A Novel Control Systems Architecture for Hybrid Electric and Fuel Cell Vehicles

In order to satisfy the requirements of increasingly stringent environmental legislation, the international automotive industry is attempting to make a step-change in the level of vehicle technology with the market introduction of hybrid electric vehicles (HEVs) and the proposed introduction of fuel cell vehicles (FCVs). However, the global automotive market is characterised by very high levels of competition in which manufacturers must continually introduce new products while concurrently reducing development time and costs. As a result, the long term viability of these technologies will be largely dependent on the ability of the automotive industry to design, integrate and test the different powertrain concepts at a cost and within a time frame that is comparable to that associated with conventional vehicles. In order to ascertain the most cost-effective and innovative powertrain architecture manufacturers are concurrently investigating different vehicle concepts. These include both parallel and series hybrid electric configurations in which an internal combustion engine and electrical machine are integrated into the vehicles powertrain. In more recent years, considerable attention has been given to FCVs in which the fuel cell either operates in isolation or is combined with a secondary energy storage medium such as a high voltage battery or ultracapacitor.Irrespective of the exact configuration of the vehicle, such powertrains can be thought to contain generic subsystems that can either source energy, sink energy or both sink and source energy. This view translates to a number of generic vehicle control objectives; the need to minimise the vehicles net energy consumption through a combination of regenerative braking and on-board energy management and the need for integration and management of, potentially, multiple prime-movers within the powertrain. Hierarchical control schemes are often required in order to achieve the desired levels of vehicle refinement, driveability and fuel consumption.The need for complex energy management and supervisory control functions, coupled with such vehicles inherent dependency on by-wire technology will further increase the software and control system content of future hybrid and fuel cell vehicles. The traditional model within the automotive industry is for the vehicle manufacturer to outsource the development of a complete system to a supplier. The vehicle manufacturer then acts as the systems integrator, combining the subsystems that are received from the different suppliers. The OEM must ensure that the required levels of product quality and safety are met through a time-consuming, expensive and resource intensive programme of testing and vehicle calibration. One means of reducing the development time, costs and therefore risk, would be the ability to easily interchange control and software functions between the different vehicle platforms and derivatives.The primary aim of this research proposal is the design of a novel, generic, control architecture for HEVs and FCVs that supports the easy integration and evaluation of different powertrain concepts. In addition to providing a flexible development environment for systems integration, the new control architecture will also address the fundamental issues of reliability, robustness and safety that are of critical importance to the automotive industry. A major recent technological development within the automotive research domain is the study of service/based and object oriented control architectures. The design and validation of the proposed new control and systems integration architecture will be used as the basis for demonstrating how a systematic design process, based on the principles of object orientation, can be employed to progress the state-of-the-art beyond the current prototype control architectures that are often associated with many FCV and HEV research programmes.