Characteristics research of an underactuated manipulator basing on the statics and dynamics analysis

A novel underactuated manipulator possessing high self-adaptation ability is designed. The manipulator is highly underactuated as it contains several cable-bar units controlled by a single motor through a cable. The transfer matrix which reveals the correlation among cable tension force, joint frictional torques and grasping force is established by using vector mechanics and the principle of virtual work. Basing on the stiffness matrix which is established on basis of statics analysis, the influence of length ratio of cable-bar units on structural stiffness is discussed. The correctness of statics analysis is validated by simulating in ADAMS. Then, the dynamic model is established by using Lagrangian method. The correctness of dynamics analysis is validated by comparing calculation results and simulation results basing on the same grasping strategy.