The Design Of The Data Acquisition System In Strapdown Navigation Computer

In the inertial navigation system, strapdown inertial navigation system with highprecision and reliability are gradually replacing the platform inertial navigation system hasbecome the development trend of the inertial navigation system. Although traditional SINShas high accuracy, the cost and power consumption is also high, therefore,that is a verydifficult thing to promote in civilian areas. But the demand for low-cost, low powerconsumption strapdown navigation system has growing in civilian areas. In order to meet thedemand for miniature strapdown navigation system in navigation performance,and to promotethe application of the SOPC technology based on FPGA in the field of civil navigation. thispaper plan to design the navigation computer system based on microcontroller andprogrammable logic array device (FPGA) with master-slave structure,the system can meetsome features with small size,low power consumption,real-time.This topic focuses on the hardware implementation of strapdown navigation system withMEMS inertial sensor at the core of strapdown navigation system sensitive devices. Thesystem measuring the raw data, combined with the specific requirements of strapdownnavigation system based on MEMS inertial device, design of data acquisition circuit and thefollow-up of navigation calculating hardware module, and based on this research is mainlyfocused on the method of communication between the double CPU.The major work done by the writer is summarized as follows:1. First, the paper describes the background knowledge of relevant topics such as inertialnavigation, then further introduce the basic principles of the strapdown inertial navigationsystem, followed by an overview of the overview of the development of MEMS inertialsensitive devices, and then explain the development of the navigation computer technologyprocess, and finally discusses the significance of the research and paper work.2.The paper introduced the Core processor-SINS navigation computer, its main task: asensor signal; acquisition gyroscope, accelerometer, GPS navigation solver with data update;Third, the output various types of navigation information to the control and display module.Then discusses the basic knowledge and works of the strapdown navigation system, forexample, part of the Earth’s parameters, six commonly used coordinate system, coordinatetransformation, the basic equation of the inertial navigation system, the carrier’s attitudeequation. The issue is not related to the GPS module introduces and analyzes focus strapdownnavigation. 3. Next, the paper gives the overall design of the strapdown navigation system.Navigation computer should guarantee a sufficient accuracy and computational speed, so wecan see the navigation computer must not only have a better computing power, should alsohave a better ability to control. First FPGA chip hardware implementation of certainalgorithms, parallel processing of data capacity greatly improved. Thus, in real-time andcomputing power of the system has been very good improvement, this article is based on thisidea, the proposed combination of navigation computer design program based on MCU andFPGA. Then paper describes the overall planning of the SINS system, followed by a detailedMEMS inertial devices error model and some of the key performance indicators, and finallySINS computer FPGA technology and SOPC technology, such as hardware descriptionlanguage, Quartus and Nios software infrastructure and SOPC throughout the developmentprocess.4. Then, the paper introduced hardware circuit based on MCU and FPGA of Strapdownnavigation system. Altera Cyclone series chip and STC51microcontroller is used in thenavigation computer chip selection; For data acquisition module is I2C mode; then elaboratedon the power supply circuit and memory circuit of the navigation computer hardware platform,and then tells the FPGA peripherals specific circuits, such as the AS mode and JTAG modeconfiguration, reset and clock circuits, FPGA and host computer communication circuit, etc.;final focus on the analysis of the interface between the microcontroller and the FPGA circuitusing Verilog HDL language to achieve MCU and FPGA parallel interface and validation,good transmission effect.5. The software design part of strapdown navigation computer. The navigation computersoftware development environment is divided into the keil software with the uVision and NiosII IDE environment of Altera Corporation. Followed by analysis system functionalrequirements, draw strapdown navigation system main program designed to complete the task:read the MEMS gyroscope and accelerometer data, navigation data solver, communicationwith external devices; then Intro the data acquisition module and navigation solver modulesoftware design content, and finally focuses on FPGA and microcontroller parallel thecommunication microcontroller aspects of software development process.6. Verification debugging and results analysis section of the System. Due to the structureof the present system is more complex, involving more modules, and therefore must behardware testing and software testing. Firstly, the overall performance of the hardwareplatform, strapdown navigation system basically meet the requirements for highly integrated,low power consumption; integrated debugging based on the hardware platform, including the overall test of the circuit board and system software testing; and then on inertial sensors piecevalidation assessment; thus the dual-CPU communication simulation analysis to verify theaccuracy of the transmission hardware analysis and simulation; followed by the results of thenavigation solution; final detailed system debugging encountered a series of questions.Finally is to the full text expounds and summarized, and prospects the futuredevelopment direction and focus.