Research on Atutonomous Truss Assembly by Space Robot Using Object-Oriented World Model

点击翻译按钮获取中文摘要

A visual sensing system for autonomous robot and the autonomous truss assembly by a space robot are studied. The results are summarized as follows.1. A stereo vision system for an autonomous robot is developed. An effective segmentation method using a hierarchical shape graph is introduced to reconstruct the 3D structure of the world. In the identification of the targets, using database built by CAD, a reliable model matching method with error rejection is proposed. To observe motions of the objects in real-time, high-speed image processing algorithm by a single vision system is used to calculate the position and posture of the targets. Combining both processes by parallel programming, the real-time motion tracking is realized.2. A new segmentation method is proposed to distinguish a curved outline of the object. The stereo matching is performed for the corresponding curves between left and right images under an Epipolar constraint. Then, the three-dimensional geometrical feature of the object is reconstructed. In the model matching, information of the size and the shape is compared between the reconstructed object and the data model.3. An autonomous assembly of truss structures using an space robot is studied. An experimental air-table system realizes a two-dimensional frictionless condition on the ground. According to the prescribed order of the truss assembling, the stereo camera system recognizes the positions and attitudes of the target and the obstacles. Then, the manipulator path is generated by a potential method to attain the desired position and attitude of the hand avoiding collision with obstacles. Considering the base structure of the truss as an obstacle, the manipulator can carry each truss element to the base structure without collision. The smooth assembling is realized by the force control using torque sensors on the manipulator. The feasibility of the autonomous assembly of the truss structure is demonstrated by the hardware experiment.