On Minimizing the Energy Cost of a Safe Spring-Assisted Modular and Reconfigurable Robot

Safety must be guaranteed over the desire for lower energy consumption in our multiple working mode (MWM) approach to collaboration safety with a spring-assisted modular and reconfigurable robot (SA-MRR) arm. In this work we developed an energy-aware, antagonistic MWM actuation strategy which satisfies stringent constraints for SA-MRR spatial safety, and which is simultaneously capable of minimizing its own implementation energy cost. Numerical optimization has been applied to seek the spring stiffness and the motor torque saturation threshold contributing to the lowest task-specific energy consumption of the proposed MWM safety strategy. It was discovered that the actuation strategy could reduce cumulative motor energy consumption by 72.1% in a simulated safety-critical manipulation task without compromising safety. Numerical simulations have demonstrated the energy effectiveness of the proposed MWM actuation strategy for SA-MRR spatial safety in collaboration-inspired tasks where the manipulator is confined to a relatively smaller, task-specific region of its work envelope.