CN-121977548-A - Inertial navigation tight coupling correction method and system based on time-sharing cooperative underwater acoustic beacon

CN121977548ACN 121977548 ACN121977548 ACN 121977548ACN-121977548-A

Abstract

The invention belongs to the technical field of deep sea navigation positioning, and provides an inertial navigation tight coupling correction method and system based on a time-sharing cooperative underwater acoustic beacon, wherein the technical scheme is that an AUV (autonomous underwater vehicle) navigation state containing accumulated errors is obtained by adopting a pure inertial navigation mode and performing inertial navigation calculation based on acquired IMU data and depth sensor data before acoustic auxiliary information arrives in the navigation process; after the acoustic auxiliary information arrives, switching to a combined navigation mode for resolving, utilizing beacons at different positions to cooperatively broadcast acoustic information in a time-sharing mode, resolving the horizontal distance between the AUV and each beacon, applying a vertical coordinate constraint, and carrying out fusion processing on the AUV navigation state containing the accumulated error based on the measured distance and the AUV navigation state by a tight coupling filtering algorithm to correct the accumulated error in the AUV navigation state so as to obtain a corrected AUV positioning result. Long-endurance and high-precision underwater positioning of the AUV is realized.

Inventors

ZHANG TONGWEI
WANG YIBIN
XU XIYANG
LV BOWEI
XU HAO
ZHOU XINYU
DU YUCHENG
ZHANG CHENG
FENG JIE
LI GUANGSHENG
JI BAOPING
BAI HUAJUN
LI RONGCHANG

Assignees

山东大学

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (10)

1. The inertial navigation tight coupling correction method based on the time sharing cooperative underwater acoustic beacon is characterized by comprising the following steps of: receiving broadcast acoustic signals sent by all stationary beacons simultaneously, and performing initial position calculation to obtain the initial position of the AUV; In the navigation process of the AUV, when acoustic auxiliary information is not received, adopting a pure inertial navigation mode, taking the initial position of the AUV as a starting point of resolving, and combining acquired IMU data and depth sensor data to carry out inertial navigation resolving to obtain an inertial navigation error ellipse representing the prior probability distribution of the current error state predicted value; When acoustic auxiliary information is received, switching to combined navigation mode calculation, broadcasting acoustic signals by a plurality of static beacons in turn according to a preset period, calculating the three-dimensional space position between the AUV and the beacons according to the received acoustic signals of the current static beacons, combining depth information, forming strong constraint on the vertical coordinates of the AUV to obtain a two-dimensional distance constraint circle representing an observation likelihood function, filtering and fusing an inertial navigation error ellipse and the distance constraint circle, and calculating to obtain an updated optimal position and probability distribution boundary.
2. The inertial navigation tight coupling correction method based on time sharing collaborative underwater acoustic beacons of claim 1, further comprising deploying at least three stationary beacons according to a preset scheme to ensure that an AUV working area is within acoustic coverage of the plurality of beacons, the preset scheme being to deploy the plurality of stationary beacons in a configuration that optimizes a geometric precision factor for the beacons.
3. The inertial navigation tight coupling correction method based on time sharing collaborative underwater acoustic beacons according to claim 1 is characterized in that a specific mechanism of alternately broadcasting acoustic signals by a plurality of stationary beacons is that a broadcasting period T is set, three beacons are sequentially and circularly broadcast in the set broadcasting period T, a starting time T0 is broadcast by a beacon 1, beacons 2 and 3 are in a receiving or dormant mode, t1=t0+T time, beacon 2 is broadcast, beacons 1 and 3 are in a receiving or dormant mode, t2=t0+2T time, beacon 3 is broadcast, beacons 1 and 2 are in a receiving or dormant mode, t3=t0+3T time is circulated to beacon 1 to be broadcast, and the sequential circulation is performed.
4. The inertial navigation tight coupling correction method based on time sharing collaborative underwater acoustic beacons of claim 1, wherein the solving the three-dimensional spatial position between the AUV and the beacon based on the received acoustic signal of the current stationary beacon comprises solving a spatial skew between the AUV and the beacon based on signal propagation time, the spatial skew defining a sphere with the beacon as a center and the skew as a radius, the AUV being located on the sphere.
5. The inertial navigation tight coupling correction method based on time sharing collaborative underwater sound beacons of claim 4, wherein the combining depth information forms a strong constraint on vertical coordinates of an AUV to obtain a two-dimensional distance constraint circle characterizing an observation likelihood function, comprising: The AUV must be located on the horizontal plane corresponding to the current depth, the horizontal plane intersects with the sphere, the projection of the intersection line on the horizontal plane is a two-dimensional horizontal distance constraint circle, and the circle center is the horizontal projection coordinate of the beacon The radius is the horizontal distance R calculated according to the slant distance and the depth difference.
6. The inertial navigation tight coupling correction method based on time sharing collaborative underwater acoustic beacons of claim 1, wherein the filtering fusion of inertial navigation error ellipses and distance constraint circles, the calculation of updated optimal positions and probability distribution boundaries, comprises: Calculating an expected observation value based on the current error state predicted value, and performing first-order Taylor expansion on the expected observation value at the current error state predicted value to obtain an observation matrix; Calculating Kalman gain by combining covariance matrix, prediction uncertainty and observation matrix of observation noise; based on Kalman gain, the observation information is merged into the prior estimation to obtain posterior probability distribution and oblique variance, wherein the mean value of the posterior probability distribution is updated optimal position estimation, and the covariance is a new probability distribution boundary.
7. Inertial navigation tight coupling correction system based on timesharing cooperation underwater sound beacon, its characterized in that includes: the initial position determining module is used for receiving broadcast acoustic signals sent by all the static beacons at the same time, and performing initial position calculation to obtain the initial position of the AUV; The accumulated error acquisition module is used for carrying out inertial navigation calculation by taking the initial position of the AUV as a calculation starting point and combining the acquired IMU data and depth sensor data when the AUV does not receive acoustic auxiliary information in the navigation process, so as to obtain an inertial navigation error ellipse representing the prior probability distribution of the current error state predicted value; the coupling correction module is used for switching to combined navigation mode calculation when acoustic auxiliary information is received, broadcasting acoustic signals by a plurality of static beacons in turn according to a preset period, calculating the three-dimensional space position between the AUV and the beacons according to the received acoustic signals of the current static beacons, forming strong constraint on the vertical coordinates of the AUV by combining depth information to obtain a two-dimensional distance constraint circle representing an observation likelihood function, filtering and fusing an inertial navigation error ellipse and the distance constraint circle, and calculating to obtain an updated optimal position and probability distribution boundary.
8. A computer readable storage medium having stored thereon a computer program, which when executed by a processor, implements the steps of the inertial navigation tight coupling correction method based on time sharing collaborative hydroacoustic beacons according to any of claims 1-6.
9. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor, when executing the computer program, implements the steps of the inertial navigation tight coupling correction method based on time sharing collaborative underwater acoustic beacons as claimed in any of claims 1-6.
10. A program product, which is a computer program product comprising a computer program, characterized in that the computer program, when being executed by a processor, implements the steps of the inertial navigation tight coupling correction method based on time sharing collaborative hydroacoustic beacons according to any of claims 1-6.

Description

Inertial navigation tight coupling correction method and system based on time-sharing cooperative underwater acoustic beacon Technical Field The invention belongs to the technical field of deep sea navigation positioning, and particularly relates to an inertial navigation tight coupling correction method and system based on a time-sharing cooperative underwater acoustic beacon. Background The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. With the rapid increase in task demands in the fields of marine science research, resource exploration, environmental monitoring, etc., autonomous underwater vehicles (Autonomous Underwater Vehicle, AUV) have become key technical equipment for performing the above tasks due to their high autonomy, high efficiency, and the ability to replace the advantage of human access to dangerous or remote waters. The navigation positioning accuracy of the AUV is one of the core factors for determining success or failure of the AUV task, and the accumulated navigation error may not only cause task failure, but also seriously reduce the quality and effectiveness of the acquired data. Therefore, in order to ensure the AUV, the task can be efficiently, reliably and long-endurance performed, and a set of robust and reliable underwater navigation positioning system is a prerequisite. Because of the strong attenuation effect of seawater on electromagnetic waves, the global navigation satellite system (Global Navigation SATELLITE SYSTEM, GNSS) cannot be directly used for an underwater vehicle, so that the underwater navigation positioning faces special challenges. At present, underwater navigation positioning systems can be mainly divided into three types, namely autonomous navigation systems based on body sensors, positioning systems based on acoustics and navigation systems based on geophysical matching. Autonomous navigation systems (such as strapdown inertial navigation systems or Doppler log) based on body sensors have autonomy, but the former have the problem of error accumulation, usually rely on high-cost external acoustic auxiliary means for correction or periodically float up to acquire GNSS signals for correction, and have higher self-power consumption, while the latter have performances which are greatly reduced in deep sea or far-bottom environments due to high dependence on the relative distance between the aircraft and the seabed/water layer. Although the positioning system (such as a long baseline system and a short baseline system) based on the acoustics has higher precision, the positioning system has the defects of complex deployment, high cost, poor concealment and the like. Navigation systems based on geophysical matching (such as terrain matching and geomagnetic matching) have strong dependence on priori maps, have limited application range and have higher equipment cost. In general, existing underwater navigation positioning schemes have difficulty in balancing system cost, deployment convenience, operation concealment, long-endurance performance and navigation accuracy. This contradiction severely limits the operational performance of the AUV in long-endurance, large-scale resource exploration and the like in deep open sea scientific investigation and large-scale tasks. In recent years, inertial navigation has been aided into the field of investigation using acoustic information. Among them, inertial integrated navigation schemes based on single beacons are attracting attention because of their ability to simplify system deployment. However, this approach suffers from the inherent disadvantage of insufficient observability that the ranging information of a single beacon cannot uniquely determine the global position of the aircraft, resulting in limited ability to correct inertial navigation accumulated errors. Disclosure of Invention In order to solve at least one technical problem in the background art, the invention provides an inertial navigation tight coupling correction method and system based on a time-sharing cooperative underwater acoustic beacon, which can simultaneously overcome the defects of 'multi-beacon high-frequency sounding (causing high power consumption and signal conflict)' and 'single beacon insufficient observability (causing low precision)' by an innovative beacon working mode and an information fusion mechanism on the premise of not increasing the cost, complexity and power consumption of the system, and realize long-endurance and high-precision underwater positioning of an AUV. In order to achieve the above purpose, the present invention adopts the following technical scheme: The first aspect of the invention provides an inertial navigation tight coupling correction method based on a time-sharing cooperative underwater acoustic beacon, comprising the following steps: receiving broadcast acoustic signals sent by all stationary beacons simultaneously,