Towards the Unification of System Design and Motion Synthesis for High-Performance Hopping Robots

Robotic hopping requires high performance and precision, due to its extreme interactions with the environment. Designing a system that will perform optimally, or even stably, for this motion primitive is a significant challenge. In previous work, it was shown that designing a robot with two springs (one in series and one in parallel with the actuator) could dramatically improve performance. However, selecting these springs was an intricate process since their dynamics were tightly coupled, and accomplished through trial and error. This work presents a general optimization framework for interconnected systems that designs the time-based hopping motion, while also designing the shape of nonlinear springs on the robot to yield efficient hopping. Utilizing this method, hopping motions and spring designs were generated simultaneously and experimentally verified on a novel hopping robot.