多机械臂抓取物的内力不变性

ON THE INVARIANCE OF INTERNAL FORCE OF OBJECTS GRASPED BY MULTIPLE ROBOTIC ARMS

对多机械臂抓取物的受力分析表明，现有物体内力的定义不具备欧几里德直射变换下的不变性，导致模型化的内力与物体实际所受内力不符，基于这样的定义进行载荷分配并实施协调控制会造成物体或机械臂的损坏．本文定义了两投影算子，把手臂作用力分解成两部分，一部分只影响物体运动，另一部分不导致物体运动而产生内力效应．基于力分解定义的内力具备欧几里德直射变换下的不变性。

Internal force analysis for objects grasped by multiple robotic arms is presented in this paper.It is pointed out that the existing definition of internal force is not invariant to Euclid collineration. This leads to some difference between the modeled internal force and the real one. Load distribution and coordination control based on the wrong definition may cause damage to robotic arms and/or manipulated objects.With the use of two new projection operators,the forces imparted to the object by robotic arms are decomposed into two parts,one affects only the motion of the object and another leads to no motion of the object but internal force.Internal force defined in this way is invariant to Euclid collineration.