串联九自由度喷涂机器人及其运动学分析

Design and Kinematics’ Analying of a Series Nine-degree-of-freedom Spraying Robot

在工业生产中,喷涂是重要的加工过程,喷涂机器人已经广泛应用于喷涂行业,但复杂工件的内表面喷涂还多依赖人工完成。针对多腔室多障碍的大型构件内壁的喷涂,提出一种新型九自由度喷涂机器人。根据多腔室多障碍大型构件的结构特点,按功能将此机器人结构划分为工作定位装置、工作执行装置和辅助支撑装置;基于D-H参数法,建立此机器人的数学模型,进行正解的求取;给出一种冗余机器人计算反解的方法:根据喷涂不同方位的腔壁对前三个关节进行角度预设,从而保证喷涂目标面处于工作执行装置的灵活工作空间;根据关节7工作空间的特性,采用正向求解和逆向求解分别得到关节7的位置坐标,并反推关节6的位姿,进而得到其他关节角度值完成反解。此求解方法得到的反解能够保证机器人在对同一壁面喷涂时具有相似的构型姿态,解决了反解过多、求解难度大、解筛选困难的问题,极大地提高反解的求解速度。

Spraying is an important process in industrial production. Spraying robot has been widely used in spraying industry, but the task of spraying the inner surface of complex workpiece still depends on manual operation. The main content of this paper is to design a new spraying robot to spray the inner wall of large components with multiple compartments and obstacles. According to the structural characteristics of multi-chamber and multi-obstacle large components, a robot with 9 degrees of freedom is presented, the robot manipulator is divided into working positioning device, work execution device and auxiliary support device. Based on the D-H parameter method, the mathematical model of the nine-degree-of-freedom robot is established, and the positive solution is obtained. A new method for calculating the inverse solution of redundant robot is proposed. According to the different directions of the cavity wall, the angles of the first three joints are preset to ensure that the spraying target plane is in the flexible working space of the working execution device. Considering the characteristics of the workspace of joint 7, the position coordinates of joint 7 are obtained by forward solution and inverse solution, the position and posture of joint 6 are derived, and then the inverse solution is completed by solving the angle values of other joints. The inverse solution obtained by this method can ensure that the robot has a similar configuration pose when spraying on the same wall, which solves the problems of the selection of too many inverse solutions, and greatly improves the solving speed of the inverse solution.