Research And Design Of Multi-control Terminal Refueling System Based On Network

With the rapid development of embedded systems and industrial network technologies,to achieve automated management system have become a major tool in various of industries to improve management and efficiency.In the past,traditional manual refueling way due to the greater influence of operator,not only the amount of fuel error is larger,but also cause a small increase,wrongs,plus risk of human errors,etc.These can not meet to achieve the aircraft fast and secure fuel supplies in the refueling process.To solve these problems,improving aircraft fuel efficiency and management effectiveness,taking the cost of manufacturing fuel systems into account,and meeting the requirements of the civil aviation industries and efficient operations,this paper design a multi-control terminal refueling system based on network.According to the functional requirements and performance targets,studies the design of refueling control system,including to system power supply channel,the electric valve control channel,pressure and opening signal acquisition channel,traffic signal acquisition channel,contact signals and lights control channel,intrinsical safe bus interface and Ethernet communication interface and other features channel,etc.In hardware circuit aspects,applying LPC2294 microcontroller to the control core,through the hardware circuit designed,achiving 4-20 mA electric valve control signal output,collecting 4-20 mA or 0-10 mA pressure signals,4-20 mA opening signals and 5KHz flow signal.In order to achieve full-duplex communication with an external terminal,design two ways of 485 communication interface,and access to the communication barrier,which is composed of intrinsical safe bus interface.In order to ensure stable and reliable Ethernet communications,this system uses dual Ethernet interfaces,increasing the reliability of a redundant system.In control software aspects,through cutting the ?C/OS-II embedded operating system,then transplanting it to the ARM7 core LPC2294 microcontroller.In software designs,writing DA chip drivers to achive the control of electric valve;writing AD chip conversion function and filter function to collecte flow and opening signal.The paper use microcontroller as a slave and collecting pulse signal,communication information exchange with the host controller by SPI bus.In network communications aspects,both intrinsical safe bus and Ethernet communications networks technologies are studied respectively.In intrinsical safe communication module,by comparison of several intrinsical safe bus communication protocols,we choose 3964(R)protocol,and custom application layer data packets.In Ethernet communication module,trough embedded TCP/IP protocol stacks analysis,and preparation of Ethernet controller chip initialization,sending and receiving programe.On this basis,defining the data communication messages.Trough the hardware and software debugging,the designed refueling control system can communicate with external terminals by intrinsically safe bus.Ethernet can communicate with the centralized control station,by experimental results prove the system is stable,and have a certain value.