| Based on the advantages and disadvantages of rigid drive and rope drive parallel mechanism,a new type of cable-rod hybrid drive parallel mechanism is designed.This mechanism combines the advantages of the two structures and improves the working performance of the parallel mechanism.The structure composition,kinematics modeling and simulation,statics and dynamics of cable-rod parallel mechanism are analyzed in this article.Firstly,the advantages and disadvantages of flexible cable driving and rigid driving parallel mechanism are analyzed.The parallel mechanism structure and motion mode of cablerod hybrid drive are designed and the freedom and driving mode of the mechanism are analyzed.The overall model of the mechanism is designed in Solidworks software and the test prototype is built.Secondly,the kinematics analysis is carried out in this article.The coordinate system is established for the mechanism model in Solidworks software.The inverse solution and positive solution mathematical model of the mechanism are obtained by using vector closure principle and Newton-Raphson iterative algorithm,and numerical simulation verification of this mathematical model is performed.The velocity Jacobian matrix of the system is deduced.In Matlab software,the change diagram of the stretching speed of each driving branch chain during the movement of the terminal moving platform is drawn.Thirdly,the static equilibrium equations are obtained by analyzing the stress equilibrium relations in the static state of cable-rod hybrid drive parallel mechanism.Based on the Matlab software,the statics model is simulated and the curves od the force of each driving chain with the position and posture are drawn.The dynamic problems of the parallel platform are analyzed,and the mathematical model of the whole system of parallel mechanism is established by Newton-Euler method,which lays a good theoretical foundation for the realization and optimization of the control method.Finally,a simulation model of cable-rod hybrid drive parallel mechanism is created in Adams software.Kinematic and statics simulation analysis of the mechanism is carried out,and the model simulation results and Matlab numerical simulation results are compared to verify the accuracy of kinematics analysis and statics analysis of cable-rod parallel mechanism and the effectiveness of model simulation. |
