The solution of tension distributions is infinite for cable-driven parallel manipulators（CDPMs） with redundant cables. A rapid optimization method for determining the optimal tension distribution is presented. The n...The solution of tension distributions is infinite for cable-driven parallel manipulators（CDPMs） with redundant cables. A rapid optimization method for determining the optimal tension distribution is presented. The new optimization method is primarily based on the geometry properties of a polyhedron and convex analysis. The computational efficiency of the optimization method is improved by the designed projection algorithm, and a fast algorithm is proposed to determine which two of the lines are intersected at the optimal point. Moreover, a method for avoiding the operating point on the lower tension limit is developed. Simulation experiments are implemented on a six degree-of-freedom（6-DOF） CDPM with eight cables, and the results indicate that the new method is one order of magnitude faster than the standard simplex method. The optimal distribution of tension distribution is thus rapidly established on real-time by the proposed method.展开更多
The return capsule needs to be launched to the moon and return back to earth in the third stage of the Chinese lunar exploration project.Therefore,it is necessary to perform simulations on the ground.This paper presen...The return capsule needs to be launched to the moon and return back to earth in the third stage of the Chinese lunar exploration project.Therefore,it is necessary to perform simulations on the ground.This paper presents an 8-cable-driven parallel manipulator to achieve end-force output in a low-gravity environment.End-force output refers to the vector sum of the external force on the end-effector.A model of end-force output is established based on a kinematics model,a dynamic model,and a force analysis of an 8-cable driven parallel manipulator.To obtain end-force output in a low-gravity environment,the cable force has to be controlled to counteract gravity.In addition,a force-position mix control strategy is proposed to proactively control the cable force according to the force optimal distribution given by the closed-form force distribution method.Furthermore,a suitable choice for an end-force output is obtained by modeling the effect of cable force on end-force output.Experimental results show that the actual cable force agrees well with the calculated force distribution,indicating that it is feasible to realize end-force output in a low gravity environment.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51275500)Research Project of State Key Laboratory of Mechanical System and Vibration(Grant No.MSV201502)+1 种基金USTC-COOGOO Robotics Research Center(Grant No.2015)Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2012321)
文摘The solution of tension distributions is infinite for cable-driven parallel manipulators（CDPMs） with redundant cables. A rapid optimization method for determining the optimal tension distribution is presented. The new optimization method is primarily based on the geometry properties of a polyhedron and convex analysis. The computational efficiency of the optimization method is improved by the designed projection algorithm, and a fast algorithm is proposed to determine which two of the lines are intersected at the optimal point. Moreover, a method for avoiding the operating point on the lower tension limit is developed. Simulation experiments are implemented on a six degree-of-freedom（6-DOF） CDPM with eight cables, and the results indicate that the new method is one order of magnitude faster than the standard simplex method. The optimal distribution of tension distribution is thus rapidly established on real-time by the proposed method.
基金This research was supported by National Natural Science Foundation of China(No.91648107)Beijing Natural Science Foundation(No.L182041).
文摘The return capsule needs to be launched to the moon and return back to earth in the third stage of the Chinese lunar exploration project.Therefore,it is necessary to perform simulations on the ground.This paper presents an 8-cable-driven parallel manipulator to achieve end-force output in a low-gravity environment.End-force output refers to the vector sum of the external force on the end-effector.A model of end-force output is established based on a kinematics model,a dynamic model,and a force analysis of an 8-cable driven parallel manipulator.To obtain end-force output in a low-gravity environment,the cable force has to be controlled to counteract gravity.In addition,a force-position mix control strategy is proposed to proactively control the cable force according to the force optimal distribution given by the closed-form force distribution method.Furthermore,a suitable choice for an end-force output is obtained by modeling the effect of cable force on end-force output.Experimental results show that the actual cable force agrees well with the calculated force distribution,indicating that it is feasible to realize end-force output in a low gravity environment.
