Study On Night Vision And Navigation System On Vehicle

In order to drive snugly the vehicle at night, the forward situation and directionof vehicle must be acquired snugly and real timely without the assistance ofillumination. The new Night Vision and Navigation System on Vehicle (NONSV) hasbeen presented and studied. It is a minitype wide field low-light-level night visiondevice which has independent and passive navigation function as assistantance.The main researched contents and achievements are as follows:(1) A elementary prototype of the new NONSV is studied and produced. Becausethe Field of View (FOV) of the existing night vision device is about 30°to 40°, thedemand of driving vehicles can't be satisfied. In order to solve this problem, NONSVhas been presented and studied in the dissertation. The designed NONSV canautomatically and real timely provide a wide field forward road image and have thecovert navigation function.(2) The study of Image Mosaics System based on Digital Signal Processor(IMS-DSP). The system was mainly studied on how to acquire wide fieldlow-light-level images. The image mosaics technique had been adopted in the systemby analysising many methods to enlarge the FOV. According to the demand of theactual project, DSPs was adopted as main processor. The system can run withoutcomputer so that it ensures miniaturization and carry-home trait. The test result provesIMS-DSP can obtain a seamless wide field low-light-level video image at 20FPS withFOV of 120°and its back vision module provides a substitute of the backup light.(3) The study of the hardware design of IMS-DSP. The overall framework ofIMS-DSP was demonstrated and designed by studying the high speed DSPs andmemory technology. The used device was chosen reasonably, the whole hardwarecircuit plot was designed, and the PCB was designed and made. By the primarydebugging for the system, it is proved that the hardware design of the system iscorrect and feasible, and that the hardware platform is established to realize the capture of wide field low-light-level video images.(4) The study of image mosaicing algorithm. According to DSPs characteristic,to meet the actual needing, many image mosaicing algorithms were analysised andcompared, and the entire image processing algorithm mode of the system wasdesigned by combining the image registration algorithm based on subpixel phasecorrelation with image fusion algorithm based on the wavelet transformation. Byanalysing the function module of IMS-DSP, the software design methods onDSP/BIOS was adopted, EDMA and EMIF resources were utilized reasonably, andmultithreading software design of the system was obtained. The speed of video imagewas 20FPS in the test result, the frame was refurbished in 0.05 second, the vehicle'smaximum speed was 50 kph (14 meters per second), and the vehicle ran 0.7 meterswhen the image was refurbished, so the speed of video image can satisfy the practicalneed. It is proved that the entire image processing algorithm mode of the system andsoftware design method was reasonable.(5) The study of digital compass system. The study of the system provides anapproach to solve that the driver can't obtain direction at night. By studying andcomparing many navigation techniques, and considering the need of concealment, thenew digital compass system was studied and produced. The passive mode was used tomeasure direction information in the system, so the shortcoming of the satelliteposition navigation system that is prone to be disturbed and controlled by others canbe overcomed. By analyzing the forming principle of deviation and magneticdeviation, and using Poisson equation, an algorithm to remove deviation wasestablished, and the new proposed algorithm can overcome the shortcoming of thetraditional compass that can't automatically remove the deviation and magneticdeviation. The elementary protype of the digital compass system can snugly providethe direction information, and can successfully and automatically remove thedeviation and magnetic deviation, and its precision is 0.5°.