Application Of Rtos Vxworks In Laser Gyro Attitude & Heading Measurement System

Attitude&Heading measuring system outputs the real-time information of the carriers concerning Attitude&Heading, speed and location, through calculating the data measured by the inertial sensors. The primary works of the embedded computer used in the Attitude&Heading measuring system are as follows: data acquisition, digital filtering, Attitude&Heading calculation, compensation and control. It is one of the key elements to select a suitable operating system in order to achieve stable and highly efficient measurement. According to the need of the multitasking applications in laser gyro inertial measurement system, the real-time operating system (RTOS) VxWorks has been introduced, and the cross-development environment has been built. Software modules such as high-speed PCI bus data acquisition, UDP network communication and data storage have been designed. This dissertation has completed the following works.1. The requirements of software in the system have been analyzed, and the operating platform and operating system have been selected. The basic components of the Attitude&Heading Measurement System, characteristics and flows of the sensors'output have been systematically studied. And the idiographic hardware and software requirements of embedded computer have been put forward. PMP PC/104 produced by SBS Corporation has been selected as the processing computer, the 32G innodisk electronic disk as the storage medium, and VxWorks as the operating system after comparing the features and application environments of several common embedded computers and RTOS.2. Software modules such as high speed PCI bus data acquisition, UDP network communication, data storage and so on have been designed. Board support package (BSP) has been modified according to the parameters of hardware after the set-up of the cross-development environment, and then the program in the applications has been debugged. According to the task requirements of the Attitude&Heading measuring System software, the segmentation of the program tasks, the proper distribution of the system's priorities and the set-up of the communication mechanism among the tasks have been completed to assert the reliable data transmitting. Configuration space, interface and interrupt processing of the PCI bus have been studied in theory and experiment, and the problems of the data acquisition program are analyzed. UDP network communication has been designed based on VxWorks, according to the real-time requirements of network tasks in the system. Multi-file pointer and file segmentation store have been proposed to solve the data storing problems.3. The response to the external trigger and the program execution time delay has been tested. The methods for measuring time delay of the system and program execution have been proposed separately, one of which was used to test the parallel ports'output with oscilloscope, and the other, called as timestamp method, was used to test the program execution time.Software based on VxWorks has been developed and brought into a certain Attitude&Heading Measurement System. Performance of the methods developed in this dissertation has been tested practically, which can satisfy the real-time and reliable requirements of the system according to the experiment results.