tailieunhanh - Advances in Theory and Applications of Stereo Vision Part 6

Tham khảo tài liệu 'advances in theory and applications of stereo vision part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | A High-Precision Calibration Method for Stereo Vision System 115 The hazard detection cameras are used to real-time obstacle detection and arm operation observation. The navigation cameras can pan and tilt together with the mast to capture environmental images all round the rover then these images are matched and reconstructed to create Digital Elevation Map DEM . Simulation environment can be built including camera images DEM visulization interface and simulation space rover as indicates. In real application rover sends back images and status data. Operators can plan the rover path or arm motion trajectory in this tele-operation system Backes Tso 1999 . The simulation rover moves in the virtual environment to see if collision occurs. The simulation arm moves in order to find whether the operation point is within or out of the arm work space. This process repeats until the path or the operation point is guaranted to be safe. After these validations instructions are sent to remote space rover to execute. Fig. 2. Space rover simulation system. 3. Camera model The finite projective camera which often has pinhole model is used in this chapter just like Faugeras suggested Faugeras and Lustman 1988 . As shows left and right cameras have intrinsic parameter matrixes Kq k Kq uq sq u0q 0 k-vq 0 0 1 J q 1 2 1 116 Advances in Theory and Applications of Stereo Vision The subscript q 1 2 denotes left and right camera respectively. If the number of pixels per unit distance in the image coordinates are mx and my in the x and y directions f is the focal of length kuq fmx and kvq fmy represent the focal length of camera in terms of pixel dimensions in the x and y directions respectively. Sq is skew parameter which is zero for most normal cameras. However it is not in some instances like x and y axes is not perpendicular in the CCD array. u0q and v0q are the pixel coordinates of image center. The rotation matrix and translation vector between camera frame Fcq and world .