Research On Mover Position Measurement Method Of Linear Motor Based On Stripe Edge Feature ESPCM

In the ultra-precision manufacturing industry,linear motor servo systems have been widely used.As the execution unit of the precision machine tool system,the linear servo system directly limits the machining accuracy of the machine tool.For high-end CNC machine tools,it is necessary to develop high-precision,precise,and stable systems and control equipment.Focusing on high-precision retention and reliability as the key research direction,the position of the linear motor servo system as the core functional component of the machine tool is particularly important.The linear motor has a series of advantages such as high positioning accuracy,wide speed range and stable operation,and has been widely used in the field of high-precision large-stroke machine tools.For linear servo system drive requirements,the linear motor mover position feedback system needs to achieve high-travel precision measurement.The accuracy of the position detection directly affects the control accuracy of the servo system,which in turn determines the machining accuracy of the machine tool product.The traditional linear motor mover displacement measurement mainly relies on the position sensor.Although the technology is relatively mature,the installation requirements are high,the environmental adaptability is not strong.Therefore,it is especially important to study a high-precision and stable measurement method for the position of a linear motor mover.Image measurement technology in the field of machine vision has the advantages of high precision,intelligence,high stability,and has an irreplaceable advantage in target displacement detection.In order to avoid the deficiencies of the traditional detection methods,image detection is introduced into the precision measurement of the linear motor mover position.This paper proposes a high-precision sub-pixel algorithm based on Extended Sampling Phase Correlation Method(ESPCM),which provides a novel reference for the measurement of moving objects.The specific research contents of this topic are as follows:1.The application background of linear motor mover position measurement is introduced,and the shortcomings of the traditional position detection method are expounded,thereby applying the machine vision image detection method to the position measurement system.The research status of image detection algorithms is analyzed in detail,and the characteristics of different image displacement measurement methods are compared,and the main contents of this paper are derived.2.An image measuring system for linear motor mover position is built.According to the characteristics of the mover motion,the principle of position measurement using image matching method is introduced.According to the frequency domain characteristics of the image,the basic theory of moving target detection method based on frequency domain phase information is clarified.In order to suppress the influence of interference on the measurement displacement,the edge feature extraction measures are adopted for the non-periodic stripe image to ensure the high precision of the measurement.3.In order to meet the high precision and stability requirements of linear motor positioning,an image measurement method based on Extended Joint Transformation Correlation(EJTC)is proposed and applied to linear motor mover position measurement.Based on Joint Transformation Correlation(JTC),the joint power spectrum function of adjacent fringe images is obtained,and the zero-order diffraction peaks are eliminated,and then the oversampled Discrete Fourier Transform(DFT)is introduced achieves sub-pixel precise positioning.The fuzzy edge detection method is used to extract the edge information of the image,which improves the stability of the measurement.The simulation experiment proves that the method can meet the high-precision measurement requirements of linear motor mover positioning.4.Aiming at the high precision and anti-interference problem of linear motor mover position,an extended sampling phase correlation method based on stripe image edge feature is proposed.The high-speed camera is used to collect the fringe image before and after the displacement.In order to suppress the influence of noise and light changes on the measurement results,the edge feature of the image is extracted by the edge detection technique with fusion T entropy,and the edge feature information is used for phase correlation matching to measure the integer pixel location.Then,the matrix Fourier transform is used to up-sample in the neighborhood of the integer pixel positioning point,and then the phase correlation is calculated in the sampling region,and the precise positioning of the sub-pixel level is measured,thereby realizing high-precision measurement of the image.The correctness and effectiveness of the proposed edge-based ESPCM are verified by simulation experiments.5.A moving position image detection experiment platform was built,and a non-periodic stripe image was prepared as the target image.By introducing different displacement detection methods for comparison experiments,by comparing the experimental results and the analysis error,it is shown that the stripe edge feature ESPCM proposed in this research has high detection accuracy and strong anti-noise ability.The algorithm can be effectively applied to the image measurement system,which achieves the anti-interference and high-precision requirements of linear motor mover position detection,and provides a new method for linear motor mover position detection.