Optimal Design Of Vehicle FOG Strapdown Inertial Navigation System

Vehicle strap down navigation system can provide accurate navigation information for vehicles in actual operation,which plays an important role in military vehicles.Due to the bad application environment of military vehicles or large engineering vehicles and the large vibration impact,the performance of the system in the process of use is degraded,or even can not work normally.In this paper,based on the application requirements of military vehicles and large engineering vehicles,the strapdown inertial navigation system is optimized.The structure,shock absorber,power supply and accelerometer sampling circuit of the system are optimized.After optimization,the accuracy,volume,power consumption and adaptability to the environment of the system are improved,and the requirements are verified by experiments According to the actual application requirements,it can achieve accurate navigation for vehicles.The main contents of this paper are as follows:(1)Overall optimization design and implementation of vehicle sins.This paper investigates the current situation of the vehicle strapdown inertial navigation system,accurately grasps the research status and shortcomings of the vehicle strapdown inertial navigation system at this stage,and puts forward the overall optimization design and implementation scheme;according to the design index,the main components are selected;the mechanical structure,damping mechanism,accelerometer connecting line,system power supply and accelerometer sampling circuit of the system are analyzed The overall optimization design was carried out.The basic principle and error equation of inertial navigation system are analyzed;the error of inertial device is analyzed by Allan variance.(2)The shock absorber design of vehicle sins.This paper analyzes the causes of vibration in vehicle environment and the principle of shock absorber;carries out type selection design,structural design and parameter design of shock absorber,and carries out angular vibration and linear vibration test on the designed shock absorber.The test shows that80% of the vibration noise can be isolated for the noise of 2 ? 200 Hz.(3)Accelerometer signal acquisition system optimization and temperature compensation.This paper introduces the scheme of the previous acquisition circuit,and analyzes the improved accelerometer acquisition method.Verified by the circuit linearity test,accelerometer stability test and nonlinearity test,the linearity of the improved acquisition circuit is improved by one order of magnitude;the error of zero bias and scale factor of stability test becomes smaller;the nonlinearity of accelerometer with if mode is similar to that of AD,both of which are below 100 ppm.The zero bias and scale factor of the accelerometer are compensated by the least square method.(4)The experimental verification of vehicle sins.In order to verify the performance and stability reliability of the optimized system,the power function test,environment test,alignment test and dynamic sports car test are carried out.The experimental results show that the initial alignment accuracy is better than 0.02 ° for horizontal attitude and 0.1 ° for heading,and the alignment time is less than 5 minutes,and the positioning error is better than 1nm / h.The optimized system has higher performance,more stable and reliable work,and is more suitable for the actual environment.