Tham khảo tài liệu 'contemporary robotics - challenges and solutions part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Robot-Based Inline 2D 3D Quality Monitoring Using Picture-Giving and Laser Triangulation Sensors 81 Time-optimal dynamical path planning Vision-based inspection. Fig. 2. Quality monitoring of aircraft fuselages with wide- and short-range inspection sensors. Left Inspection station and test environment. The movement of production pieces is carried out by monorail conveyors which do not allow precise positioning. Right Development and demonstration platform DDP . Fig. 3. Sensor magazine. Localisation of unfixed industrial test objects As the first step of the presented quality monitoring chain the exact position of a production piece is determined with a wide-range picture-giving sensor Fig. 2 which is - depending on the object size - mounted in an adequate object distance . not necessarily fixed on an inspection robot s end-effector. A marker-less localisation calculates the exact object position in the scene. This procedure is based only on a 3D CAD-model of the test object or at least a CAD-model which represents a composition of some of its relevant main parts. The CAD-model contours are projected into the current sensor images and they are matched with sub-pixel accuracy with corresponding lines extracted from the image Muller 2001 . 82 CONTEMPORARY ROBOTICS - Challenges and Solutions Fig. 4 shows a localisation example. The CAD-model projection is displayed in yellow and the object coordinate system in pink colour. The red pixels close to the yellow projection denote corresponding image line pixels which could automatically be extracted from the image plane. The calculated object pose consisting of three parameters for the position in 3D scene space as well as three parameters for the orientation see the red text in the upper part of the figure can easily be transformed into the global scene coordinate system displayed in green colour . Known test zones for detail inspection as well as associated sensor positions and orientations or required sensor .
