Statement of Research Interest

My research focuses primarily on optimal control of systems in domains with contacts, equipped with variable impedance actuators. The control of such robots is non-trivial due to the the discontinuity in the dynamics which is introduced by mechanical contact with the environment. The traditional optimal control approach is designed to handle smooth continuous system dynamics for tasks over a predetermined time horizon. Several modifications, such as the hybrid dynamics formulation, exist in order to cope with discontinuities. These methods have proven feasible, under certain restrictions and constraints on both the plant dynamics and the environment [1, 2, 3, 4]. In spite of the substantial amount of research on hybrid dynamics, examples in the optimal control literature are confined to low-dimensional and simple dynamical systems, and only a few robotic applications for optimisation of movements over multiple phases are available [5, 4]. The use of variable impedance actuation is motivated by investigations into how biological systems employ the use of impedance control [6, 7]. These systems use motions that exploit, rather than overcome, the non-linearities of the physical systems. Many passive variable stiffness actuators still rely on active control schemes to realise damping requirements [8], and there are very few actuator designs that are able to passively vary damping [9].