Design And Implementation Of Distance Measurement System Based On CCD Laser Triangulation Method

As one of the basic technologies to promote the development of industry and science and technology,the non-contact distance measurement technology has developed rapidly in recent years.However,compared with the developed countries such as Europe and the United States,the non-contact ranging system designed by China had some shortcomings such as low measurement accuracy,complicated circuit structure and high cost.Therefore,in this paper,the ARM Cortex-M3 core chip and CCD sensor are applied to design a laser triangulation ranging system which is precise,practical,low cost and functional.Firstly,this paper studies the measurement principle of the laser triangulation ranging system,and determines the optical system design using the straight triangulation method under Scheimpflug conditions,and describes the overall design of the system and the entire workflow.Secondly,the optical path structure of the ranging system was studied and the parameters of the optical system were determined.The influence of the optical system parameters on the performance of the ranging system was analyzed by MATLAB software.In addition,a method for determining the optical system parameters was proposed in this paper.This method was solved by nonlinear programming and Monte Carlo simulation.By using this method,the time of obtaining parameters can be shortened,and the optical parameters can be optimized.Thirdly,the hardware circuit of the distance measuring system was designed and the PCB sample was completed.The main controller of this subject was selected as STM32F103ZET6 chip,which was a chip of the Cortex-M3 core.In order to achieve the expected function,peripheral devices were added on the chip minimum system,such as LED prompt lamp,mode button,serial port module,AT24C02 data storage chip and LCD12864 screen.Fourthly,In Keil MDK5.20 development environment,the embedded software program was developed and completed.It mainly includes: CCD sensor module driver,data processing integration program,spot center location program,measurement distance calculation program,key scanning program,serial communication program,24C02 data storage program,LCD display program.At last,The function debugging and system calibration of the distance measuring system had been completed.Under the working mode 1,the starting point of measurement is 87 mm,the range is 50 mm,and the root mean square error of the measured data using Fourier three times fitting is 0.0436mm;Under the working mode two,the starting point of measurement is 138 mm,the range is 280 mm,and the root mean square error of the measured data using Fourier eight times fitting is 0.1820 mm.The whole ranging system has the functions of control,measurement and display.The ranging system can complete the distance measurement independently without using the computer.And it can save measurement data.The practicability of the distance measuring system is high.