Co-optimization of Acrobot Design and Controller for Increased Certifiable Stability

Unlike fully actuated systems, the control of underactuated robots necessitates the use of passive dynamics to fulfill control objectives. Hence, there is an increased interdependence between their design parameters and the closed loop performance. This paper proposes a novel approach for co-optimization of robot design and controller parameters for increased certifiable stability obtained with means of region of attraction analysis and gradient free optimization. In particular, it discusses the co-optimization problem of a gymnastic acrobot robot where the design and the controller are optimized to have a large region of attraction (ROA) taking into account the closed loop dynamics of the non-linear system stabilized by a linear quadratic regulator (LQR) controller. The results are validated by extensive simulation of the acrobot's closed loop dynamics.