Research On Navigation Algorithm Of Autonomous Underwater Vehicle

Technical precondition of high precision underwater navigation and positioning technique for AUV underwater operation and safe operation,safe operation and determine its return,is particularly important in many key technologies,are often used as a measure of maturity of AUV and an important indicator of the practical.Because of the complex underwater environment and the rapid attenuation of electromagnetic signals in water,a common navigation equipment based on radio navigation,such as GPS and Loran C,can not operate normally underwater.The error of strapdown inertial navigation system is accumulated over time,and the accuracy of the system will weaken with time.It is difficult to meet the AUV long distance and high precision navigation and positioning requirements.The Doppler velocimeter is a all-weather navigation and speed measuring device,which is closely related to the operating environment of AUV.The integrated navigation system integrated with strapdown inertial navigation system and Doppler velocimeter plus some other auxiliary navigation systems is conducive to improving the accuracy and reliability of navigation,and is very suitable for AUV's underwater navigation and location.According to the actual demand,we design the navigation system of federated Kalman filter based on UKF,which is composed of a strapdown inertial navigation system as a main navigation system and a Doppler velocimeter and a magnetic heading instrument as an auxiliary navigation system.This paper first introduces the working principles of each subsystem,and carries out error analysis for them,establishes the error models of each auxiliary navigation system,and determines the mathematical model of integrated navigation system.Considering that the standard Kalman filter can not deal with the nonlinear system,and the extended Kalman filter has poor filtering effect for the strong nonlinear system,we choose the unscented Kalman filter(UKF)to do the filtering process,and simulate it.Since there are many subsystems in the integrated navigation system,data fusion for them is helpful to improve the performance of the system.Therefore,the federated Kalman filter with better flexibility and fault tolerance is selected for data fusion.Firstly,the federated filtering technology is introduced,firstly introduces the structure and working process,and introduces the application of fault tolerance technology in federated filtering,UKF and federated filtering technology are combined to design a local feedback federal filtering device based on UKF Kalman,and has carried on the simulation experiment that,local feedback federal Kalman technology in the integrated navigation system can effectively improve the navigation accuracy and provide better fault-tolerant performance.