Parallel Spine Design and CPG Motion Test of Quadruped Robot

Abstract

The spine of mammals aids in the stability of locomotion. Central Pattern Generators (CPGs) located in spinal cord can rapidly provide a rhythmic output signal during loss of sensory feedback on the basis of a simulated quadruped agent. In this paper, active spine of quadruped robot is shown to be extremely effective in motion. An active spine model based on the Parallel Kinematic Mechanism (PKM) system and biological phenomena is described. The general principles involved in constructing a neural network coupled with limbs and spine to solve specific problems are discussed. A CPG mathematical model based on Hopf nonlinear oscillators produces rhythmic signal during locomotion is described, where many parameters to be solved must be formulated in terms of desired stability, often subject to vertical stability analysis. Our simulations demonstrate that active spine with setting reasonable CPG parameters can reduce unnecessary lateral displacement during trot gait, improving the stability of quadruped robot. In addition, we demonstrate that physical prototype mechanism provides a framework which shows correctness of simulation, and stability can thus be easily embodied within locomotion.

Modeling and control system design of 6-DOF bionic parallel mechanism with compliant modules

“…Zhao et al (2013) exploited a silicon block spine that allows flexible bending around the pitch and yaw axes. A 3-DOF parallel spine designed by Wang et al (2020a) not only enables pitch and yaw bending but also telescopes in the direction of motion. The 2-DOF articulated torso recently developed by Zhang's team mimics the flexion and extension motion of the spine of a cheetah during running by two sets of pitching motions (Wang et al, 2022).…”