Design And Analysis Of Tensegrity Robot With Six Rods

The tensegrity robot is a new type of planetary exploration robot based on tensegrity structure,which is a kind of icosahedral space network structure composed of rigid rods under pure pressure and flexible cables under pure tension.Tensegrity robots generate motion by changing shapes,and have the property of distribute impact forces because of its unique structure.In this paper,a tensegrity robot with six rods and 24 cables is taken as the research object,studied and simulated the rolling gait and impact resistance of the robot and developed and tested the prototype of the robot.This paper is organized as follows:Designed the overall configuration of the tensegrity robot with six rods and 24 cables,according to the existing general tensegrity structure.Then determined the connectivity between cables and bars and analyzed and designed the structure type of each rod.And changing cable lengths was chosen to perform active motion of robot.Then established the dynamic model of flexible cables based on ANCF and obtained the general equation of motion for robot system based on Euler-Lagrange formulation.Based on the overall configuration of the robot,the structure topology diagram and dynamic model of the robot are established.Then chosen rolling locomotion as the basic locomotion pattern of the robot and analyzed the motion mechanism of the rolling gait of the robot.On this basis,two kinds of rolling gait control strategies are found by utilizing the strategy search algorithm based on greedy method.Then,verified the correctness of these control strategies by the multi-gait rolling motion simulation of the robot.Furthermore,established the relation between the performance criteria of rolling gait of tensegrity robot and the driving parameters and material parameters.The influence of different driving parameters and material parameters on the performance of rolling gait of tensegrity robot is analyzed by simulation,which provides a theoretical basis for setting and selecting the parameters of robot prototype.Studied and analyzed the anti-impact performance of six-bar tensegrity robot.A method for calculating the impact force of tensegrity structure is proposed by establishing an equivalent collision model,and analysed the magnitude of impact force under different landing points and landing positions.Simulated the landing process of six-bar tensegrity robot with different landing points and compared the anti-impact performance of the robot with the same number of landing points.Then,optimized the anti-impact performance of landing with three-points.Finally,the detailed mechanism design and electronic control system design of the six-bar tensegrity robot are carried out.Completed the assembly and debugging of the robot prototype.Then,carried out the rolling locomotion tests of the two kinds of rolling gaits.At the same time,the differences of the motion performance of the robot under the same rolling and different actuation strategies are compared.Verified the feasibility of rolling gait of tensegrity robot and proved the correctness of theoretical research.