Research On Real-time Performance Of SINS Software Based On Embedded Linux Operating System

Although VxWorks system fully meets the requirements of real-time,multi-task scheduling and high reliability of strap-down inertial navigation software,it is protected by copyright,and is developed by the United States WindRiver company,therefore,the VxWorks system is not suitable for the application of autonomous defense equipment,we need to seek other operating systems.Because of the characteristics like open-source,security,and cross-platform transplantation,Linux system is considered.Based on the research of the requirement and the working environment of the SINS,this essay chose the appropriate software and hardware platform,and improved the real-time performance of Linux system.The main task of this essay is as follows:1.The composition and working principle of SINS and the basic principle of the navigation solution were researched.Through analysis of the mission requirements and working environment of SINS,the software and hardware platform of the system was put forward.PC/104 board with high performance CPU,good stability and compact structure,was selected as the hardware platform,Linux with the advantages of open-resource,flexibility and soft real-time,was selected as software platform.2.The task requirement of SINS was researched,and the embedded Linux system based on PC/104 was constructed.Because the system selected high-speed data acquisition system based on PCI bus,this paper realized the PCI driver based on Linux,which lay the foundation for the data acquisition and navigation solution.3.The real-time performance of SINS was researched,including the real-time performance of Linux system,strapdown inertial navigation software and UDP mode.Firstly,the process scheduling mechanism of Linux was analyzed,and the signal delay time and the signal delay were tested,then the interrupt delay was tested and analyzed;Then the real-time performance of strapdown inertial navigation software based on Linux system was tested and analyzed;At last,the real-time performance of UDP communication between PC/104 and upper computer was tested and analyzed.The test results showed that the Linux system can meet the requirements of the 1ms delay,data acquisition and navigation solution of SINS.4.The working principle of Xenomai was researched,then constructed Xenomai/Linux system based on Linux;then the real-time performance of the system was tested and analyzed.The results showed that the system has strong real-time performance,and the feasibility of Xenomai/Linux was verified.