Structural Design And Bionic Control Of A Quadruped Robot With Actuated Spine

Quadruped robot has always been a hot topic in the field of bionic robots due to their flexible movement capabilities and their high adaptability to the unknown unstructured environment.With the technology improvement,the study of quadruped robots has the trend toward high speed,high dynamics,and high adaptability.Biological studies have found that many quadrupeds in nature make full use of the flexion and extension of their spines to achieve high-speed,high-dynamicity,and highly adaptive movements.In contrast,most existing bionic quadruped robots use rigid torso,ignoring the important role of spinal joints in quadrupeds.Therefore,this paper designs a quadruped robot D-Cat III with actuated spine based on the cheetah,and compares it with rigid spine and passive elastic spine.Through simulation and prototype experiments,we study the effect of spinal joints on the bound gait movement of the quadruped robot.It is of great significance to help people further understand the mechanism of the spine during the rapid movement of quadrupeds and the development of high-speed quadruped robots.The main works of the dissertation are summarized as follows:Firstly,the biological knowledge of the cheetah's skeletal structure and spine morphological characteristics were investigated to determine the structural design and the size of D-Cat III.The processing of D-Cat III was completed.At the same time,a rigid spine and a passive elastic spine were designed for comparative experiments.Secondly,the motion control methods of the legged robot are investigated.For the quadruped robot prototype with 9 degrees of freedom,a two-layer CPG network control model with ten coupled Hopf oscillators is established.Referring to the kinematic characteristics of quadrupeds' bound gait,the bound gait CPG control parameters of the quadruped robot were determined.Then,three kinds of quadruped robot virtual prototyping models with different spine configurations were established in Adams.The two control parameters of the active spine's motion amplitude As and coupling phase difference ?91 were investigated.The conclusions were drawn from the comparing and analyzing of results of the simulation experiments:the spine joints can increase the horizontal movement speed of the quadruped robot.The actuated spine is more effective than the passive elastic spine in increasing the speed of the quadruped robot.The actuated spine can increases the foot force in the process of the quadruped robot movement.The spinal joints can improve the energy efficiency of the quadruped robot and the quadruped robot with the actuated spine has the higher energy efficiency,but the quadruped robot with the passive elastic spine consumes the least energy during the same time.At last,the control system of the quadruped robot was set up,including the hardware part and software part.The bounding experiments of three different quadruped robots with different spine were respectively carried out.The experimental results prove the feasibility of the proposed CPG network control model and confirm the conclusion of the simulation experiment.At the same time,it was also found that the adjustment of the spinal joints effectively improved the hind leg dragging problems during the movement of the robot and improved the stability of the robot movement.