Abstract
Energy-aware motion planning for robotic systems has received increasing attention during recent years, due to environmental and economic reasons. This letter presents a framework for defining and solving different types of optimal control problems for variable stiffness actuated robots. These robots can store and release energy during task execution, but motion planning and control are made difficult by the presence of several physical constraints. In the optimal control problems formulated in this letter, constraints on power and energy are explicitly accounted for, while minimizing energy consumption or maximizing performance. The validity of our approach has been tested on a ball-throwing case study, for which simulation and experimental results are presented and discussed.