A method for calculating static conditions of a dragline excavation system using dynamic simulation

-A technique to numerically obtain the static equilibrium s ta te of a conventional dragline excavation system is reported, including static pose of the bucket as well as internal loads acting on elements of the excavation system. Equilibrium conditions are generated by numerically integrat ing the dynamic equations of motion with the hoist and drag rope lengths fixed. It is shown tha t this method can be greatly accelerated with the application of artificial forces and moments proport ional to the velocity of the bodies tha t comprise the dragline excavation system. The benefits of appending artificial forces and moments are demonstra ted on an exemplar conventional dragline excavation system using a complex three-dimensional dynamic simulation model. In this model, the bucket, spreader bar, hoist cluster, and drag cluster are modeled as rigid bodies wi th 6 degrees of freedom apiece while the drag rope, hoist rope, dump rope, hoist chains, and drag chains are discretized into a finite number of visco-elastic elements. Results generated from the numerical stat ic pose simulation are compared against measured static pose da ta and agree favorably. © 2004 Elsevier Ltd. All rights reserved. Keywords--static pose, Dragline excavator, Dynamic simulation. N O M E N C L A T U R E XB, YB, ZB components of the position uR~, ve~, wa~ vector of the center of mass of a body in an inertial reference frame components of the position PB, qB, rB vector of the ith particle on a rope segment in an inertial reference frame Euler roll, pitch, and yaw angles of a body xzrQ, YFQ ~ zR i dPB, OB, %bB XB,YB,ZB components of the velocity vector of the i th particle on a rope segment in an inertial reference frame components of the angular velocity vector of a body in the body reference frame total applied force components on a body in an inertial reference frame 0895-7177/04/$ see front mat te r (~) 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.mcm.2004.03.001 Typeset by JtA&S-TEX 234 M. COSTELLO AND J. KYLE