空间多自由度串联机械臂的避障运动规划方法研究

发布时间：2018-05-03 08:44

本文选题：空间串联机械臂 + 碰撞检测模型　；参考：《合肥工业大学》2017年硕士论文

【摘要】：在工业4.0及中国制造2025的双重背景下,机器人技术已逐渐成为智能制造业的主要标志之一。目前,以各型机械臂为代表的机器人已经涉足于工业制造、航空航天、娱乐服务业、医疗、军事等领域。在这些领域中,空间多自由度串联机械臂是应用最广泛的一种机器人,针对其运动学、动力学的相关理论研究也一直是机器人领域的一个重要研究热点。其中,对机械臂的运动路径规划方面的研究是机器人运动控制的关键技术,其规划效果直接影响机械臂运动学、动力学的性能表现。而在实际应用中,机械臂的工作环境多为复杂障碍物地形,在运动过程中需要进行有效的避障规划。因此,本文主要以空间多自由度串联机械臂为研究对象,分别在笛卡尔空间和关节状态空间中对其进行避障运动规划方法的研究,最终实现无碰撞路径规划,对机器人运动控制具有一定的理论意义和实际应用价值。本文主要从以下四个方面展开研究:首先,基于D-H理论对常见的六自由度空间串联机械臂为例进行数学建模,并基于机械臂正、逆运动学原理进行方程推导。其次,就机械臂路径规划过程中机械臂与环境障碍物碰撞问题,本文提出了三种常见的空间几何体包络模型,即圆柱体包络模型、长方体包络模型及球体包络模型,并通过简化机械臂模型,把机械臂各关节干涉及与障碍物实体碰撞检测问题转化为空间点-线-面之间的位置关系判断问题,然后通过空间解析几何知识进行分析求解。之后,本文提出了两种机械臂避障路径方法:一种是笛卡尔空间中基于A~*算法与机械臂逆解结合的避障路径规划方法,该方法只适用于满足Pieper准则的机械臂;另一种是关节空间中基于改进RRT算法结合机械臂正解的路径规划方法,该方法通过罚函数法建立以机械臂运动平稳性和机械臂末端最优性为代价适用度函数,且适用于任意自由度串联机械臂。最后,为验证上述理论工作,本文建立虚拟样机进行仿真实验,并搭建机械臂实物样机进行运动演示。经验证,两种路径规划方法都能令机械臂实现一条自起始点到终止点最优路径,且在运动过程中能够避开所有存在于工作空间中的障碍物。
[Abstract]:Under the dual background of industry 4.0 and made in China 2025, robot technology has gradually become one of the main symbols of intelligent manufacturing. At present, robots represented by various types of robotic arms have been involved in industrial manufacturing, aerospace, entertainment services, medical, military and other fields. In these fields, the spatial multi-degree-of-freedom serial manipulator is the most widely used robot. The kinematics and dynamics of the manipulator has been an important research hotspot in the field of robot. The research on motion path planning of manipulator is the key technology of robot motion control, and its planning effect directly affects the performance of kinematics and dynamics of manipulator. However, in practical application, the working environment of the manipulator is mostly complicated obstacle terrain, and effective obstacle avoidance planning is needed in the process of motion. Therefore, this paper mainly studies the motion planning method of multi-degree-of-freedom series manipulator in Descartes space and joint state space, and finally realizes collision free path planning. It has certain theoretical significance and practical application value for robot motion control. In this paper, the following four aspects are studied: firstly, based on D-H theory, the mathematical model of six degree of freedom space series manipulator is established, and the equations are derived based on the forward and inverse kinematics principle of the manipulator. Secondly, with regard to the collision between manipulator and environmental obstacles in the course of path planning, three kinds of spatial geometric envelope models, namely cylindrical envelope model, cuboid envelope model and sphere envelope model, are proposed in this paper. By simplifying the model of manipulator, the problem of joint interference and collision detection with obstacles is transformed into the problem of determining the position relationship between points, lines and surfaces in space, and then analyzed and solved by the knowledge of spatial analytic geometry. Then, two obstacle avoidance path methods are proposed: one is the obstacle avoidance path planning method in Cartesian space based on the combination of Awe * algorithm and inverse solution of the manipulator, which can only be applied to the manipulator that meets the Pieper criterion; The other is a path planning method based on the improved RRT algorithm and the forward solution of the manipulator in the joint space. The penalty function method is used to establish the cost applicability function of the manipulator motion stability and the end optimality of the manipulator. And suitable for any degree of freedom series manipulator. Finally, in order to verify the above theoretical work, a virtual prototype is established to carry out simulation experiments, and a prototype of the manipulator is built to demonstrate the motion. It is proved that both of the two path planning methods can make the manipulator realize an optimal path from the starting point to the termination point and avoid all obstacles existing in the workspace during the process of motion.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP241

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