Static Analysis and Dimensional Optimization of a Cable-Driven Parallel Robot

A cable-driven parallel manipulator has been chosen to suspend and navigate instruments over a phenotyping research facility at the University of Nebraska. This paper addresses the static analysis and dimensional optimization of this system. Analysis of the system was performed with catenary simplification to create force equilibrium equations and define a mathematical model. The model incorporates flexibility due to catenary sag of the cables. Cable axial stiffness was not included because stiffness is dominated by catenary flexibility for the expected cable tensions. The model was used to optimize system dimensions, and a twelfth-scale system was constructed to verify the model as well as enable dynamic and control system experimentation during full-scale system construction. Miniature end-effectors were used to obtain end-effector orientation and cable tension measurements which were comparable to model predictions. The mathematical model was thereby shown to be accurate for the purpose of system static analysis.