Surface Tracking Control of Robots Based on Autonomous Trajectory Generating Servomechanism

Abstract

This paper deals with an autonomous surface tracking control. The novel control system comprises the principle of the Autonomous Trajectory Generating Servomechanism (in short, ATGS) and the multifunctional proximity sensor for simultaneous measurements of the distance and two dimensional inclination angles of an object's surface (Both of which were developed by authors). At first, the principle of ATGS is explained briefly. The ATGS system has a trajectory planner in the control loop and realize the trajectory from a nominal path given as the intersection of two surfaces and the tangential speed memorized in the planner as the trajectory model.Next, the surface tracking control is formulated as the trajectory control which controls the motion of the tip of end-effector of robot along a path specified on the object surface keeping its relative pose to the object's surface and tangential speed constant. The path is given as the intersection of the undefined object's surface and an appropriate constraint surface. To realize such system, the nominal trajectory is deduced from the geometrical information of an undefined object's surface detected by the proximity sensor, a specified constraint surface and the tangential speed. Combining the principle of ATGS and the nominal trajectory generating algorithm, the surface tracking control system is obtained.The validity and effectiveness of the proposed method is confirmed by the simulation results.