A simple model of flexible manipulators with six axes and vibration control by using accelerometers

A simple model of flexible manipulators having a heavy end‐effector is presented by introducing a set of equivalent springs which represent all flexibility of manipulators. The equations of vibrations of the end‐effector and the equations of motion of robot links are derived on the basis of the proposed model. Accelerometers are installed on the end‐effector for measuring the vibrations, and output signals of the accelerometers are fedback for suppressing the vibrations. A feedback control law incorporating a state observer is proposed, and stability problem of the feedback system is treated by using small gain theorem. Several satisfactory experimental results are shown.