| With advancing in deep space exploration technology,future planetary landing missions will be more likely to be carried out in complex,dangerous terrain environments.This requires the lander to have a stronger obstacle recognition capability.In order to solve the problem of the future landing mission on Mars,some methods based on passive vision obstacle detection are searched.The methods designed in this paper are focusing on solving the obstacle detection problem in complex terrain environment.The main work of this paper is as follows:In complex terrain situations,multi-scale craters exist at the same time which brings difficulties to effectively determine the craters detection window scale.In this paper,a method is proposed to detect the region of interest area of craters by using Bandeira edge detection method.Which has a stronger response to the crater lip.After the ROI regions been chosen,the interference terrain without craters can be effectively eliminated.Then,the bright and dark regions are selected and matched by size constraints and light direction constraints in the region of interest.Finally,the work of locating one single crater is completed.In complex terrain situations,there is no unified description of all kinds of obstacles.In this paper,a significant obstacle detection method is proposed.first,The two-dimensional histogram is used to organically combine the saliency detection result with the gray-scale variance detection result.second,the segmental Gamma correction is used to enhance the detection result.In the end,the two-dimensional histogram is divided by the maximum variance of the two-dimensional category of the re-partitioning to complete the detection of the complex obstacle topography.For the simple method of obstacle detection based on gray level and texture information,it is difficult to effectively detect the slope obstacle.To deal with this problem,it is necessary to reconstruct the three-dimensional information of the landing area by using stereo vision,and estimate the slope and roughness of the terrain by fitting local median plane.The final result is a quantitative estimate of the slope and roughness.Finally,some experiments have been done in order to test the performance of each chapter algorithm.According to the performance characteristics of each algorithm,a landing hazard detection method is designed.The simulation experiment of the designed landing obstacle detection process is carried out by using the sand table and the motion simulation platform of the laboratory.The experiment proves that the algorithm can effectively find out the flat area which meets the requirement of landing from the complicated terrain environment. |
