Design And Study Of A 3-DOF Rigid-flexible Coupled Parallel Robot

The flexible cable parallel robot is a new type of parallel robot which appears after the series manipulator and the parallel platform mechanism.The mechanism is driven by servo motor or linear distributor to adjust the change of cable length and tension.In this paper,a 3-DOF parallel mechanism based on rigid-flexible coupling is designed and studied,and its structure,tension force distribution,kinematics modeling and simulation are analyzed.First of all,this paper designs a kind of rigid-flexible coupling three-degree-of-freedom parallel mechanism,which is used to design the configuration of rigid-flexible coupling robot.The structure composition,working principle,degree of freedom and so on are analyzed.An innovative winding mechanism is designed which can reduce the vibration and friction of the flexible cable.Secondly,the dynamic static equilibrium equation of the flexible cable in the linear state and the catenary equation under the action of gravity and tension are analyzed,based on the solution equation of the cable tension.The dynamic model and optimization model of cable tension are established and solved by 2-norm algorithm and MATLAB function call.The pretension force and the bearing range of cable tension in the mechanism are obtained.It provides a theoretical basis for the driving control of the flexible cable and the stability of the moving platform.Thirdly,the kinematics of parallel mechanism is analyzed using screw theory.The inverse solution of position and orientation of the parallel mechanism is calculated using closed loop vector method,and the forward kinematic solution of parallel mechanism is obtained using Newton iteration method.Then,the factors influencing the workspace of the parallel mechanism are analyzed.Finally,the three-dimensional model of the mechanism is established using SolidWorks.Based on the inverse kinematics solution of the mechanism,the reachable workspace diagram of the parallel mechanism is calculated and drawn using searching method.Better for the mechanism parameter setting and optimization design to provide help.Finally,the flexible cable model is established by the force of the Bushing shaft sleeve,the model of the three-degree-of-freedom rigid-flexible coupling parallel robot and the equivalent virtual prototype are built using ADAMS software,and the trajectory planning of the mechanism is carried out,so that the mechanism moving platform can realize the expected motion trajectory.On the basis of the simulation results,the variation law of displacement,velocity and acceleration of the mechanism are obtained.