Research On The Control System Of Piezoelectric Laser Scanner Based On FPGA

Laser scanning technology can accurately control the direction of laser beam,and can be widely used in the fields of lidar,laser measurement micro-imaging,laser processing and so on.In recent years,it has been widely studied by scientific research and industry.Compared with the traditional laser scanner,the piezoelectric laser scanner studied in this paper can achieve high precision scanning in a small angle range,solve the problem of the interference between the axis of the laser scanning.But due to the hysteresis nonlinearity of piezoelectric actuators effect,make the scanning accuracy is limited.In the research of this thesis is based on piezoelectric ceramic driving laser scanner,uses the FPGA platform,designs and realizes the closed loop feedback sliding mode control algorithm,improves the piezoelectric scanning linearity and precision of the laser scanner,fully embodies the piezoelectric drive laser scanner the advantages of small size and high precision of control.In this paper,the piezoelectric laser scanner is taken as the research object,and its digital control circuit is deeply studied.The mechanical structure design and simulation,the design of sliding mode controller,hardware circuit and software control logic are completed.The test platform is built and the system test is completed.The main contents of this paper are as follows:Piezoelectric laser scanner are introduced background and research significance of the topic,research the laser scanner,the sliding mode control algorithm and the field programmable gate array of domestic and foreign research present situation,demonstrates the feasibility of this control system,the research content of this article is determined.In the aspect of mechanical structure,the paper analyzes the working principle of piezoelectric laser scanner,the key components which influence the properties of the scanner,piezoelectric actuator has carried on the simulation and test,achieved the best structural parameters.In the aspect of control algorithm,a closed-loop negative feedback control scheme based on Position Sensitive Device(PSD)sensor is proposed firstly.Secondly,the working principle and design method of the sliding mode controller are introduced in detail.By designing the appropriate sliding mode surface and control rate,the design of the sliding mode controller of the system is completed.In the aspect of control arithmetic implementation,the hardware circuit of analog-to-digital conversion and digital-to-analog conversion based on FPGA chip is designed,and its PCB board is designed according to the layout and wiring principle.The working principle of each function module of sliding mode control algorithm based on FPGA is introduced in detail,and the designed module is simulated with modelsim,which verifies the feasibility of each module design.Set the piezoelectric laser scanner test platform control system,completed the analog-todigital and digital-to-analog conversion circuit and the test control system.The test results show that the designed sliding mode control algorithm can compensate the hysteresis nonlinearity of piezoelectric actuators in open-loop operation.