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

Abstract

Advances in vehicle technology have improved driving performance and fuel efficiency. Further increases in fuel efficiency of a heavy mining truck can be achieved by optimizing 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. The dynamic programming approach has been applied to the low-order model of the specialized off-road 30-tonne mining truck over a fixed route in a mining area. There were two competing objectives: fuel use and trip time. Weighting coefficients were used to combine these objective functions to a single value, and a Pareto curve was created to analyse the effect of the weights on the fuel use and trip time. Using the control strategy obtained from dynamic programming on the high-fidelity model, it is estimated that forty-thousand litres of fuel can be saved annually based on a mine which produces 110 kilotons of coal per day.