T. Naniwa et S. Arimoto, LEARNING CONTROL FOR ROBOT TASKS UNDER GEOMETRIC END-POINT CONSTRAINTS, IEEE transactions on robotics and automation, 11(3), 1995, pp. 432-441
A learning control scheme for a class of robot manipulators whose endp
oint is moving under geometrical constraints on a surface is proposed.
In this scheme, the input torque command is composed of two different
signals updated separately at every trial by different ways. One is u
pdated by the angular velocity error vector which is projected to the
tangent plane of the constraint surface in joint space. The other is u
pdated by the magnitude of contact force error at the manipulator endp
oint. Not only the uniform boundedness of position and velocity trajec
tory errors but also the uniform convergence of position and velocity
trajectories to their desired ones with repeating practices are proved
theoretically. In addition, it is shown that the contact force itself
converges to the desired one in the sense of L(2)-norm with repeating
practices. Computer simulation results by using a 3 DOF manipulator a
re presented to demonstrate the effectiveness-of the proposed method a
nd to examine the speed of convergence of force trajectories besides p
osition and velocity trajectories.