Trajectory control of incompletely restrained parallel-wire-suspended mechanism based on inverse dynamics

• Published in: IEEE transactions on robotics Vol. 20; no. 5; pp. 840 - 850
• Main Authors: Yamamoto, M., Yanai, N., Mohri, A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.10.2004; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Automata. Logic controller; Automatic control; Computer science; control theory; systems; Construction industry; Control theory. Systems; Cranes; Drives; Dynamical systems; Dynamics; Equations; Exact sciences and technology; Intelligent systems; Inverse dynamics; Linkage mechanisms, cams; Manufacturing; Mathematical analysis; Mechanical engineering. Machine design; Mechanical factors; Nonlinear dynamics; Parallel wire mechanisms; Robotics and automation; Robots; Stiffness; Trajectory control; Wire; Linkage mechanism; Non linear control; Gantry crane; Parallel mechanism; Overhead conveyor; Feedforward; Motion control
• ISSN: 1552-3098; 1941-0468
• DOI: 10.1109/TRO.2004.829501

This paper discusses parallel wire mechanisms where an end-effector of the mechanism is suspended by multiple wires. The mechanisms enable not only three-dimensional (3-D) positioning but also 3-D orienting of the end-effector, unlike typical wire suspension-type mechanisms such as overhead crane. To discuss the parallel-wire-suspended mechanisms generally, two forms of basic dynamic equations are presented. Then the parallel wire mechanisms are classified into two types based on the basic equations. Dynamical properties of the two types of wire-suspended positioning mechanism are discussed. In this paper, one of the wire-suspended mechanism, incompletely restrained-type parallel wire mechanism, is mainly discussed on its inverse dynamics problem and its trajectory control problem. The inverse dynamics problem for the incompletely restrained-type mechanism plays an important role on its control problem, because the mechanism has low stiffness based on incomplete constraints on the suspended object which is governed by its dynamics. The paper proposes an antisway control method for the suspended object. In the method, the inverse dynamics calculation is used for nonlinear dynamics compensation to control the suspended object of the incompletely restrained parallel wire mechanism.