Tracking control of capsule robot systems with unknown dynamic parameters

Vibro-impact capsule robots have attracted widespread attention in recent years owing to their promising applications in both industrial and medical fields. Nevertheless, the intrinsic nonsmooth and complex dynamic characteristics of such vibro-impact systems, together with the intricate behaviors arising from variations in initial states and parameter configurations, render the control of vibro-impact capsule robots a formidable challenge. This study addresses the tracking-control problem for vibro-impact capsule systems. First, based on the system’s dynamic structure, the motion states of the capsule are classified into six distinct categories. Next, a piecewise state-feedback control strategy is devised and a corresponding piecewise closed-loop system is constructed. The Lyapunov theory is then employed to derive the stability criteria and conditions required for system stabilization. Finally, numerical simulations validate the effectiveness of the proposed approach. And the results demonstrate that the desired tracking objective can be achieved regardless of the system’s initial conditions.