Research On AUV Navigation Technology Based On USBL Aided SINS

Underwater high-precision navigation and positioning technology is the key to the successful implementation of AUV underwater missions,SINS has been widely used because of its complete autonomy,concealment and output navigation information,but SINS can only output more accurate navigation information in a short time,and the positioning error will be divergent with the accumulation of time.As the electromagnetic wave signal will be divergent underwater attenuation,GPS can not be positioned in underwater;Although the long baseline positioning system has high accuracy in underwater positioning,the acoustic array laying,calibration and recycling need to spend a lot of manpower and resources.USBL array size is small,easy to install,through a reasonable design,positioning accuracy in a certain area can achieve long baseline system positioning accuracy.In this paper,the AUV positioning method of USBL assisted SINS is studied.Combined with other auxiliary navigation equipment underwater,the integrated navigation model of SINS/USBL/DVL/MCP/Depth gauge is established,which realizes the requirement of AUV underwater high precision navigation and positioning.The main research contents of this paper include:Firstly,the development status of AUV and the research status of AUV navigation algorithm are introduced in detail.According to the actual environment of AUV,the influence of underwater acoustic characteristics on acoustic positioning accuracy is analyzed in detail,and the corresponding solutions are put forward.In order to establish the underwater model of AUV simulation,the basic theory of underwater ray acoustic is studied,and the underwater channel model is simulated by BellHop software.The transmission and reception of underwater acoustic signals are simulated,which lays the foundation for the subsequent acoustic location simulation.Secondly,the navigation principle of USBL system is introduced in detail.the principle of range azimuth navigation is introduced.In order to solve the problem of time delay difference,the weighted cross-correlation algorithm is adopted to avoid the phenomenon that the peak value of the cross-correlation peak is fuzzy or false.In this paper,the method of range navigation is presented,and the distance iterative localization algorithm and Gauss Newton iterative algorithm are proposed.The feasibility and effectiveness of the two algorithms are verified by simulation.In addition,the position calibration technology of submarine sound source transmitter is introduced.Aiming at the phenomenon of sound line bending in the position calibration process,an iterative algorithm based on sound line correction is proposed.The simulation results show that the accuracy of the position calibration is improved after the sound line is corrected.Thirdly,an integrated navigation model based on SINS/USBL/DVL/MCP/Depth gauge is designed for a single inertial navigation system which can not meet the AUV high precision and long navigation problem,with the state equation and the observation equation is derived based on the centralized filtering.Aiming at the combination of USBL positioning and SINS directly,a combination method based on relative information measurement is proposed,the distance and arrival distance difference obtained by USBL are combined with the distance and arrival distance of SINS.Finally,the simulation experiments of different integrated navigation methods and the simulation of PDM assisted SINS are carried out.The simulation results show that the introduction of USBL system can effectively correct the SINS position error,and the improved SINS/USBL combination navigation method has higher positioning accuracy.In the case of the AUV navigation speed is slow and the heading error is small,the PDM aided SINS positioning is feasible and effective.