| Fuel cell is one of green energy with bright future in 21st century. It is widely used in mobile power supply and vehicle power for its superior characteristics, such as high power density, low operating temperature, high efficiency, low noise and so on. At present it is a significant direction to improving the efficiency and running life of fuel cell stack, perfecting the performance of fuel cell engine in the study of fuel cell vehicles. So monitoring and diagnosing the fuel cell engine is an important approach to advance its performance. In addition, embedded Internet can construct the higher performance-to-price ratio automatization of monitoring system in the industrial controlling system with the rapid progress of network technology. On the foundation of analyzing fuel cell engine system structure, this paper study and design fuel cell engine monitoring system through taking Ethernet as bridge of information exchange. The main contents are as follows:Firstly, this paper has analyzed the function need of fuel cell engine monitoring system. On the basis of these, using the network technique, united with the embedded system, the fuel cell engine monitoring system skelecton based on Ethernet has been proposed. This system is consisted of scene data collection system, Network communication unit and PC monitoring platform. The data collection completes the engine scene information gathering and processing; the network communication unit realizes network connecting of the data collection system and the data display and disposal has been completed with PC.Comparing with some plans of network connecting, this paper has chose more succinct and agile plan that PIC16F877A and network control chip ENC28J60 are united to turn on Ethernet. It realized data transformation between serial port and Ethernet. The software and hardware methods to realize the plan have been introduced in detail, including the structure and principle on hardware, the embedded TCP/IP protocol stack as well as the system flow on software.The monitoring system software on PC has been designed. It has been accomplished through modularizing and thinning on the platform of Visual C++. In the program the monitoring interface has been realized as well as the function of the running state displaying, parameters configuring, data storage and fault diagnosis.Finally, the fault diagnosis algorithm on fuel cell engine system was researched in detail. Take the neural network theory as the foundation, the fault diagnosis model was established based on the BP neural network and the simulation was accomplished. The simulation indicated that this method is good in fault diagnosis. |
