Title: An optimal gear-shifting strategy for heavy trucks with trade-off study between trip time and fuel economy

Authors: X.X. Zhao; A.H. Ing; N.L. Azad; J. McPhee

Addresses: Beijing School of Mechanical Engineering, University of Science and Technology, XueYuan Street 30, Beijing 100083, China ' Department of Systems Design Engineering, University of Waterloo, 200 University Avenue West, Waterloo, N2L 3G1, Canada ' Department of Systems Design Engineering, University of Waterloo, 200 University Avenue West, Waterloo, N2L 3G1, Canada ' Department of Systems Design Engineering, University of Waterloo, 200 University Avenue West, Waterloo, N2L 3G1, Canada

Abstract: We show how the fuel efficiency of heavy mining trucks can be improved by optimising the gear-shifting strategy. Using characteristic tests of the diesel engine, a high-fidelity model of a mining truck was built in MapleSim and a consistent low-order model was developed in Matlab. Dynamic programming was used to optimise the low-order model of the specialised off-road 30-tonne truck over a fixed route in a mining area. There were two competing objectives: fuel use and trip time, which were combined in a single objective function using weighting coefficients. A Pareto curve was created to analyse the effect of the weights on the fuel use and trip time. Applying the control strategy obtained from dynamic programming to the high-fidelity model, it is estimated that 40,000 L of fuel can be saved annually for a mine that produces 110 kilotonnes of coal per day.

Keywords: dynamic programming; heavy mining trucks; gear shifting strategy; Pareto curve; heavy vehicles; trip time; fuel economy; fuel efficiency; optimisation; diesel engines; engine testing; modelling; simulation; coal mines; fuel saving.

DOI: 10.1504/IJHVS.2015.073205

International Journal of Heavy Vehicle Systems, 2015 Vol.22 No.4, pp.356 - 374

Received: 03 Nov 2014
Accepted: 17 Jul 2015

Published online: 27 Nov 2015 *

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