Authors: Wei Huang; David M. Bevly
Addresses: Department of Mechanical Engineering, 1418 Wiggins Hall, Auburn University, Auburn, AL 36849, USA ' Department of Mechanical Engineering, 1418 Wiggins Hall, Auburn University, Auburn, AL 36849, USA
Abstract: In this paper, the benefit of setting optimal speed limits according to roadway geometry in minimising heavy truck fuel consumption is investigated and is proposed to replace constant speed limits. The optimal speed limits are set with reference to the truck's optimal speed trajectory, which is calculated by using a constrained Nonlinear Programming (NLP) solver to minimise the truck fuel consumption and travel time based on the road geometry. The developed truck model has a standard weight-to-power ratio for highway control design and performs the speed trajectory calculated by the NLP solver for real roads. Simulation results show that truck driving at the optimal speed velocity is able to significantly reduce fuel consumption with small travel time increases, when compared to constant speed cruise driving. Thus, the implementation of the optimal speed limits based on terrain variation could save heavy trucks' fuel consumption.
Keywords: optimal speed limits; NLP; nonlinear programming; 3D road geometry; highway terrain; powertrains; heavy trucks; heavy vehicles; energy saving; fuel consumption; truck modelling; simulation; travel time; constant speed cruising; terrain variation.
International Journal of Powertrains, 2012 Vol.1 No.4, pp.335 - 350
Received: 02 Sep 2011
Accepted: 03 May 2012
Published online: 05 Dec 2014 *