Design Of Multi-node Acquisition And Encoder Based On POWERLINK Bus

With the rapid development of aerospace industry,China has new requirements in the field of dynamic acquisition and measurement of aircraft parameters.In the flight test,many analog signals in the aircraft need to be monitored in real time.The real-time performance of data transmission and the accuracy of data acquisition have become the new development direction of the acquisition system.In view of the above requirements,this paper studies a multi-node sampler based on POWERLINK bus,adds software filtering function to the design of the traditional sampler,optimizes the hardware circuit design,and improves the acquisition accuracy of the sampler;Combined with industrial real-time Ethernet POWERLINK,the real-time performance of data transmission is improved.This thesis introduces the research background and current research status of multi-node sampler at home and abroad and introduces a variety of industrial real-time Ethernet.This thesis analyzes the functional requirements of the multi-node sampler,compares and selects the main control chip,summarizes the characteristics and advantages of the industrial real-time Ethernet POWERLINK bus,and puts forward the overall design scheme of the multi-node sampler based on the POWERLINK bus,including the design of the upper computer monitoring system and the multi-node sampler.According to the functional requirements,FPGA chip is selected as the core processor of the multi-node acquisition and editing device,and the module design of signal conditioning circuit,multi-level analog switch,A/D conversion circuit,E2 PROM and POWERLINK communication circuit is completed.The FPGA software is logically developed,the frame structure table is designed to control the switching of analog switches,and the functions of different channels and different sampling rates are realized.The recursive average filter is designed to improve the acquisition accuracy of the multi-node sampler.The upper computer monitoring system is built with Qt to realize real-time analysis and display of analog sensor data.Through real-time curve drawing,the dynamic data display is more intuitive.The data flow direction of the multi-node collector and editor is studied,the POWERLINK communication protocol is determined according to the relationship between the modules,the POWERLINK master and slave stations are built,and the real-time data transmission between the modules is realized.At last,a test platform of multi-node sampler based on POWERLINK bus is built to calibrate the accuracy of the multi-node sampler,test the POWERLINK network communication function,and test the system integration.The test results show that the whole system can complete the real-time and reliable collection and monitoring of the analog sensor data of multiple sampler nodes and verify the feasibility of the design.