Robust Gain Scheduling for Smart-Structures in Parallel Robots

Smart-structures offer the potential to increase the productivity of parallel robots by reducing disturbing vibrations caused by high dynamic loads. In parallel robots the vibration behavior of the structure is position dependent. A single robust controller is not able to gain satisfying control performance within the entire workspace. Hence, vibration behavior is linearized at several operating points and robust controllers are designed. Controllers can be smoothly switched by gain-scheduling. A stability proof for fast varying scheduling parameters based on the Small-Gain Theorem is developed. Experimental data from Triglide, a four degree of freedom (DOF) parallel robot of the Collaborative Research Center 562, validate the presented concepts