Design And Implementation Of Inertial Navigation Data Transmission And Fusion System Based On Embedded Web Server

In recent years,inertial navigation system has achieved great development from platform version to strapdown systems,but there are two limitations in traditional inertial navigation system: First,centralized task processing,the second is the way of serial data transmission.Centralized task processing makes that data reception,algorithm solution and data fusion tasks are handled in the same processor,which not only resultes in a high load of the system and the program’s high coupling,but also affects the real-time performance of the system and limits the scalability of the system function.There are many limitations for serial data transmission,such as the need for on-site wiring,install the client,slow transmission speed,closed transmission distance and so on.Aiming to solve above problems,this paper proposes an inertial data transmission and fusion system based on embedded Web server in combination with Ethernet technology.The charactor of this system is that inertial navigation algorithm solution and data fusion are separated,and were respectively processed by DSP core and ARM core.,which is that DSP-side only processes inertial navigation algorithm solution,and ARM-side achieves data transmission,data fusion and other additional features.This kind of distributed strategy can not only reduce the load on the DSP-side,but also can achieve the data transmission between Web server and browser by internet based on the Web server on ARM-side,which can solve the disadvantage of the traditional serial data transmission.In addition,the ARM-side is strongly editable,and can append data fusion or other additional functions without affecting algorithm run on the DSP-side.The focus of this paper is to achieve ARM-side data transmission function and data fusion algorithm.Hardware base uses ‘DSP + ARM’ dual-core asynchronous architecture OMAPL138 chip,two cores respectively run SYS/BIOS and Linux operating system.Besides,this paper built Boa embedded Web server based on Linux,which achieved data transmission and data fusion function through the combination of Web server and Linux application.This paper first introduces the purpose,significance and development status of the research at home and abroad.Then,according to the actual needs of the project,we design the whole idea of the inertial transmission and fusion system,and do demand analysis on Web server and web page aimed at the whole idea.Web server needs to realize the functions of navigation parameters-set,dual-core data exchange,INS/GPS data fusion and so on.The web page needs to realize the design of graphical interface,dynamic refresh of local data andsetting the basic parameters of navigation.Secondly,in order to realize the data combination the of INS and GPS,we firstly build mathematical model for inertial navigation system and GPS.Then,the measurement equations of INS and GPS are established,and the error is estimated by Kalman filter,which can improve the accuracy of INS or GPS alone.Thirdly,hardware and software of inertial data transmission and fusion system are implemented.First,we design the hardware program according to the hardware option to select OMAPL138 as the processor chip,and then select the TL138-EVM platform to design the hardware platform.The parameters of the hardware platform are also explained.After that,the system software architecture is analysed and the software platform is built accordingly,such as BootLoader porting,Linux kernel transplantation and file system migration.Then,the required protocol base in the embedded Web server are introduced,and a Boa server is built.At the same time,in order to achieve Web server and web Dynamic communication,CGI technology is realized on the Web server-side.Since the inputs of system data fusion algorithm are obtained from the DSP core,so this article implements the Sys Link component based on dual-core communication function,which makes it possible for the data obtained from DSP to be transmitted to the ARM side in time.And then,functional needing of Web servers and INS / GPS data fusion algorithm are achieved through Linux applications.At last,the web is designed and AJAX is utilized to achieve the dynamic web page data interaction.At the end of this paper,the PC and the development Board are connected,and the functions of the Web page and the Web server are tested.On the algorithm side,the algorithm of INS / GPS data fusion is verified and the correctness of the algorithm is proved.Finally this paper prove the feasibility of the distributed inertial navigation system proposed in this paper by testing the running time of algorithm on ARM and DSP.