A Gear Shifting Indication Strategy of Eco-Driving Vehicle

The current indication strategies of gear shifting indication system for manual transmission vehicles are developed based on the gear shifting strategies of the automatic transmission vehicles. In this paper, it is found that the gear shifting frequency of automatic transmission vehicles is significantly higher than that of manual transmission vehicles based on the collected driving data of several automatic transmission and manual transmission vehicles, which increases the fatigue of drivers. Aiming at this problem, this paper proposes an interval algorithm of gear shifting indication strategy based on the fuel consumption rate of engine, which uses genetic algorithm to process the data of fuel consumption rate to find the maximum and minimum values ​​in the interval of torque and engine speed and adopts the interval algorithm to transform the search of least fuel consumption value into the seeking of optimal interval to avoid the shift busyness caused by the sudden change of fuel consumption rate. The gear shifting tolerance is defined to avoid the shift busyness while the evaluation function values for a pair of adjacent gears are close in some working conditions. Then the model of gear shifting indication strategy is established in Matlab/Simulink and simulated under the WLTP cycle. The simulation results show that compared with the existing economical gear shifting strategies, the proposed interval algorithm of gear shifting indication strategy can effectively reduce the frequency of shifting gears without the increase of fuel consumption. Finally, a gear shifting indicator is produced and several road tests are done with a truck to verify the saving of fuel consumption for the interval algorithm of gear shifting indication strategy. The test results show that the indication strategy reduces the fuel consumption of the truck by 5% on average.