Research On Open System Architecture Of Engine Management System And Its Virtual Prototyping Technology

With the growing conserns about energy security and environment, the demands for higher fuel economy and lower emissions of engine products are constantly increasing. Today’s engine system must meet a widening variety of stringent requiements. The development of the engine electronic control systems is facing the continued pressure from both the rapidly increasing scale and complexity of engine control and the sharp market competition. In order to reduce cost, shorten product design cycle and ensure product global security, modern engine management systems are increasingly tending to apply open system architecture as the basis for product design. Model-based development (MBD) has also been promoted for decades in dealing with the posed complexity issue. However, MBD is currently approached mainly as a basis for partial subsystem development, that is, the software component of the overall application. In this thesis, the adoption of virtual prototyping technology and open system architecture in the engine management system (EMS) development for a desiel engine which is equipped with high-pressure common rail injection system is investigated.The foundation, methodology and technology of OSEK/VDX and AUTOSAR, which are two typical open system architectures in the automotive electronic control domain, are discussed. Based on AUTOSAR, the real-time framework technology is proposed for modern engine management system development. A layered model for the open system architecture of EMS is presented based on an available real-time framework. This architecture model shows a good example which is worth considering for establishing open EMS architecture and platform. The basic software services and hardware components in the lower layers are designed and configured in detail. An OSEK compliant operating system is realized. These basic software and hardware services are well-tested and provide a stable and reliable infrastructure platform for the EMS application.Owing to the insufficiency of conventional Structured Analysis and Design approach, the Concurrent Design Approach for Real-Time System is introduced according to the features of open EMS architecture. Based on the approach, an enhanced V-model development prosses is proposed, which supports concurrent design and increamental development and provides guidance on an effective way to develop high-reliability virtual prototype of EMS (EMS-VP). The implementation of key techniques of virtual prototyping, including modeling techniques, environment integration techniques and co-simulation techniques, is further investigated. The integrated modeling and development platform and the co-simulation platform are established for the development of EMS-VP model, which provide a new and practical way for model-based development of engine control systems.A real-time dynamic model for a common rail diesel engine is constructed. The model parameters are well calibrated and the static and dynamic performance of the model are tested and verified. The simulation results show that it provides a high precision and real-time capble plant model for EMS development. A target prototype of EMS for a common rail diesel engine is defined, including the main functions such as engine run-time monitoring, injection pressure management, injection fule mass management under cranking condition, idling condition, etc. The defined EMS-VP is developed in the integrated modeling environment and is tested and verifed by using the engine dynamic model through co-simulation.An algorithm for the rail pressure feedback control is presented, based on the theory of sliding-mode variable structure control and adaptive fuzzy logic. The system stability analysis is carried out as well. The simulation experiment results have proved that this approach has preferable control performance index, good response characteristic and tracking accuracy and strong anti-interference ability. The idle speed feedback control algorithm is designed by using fuzzy-PID control. The simulation results indicate that it has better control quality than the conventional PID control.The product implementation can be easily generated from the EMS-VP model through automatic code generation. The EMS-VP design is further verified in the hardware in the loop simulation platform.