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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Neurorobot. | doi: 10.3389/fnbot.2019.00059

Synchronization of Nonlinear Oscillators for Neurobiologically Inspired Control on a Bionic Parallel Waist of Legged Robot

 Yaguang Zhu1*, Shuangjie Zhou1, Dongxiao Gao1 and Qiong Liu1
  • 1Chang'an University, China

Synchronization of coupled nonlinear oscillators inspired by central pattern generator (CPG) can control the bionic robot and promote the coordination and diversity of locomotion. But for a robot with strong mutual coupled structure, such neurobiologically control is still missing. In this contribution, we present a σ-Hopf harmonic oscillator with decoupled parameters to expand the solution space of the locomotion of the robot. Unlike the synchronization of original Hopf oscillators, which has been fully discussed, the asymmetric factor of σ-Hopf oscillator causes a deformation in oscillation waveform. Using the nonlinear synchronization theory, we construct the transition state model of the synchronization process to analyze the asymmetrical distortion, period change and duty ratio inconsistency. Then a variable coupling strength is introduced to eliminate the waveform deformation and maintain the fast convergence rate. Finally the approach is used for the locomotion control of a bionic parallel waist of legged robot, which is a highly coupled system. The effectiveness of the approach in both independent and synthesis behavior of four typical motion patterns are validated. The result proves the importance of controllability of the oscillation waveform and the instantaneous state of the synchronization, which benefits the transition and transformation of the locomotion and makes the coupling motion more flexible.

Keywords: Bionic parallel waist, Locomotion control, synchronization, transition state, σ-Hopf oscillator

Received: 27 Apr 2019; Accepted: 11 Jul 2019.

Edited by:

Poramate Manoonpong, University of Southern Denmark, Denmark

Reviewed by:

Horacio Rostro Gonzalez, University of Guanajuato, Mexico
Arash Ahmadi, University of Windsor, Canada
Chengju Liu, Yangpu Hospital, Tongji University, China  

Copyright: © 2019 Zhu, Zhou, Gao and Liu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Prof. Yaguang Zhu, Chang'an University, Xi'an, China, zhuyaguang@chd.edu.cn