Research On Land Strapdown Inertial Navigation Computer Design And Alignment Technology

In modern ground warfare,in order to improve the combat capability of armored vehicles,in order to improve their combat capabilities,so that they have flexible maneuverability and accurate strike capability,this requires a high-precision land inertial navigation system based on real-time Provide information such as attitude,speed and position for the carrier.Therefore,land-based armored vehicles have a great demand for high-precision inertial navigation systems.Based on the actual application requirements of the land-based inertial navigation system,this paper studies the relevant algorithms of the navigation computer software and hardware platform construction and initial alignment.The research content of these two parts will produce the mobility of the land-based vehicle and its cooperative combat capability.critical use.The navigation computer is the control operation center of strapdown inertial navigation,and its reasonable design plays an important role in the accuracy and stability of the navigation system.For medium and high-precision inertial navigation equipment,in order to ensure its accuracy,it is necessary for the navigation computer to have a high sampling capacity for the output of accelerometers and gyroscopes to maintain the synchronization of data collection;At the same time,we must also take into account the calculation performance of the navigation computer and the scalability of the communication interface.In response to the above requirements,this paper proposes a three-core architecture navigation computer platform design based on DSP,FPGA and ARM processors.In terms of hardware,it includes the minimum system design of multi-core architecture,hardware platform construction of peripheral sampling circuits,power systems,communication circuits,etc.;in software,software programming for each processor,including FPGA-side data sampling based on Verilog hardware description language Program,DSP-based data solution program based on C language and ARM-side interface expansion program.So as to complete the design of navigation computer system such as data collection,calculation and external communication.In terms of algorithm,it mainly focuses on the initial alignment of strapdown inertial navigation.In this thesis,the initial alignment of land vehicle strapdown inertial navigation system is taken as the research object,which is divided into static base environment and dynamic base environment for research.First,complete the derivation of strapdown inertial navigation basic equations and error equations;then,the IMU is modeled and analyzed and discrete calibration is performed to compensate for deterministic errors.During the alignment of the strapdown inertial navigation system,for the static base environment,the principle of multi-vector attitude determination is used to perform analytical coarse alignment and one-step correction of coarse alignment to obtain coarse alignment results;Use Kalman filter to estimate the misalignment angle to complete the fine alignment process;For the shaking base environment,the carrier motion state and IMU data under the shaking environment are simulated.The solidification method is used to complete the coarse alignment,and the Kalman filter is used to find the ideal inertial system and the inertial system misalignment angle.And carry out principle research and simulation verification for the above methods.Finally,relevant experiments were conducted to verify the navigation computer and initial alignment.Experiments on signal sampling and output of the navigation computer prove that its performance basically meets the system requirements and the sampling accuracy is relatively good.After performing a separate calibration experiment on the inertial device and performing error compensation,the initial alignment experiment of the swaying base of the turntable and the static initial alignment experiment of the vehicle are performed.The experimental results show that the system can achieve good initial alignment accuracy,which roughly meets the needs of engineering applications.