Principle Research And Design Of Angle Sensor Based On Optical Triangulation

With the continuous development of information science and engineering technology,modern precision angle measurement technology has gradually matured,and it has also been widely used in modern industry.Angle sensors have always been aimed at producing features such as miniaturization,high accuracy,and high resolution.With the increasing requirements of industrial products for angle sensors,various new angle sensors have appeared on the market.The existing grating angle sensor has limited space for improving its measurement accuracy due to its manufacturing process,structure,cost and many other factors.Therefore,based on the principle of optical lever,this paper conducts an in-depth study on the measurement principle of the angle sensor,and studies a Angle sensor measurement scheme based on optical triangulation method.Because the existing grating angle sensors have many shortcomings,such as high cost and relatively low measurement accuracy,the research on low-cost,good-performance angle sensors has very important research significance.In this paper,the optical triangulation magnification method is used to realize the conversion between displacement and angle,and the angle detection is realized by a position-sensitive detector.Firstly,the advantages and disadvantages of various angle sensors are analyzed,the principle of angle measurement by optical triangulation method is deeply studied,and the structural parameters of the sensor are optimized.The Monte Carlo algorithm is used to analyze the uncertainty factors that affect the accuracy of angle measurement.Design the reflection structure parameters,hardware circuit design and signal acquisition and processing algorithms of the angle sensor.Finally,in order to further improve the measurement accuracy of the angle sensor,the position sensitive detector PSD(Position Sensitive Detectors)is used to compensate for the error and to process the repeat-ability verification experimental data and generate errors through the angle sensor measurement experiment.The reasons are analyzed.In this paper,the Monte Carlo algorithm is used to simulate and analyze the uncertainty factors of the angle measurement accuracy.It can be seen that the angle error and radius error have a very small influence on the angle sensor measurement accuracy,so this paper simplifies the angle measurement calculation formula.Due to the large measurement error of the PSD purchased in the experiment,it has a significant impact on the measurement accuracy of the angle sensor.Therefore,this paper uses the method of linear precision interpolation to compensate the measurement error of the PSD.The experimental test shows that the PSD measurement error is±400μm.After error compensation and repeat-ability experiment verification,the corrected PSD measurement error can be obtained at ± 20μm,which can further improve the measurement accuracy of the angle sensor.After processing the experimental measurement data,it is concluded that the measurement error of the angle sensor is about ±30 ’,and the main reason for the large angle measurement error is that the PSD position measurement error is too large,and the laser spot quality is not good.Finally,it summarizes the research content of this paper,and looks forward to the optimization of the optical measurement system and the improvement of angle measurement accuracy in the later period.