Structure Improvement And Gait Planning Of Four-bar Tensegrity Robot

With the continuous development of the space industry,the requirements for future robots in the process of planetary exploration are getting higher and higher.Tensegrity robot is a new research direction of tensegrity structure and mobile robot.Compared with the traditional robot,the tensegrity robot has the characteristics of light weight,high strength,few driving components and simple control,which can effectively reduce the fuel consumption for transport as a detection robot.In this paper,an in-depth study is carried out on the height-radius ratio of the four-bar tensegrity robot,structure improvement,carrying load,path planning and prototype improvement.The specific research contents are as follows:1.Four-bar tensegrity robot models with different height/radius ratio are established to analyze the influences of different height/radius ratio on the landing triangle of the robot,the force exerted on the string components,the contraction amount of diagonal string and the volume of internal available space.The specific height-radius ratio and the corresponding dimension parameters of the four-bar tensegrity robot are given.2.The structure of the four-bar tensegrity robot is improved,the straight bars are replaced by the bent bars,and the size of the bent bar is determined according to the interference condition of the bar components.By means of geometric analysis,the calculation formula of the distance of the same side diagonal strings is given and the correctness of the geometric analysis method is verified.The volume of the robot with added load is calculated,and the feasibility of increasing the internal volume of the improved robot structure is verified by comparing with the straight-bar robot.By analyzing the influence of load mass on the robot,the relationship between load mass and the contraction of diagonal strings and the force of string components is obtained.3.The path planning is carried out for the robot,and the single gait of the robot is analyzed to obtain the deflection Angle corresponding to different diagonal string contractions and the position of the landing triangle before and after the rolloff.The basic movement unit of the robot is obtained by combining the single gait of the robot,and the selection rules of the movement unit are given.When given the robot a target point,the corresponding motion gait is given according to selection rules,and the correctness of the path is verified by Adams simulation.The local gait of the robot is planned.4.The robot prototype is tested.The prototype is improved by replacing straight bars with bent bars.By adding load to the prototype and carrying out prototype test,the deformation attitude and corresponding diagonal string contraction of the robot under different landing states and driving modes are obtained.The relationship between the contractions of diagonal string and the driving force is determined by experiments.The rolling test is carried out on the prototype,Put forward the problems in the robot movement and the corresponding solutions,and the driving modes that the robot can roll under different landing states and the corresponding changes of landing triangle are given.