Fuel Consumption Simulation on the Federal Urban Drive Cycle of a Hydrostatic Transmission Vehicle modeled with Bond Graphs

摘要

Hybrid vehicles using hydrostatic transmissions with energy storage accumulators can lead to cleaner air and considerable fuel savings when driven in urban areas characterized by lower speeds coupled with stop and go driving. This paper presents a mathematical model and fuel consumption simulation of a standard compact passenger vehicle equipped with an internal combustion engine and a hydrostatic transmission while driven through the US Environmental Protection Agency Federal Urban Drive Cycle. Bond graphs are used in modeling the main vehicle components: the internal combustion engine, variable displacement engine pump, and the wheel pump/motors. A Hydropneumatic piston accumulator serves as an energy storage device allowing regenerative braking and engine road-load decoupling. Fuel consumption is calculated and summed during the drive cycle simulation and allows for the study of the possible fuel savings by implementing a controller strategy for energy management and varying the component parameters. Hydraulic hybrid designs can provide excellent fuel economy when integrated in compact vehicles used in urban driving.