper also designs a pre-processing circuit for grating moiré signals.Through this circuit,eight times subdivision of grating signals and absolute value processing of orthogonal grating sinusoidal signals are realized.The signal after the absolute value processing is combined with the 8 times subdivided signal input to the ARM processor for high-definition subdivision processing.