A concept for actuating and controlling a leg of a novel walking parallel kinematic machine tool. (December 2016)

• Record Type: Journal Article
• Authors: Rushworth, Adam; Axinte, Dragos; Raffles, Mark; Cobos-Guzman, Salvador
• Is Part Of: Mechatronics. Volume 40(2016)
• Page Start: 63
• Page End: 77
• Publication Date: 2016-12
• Subjects: Hexapod -- Walking robot -- 6-axis milling machine -- Robotised machine tool -- Leg design; Computer integrated manufacturing systems -- Periodicals; Flexible manufacturing systems -- Periodicals; Mechatronics -- Periodicals; Productique -- Périodiques; Fabrication, Systèmes flexibles de -- Périodiques; Mécatronique -- Périodiques; Computer integrated manufacturing systems; Flexible manufacturing systems; Mechatronics; Periodicals; 629.89
• DOI: 10.1016/j.mechatronics.2016.10.010
• Languages: English
• ISSNs: 0957-4158

Abstract

Highlights: Explores kinematic arrangements for the legs of a walking free-leg hexapod machine tool. Proves the feasibility of the accurate operation of the selected mechatronic concept by means of a prototype. Details the kinematics and control methodology for utilising the selected leg concept. Abstract: The scope of this paper is to present a novel method of actuating the legs of a walking parallel kinematic machine tool (WalkingHex) such that the upper spherical joint can be actively driven while walking and remain a free, passive joint while performing machining operations. Different concepts for the number of Degrees of Freedom (DoF) and methods for actuating the chosen concept are presented, leading to a description of a three-wire actuated spherical joint arrangement. The inverse kinematics for the actuation mechanism is defined and a control methodology that accounts for the redundantly actuated nature of the mechanism is explored. It is demonstrated that a prototype of the system is capable of achieving a motion position accuracy within 5.64% RMS. Utilising the concept presented in this paper, it is possible to develop a walking robot that is capable of manoeuvring into location and performing precision machining or inspection operations.