Design optimization of multi-mode power-split type architectures for awd hybrid pickup trucks

Abstract

Recently, as the need for eco-friendly vehicles has emerged due to strict fuel economy regulations, many automobile manufacturers have launched various electrified pickup trucks. Among them, battery and fuel cell powertrains need to be improved for commercialization in terms of price, mileage, and infrastructure. Although parallel hybrid pickup trucks have been commercialized, they have not met strong fuel efficiency regulations due to their low efficiency. This thesis proposes a high-efficiency, high-performance, and low-cost power-split type AWD hybrid architecture to solve these problems. In order to find a new power-split type AWD architecture, virtual design space is introduced to eliminate overlapping and screen architectures with the desired operating modes efficiently. Multi-mode architecture is constructed using multiple planetary gears and clutches to maximize the vehicle's performance. The architecture found through screening is evaluated for four performance measures (fuel economy performance, acceleration performance, maximum velocity, and maximum towing capacity) through optimal control-based simulations. A multi-objective optimization problem is formulated and solved to find the best design. By comparing the optimal design with the commercialized architecture, Toyota E-four, the optimal design demonstrates its excellence. Through this study, the newly discovered architecture is expected to be applied to vehicles that require high-efficiency and high-performance powertrains, such as sports cars and pickup trucks.