Research On Integrated Correction Technology Of Marine Strapdown Inertial Navigation System

The inertial navigation is a key technology widely used in various fields of national defense,and this technology also plays a decisive role in the field of navigation.First of all,it is extremely subtle,in the process of system work,it is impossible for it to be issued to the outside world any signal which can be captured by others.Secondly,it does not depend on any external conditions,it will work independently,and output the corresponding navigation information of carrier motion in the process.However,the navigation error of the strapdown inertial navigation system will be diverged as the use time is prolonged.While the ship is sailing on the sea,when it is unable to receive external information for a long time,the error accumulated by the strap down inertial navigation system will make the calculation result of inertial navigation system unavailable after a certain time.In order to ensure the accuracy of strapdown inertial navigation system navigation information system,people often reset the system on it's position,velocity and azimuth parameters with the combination of navigation,strapdown inertial navigation system has many error sources,during these error sources,the error from inertial device of strapdown navigation system accuracy is obvious however,the gyro drift is an important source of error,so it is necessary to be measured and compensated.This comprehensive correction technique is to compensate the drift of the gyroscope to suppress the divergence of error and return the system.This paper first introduces the basic theory of strapdown inertial navigation system,and then expounds the basic principle of strapdown inertial navigation system.Aiming at the navigation information error divergence phenomenon caused by the gyro drift and other device errors in the SINS,the system simulation is carried out.Directly display the influence of the gyro drift on the accuracy of SINS,and the necessity of estimating and compensating the gyro drift is derived.According to the widely used in shipbuilding,ship strapdown inertial navigation system,establish the error model of the system,design of comprehensive correction scheme based on strapdown inertial navigation system for observability analysis of parameters,according to the different state of motion,the results of observability analysis will be compared and analyzed.The observation results,select the appropriate working conditions for the filter,in order to improve the estimation the speed and precision filter.In order to prevent the Kalman filterfrom filtering and diverging in practical engineering,a Sage-Husa adaptive filter is designed,and its improvement is simplified,so that the filter can adapt to the change of noise better.By adding a fixed interval optimal smoothing filter,the estimation results are more accurate.The external position and speed information are introduced,the gyro drift is estimated and compensated by the filter,and the system speed,position and azimuth remodulation are carried out at the same time.The integrated correction of strapdown inertial navigation system is realized.The simulation and vehicle experiments show that the navigation accuracy of SINS is obviously improved compared with that of the SINS without correction.