Research On Magneto-electric Scanning System

Compared with traditional radar technology,laser radar has the advantages of high measurement accuracy,high time and spatial resolution and large detection range,thus becoming an important active remote sensing tool.Lidar can not only accurately measure distance,but also accurately measure speed and precise tracking.It has broad application and great development prospects in civil and military fields.In recent years,with the development of artificial intelligence,the application requirements in the fields of driverless and target recognition and tracking are increasing.The research on laser radar omnidirectional scanning detection technology and the size and weight of laser radar are required.Portability is also becoming more and more important.At present,the most widely used laser radar large-angle scanning method is mechanical rotation,which has the advantages of simple,low cost and large coverage angle,but due to the limitation of the stepping motor,its durability is not high and the volume is large.Under the rapid development of MEMS technology,the galvanometer is integrated and its control circuit is on a small module of several centimeters.This is the MEMS galvanometer.The use of MEMS galvanometer is the most popular development direction of laser radar miniaturization.It has the characteristics of small size,fast speed and fast scanning speed.It has strong technical advantages and application prospects in vehicle laser radar.In this paper,the research on laser radar scanning system is aimed at miniaturization of laser radar and reducing the volume and cost of laser radar.Inspired by MEMS scanning mirrors,the mechanical mechanism of the deflection of the galvanometer controlled by the motor is abandoned,and the magnetic field force of the energizing solenoid is used as the driving force to combine the galvanometer with the magnetoelectric driving structure;For guidance,the driving and control of the galvanometer is realized by the digital PID control method.The STM32 MCU uses the USB full-speed protocol to communicate with the host computer,and the scanned image path data generated by the host computer flows to the FPGA through the STM32.In order to achieve accurate scanning of the galvanometer,the carrier of the digital PID controller is realized by FPGA,and the position sensor is used to feedback the real-time position of the galvanometer.The position data is input into the FPGA chip through the A/D converter,and the position data and output are output in the FPGA.The data is subjected to deviation analysis calculation,and the position signal is automatically corrected by means of proportional,integral and derivative(digital PID controller),and then the output signal is converted into an analog signal by a D/A converter and enters the galvanometer driving circuit through the amplifying circuit.The drive circuit enhances the driving capability of the analog signal,and finally enters the solenoid to drive the galvanometer.In the design of the system,it is necessary to pay attention to the accuracy of the data at all times.Among them,STM32 and FPGA communication data errors and FPGA timing design are prone to timing default is the biggest problem.Through the use of professional analysis tool software,online debugging,and finally solve this problem to some extent.