【作者】 张涛；

【导师】 居鹤华；

【作者基本信息】 北京工业大学 ， 控制科学与工程， 2016， 硕士

【摘要】 巡视器就位探测任务规划是巡视器自主探测系统的重要组成部分,其作用是巡视器在规划探测任务时,保证巡视器机械臂满足不与探测环境和车体本身发生干涉的约束、机械臂位形切换次数最少的约束、机械臂探测空间覆盖探测点的约束。此外探测点还需满足平整度、光照等约束条件,以保证机械臂端接光谱仪的正常工作。本文以CE3巡视器车载3自由度正交机械臂为主要研究对象,研究了巡视器机械臂的正逆运动学,并以此为基础研究了机械臂工作空间\探测空间、月面探测环境仿真、机械臂碰撞检测等,用于机械臂无干涉的约束条件。通过探测点评估和巡视器位姿估计等研究,满足探测点的平整度、光照等约束。首先,使用DH方法对CE3巡视器机械臂各杆件建立坐标系,根据相邻坐标系间的旋转、位移关系完成机械臂的正运动学解算。针对机械臂杆件串联位姿的传递性和机械臂正交构型的特殊性,基于欧几里得范数简化计算机械臂逆运动学解析解的求解过程。机械臂正逆运动学的正确性通过正逆运动学互验实验检验。通过机械臂正运动学原理介绍了机械臂工作空间和探测空间的概念为后文奠定了理论基础。为满足机械臂与探测环境和车体自身不发生干涉的约束,提出了月面探测环境仿真方法、基于AABB包围盒的机械臂粗碰撞检测方法和基于虚拟传感器的机械臂细碰撞检测方法。该碰撞检测方法为巡视器就位探测任务规划中的安全性奠定了理论基础。其次,通过对A*算法的研究分析,提出了一种改进型SA*算法。改进后的SA*算法通过机械臂关节相同转动方向节点的代价削减和祖孙节点合并的方法满足机械臂位形切换次数最少的约束。通过扩展节点时对所有叶节点的机械臂位形进行碰撞检测的方法进行机械臂展开避障,保证机械臂运动过程中的安全性。由仿真实验结果可以看到SA*算法可以规划出机械臂遥控指令最少的机械臂运动序列。然后,提出探测点评估方法,即使用探测点相邻点集的方差评估探测面的平整度和通过星历、点云数据中探测面的地理信息计算太阳光反射角和光谱仪轴线夹角的方法评估探测点光照,解决了巡视器执行探测任务时探测点的光照、平整度约束。针对探测点不在巡视器机械臂工作空间中,需通过图像系统多次调整巡视器位姿的问题,提出了基于机械臂工作空间几何中心投影估计停泊位置和基于碰撞检测、向量归一化估计巡视器姿态的巡视器定位定姿方法。归纳总结出CE3巡视器就位探测任务规划算法,提高了巡视器探测效率。最后,在VS2008开发平台上基于Open Inventor图像库,开发了一套巡视器探测三维仿真软件。该软件集成了机械臂正逆运动学、碰撞检测、机械臂工作空间\探测空间、巡视器停泊规划、机械臂展开规划等功能。通过友好的人机交互模式和可视化的3D仿真,不仅证明了涉及巡视器探测任务的各种原理算法的正确性,还极大的提高了用户体验。针对多系统协同工作时的数据交换和资源共享,提出了一种快速扩展HLA Web服务的方法,该方法对各系统与编程语言和操作系统进行解耦,降低了开发成本,增强了系统开发的灵活性。更多还原

【Abstract】 The task planning of rover parking in place to probe is an important part of rover autonomous detection system. The purpose of the planning algorithm is that to satisfy the constraints that manipulator should not collide with the detection environment, number of switches of manipulator is minimized and the work space of manipulator covers the detection point. Besides, the detection point should also satisfy constraints of smoothness and lighting to ensure that the spectrometer works correctly. In this paper, the main research object is the 3-DOF manipulator of the CE3 rover. In the paper, the forward and inverse kinematics model of the manipulator is researched. Based on the research, the work\detection space of manipulator, simulation of detection environment and collision detection of the manipulator is also researched. The smoothness and other constraints are satisfied by the estimation of detection point and calculation of the attitude of rover.First of all, the coordinate of each rod of the CE3 rover’s manipulator was created using the D-H method. According to the rotation vector relation of adjacent coordinate, the forward kinematics of the manipulator is solved. The calculation of inverse kinematics was simplified by the transfer of the position and the Orthogonal configuration of the manipulator. The correctness of the forward and inverse kinematics of the manipulator is verified by the experiment. The concepts of work and exploration space are introduced using the principle of the forward kinematics, which establishes the theoretic foundation. The simulation of the environment, the collision detection method based on the AABB bounding box and virtual sensor is presented to satisfy the collisionless constraint. The safety of the new planning algorithm can be guaranteed by the collision detection method.Secondly, An improved SA* algorithm is proposed based on the analysis of A* algorithm. The constraint of minimum switches of manipulator is satisfied by costing cuts the same direction of the rotation and merging the adjacent points. The safety of the manipulator movement is guaranteed by the collision detection when the leaf nodes is extended. The test results show that SA* algorithm could plan the fewest control commands.Then, using the variance of the adjacent points of the detection point to evaluate the flatness of the probe surface. The lighting constraint is evaluated by calculating the angle between the sun reflected light and the spectrometer axis. Focusing on the problem of detection point is not in the work space and need to adjust the attitude of the rover many times, a new method of position and orientation is presented by vector projection and collision detection. The task planning of the CE3 rover parking in place to probe algorithm is summarized, which improves the detection efficiency.Finally, a 3D rover simulation software system was developed based on VS2008 and Open Inventor graphics library. The software integrates a variety of features. Not only proved the correctness of the principles involved in this thesis, but also improve the user experience. A fast method to extend HLA Web services is presented for data exchange and resource sharing in multi system. This method decouple the system and the programming language, reduce development cost and enhance the flexibility of the system development.更多还原