CN-122015873-A - Method for realizing high-precision underwater integrated navigation by fusing AUV dynamics speed and acoustic data of single beacon

CN122015873ACN 122015873 ACN122015873 ACN 122015873ACN-122015873-A

Abstract

The invention provides a method for realizing high-precision underwater integrated navigation by fusing AUV dynamics speed and acoustic data of a single beacon, and belongs to the technical field of underwater navigation and positioning. The method comprises the steps of estimating the water dead-reckoning speed under a carrier coordinate system by utilizing the rotating speed of a propeller and the current of a motor, fusing SINS gestures to decompose the SINS gestures into a navigation coordinate system, obtaining AUV three-dimensional motion speed, obtaining a preliminary position based on dead reckoning, adaptively selecting a navigation strategy according to the operation duration and the acoustic availability, wherein a short-time task adopts pure dynamics dead reckoning, a long-time operation introduces single beacon distance information, and carries out periodic constraint on a dead reckoning result through a geometric projection filtering algorithm of a reset starting point to obtain a corrected navigation position. Compared with a single data source, the invention obviously improves the navigation precision and reliability and effectively solves the technical problem that the application of the acoustic sensor in the deep sea environment is limited.

Inventors

GAO FAN
LI YUQING
XU TIANHE

Assignees

山东大学

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (6)

1. The method for realizing high-precision underwater integrated navigation by fusing the AUV dynamics speed and the acoustic data of the single beacon is characterized by comprising the following steps: S1, calculating the coupling relation between the rotating speed of an AUV propeller and the driving current of a motor in real time, and obtaining the speed of the ship to water under a carrier coordinate system; s2, fusing gesture data provided by a strapdown inertial navigation system SINS, decomposing the water navigation speed under a carrier coordinate system to a navigation coordinate system, and obtaining the three-dimensional movement speed of the AUV; S3, dead reckoning is carried out based on the three-dimensional motion speed, and initial position estimation of the AUV is obtained; And S4, adopting a filtering algorithm of a reset starting point, and periodically restraining a navigation result of the dynamic dead reckoning by using distance information provided by a single beacon to obtain a corrected navigation position.
2. The method for realizing high-precision underwater integrated navigation by fusing AUV dynamics speed and acoustic data of a single beacon according to claim 1, wherein the specific implementation process of the step S1 is as follows: S11, establishing a quasi-steady-state model of the propeller thrust T and the torque Q, and determining a propeller performance curve based on the linear relation between the thrust coefficient K T (J) and the torque coefficient K Q (J) and the speed coefficient J: , , wherein D is the diameter of the propeller, The sea water density, n is the rotating speed of the propeller, T is the thrust of the propeller, Q is the torque of the propeller, and J is the advance coefficient; S12, collecting driving current of an AUV propulsion motor, and determining torque Q under the current working condition according to the corresponding relation between the motor current and the torque; S13, quantitatively controlling the geometric relationship of the hydrodynamic attack angle of the propeller blade by the advance coefficient J, wherein the specific formula is as follows: , Wherein w is the accompanying flow fraction, D is the diameter of the propeller, n is the rotating speed of the propeller, and v is the speed of the aircraft; S14 integrating S11 over a limited operating range, the thrust coefficient K T (J) and the propeller torque coefficient K Q (J) can be expressed as: , , Wherein, K T (0) and K Q (0) are zero flow coefficients determined through experiments, and alpha and beta represent dimensionless coefficients; s15, further deducing the speed u of the aircraft according to the variables obtained in the steps: 。
3. The method for realizing high-precision underwater integrated navigation by fusing the AUV dynamics speed and the acoustic data of the single beacon according to claim 2, wherein in step S14: using AUV to obtain DVL measured value as true value in shallow sea, and using least square method to obtain coefficient beta: , Where v d is the velocity measured by the DVL and v i is the velocity obtained by using dynamics.
4. The method for realizing high-precision underwater integrated navigation by fusing AUV dynamics speed and acoustic data of a single beacon according to claim 1, wherein the specific implementation process of the step S2 is as follows: s21, acquiring attitude data which are output in real time by SINS and comprise roll angles Pitch angle θ and heading angle ; S22, obtaining a direction cosine matrix by using the gesture data, and converting the speed of the obtained carrier coordinate system into a navigation coordinate system.
5. The method for realizing high-precision underwater integrated navigation by fusing AUV dynamics speed and acoustic data of a single beacon according to claim 1, wherein the specific implementation process of the step S3 is as follows: S31, initializing a dead reckoning parameter, setting a position at an initial time k=0 as P 0 , obtaining the initial position by GNSS positioning before AUV entering water, setting a position P last = P 0 after the last acoustic correction, and setting a last acoustic correction time index k last =0; S32, defining a time sequence of dead reckoning, wherein a sampling interval is deltat, a time index is k=1, 2,3, & N, defining an acoustic ranging time sequence is t j , j=1, 2, & M, wherein M is the total number of acoustic ranging times; s33, establishing a dead reckoning position updating formula, and recursively estimating based on the three-dimensional movement speed V i = [V E-i , V N-i , V U-i ] T obtained in the step S2: , Wherein P DR (k) is a predicted position based on dead reckoning at time k, P last is a position after last acoustic correction, k last is a time index of last acoustic correction, and Δt DR is a sampling time interval of a dynamic speed; S34, when new acoustic distance information is not received, dead reckoning is continuously performed by using the step S33, and a preliminary position estimate P DR (k) is output as the current navigation position of the AUV; s35 for the vertical position estimation, directly replacing the heaven component in P DR (k) with the depth value h (k) measured by the pressure sensor, namely: 。
6. The method for realizing high-precision underwater integrated navigation by fusing AUV dynamics speed and acoustic data of a single beacon according to claim 1, wherein the specific implementation process of the step S4 is as follows: S41, presetting an acoustic ranging period T acoustic , and starting an acoustic ranging process when the AUV navigates to a preset ranging moment or receives a ranging request triggered by an acoustic beacon; S42, ranging is carried out through an acoustic transducer carried by the AUV and a single beacon arranged on the seabed, a slope distance measurement value Z k of the current moment k is obtained, meanwhile, the accurate position B= [ x B , y B , z B ] T ] of the beacon under a navigation coordinate system is recorded, and a distance measurement model is as follows: , Wherein, the Noise is measured for distance; S43, calculating the geometric distance d DR from the dead reckoning position P DR (k) to the acoustic beacon B in the step S3: ; S44, calculating a geometric scaling factor alpha k : ; S45, performing geometric projection correction on the dead reckoning position based on the scaling factor to obtain a corrected fusion position P fused : , If alpha k is larger than 1, the dead reckoning distance is estimated to be underestimated, and the estimated position needs to be expanded outwards, if alpha k is smaller than 1, the dead reckoning distance is estimated to be overestimated, and the estimated position needs to be contracted inwards, and if alpha k =1, the dead reckoning position is consistent with the ranging value, and correction is not needed; S46, resetting the dead reckoning parameters by taking the corrected position P fused as a new dead reckoning starting point: , and S47, returning to the step S3, and continuing dead reckoning at the subsequent moment by taking the corrected position as a starting point, and repeating the steps S41-S46 until the acoustic ranging information is received next time, so as to realize the periodic constraint on the dynamic dead reckoning error.

Description

Method for realizing high-precision underwater integrated navigation by fusing AUV dynamics speed and acoustic data of single beacon Technical Field The invention relates to the technical field of underwater navigation, in particular to a method for realizing high-precision underwater integrated navigation by fusing AUV dynamics speed and acoustic data of a single beacon. Background An Autonomous Underwater Vehicle (AUV) is widely applied to the fields of submarine topography mapping, resource exploration, underwater reconnaissance and the like as core equipment for ocean exploration and development, and has higher requirements on the performance of a navigation system thereof. Currently, corrections for underwater velocity and position rely primarily on acoustic means. The Doppler velocimeter can provide high-precision seabed tracking speed, but the effective working range is limited by the height from the seabed, so that the Doppler velocimeter is only suitable for offshore or near-bottom operation, the acoustic Doppler velocimeter mainly measures the speed of relative water body instead of the ground speed and faces the signal attenuation problem in a deep sea environment, the electromagnetic current meter can only measure the speed of relative water body, is easily influenced by the conductivity of sea water and the distribution of geomagnetic field, and has the advantages of easy drift of zero point and measured value and frequent calibration. In deep sea environments beyond the range, the sensor fails because the bottom tracking signal cannot be acquired. Therefore, how to obtain reliable speed information under the condition of complex acoustic environment or deep sea has become a key problem to be solved in the current underwater navigation field. To address this problem, speed estimation using an AUV own dynamics model provides a viable alternative. Unlike sensors that rely on external acoustic signals, the dynamic speed is derived from internal information such as the rotational speed of the propeller in the propulsion system, and has the significant advantages of being strong in autonomy and not prone to environmental interference. The idea was first proposed by Koifman and Bar-Itzhack in 1999, and inertial navigation is assisted by combining Kalman filtering with an aircraft dynamics model. This idea is then extended to the field of underwater vehicles. Studies represented by HUGIN AUV series show that the speed output by the dynamic model constructed based on the sea test data has high consistency with the actual measured value of the DVL, and the feasibility and the effectiveness of the dynamic model as a speed auxiliary means during the failure period of the DVL are fully verified. However, while the dynamic model assistance can provide velocity information when the DVL fails, the problem of cumulative drift remains alone, and it is difficult to meet the needs of long-term, high-precision navigation tasks. In a deep sea operation scene, due to the limitation of deployment conditions, an AUV can only receive acoustic signals of a single beacon to perform periodic position correction, and a constraint positioning method based on single beacon ranging becomes a research hot spot. It should be noted that, most of the existing methods are used for carrying out fracture treatment on a dynamic model and an acoustic positioning means, and the dynamic information of the AUV cannot be deeply fused to provide continuous motion constraint, so that the overall robustness of the navigation system in a long-time task is insufficient, and error accumulation cannot be effectively restrained. In summary, how to combine the dynamics speed with the limited external acoustic observation depth to realize the acoustic loss and the high-precision and high-reliability navigation of the AUV in the deep sea environment is a technical problem that needs to be solved by those skilled in the art. Disclosure of Invention In order to solve the technical problem that the acoustic sensor is limited in application in a deep sea environment, the invention provides a high-precision underwater integrated navigation method integrating AUV dynamics speed and single-beacon acoustic data. The method aims to avoid the limitation that the traditional speed sensor cannot be suitable for deep sea operation, and has the core innovation that a dual-mode navigation strategy is provided, and the navigation mode is adaptively selected according to the operation duration and the availability of acoustic data, so that the accuracy is ensured and the system robustness is considered. The method comprises the steps of obtaining the water-aligning navigational speed under a carrier coordinate system by resolving the coupling relation between the rotational speed of an AUV propeller and the driving current of a motor in real time, further fusing gesture data provided by a strapdown inertial navigation system, resolving the navigational speed to a na