Vibration Suppression Control for a Two-Inertia System Using a Device Simulating Lost Motion

Many gears and reducers are built in the joints of industrial machinery and robots. The harmonic drive is used for many robots. However, harmonic drive has nonlinear characteristics such as lost motion and hysteresis. The vibration suppression performance deteriorates when a parameter fluctuation occurs during vibration suppression control. In the proposed control method, a state feedback is constructed, and the control gain is sequentially changed according to the spring constant during operation, based on the torsion angle θ_s and previously measured spring characteristics. The effectiveness of the proposed method is confirmed by simulation and experimental results.