Real-Time Collision Avoidance Algorithm for Surgical Robot Based on OBB Intersection Test

To improve flexibility and adaptability, a surgical robot normally has a number of arms and redundant degrees of freedom, which may cause collision between robotic arms. In this paper, a real-time collision avoidance algorithm based on OBB (Oriented Bounding Box) intersection test was presented to solve this problem. The cube model of each arm was established based on OBB. According to the distance between any two OBBs, probable collision components can be found. Along with the kinematics of the surgical robot, maximum motion range of each joint can be obtained under the condition of no collision. Then the concept of Collision Index was proposed to represent the relationship between the angular position and the maximum motion range of each joint. In order to avoid collision, Collision Indexes were used to limit the motion of each joint. Experimental results show that the algorithm is effective and could avoid collision between manipulators.