Wheel design and motion analysis of a new heavy-duty AGV in aircraft assembly lines

Abstract

Purpose The flexible automatic transportation and manual assembly jobs for large aircraft components demand an automated guided vehicle (AGV) system with heavy-duty capacity and omnidirectional movability. This paper aims to propose a four driving-steering wheels-four supporting-steering wheels (4DSW-4SSW) layout plan to enhance the controllability and moving stability of AGV. Design/methodology/approach The anti-vibration structure of DS wheels and high-torque steering mechanism of SS wheels with tapered rolling bearings are rigorously designed to meet the functional requirements. Based on the specific wheel layout and vehicle dynamics, the rotational kinematic model as well as the straight and rotational dynamic models of AGV are established by the authors. To well verify the motion characteristics of wheels under heavy load in three motion states including straight motion, self-rotation and rotation around a certain point, the simulations in ADAMS and factory experiments have all been conducted. Findings Simulation results indicate that normal and friction forces of DS wheels and SS wheels are very stable except for some small oscillations, which are caused by non-center load distribution on AGV. Experimental results on driving speed of AGV have directly demonstrated that its positioning accuracy is enough for use in real aircraft assembly lines. Practical implications The designed AGV system has been applied to the final assembly line of a certain aircraft in Aviation Industry Corporation of China, Ltd, whose assembly efficiency and flexibility have been significantly improved. Originality/value A new layout plan of wheels for an omnidirectional heavy-duty AGV is proposed, which enhances the operating and moving capacity of AGV. A function of human-machine collaboration is also offered by the AGV for transporting large workpieces intelligently and economically in aerospace and other heavy industries.