【作者】 欧阳帆；

【导师】 张铁；

【作者基本信息】 华南理工大学 ， 机械设计及理论， 2013， 博士

【摘要】 现代工业的发展和机器人技术的进步使得机器人的性能不断提高，机器人应用的领域和范围正不断扩展，机器人将会越来越多地代替人类去执行更多更复杂的作业。为了适应不断提高的任务复杂性、操作智能性以及系统柔顺性等要求，双机器人乃至多机器人之间的协调和协同作业是机器人技术在工业环境中进行推广和应用急需解决的关键技术之一。由于多机器人系统(主要是多机器人操作臂)操作物体时形成闭链系统，存在受限运动及冗余度控制问题，意味着多机器人系统需要解决规划方法、解析方法和可行的控制方法等问题。本文以两台六自由度工业机器人的运动学协调和带有力控制的协调作业方法为研究对象，对双机器人系统的避碰路径规划方法、双机器人之间坐标系标定、协调运动轨迹规划和优化方法、带有力反馈控制的协调作业方法等问题进行了系统深入的研究，主要内容如下：针对双机器人系统的碰撞检测和避碰路径规划问题，提出了基于八叉树数据结构的三层球体碰撞检测模型、用于有向包围盒（Oriented Bounding Boxes，OBB）之间最短分离距离和最短穿透距离计算的SAT-SDPD算法。通过仿真验证了提出方法的有效性和可行性，比较和分析了不同包围盒建模方法的快速性和准确性。提出了基于速度排斥场的避碰路径规划和优化方法，通过数值仿真分析证明了使用改进的速度排斥场模型在双机器人避碰路径规划中具有较好的效果。双机器人协调焊接轨迹规划方法的研究是进行双机器人协调焊接以及保证焊接质量的前提。论文对焊缝进行了离散化及建立离散点的坐标系，提出在船型焊约束下对工件坐标系{WP}进行位姿规划的非主从式双机器人协调焊接轨迹规划方法，并提出在笛卡尔空间中基于操作性最优的工件坐标系{WP}位置的优化搜索方法。通过仿真验证了协调焊接轨迹规划方法和工件坐标系{WP}位置优化搜索方法的有效性。运动学协调是双机器人协调作业的基础，也是实现带有力控制的协调的前提。论文提出了获得两台机器人基座坐标系之间位姿矩阵的三点标定方法，通过数值仿真验证了提出方法的有效性；提出了通过离线计算，自动生成所需的从机器人的协调跟随运动路径点和协调镜像运动路径点的协调路径生成方法。试验结果表明，从机器人协调运动轨迹精度满足工业应用要求，验证了该离线计算方法的有效性。针对双机器人协调搬运作业中的内力控制问题，对双机器人共同抓取一个物体的静力学进行分析，基于现有的位置/力混合控制与阻抗控制这两种典型力学控制方法，提出了基于遗传算法优化的双机器人协调搬运速度阻尼PD控制方法。试验结果表明，相比优化前的速度阻尼P控制误差减小，验证了提出的控制方法和优化算法的有效性。最后为验证轨迹规划方法和力控制方法的有效性和可行性，搭建了双机器人运动学协调和力学协调两个实验平台进行试验研究。试验分为两部分，第一部分为运动学协调试验，包括了两个试验，分别为在已知主机器人末端运动路径的条件下，离线生成从机器人协调跟随运动路径试验，以及离线生成从机器人协调镜像运动路径试验。第二部分为基于力反馈阻尼控制的双机器人力学协调搬运试验。试验结果表明，双机器人运动学协调轨迹精度达到工业机器人作业要求，双机器人协调搬运内力控制具有较好的瞬态性能，跟踪精度和鲁棒性。更多还原

【Abstract】 The development of modern industry and the improvement of robotic technology arefacilitating the performance of robots, therefore, the application field and scope of robots iscontinuously expanding and the application of them performing more works, which are evenmore complicated, instead of human, is increasing. In order to adapt to the increasingrequirement of work complexity, operation intelligent and system flexibility, the coordinationand collaborative operation of dual robot or multi-robots is the key technology, which iscritically need to be mastered, to promote and implement robotics in industrial environment.The closed chain system when multi-robot systemsoperate on objects restricted leads tomotion and redundancy control problems, which need to adress the issues in planning,analytic method and feasible control method in multi-robot system.The research object of this paper is the operation methods of kinematics coordination andforce control coordination by two6DoF industrial robots. Systematic and in depth study aremade on the collision avoidance path planning, coordinate system calibration, trajectoryplanning and its optimization method of coordinated motion by dual robots, the main contentsare as follows.In order to solve the problem of collision detection and collision avoidance path planningof dual robot systems, collision detection model of three layers’ sphere based on octree datastructure and the SAT-SDPD algorism, which is used to compute the shortest separationdistance and the shortest penetration distance between oriented bounding boxes, are proposed.Simulations are performed to verify the effectiveness and the feasibility of the algorism aswell as to compare and analyze the efficiency and accuracy of different modeling methodusing bounding box. Collision avoidance path planning and optimization methods, based onrepulsive velocity field, are proposed. It is proved by numerical simulation analysis that theimproved repulsive velocity field model has a good effect on collision avoidance pathplanning of dual robots.The study of trajectory planning method of coordinated welding by dual robots is thepremise to guarantee success of coordinated welding and the welding quality. This paperestablishes the coordinate systems of weld discrete points, non-master-slave trajectoryplanning methods for dual robots coordinated welding have been proposed, whose positionand pose planning are performed in the workpiece coordinate system{WP}under down handwelding constraints. Besides, optimal value search algorithm for the position of workpiececoordinate system in Cartesian space has been proposed. The effectiveness of the trajectory planning method of coordination welding and optimization algorithm for the position ofworkpiece coordinate system is verified by simulations.The kinematics coordination is not only the foundation of coordinated operation by dualrobot, but also the premise of realizing force control and coordination. In this thesis, athree-point calibration method, which is used to acquire the position and pose matrix betweenthe base coordinate of dual robots, has been proposed, its effectiveness is verified bynumerical simulation. The coordinated path generation method for slave robot’s coordinatedpath points are proposed, the slave robot’s path points of both coordinated following motionand mirror motion are generated through off-line computing. The results of the experimentsindicate that the accuracy of the motion trajectory by dual robots coordination can meet therequirements of industrial applications. Therefore, effectiveness of the proposed off-linecomputing method is verified.To solve the problem of internal force control in coordinated transportation by dualrobots, static analysis of dual robots’ grabbing an object collaboratively is presented. Anoptimized velocity damping PD control method, which is based on two existing typicalmechanical control methods, namely position/force hybrid control method and impedancecontrol, for coordinated transportation by dual robots based on genetic algorithm, has beenproposed. Experiment results indicate that the optimized control method has smaller controlerror than that of the common velocity damping PD control method, which justifies theeffectiveness of the proposed control methods and optimization algorithm.Finally, to verify the effectiveness and feasibility of the trajectory planning method andforce control method, two experimental platforms for dual robots kinematic coordination andforce coordination are respectively established. The experiments consists of two parts, thefirst part is kinematic coordination experiments, which includes off-line generatingslave-robot coordinating follow motion path experiments as well as off-line generating slaverobot’s coordinating mirror motion path experiment under the condition that motion path ofthe end of master robot is known. The second part is the experiment about coordinatedtransportation by dual robots based on force feedback damping control. The results of theexperiments show that the precision of trajectory of kinematic coordination, whose internalforce control has good transient performance, tracking accuracy and robustness, by dualrobots can meet the requirement of industrial robots operation.更多还原