Closed-form solutions were developed to optimize kinematics design of a 2-degree-of-freedom (2DOF) planar parallel manipulator. The optimum design based on the workspace was presented. Meanwhile, a global, comprehensive conditioning index was introduced to evaluate the kinematic designs. The optimal parallel manipulator is incorporated into a 5-DOF hybrid machine tool which includes a 2-DOF rot...

In this paper, some definitions and traditional formulas for calculating the mobility of mechanisms are represented, e.g. Grubler formula, Somov - Malyshev formula, and Buchsbaum - Freudenstei. It is discussed that there are certain cases in which they are too ambiguous and incorrect to use. However, a matrix method is suggested based on the rank of the Jacobian of the mechanism and its applica...

In this paper a general formulation for finding the maximum allowable dynamic load (MADL) of flexible link mobile manipulators is presented. The main constraints used for the algorithm presented are the actuator torque capacity and the limited error bound for the end-effector during motion on the given trajectory. The precision constraint is taken into account with two boundary lines in plane w...

In Theorem 3 of A. Karger, Architecturally singular non-planar parallel manipulators, Mechanism and Machine Theory, Vol. 43, No.3, pp. 335-346, 2008 all types of architecturally singular parallel manipulators with four collinear anchor points are listed. As the manipulator is assumed to be architecturally singular in the cited theorem the given conditions for each entry of this list are suffici...

This paper deals with the kinetostatic model for a planar point mass cable-driven parallel manipulator when the cable elasticity and configuration have been fully taken into account. An exact model solution for the statics is obtained by consider elastic hefty cables. The proposed formulation allows considering specific behavior of cables for large dimensions cable-suspended robots in which the...

This paper describes an experimental testing apparatus set up by the authors in order to validate the effectiveness of the motion input pre-shaping technique for the open-loop control in microgravity environment. The system consists of a two flexible links planar manipulator suspended on special air-pads floating on a planar friction-free glass surface. Since the friction between the two pads m...

The paper deals with kinematic control algorithms for on-line obstacle avoidance which allow a kinematically redundant manipulator to move in an unstructured environment without colliding with obstacles. The presented approach is based on the redundancy resolution at the velocity level. The primary task is determined by the end-effector trajectories and for the obstacle avoidance the internal m...

Joint-coupling (JC) is introduced in the design and control of parallel manipulators for managing manipulator singularities. The underlying idea consists of coupling the motions of several manipulator joints by driving the joints with a single actuator. This can be done by mechanical or electronic means, while preserving the mobility of the manipulator. Such JC is intended to alter the direct s...

Based on a proven exact method to solve the forward kinematics problem , this article investigates the forward kinematics problem formulation specifically applied to planar parallel manipulators. This first part focuses on the position-based equation systems. The majority of planar tripods can modeled by the 3-RPR parallel manipulator. This manipulator is a tripod constituted by a fixed base an...

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...