Robust adaptive motion/force control for motion synchronization of multiple uncertain two-link manipulators

• Force coupling dynamic characteristics caused by synchronization motion are derived.
• A novel force control method is proposed in this paper.
• The uncertainties are considered in controller design.

High-performance robust adaptive synchronization motion control for multiple two-link manipulators with parametric uncertainties and uncertain nonlinearities is considered. The proposed control approach considers synchronization motion as constraint motion. The Lagrange multiplier method is used to derive the coupling dynamic characteristics caused by synchronization constraint conditions. In order to track desired trajectories while maintaining the synchronization motion, a motion/force control strategy is developed. Motion control is used to track desired trajectories for independent joints. Force control is used to realize the synchronization motion by guaranteeing the constraint force to be zero. In order to improve the performance of force control, a first-order low-pass filter is introduced. Simulation results demonstrate that the proposed method can effectively improve the performance of synchronization motion and tracking performance compared with other methods.