Research On The Design And Control Method Of Flexible Spine Mechanism For A Quadruped Robot

Compared to the mobile robots,bionic quadruped robots have unparalleled advantages in flexibility and non-structural adaptability to the environment,and have great potential in military support,indoor rescue and indoor entertainment services.After years of development and research,the technologies of bionic quadruped robots have been made many major breakthroughs in all aspects.However,most of rigid body quadruped robots are still unable to achieve a rapid,flexible and steady movement,which quadruped animal can do it.In order to solve this problem,from the view of biological spine bionic,a double-joint series flexible spine structure that based on series elastic actuators was proposed,the structural characteristics,system integration and high-precision servo control methods were studied:First of all,the quadrilateral mammalian spine physiological structure and the elastic driving characteristics of the joint were analyzed.Based on this,the overall configuration of the spine mechanism in double joint series was proposed and the spinal joint elastic driving scheme that based on the series elastic actuator(SEA)was determined.Then based on the overall configuration of the spine mechanism and the joint drive scheme,the double-joint flexible spine mechanism was designed.The structural characteristics and working principle of the flexible spine mechanism were discussed.Secondly,based on the movement and morphology of the spine in the quadruped mammals at high speed,the kinematics and dynamics of the spine for quadruped robot were analyzed.And then the research of Torque control was done: the dynamic model of flexible spine joint was established by force source method.The effect of joint stiffness on system stability,dynamic response and control bandwidth was analyzed.The output torque of spine joint is controlled by PID,and the PSO algorithm was used to analyze the PID parameters.After this,The control simulation was analyzed by Matlab.Finally,the experiment platform of flexible spine joint control system was set up.Combined with the control simulation experiment,the experimental program of motion control is established,and the simulation experiment and the proposed control method were verified and analyzed.The experimental results showed that the flexible spine has high torque tracking accuracy.The stability and reliability of the spine mechanism and its control system were verified.The research results of this paper lay the foundation for introducing the flexible spine mechanism into the quadruped robot in the follow-up,which he flexible spine mechanism as an independent functional module of quadruped robot.It was a preparation for the later study of the coordination between spine and limbs.This is a great significance to improve the agility and stability of the quadruped robot.