Study On Optical Three-dimensional Angle Measuring System With Arcsecond Precision And Microminiature Structure Based On PSD

The laser gyroscope in Inertial Measurement Unit(IMU)is fixed on the shell of IMU by the shock absorbers.The shock absorber is exerted an external disturbance which comes from the slight vibration of the shell and results in an additional angular acceleration output from gyro.In order to improve the measurement accuracy of IMU,it is necessary to compensate the additional angular acceleration by measuring the deformation of the shock absorber.Aiming at the deficiency of the existing angle measuring device in the aspects of increasing dimension measurement,structure appearance,temperature stability and so on,combing the actual needs of designing an inertial navigation equipment,this dissertation proposes a microminiature three-dimensional optical self-collimation angle measuring program based on high-precision position sensitive device(PSD).The main components of the angle measuring system are designed in detail,this dissertation also using the experimental method to verify the feasibility of the program.The main contents of this dissertation are as follows:1.Aiming at the optical imaging process of the self-collimation measuring method,this dissertation studied the influence on measuring results resulting from the imaging quality.This dissertation established a new self-collimation measuring model based on matrix transformation,vector operation and beam transformation theory from the optical structure of the typical self-collimation measuring system.The simplified model error,spot imaging distortion and image trace in the process of measurement were analyzed by numerical simulation.The model can provide a theoretical guidance for the selection and optimization of parameters and the analysis of imaging quality during the construction of the three-dimensional optical self-collimation measuring system.The non uniformity of the spot and the temperature stability of the angle measuring instrument based on the four quadrant detector were studied by experimental method,the shortcomings of this instrument were also pointed out in this dissertation.2.This dissertation designed the optical three-dimensional self-collimating optical path,verified the feasibility of the measuring program by simulating method and analyzed the various factors,which would result in the measuring errors in the measuring system.This dissertation accomplished the selection of the appropriate light source and detector and the design of the optical three-dimensional angle measuring device in order to meet the requirements of high precision and miniaturization.The self-collimation three-dimensional angle measuring optical path and the feasibility of the measurement program was simulated and verified by the non-sequence design function of the ZEMAX optical design software.Means of theoretical derivation and simulation analysis were used to analyze the several error factors which affecting the measuring accuracy of self-collimation measurement.Each error factor correction method was also proposed by this dissertation.3.The optical path of the self-collimation measuring method was established to test the measuring characteristics of the designed program.According to this program,the optical path of the three-dimensional self-collimation measuring method was established on the optical platform to verify the main characteristics of the selected light source and photoelectric detector and test the stability,repeatability and resolution of the measuring system.Experimental results show that the stability of the system error is within 3 ",the three-dimensional measuring accuracy is better than 3".