Design Of The Distributed Measurement System Based On Multi-bus Fusion

With the comprehensive promotion of avionics technology, it raises higher on various of aircraft airborne electronic equipments’maintenance and testing. Nevertheless, now most of test systems of airborne equipments are still using the unique testing equipment based on different bus standards, which leads to different compatibilities of the measurement system with the poor universality and the difficulties of upgrading technology. It’s hard to meet the present stage, especially the flight safety and practical comprehensive security requirement in the future.In the view of this, with the analysis of the system’composition and requirements, the paper designs a distributed measurement system based on multi-bus fusion technology, and proposes the overall design of the testing system. The design accomplishes the structure of the system, including the design of distributed test node hardware and software, the distributed test center software, furthermore, the following key technologies are carried out in this paper.1. The paper introduces two kinds of data fusion method, which are commonly used. Through the comparative analysis, design a new multi-bus fusion method based on Ethernet that map the multi-bus to Ethernet, and the method makes up for the deficiency of other multi-bus fusion methods.2. The application layer’s communication interface adopts the Modbus protocol which is introduced to improve the transmission efficiency and real-time performance. According to the characteristics of the designed system, the paper puts forward the improvement method of Modbus protocol. Through the analysis of the performance of the Modbus protocol, we can prove that the protocol reduce the communication load effectively when the system is stable.3. Through the analysis of several common clock synchronization methods, the paper proposed the hybrid clock synchronization method based on hard-wired to improve the synchronization precision. Then, carried on a contrast analysis among unsynchronized, communication synchronized and hard-wired synchronized based on 100,1.6 and 1 microseconds, we can learn that the hybrid synchronized method gets the best result.4. Aimed at the key function of the power module, the paper designed a safer and more reliable power self-detection function, adding monitoring circuit for the power circuit and adding self-detection circuit for the monitoring circuit itself, so that the power module has two-stage protection.5. In the node software design of the system, the model simulation software take the technology of the automatic code generation function of Matlab:building the system module in the Simulink and configuring the target ert.tlc file for code generation, then generating embedded application code and getting the report. The very method can reduce the human error during coding and reduce the debugging time.Based on the idea of modern measurement system and combined with Ethernet technology, the paper proposed a system solution about a kind of distributed measurement system based on multiple bus fusion, and several key technologies are studied and verified on other platforms. Through the study of the thesis, not only make the system feasible, effective, practical, and achieve the expected purpose, but also the measurement system’s development technology and the method have a certain universality, so that provides a good reference to researches and applications for other bus standard measurement system.