Nonlinear torque control of a single-link flexible robot

In this research, a nonlinear torque control law with a free function is ap plied to the simultaneous motion and vibration control of a single-link fle xible robot. A rigorous proof of the asymptotic stability of the closed-loo p system is provided and experiments are conducted by taking the free funct ion in the feedback law as the output of one of the following vibration sen sors: strain, shear force, reaction force, tip acceleration, and accelerati on at some intermediate point. The experimental results demonstrate that th e use of strain, shear force, and reaction force information in the control law can substantially suppress vibrations in the arm, while the effect of incorporating the acceleration information can be better or worse, dependin g on where the accelerometer is placed. (C) 1999 John Wiley & Sons, Inc.