Research On Autonomous Bionic Positioning Method Based On Skylight Polarization

Navigation and positioning technology emerges with the development of political, economic, and cultural of human society. Key technologies of Navigation and positioning involves in cutting-edge research in the field of electronic information technology, computer science, image processing technology, detection technology and many other disciplines.As the most commonly used navigation and positioning method, GPS has unparalleled advantages. However, it would lose its navigation and positioning information when the satellite failure, GPS signal disturbed, or GPS signal cheated occurs because of its dependence on satellite; While as the most commonly used autonomous navigation method, INS has a fantastic anti-interference ability. But it would get a accumulated error after a long time due to its working principle of using path integration to derive the relative position with respect to the initial point; CNS has a brilliant anti-interference ability features. Yet it has a disadvantage of computationally intensive, complex equipment, and low-altitude aircraft navigation in the atmosphere because of relatively weak of the star intensity in the atmosphere.It is found that many insects are able to use the skylight polarization information to navigate their way home. However, since the polarization navigation sensor can only derive the polarization angle and polarization degree of the skylight, the polarization angle is used as reference direction information in the path integration, or as a part of GPS, INS, but cannot get the geographic position independently.In order to find an autonomous positioning method, which overcomes the dependent on satellites of GPS, the accumulated error of INS, and the complicated, heavy and inefficient within the atmosphere of CNS, a bionic positioning method based on skylight polarization angle and taking advantage of navigation triangle was proposed to measure the latitude and longitude of the current position by two independent observations of the polarized skylight. Our research includes the following several aspects, specifically:1) This paper made a detailed summary on the history of navigation and positioning technology, the principle and current situation of the non-autonomous navigation method and autonomous navigation method. The biological navigation mechanism of the ant Cataglyphis by taking advantage of the polarized skylight, as well as the present situation of the bionic navigation and positioning method based on skylight polarization were summarized and explained in depth. Thereby, we understood the problems and difficulties faced by the research of bionic skylight polarization navigation.2) This paper proposed a bionic positioning method based on skylight polarization. The current geographic position is able to be determined by the course angle, the polarization angle and the relative position between the solar and the earth.3) To evaluate the positioning accuracy, a positioning error model was proposed, and the impact factors including the precision of the sensors, the accuracy of solar declination, and the location of the observer was analyzed.4) A bionic skylight polarization system consists of a three-camera skylight polarization angle measuring module, a course angle measuring module and a computer processing module has been setup as the experimental platform to implement outdoor tests. The results of outdoor test shows that the polarization angle is stable in a period of time which coincides with the pattern of skylight polarization, and the experiment results are relatively stable which shows that the bionic positioning method is feasible and the positioning system is workable. The advantages and shortages of the proposed bionic positioning method were summarized. Future research directions were also proposed.