Research On Laser Range-gated Super-resolution 3D Imaging Technology Based On FPGA

With the improvement of image quality requirements,traditional passive imaging has been unable to meet people's needs.Laser range-gated super-resolution three-dimensional imaging technology has been widely used in industry,civil,aerospace,military and national defense because of its advantages of long imaging distance,high imaging resolution,rich image information and little impact by rain,snow,haze and other adverse environmental factors.Such as personnel search and rescue,ocean exploration,port detection,spacecraft soft landing and so on.In this paper,the range-gated super-resolution three-dimensional imaging technology is studied,and its experimental design is carried out.Firstly,the scheme design and theoretical analysis of range-gated three-dimensional imaging technology are carried out,and the synchronization control schemes of range-gated are compared and analyzed,and the external synchronization control scheme is chosen to design the experiment.In the selection of electrified imaging equipment,ICCD is selected to obtain image information after comparison.In addition,the working principle of several commonly used laser range-gated three-dimensional imaging technologies is also described.A set of code channel waveforms for coding super-resolution gated control is designed,aiming at the super-resolution methods based on trapezoidal and triangular range-energy correlation algorithm.Secondly,based on the principle of super-resolution three-dimensional imaging technology,an experimental platform is designed and built.This paper uses Altium Designer software platform to design and draw the schematic diagram of the control circuit board of the FPGA.It mainly consists of the minimum system of the FPGA,power management module,synchronous level conversion module,analog image acquisition module,storage module,serial communication module and Cameralink output module.Then,in the aspect of software design,we use Verilog language to realize the programming design of the FPGA on ISE14.7 software platform.It mainly includes the design of serial communication module needed by the host computer to send instructions to the FPGA,the design of synchronous control timing between pulse laser and ICCD,the design of analog image acquisition and conversion to digital image information module,and the design of SRAM "ping pong" storage module.The design of median filter and thedesign of Cameralink module which transmits the pre-processed image data information to PC.Finally,Boxes at 17.1m indoor and towers at 205 m outdoors and buildings at 220 m outdoors have been selected as experimental targets.Laser range-gated super-resolution three-dimensional imaging experiments have been carried out,and the experimental data have been processed and analyzed.Through the corresponding distance energy correlation algorithm,the inverted three-dimensional pseudo-color image is obtained by using the software of matlab.