Robust force control based on compensation for parameter variations of dynamic environment

Force control strategies that are robust against disturbance and parameter variations are proposed. These strategies are expansions of disturbance observer-based control strategy, and require little computation. Observers are proposed that estimate parameter variations of the dynamic environment on which the force is imposed are introduced. Since the observer-based control represents a nominal system, a second derivative of force can be controlled. A force control strategy for controlling the second derivative of force is also proposed. The force response similar to the force command is realized by these strategies in spite of the disturbance and the parameter variations of the control object. The effectiveness of the proposed methods is confirmed by simulation and experimental results.>