Modeling and motion control of helical microrobots using the dual quaternion framework and adaptive sliding mode strategy

This study investigates the tracking control problem of helical microrobots (HMRs) in complicated blood environments. The integrated relative motion model of HMRs is established by resorting to the dual quaternion method, which can describe the coupling effect between the rotational and translational motions. Subsequently, an original apparent weight compensator (AWC) is designed to alleviate the adverse effects of the HMR sinking and drifting owing to its own weight and buoyancy. An adaptive sliding mode control based on the developed AWC (AWC-ASMC) is constructed to guarantee the fast convergence of the relative motion tracking errors in the presence of model uncertainties and unknown perturbations. The chattering phenomenon of the classical SMC is significantly reduced using the developed control strategy. Furthermore, the stability of the closed-loop system under the constructed control framework is demonstrated by the Lyapunov theory. Finally, numerical simulations are performed to demonstrate the validity and superiority of the developed control scheme.