大部件喷涂中的移动机械臂站位规划

Base position planning of mobile manipulator for large parts painting

由于机械臂的后三个关节具有极大的灵活度,且其运动对腕心的位置没有影响,因此以腕心为假想基座,采用D-H方法对机械臂进行重新建模,于是机械臂基座成为姿态固定的名义末端执行器。由名义末端执行器的可达位置的集合构成机械臂实际基座可行位置空间。在喷涂作业过程中,基座可行位置空间随腕心位置移动。通过对基座可行位置空间的交集进行分析,即可确定机械臂在实施区域喷涂作业时的可行站位区域。仿真试验结果表明:与固定规则站位生成方法相比,通过引入基座可行位置空间的概念能够快速确定机械臂站位的可选区域,扩大单次停站作业范围。

Considering that the last three wrist joints of a manipulator are highly dexterous and hove no influence on the position of the writ center point when moving, a mathematical model of the manipulator is reconstructed with origin at the wrist center point. Thus, the base of the manipulator becomes the nominal end effector with fixed orientation. All possible locations of the new end effector can be viewed as the Base＇s Workable Location Space （BWLS）. The BWLS moves along with the wrist center point during the painting task. Through analysis of the intersection set of the BWLSs, the feasible base position area of the manipulator is established. Motion simulations on painting plane and curved surfaces referred to the concept of BWLS are performed. The results show the optional base position area of the manipulator can be quickly obtained and the once stop painting area is extended compared to the fixed rules.