Research On Algorithms Of Geomagnetic Adided Navigation For Remote Operated Vehicle

Inertial navigation system(Inertial navigation system,INS)is capable of autonomous and covertly continuous location and navigation in all weather conditions.It provide continuous and real-time navigation parameters for the carrier,in a short time with high navigation precision.While the navigation precision drops due to the navigation error of INS will increase with time,it is necessary to correct navigation error through effective aided navigation.Geomagnetic field is a natural magnetic field and vector field,at the same time any point on the earth has a corresponding magnetic vector and its only value.So taking geomagnetic field as an object of study aided inertial navigation system has theoretical significance and practical application value.There are a number of important technical difficulties in underwater geomagnetic navigation,such as:the compensation of magnetic interference fields from remote operated vehicle(Remote Operated Vehicle,ROV),geomagnetic field model in local area,suitability evaluation of geomagnetic chart in navigation area and geomagnetic matching algorithm.This paper research the above issues,research work focused on the following aspects:Research the compensation algorithm of ROV carrier magnetic interference.According to the feature of magnetic interference field generated by vectors and the main features in the attitude of the voyage,we propose a magnetic interference compensation algorithm based on carrier rotation measurements.The traditional methods are to build magnetic interference field model and solve model parameters.However,the traditional method is complex,and it needs to study the navigation.There will be coupling phenomena of carrier attitude in the learning navigation.These will cause parameters easily into a singularity and difficult to solve and the compensation accuracy is not easy to control.In this paper,we use carrier rotation instead of the carrier learn to sail,and simplify the learning process of model.We obtain the corresponding compensation model via the relationship between magnetic interference field and the rotation angle during the ROV rotation.During the navigation,the compensation model is used to real time compensation the magnetic disturbance field generated by the carrier.Research algorithm of construction of the regional magnetic chart and suitability evaluation geomagnetic chart.Precision geomagnetic chart is the prerequisite in geomagnetic aided navigation.To solve the problem of construction issues for regional magnetic chart,we construct a high-precision magnetic map area via taylor polynomials geomagnetic field model based on the analysis and summary of the existing geomagnetic model,and obtain optimal cut-off order of model and measurements to reduce the edge effect.Geomagnetic information-rich region is beneficial to the correction of INS navigation error.For the concern of regional geomagnetic map suitability evaluation,we extract a plurality of major geomagnetic eigenvalues and comprehensive evaluate area suitability by principal component analysis based on multiple attribute decision thoughts.The algorithm solves the defect of single characteristic values evaluation incomplete and the process is simple,easy to use,etc.Simulation results show the geomagnetic map suitability evaluation values from principal component analysis in the candidate region are in good agreement with the geomagnetic match probability in the region.Research geomagnetic matching algorithm.The MAGCOM algorithm based on Hausdorff distance has higher accuracy and strong anti-interference ability in the absence of rotation deviation.The ICCP algorithm using angle tolerance is very effective for the treatment of the rotation error,but calculation is time consuming.Through combinatorial optimize two algorithms,we reduce time-consuming in search algorithm region by error ellipse and improve the algorithm in real time by a shift register.In addition,this paper simulates the effects of the suitability evaluation candidate region on matching algorithm correction accuracy.Simulation results show that the region of high suitability evaluation value is beneficial to improve the correction accuracy of matching algorithm.Research experiment in Songhua Lake.To verify the correctness and validity of the above theoretical research,we carried out underwater geomagnetic aided navigation tests based on the ROV in Songhua Lake of Jilin province.Tests show:the magnetic compensation algorithm based on carrier rotation can effectively compensate magnetic interference field generated by carrier;results via principal component analysis evaluation can determine the appropriate navigation area;the combination algorithm has a high correction accuracy to cumulative error of inertial navigation system in suitable area.