Gait simulation of a motor hexapod robot based on impedance control

LIU Jun; HAO Xing'an; HUANG Xiaolin; LIU Hongming; WANG Yong

doi:10.16578/j.issn.1004.2539.2025.12.012

Abstract：[Objective]In order to improve the maneuverability of hexapod robots under complex terrains,a motorized hexapod robot with 3 degrees of freedom in one leg was designed based on the bionic principle.[Methods]By referring to the bionic topology structure of the leg of arthropods,the proportional relation between the lengths of the leg segments was analyzed,and the lengths of the leg segments were determined.The motion space of the single leg was obtained through Matlab software simulation,and the corresponding trajectory planning of the foot end was made based on the motion space.The contact model of the mechanical leg and the ground was analyzed,the mathematical model of the impedance control based on the position was established,and the effect of the impedance control parameter on the impedance control performance was analyzed,in order to make the leg have better control accuracy as well as supple performance to adapt to different environmental stiffness.A single leg support test was completed to verify the accuracy of the impedance control algorithm on the tracking response of the desired trajectory.The Matlab-Adams joint simulation was used to simulate the motion process of the whole machine under the stepped terrain to verify the reasonableness of the structural design and the feasibility of the impedance control.[Results]The results indicate that the structural design of this bio-inspired hexapod robot is rational,its controller exhibits precise and effective performance,and it demonstrates strong adaptability to complex terrains.During the stair-climbing process,the robot maintains a stable state,thus meeting the pre-designed motion requirements.