Practically Oriented Finite-Time Control Design and Implementation: Application to a Series Elastic Actuator

This paper proposes a practically oriented finite-time control design for nonlinear systems under a less ambitious but more practical semiglobal control objective. As one main contribution, the designed finite-time controller can be expressed as a very simple form while the control gain tuning mechanism follows a conventional pole placement manner, which enhances its facility in practical implementations. Moreover, by utilizing a modified nonrecursive homogeneous domination design without preverifying any nonlinearity growth constraints, the control scheme can be directly obtained by totally neglecting the recursive calculations of series virtual controllers. Rigourous semiglobal attractivity and local finite-time convergence analysis are presented to ensure the theoretical justification. A control application and experimental verification to a series elastic actuator demonstrates the control effectiveness and significant performance improvements compared with asymptotical state feedback controllers.