A concept for actuating and controlling a leg of a novel walking parallel kinematic machine tool

Rushworth, Adam; Axinte, Dragos; Raffles, Mark; Cobos-Guzman, Salvador

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.

Citation

Rushworth, A., Axinte, D., Raffles, M., & Cobos-Guzman, S. (2016). A concept for actuating and controlling a leg of a novel walking parallel kinematic machine tool. Mechatronics, 40, https://doi.org/10.1016/j.mechatronics.2016.10.010

• Journal Article Type: Article
• Acceptance Date: Oct 7, 2016
• Online Publication Date: Dec 7, 2016
• Publication Date: Dec 7, 2016
• Deposit Date: Feb 8, 2017
• Publicly Available Date: Feb 8, 2017
• Journal: Mechatronics
• Print ISSN: 0957-4158
• Electronic ISSN: 1873-4006
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 40
• DOI: https://doi.org/10.1016/j.mechatronics.2016.10.010
• Keywords: Hexapod; Walking robot; 6-axis milling machine; Robotised machine tool; Leg design
• Public URL: https://nottingham-repository.worktribe.com/output/836320
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0957415816301222
• Contract Date: Feb 8, 2017