Design Of Engine Room DPU Module Upgrade System

With the emergence of some new development trends in the shipping industry,such as large data of ships and intelligent ships,more requirements are put forward for acquiring engine room data.Higher requirements are put forward for the firmware program life cycle maintenance of the engine room distributed processing unit.This thesis takes the distributed processing unit of the fieldbus-based engine room monitoring system as the research object,and designed and implemented the firmware program upgrade system of the distributed processing unit.The upgrade system of distributed processing unit based on operation station and fieldbus is analyzed,the worst response time model of Controller Area Network node is established,the influence of transient load of Controller Area Network on real-time performance is studied,and an upgrade system of firmware program data based on Ethernet transmission is proposed.The development trend of distributed processing unit is analyzed in depth,on the basis of conforming to relevant industry standards,a general distributed processing unit is designed,which can effectively reduce the types of distributed processing units in engine room.The communication mechanism between Fieldbus and Ethernet protocol are analyzed.Flash memory is divided into firmware data and shared configuration data partition,firmware data communication program and the mechanism of verification are designed.The binary file data structure of firmware program is analyzed.A firmware data package download method based on hypertext transfer protocol is designed.In this thesis,the In Application Programming mechanism of microcontroller is studied,and a program jump method of "variable location" and "virtual restart" is proposed,which effectively avoid the interference of interruption on program jump and use the mechanism of decentralized loading to switch the working mode of distributed processing unit.Three firmware upgrade methods are compared and analyzed,and the upgrade strategy of distributed processing unit is proposed.On the basis of theoretical analysis and system implementation,the time of downloading firmware program by three approaches of upgrades is tested,and the data integrity of downloading firmware program by In Application Programming is verified.The validity of program jump method and shared configuration data mechanism is verified by the PC software of the upgrade system.The validity of digital channel and the accuracy of analog channel in distributed processing unit are tested.