Design and implementation of a robust switching control scheme for a class of constrained robot tasks

The focus of the paper is on the design and real-time control implementation issues of a switching control scheme for a robot interacting with a constraint surface. One key aspect that is investigated is the effect of uncertainty in the location of the constraint surface. A switching controller that is robust to uncertainty in the location of the constraint surface is given; overall stability of the controller for a typical constrained robot task is shown. A strategy for real-time trajectory modi. cation, which is required to compensate for the discrepancy in the a priori known location and the actual location of the constraint, is given. An experimental platform consisting of a planar robot manipulator equipped with a force sensor and a robotic surface finishing tool is described; typical experimental results for the manipulator following straight and circular surfaces are given for the proposed real-time implementation scheme. The proposed research can find applications in robotic surface finishing operations such as polishing, chamfering and deburring, etc.