Research And Implementation Of Fiber-optic Beam Collimation Algorithm Based On FPGA

With the application and popularization of optical fibers,it not only promotes the development of communication and information,but also has obvious advantages in the illumination of medical surgical microscopes.The good surgical lighting effect depends on the quality of the fiber.When measuring the fiber beam quality parameters,the fiber beam must be collimated first to ensure the accuracy of the measured quality parameters.In recent years,many collimation schemes have been researched both at home and abroad to improve the collimation speed and accuracy and reduce the cost of collimation,such as using CCD/CMOS face detection methods,various lens combinations,platform automation and so on.In order to improve the speed and accuracy of collimation,this paper compares and analyzes various collimation schemes,studies the fiber beam collimation process,and proposes a fiber-optic beam collimation algorithm based on FPGA.The main research work is as follows:(1)FPGA-based fiber beam collimation scheme design.Starting from the characteristic parameters of the single-mode fiber,the necessity of fiber beam collimation is demonstrated.The collimation scheme was compared and analyzed,and a fiber-optic beam collimation scheme based on a hardware platform was designed.Design the collimated hardware structure,complete the design of the mechanical arm selection and communication protocol,and use a robotic arm to build a fivedimensional control platform.(2)Collimation control algorithm research and its MATLAB simulation analysis.The fuzzy control algorithm and Generalized Predictive Control(GPC)algorithm are studied.The control algorithm simulation based on MATLAB platform is completed and analyzed.The advantages of the GPC algorithm as the collimation algorithm are highlighted.The GPC algorithm is improved to reduce the amount of calculation and improve the speed of the algorithm.(3)FPGA implementation of the collimation algorithm.Using FPGA parallelism,three array structures are designed and used as the basic computing unit of the GPC algorithm to implement recursive inversion matrix,parameter identification,and incremental control solution.The correctness of each module based on the VHDL algorithm is verified by ModelSim simulation.The parallel acceleration of the GPC algorithm is realized,compared with the traditional FPGA implementation of predictive control,it performs faster.(4)Build a fiber-optic beam collimation experiment platform to implement the collimation algorithm for testing and verification.Analyze the performance and error of the experimental system,and analyze the beam collimation parameters and beam quality parameters of planar fiber and wedge fiber to improve the collimation speed and accuracy.It ensures that the measurement error of the divergence angle is within the allowable range of the system,the measurement of the off-axis degree is achieved and the measurement requirement of the optical fiber beam is achieved.