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This article introduces a novel modification of a Delta-type parallel robot. The robot has five degrees of freedom and provides its end-effector with a 3T2R motion pattern (three translational and two rotational degrees of freedom). The fifth degree of freedom (rotation) is kinematically decoupled from the other four motions, and it is controlled by two drives. Thus, the proposed robot has a redundant actuation. In this article, we present an algorithm to solve the inverse kinematics of this robot and apply it to a path modeling example of a spiral-like trajectory. Numerical simulations illustrate the algorithm and show how the actuated coordinates change along the considered trajectory. Forward kinematics follows next, and an approach is introduced to determine all end-effector configurations for the specified displacements in the actuated joints. A numerical example presents four assembly modes of the robot corresponding to four real solutions of the forward kinematic problem. Finally, this article demonstrates a computer-aided design and analysis of the proposed robot: we describe a procedure for analyzing inverse kinematics and calculating actuation torques. This study forms the basis for the future manufacturing and experimental analysis of a robot prototype. [ABSTRACT FROM AUTHOR]

This article introduces a novel modification of a Delta-type parallel robot. The robot has five degrees of freedom and provides its end-effector with a 3T2R motion pattern (three translational and two rotational degrees of freedom). The fifth degree of freedom (rotation) is kinematically decoupled from the other four motions, and it is controlled by two drives. Thus, the proposed robot has a redundant actuation. In this article, we present an algorithm to solve the inverse kinematics of this robot and apply it to a path modeling example of a spiral-like trajectory. Numerical simulations illustrate the algorithm and show how the actuated coordinates change along the considered trajectory. Forward kinematics follows next, and an approach is introduced to determine all end-effector configurations for the specified displacements in the actuated joints. A numerical example presents four assembly modes of the robot corresponding to four real solutions of the forward kinematic problem. Finally, this article demonstrates a computer-aided design and analysis of the proposed robot: we describe a procedure for analyzing inverse kinematics and calculating actuation torques. This study forms the basis for the future manufacturing and experimental analysis of a robot prototype.

Motion-force interaction performance analyses of redundantly actuated and overconstrained parallel robots with closed-loop subchains are an open problem considering two challenges: (a) how to take all the internal wrenches into account at the same level when the mobile platform suffers uncertain loads and (b) how to disclose the influence of the structural parameters inside the closed-loop subchains on the robot's performance. To tackle this problem, based on the blocking-and-acting strategy, this paper proposes a new screw-based method to analyze the motion-force interaction performance of such parallel robots. Two aspects of performance are focused, i.e., the distal and proximal motion-force interactability. The two proposed indices focus on reflecting the load-carrying capacity and the motion-transmission capacity, respectively. To evaluate the comprehensive performance of the parallel robot at a certain pose, a local interaction index (LII) is defined as the minimum value of indices of the minimized distal and proximal interaction performance. The feasibility and validity of the proposed indices are illustrated by the motion-force interaction analysis of some redundantly actuated and overconstrained parallel robots with closed-loop subchains. [ABSTRACT FROM AUTHOR]