Multi-rate model predictive control based tracking control for on-orbit manipulation through contact

The autonomous implementation of space manipulation by space robots are trends for future on-orbit services. Existing researches are constrained by a framework of capturing before operating, which fails to fully utilize dynamics of space robots and relies on specialized capturing structures, lacking good generality. Although some studies have attempted to leverage contacts to adapt to different targets in space manipulations, hybrid and underactuated dynamics caused by contacts made their tracking control difficult to realize. This paper proposes a hierarchical control framework that employs model predictive control as a low-frequency planner and control barrier function based optimal control as a high-frequency tracker. This control strategy tracks trajectory of contact-based operations effectively.The stable tracking with reduced computational consumption of model predictive control makes the strategy suitable for online applications.A simulation case is provided to demonstrate the effectiveness and reliability of the hierarchical control strategy.