Research On The Positioning Of Underwater Carrier Based On Single Beacon Ranging

Based on the requirement of long time,large range and long distance in underwater acoustic positioning,positioning technology based on single beacon ranging is a new research direction of underwater acoustic positioning technology.It is the combination and simplification of traditional underwater acoustic positioning system.The simplification is because it only needs to put a sound beacon on the seabed,which improves the convenience and efficiency of the system.The combination means the combination of the acoustic ranging positioning device and the carrier motion sensor.Due to the fact that the single distance measurement can not determine the specific location of the water body,this paper introduces the concept of virtual range beacon to the system,which is based on the traditional long baseline array.The main purpose of this paper is to improve the positioning accuracy and stability of the system.This paper has researched on the localization technology based on virtual beacon,the iterative divergence suppression technology which overcomes the nonidealities of virtual beacon geometric distribution,the method to handle the fixed error of heading angle,and the data processing technology which can deal with the non concurrency of the acoustic ranging transmitting and receiving.Single distance measurement is not enough to determine the specific location of the underwater carrier.In this paper,the concept of virtual range beacon is introduced to the system according to the traditional long baseline array,and the model for positioning system based on virtual range beacon has been built.The initial position for iteration and the ranging error imposing effects on the positioning accuracy have been simulated and analyzed,and the experimental data has been used to verify the feasibility and effectivenessof this method.The geometric distribution of the virtual beacon is determined by the navigation path of the vehicle.The nonideality of the geometric distribution of virtual beacon will lead to the singular or ill conditioned coefficient matrix and therefore result in the failure of convergence of iteration process.In order to overcome the bad condition of the coefficient matrix caused by the nonideality of geometric distribution of the virtual beacon,this paper proposes a new iterative divergence suppression technology.The adaptive adjustment diagonal element is added to make the coefficient matrix positive definite,which can restrain the divergence of position correction in the iteration process.Sea measurement data show that,when the geometric distribution of the virtual beacon is not ideal,the proposed method can effectively suppress the divergence of the positioning result and converge to the vicinity of the integratednavigation system;When the geometric distribution of the virtual beacon is ideal,the results of the Gauss Newton method and the damping diagonal element method match very well.The coordinate rotation matrix is composed of the carrier attitude angle,and the error of attitude angle will be transmitted to the position of the virtual beacon,which will affect the positioning result.Among all the elements,the biggest effect is from carrier heading angle.In order to overcome the influence of the fixed error of the carrier heading angle,a weighted fusion algorithm based on the least mean square error is proposed.The simulation results show that the method is greatly influenced by the relative position of the carrier track and the beacon.According to the theoretical analysis result that the difference of the positioning results of single beacon is only related to the location of the beacon.The heading angle compensation algorithm based on the single positioning difference is proposed.The feasibility and effectiveness of the proposed method is verified by the analysis of the experimental data,and the positioning result converges to the integrated navigation result.The traditional localization method based on acoustic ranging is based on the static acoustic ranging model,which ignores the noncommon points of acoustic ranging transmitting and receiving caused by the movement of the carrier.Half of the two-way propagation delay has been simply used as one-way propagation delay observation,and the observation value is neither equal to the true value between the transmitting point and the beacon and the true value between the receiving point and the beacon.In order to overcome the influence of non concurrent acoustic ranging,localization method based on virtual transceiver beacon is proposed.The two-way transmission delay is directly used through the virtual transmitter and receiver,but the improvement of the positioning accuracy is greatly affected by the measurement error.Therofore,a robust Kalman filter related to the state equation and measurement equation is proposed.On one hand,the joint of acoustic ranging equipment and the carrier motion sensor constitute a two-way propagation delay measurement equation.On the other hand,the system state equation and measurement equation of the system are correlated.The simulation and lake measurement data process show that,the convergence speed is improved and the estimation accuracy is improved when the filter parameter is reasonable,the estimation error is reduced when the filter parameter is not reasonable.