Local Ultrastability in a Real System Based on Programmable Springs

Abstract

A way to move gradually towards an objective is by making sure at every step that there is as little deviation as possible while adapting to obstacles. This has inspired us to model a local strategy to eventually attain viability (equilibrium) in a real complex dynamical system, amidst perturbations, using ultrastability to make sure that the path to viability itself is viable. We have tested this approach on a real actuator powered by a technology called “programmable springs” that allows for real-time non-linear programmable actuation. Our experiment involves a problem in adaptation similar to the pole-balancing problem. To solve it, we use ultrastability in a novel way, looking at the viability of dynamical transitions of the system in its phase space, to tweak the local properties of the actuator. Observations show that our approach is indeed effective in producing adaptive behaviour although it still requires further testing in other platforms, thus supporting the original hypothesis that ultrastability can be an effective adaptive mechanism [3] and laying a foundation for a promising new perspective in ultrastable robotics.