Energy Efficient Locomotion with Adaptive Natural Oscillator

Abstract

We are presenting a novel adaptive oscillator, called Adaptive Natural Oscillator (ANO), to exploit natural dynamics in robotic application. This tool is built upon Adaptive Frequency Oscillator (AFO), and can be used as pattern generator. Like AFO that adapts to the frequency of an external signal, ANO adapts to the natural dynamics of a system. In this work, we prove that for linear systems, ANO adapts to the natural frequency. We show that this tool exploits the natural dynamics for energy efficiency through minimization of actuator effort. Proposed tool can be used in cyclic robotic applications, especially legged locomotion systems. Lyapunov Stability for Linear case Having the dynamics of the system, applied force for a certain trajectory can be calculated as: ̈ Considering the ANO dynamics, and with the assumption of perfect tracking ( ), we can calculate the applied force as follows: