Development of a 6-DOF Redundantly-Actuated 12-Legged Parallel Manipulator for Heavy-Load Applications

Abstract

This paper presents the design and modeling of a new 6-degrees-of-freedom (DOF) 12-legged parallel manipulator (PM). A vector method is adopted to establish the kinematics model of the PM. The dynamics model is then developed using the principle of virtual work and the pseudo-inverse. Under equivalent conditions, the maximum driving force of the 6-DOF 12-legged PM is found to be only 55% of that of the traditional Gough–Stewart platform, indicating that the proposed PM achieves excellent dynamic performance and has huge load-bearing potential. In terms of control, a force/position hybrid control strategy is adopted to control the PM. The core of the position and force control systems are a proportional–integral–derivative (PID) controller and an interval type-2 fuzzy proportional–integral–derivative (IT2F-PID) controller, respectively. The correctness of the dynamic model and the effectiveness of the control method are verified through simulation analysis. The investigations of this paper provide new approaches for designing large-size and heavy-load PMs.