Kinematic Analysis of an Under-Actuated, Closed-Loop Front-End Assembly of a Dragline Manipulator

Abstract

Dragline excavators are closed-loop mining manipulators that operate using a rigid multilink framework and rope and rigging system, which constitute its front-end assembly. The arrangements of dragline front-end assembly provide the necessary motion of the dragline bucket within its operating radius. The assembly resembles a five-link closed kinematic chain that has two independent generalized coordinates of drag and hoist ropes and one dependent generalized coordinate of dump rope. Previous models failed to represent the actual closed loop of dragline front-end assembly, nor did they describe the maneuverability of dragline ropes under imposed geometric constraints. Therefore, a three degrees of freedom kinematic model of the dragline front-end is developed using the concept of generalized speeds. It contains all relevant configuration and kinematic constraint conditions to perform complete digging and swinging cycles. The model also uses three inputs of hoist and drag ropes linear and a rotational displacement of swinging along their trajectories. The inverse kinematics is resolved using a feedforward displacement algorithm coupled with the Newton-Raphson method to accurately estimate the trajectories of the ropes. The trajectories are solved only during the digging phase and the singularity was eliminated using Baumgarte's stabilization technique (BST), with appropriate inequality constraint equations. It is shown that the feedforward displacement algorithm can produce accurate trajectories without the need to manually solve the inverse kinematics from the geometry. The research findings are well in agreement with the dragline real operational limits and they contribute to the efficiency and the reduction in machine downtime due to better control strategies of the dragline cycles.

Department(s)

Mining Engineering

Comments

Published online: 05 Mar 2020

The funding from the Robert H. Quenon Endowment at Missouri S&T for this research is greatly acknowledged.

Keywords and Phrases

Baumgarte's Stabilization Technique (BST); Dragline Mining Manipulator; Feedforward Displacement; Generalized Speeds; Underactuated Closed-Loop Mechanism

International Standard Serial Number (ISSN)

1476-8186; 1751-8520

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2020 Institute of Automation, Chinese Academy of Sciences and Springer-Verlag GmbH Germany, All rights reserved.

Publication Date

01 Aug 2020

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