Adaptive impedance control in robotic cell injection system

The time-varying force control in cell injection is a difficult work that suffers from low precision, non-repetition and uncontrollable characteristics, especially when the uncertainties from both the robotic model and the injected cells (uncertain environment position and stiffness) are considered. In this paper, a simple adaptive impedance control method combining an inner-loop impedance controller and an outer-loop trajectory tracking algorithm is proposed to cope with the time-varying compliant force control. The time-delayed joint controller is utilized to compensate for the uncertainties in the robust position controller, and in the inner-loop, previous information of certain system parameters are applied to design the adaptive law. Stability and convergence have also been analyzed and simulation studies are shown to verify the effectiveness of the proposed controllers.