Dynamic modelling and friction compensated control of a robot manipulator joint

The authors describe a dynamic modeling of a robot joint drive, based on experimental results. The friction model is a function of angular position and velocity. This model was used for the design of mechanisms to compensate for internal disturbances. Two friction compensation mechanisms were tested experimentally: one for the position-dependent part and another for the velocity-dependent part. The velocity-dependent friction torque component was written in a different form. This made possible an analysis of closed-loop poles behavior, that can be useful in the elaboration of gain scheduling control laws.