It is known that a parallel manipulator at a singular configuration can gain one or more degrees of freedom and become uncontrollable, that is, it might not reproduce a stable motion along a prescribed trajectory. However, it is proved experimentally that there is possible passing through the singular zones. This was simulated and shown through numerical examples and illustrated on several para...

This paper describes the design, construction, and control of a planar three degree-of-freedom (dof) inparallel-actuated manipulator at Ohio University. The actuators are three pneumatic cylinders. Using real-time closed-loop feedback control for each actuator length independently, we develop inverse pose and resolved-rate control for this manipulator. The objective of this work is to implement...

In this work, the 3-RPRR, a new kinematically redundant planar parallel manipulator with six degrees of freedom, is presented. First the manipulator is introduced and its inverse displacement problem discussed. Then, all types of the singularities of the 3-RPRR manipulator are analysed and demonstrated. Thereafter, the reachable and dexterous workspaces are obtained and compared with those of t...

The dynamic formulation and performance evaluation of the redundant parallel manipulator are presented in this paper. By means of the principle of virtual work and the concept of link Jacobian matrices, the inverse dynamic model of the redundant parallel manipulator is set up. It consists of six linear consistent equations with eight unknown quantities. Then, the optimum solution of the actuati...

Despite the voluminous publications on robot dynamics and control, the literature to date is based solely on the serial link manipulators. Little attention has been given to the alternative manipulator design based on the concept of in-parallel actuated mechanism, which is characterized by its excellent rigidity, high strength-to-moving-weight ratio, and relatively simple inverse kinematics. Th...