Neural control for coordinated natural oscillation patterns

We consider linear mechanical systems with asymmetric stiffness matrices. The class of systems captures essential body dynamics of animal/robotic locomotion. In particular, rhythmic body movements similar to those observed in animals can be found as a properly defined natural oscillation of the linear system. The objective is to design a nonlinear feedback controller that achieves the natural oscillation as a stable limit cycle for the closed-loop system. The controller structure we employ is inspired by neuronal circuits for animal locomotion. We translate the design requirement into a multivariable harmonic balance condition, and provide characterizations of neural controllers satisfying the condition.