Design And Control Of Two-axis Swing Underactuated Cable-Driven Parallel System

The Two-axis Swing Underactuated Cable-Driven Parallel System is a cable-driveled system that enables the end effector to achieve two-axis swing.Compared to traditional two-axis swing systems,only a small amount of cable is used to control the end effector.It has more excellent performance in terms of manufacturing cost,floor space,and experimental interference,and has broad application prospects and important research value in the fields of hoisting and testing experiments.Since the system is not completely constrained,how to control the cable length to stabilize the end effector at the desired position and attitude requires modeling and analysis of the static equilibrium inverse kinematics of the system.Secondly,to determine the range within which the end effector can maintain a stable pose.It is necessary to solve and evaluate the workspace performance of the system and optimize the structure configuration.Finally,how to make the end effector transition smoothly between different poses.It is necessary to plan the trajectory reasonably.The axis swing system controls the movement of the end effector so that it can be stabilized under different attitudes,and trajectory planning is performed between different attitudes.The software is used for simulation to verify the effectiveness of the system structure design and rest-to-rest trajectory planning,which provides a powerful reference for the engineering application of the incompletely constrained cable traction system.The content of this thesis are as follows:The inverse geometrico-static model of the incompletely restrained positioning mechanism(IRPM)is established.The kinematics are added to the radius and rotation angle of the universal pulley,and the force closure equation and geometric closure equation of IRPM are established.Considering the constraints of cable tensions,the above equations are solved simultaneously using the convex optimization solution method with boundary conditions.Through an example of an 3-6 cable-driven parallel system,the attitude of the center of mass of the end effector at different positions is analyzed,and the lengths of cables under those poses are solved.A quality estimation method for the Static-Equilibrium Workspace(SEW)of the IRPM system is proposed.The Wrench-Closure Workspace(WCW)and Wrench-Feasible Workspace(WFW),based on completely restrained positioning mechanisms(CRPM)and redundant restrained positioning mechanisms(RRPM)is analyzed.The SEW for IRPM has been defined.And proposes a solution strategy for SEW based on the inverse geometrico-static model solving method.Then,by analyzing the quality evaluation indicators of WCW and WFW,combined with the characteristics of SEW,an evaluation method for IRPM is given.The SEW is solved by an example of an 3-6 cable-driven parallel system,and its quality is evaluated.The system structure parameters are optimized by Taguchi experiment and full factor orthogonal experiment.A rest-to-rest trajectory planning method for IRPM system is proposed.The internal dynamics model of the IRPM system is established,linking the controllable degrees of freedom with the uncontrollable degrees of freedom.By modifying the motion law function of the traditional rest-to-rest trajectory planning algorithm and adding dynamic constraints into the process of traj ectory planning,the rest-to-rest trajectory planning of the IRPM system is proposed.Through an example of an 3-6 cable-driven parallel system,three trajectories around the x axis,the x,y axes,and the y axis are planned respectively,and the trajectory planning algorithm is proved.An Two-axis Swing Underactuated Cable-Driven Parallel Systems is designed,and the principle experimental verification is carried out using Simulink-simscape multibody software.Through previous research,the Two-axis Swing Underactuated Cable-Driven Parallel Systems is designed and optimized,the system is modeled by Simulink-simscape multibody,and the simulation of the trajectory planning experiment is carried out.The simulation results verify the reliability of the system design and trajectory planning method.