CN-121977513-A - Lake underwater topography measurement method and visualization system based on environmental characteristics

CN121977513ACN 121977513 ACN121977513 ACN 121977513ACN-121977513-A

Abstract

The invention provides an environment-characteristic-based lake underwater topography measurement method and a visualization system, and relates to the field of lake underwater topography measurement and three-dimensional visualization. The method comprises the steps of feeding back the newly added sensing dataset to the multi-source sensing dataset, repeatedly executing the heterologous data fusion processing, the identification and planning processing and the fine complement processing to form iterative execution control, and generating a lake underwater topography model when the confidence index of the whole region meets the preset requirement. According to the lake underwater topography measurement method based on the environmental characteristics, the underwater robot of the laser radar and the multi-beam sonar is synchronously triggered and controlled to obtain a multi-source sensing data set, and a topography gradient consistency algorithm is adopted to fuse the data, so that a preliminary topography curved surface is generated. By planning and finely complement the dynamic measurement path of the confidence index, the measurement accuracy and coverage are improved, and more accurate lake underwater topography data is obtained.

Inventors

LI RONG
LI RUIJIA
HAO YI
MAO CHEN
YUAN SHUAI
LIU YUEYANG

Assignees

中国地质调查局呼和浩特自然资源综合调查中心

Dates

Publication Date: 20260505
Application Date: 20260121

Claims (10)

1. The lake underwater topography measurement method based on the environmental characteristics is characterized by comprising the following steps: S1, performing synchronous trigger control on an underwater robot carrying a laser radar and a multi-beam sonar to obtain a multi-source sensing data set; S2, carrying out data gridding on the multi-source sensing data set to form a heterogeneous water depth grid, carrying out heterogeneous data fusion processing on the heterogeneous water depth grid to form a preliminary topographic curved surface, wherein the preliminary topographic curved surface is provided with a confidence index, and calculating the confidence index of the heterogeneous water depth grid by adopting a topographic gradient consistency algorithm in the heterogeneous data fusion processing; S3, identifying and planning the confidence index to form a dynamic measurement path; s4, controlling the underwater robot to conduct fine complement on the complement area according to the dynamic measurement path to obtain a newly-added sensing data set; S5, feeding the newly added sensing data set back to the multi-source sensing data set, repeatedly executing the heterologous data fusion processing, the identification and planning processing and the refined complement processing to form iterative execution control, and generating a lake underwater topography model when the confidence index of the whole area meets the preset requirement.
2. The method for measuring underwater topography of lakes based on environmental features of claim 1 wherein said synchronous triggering control comprises sending synchronous clock pulse signals to a hardware triggering interface of said lidar and said multi-beam sonar.
3. The method for measuring the underwater topography of a lake based on environmental characteristics according to claim 1, wherein the topography gradient consistency algorithm comprises the following steps: S21, the multi-source sensing data set comprises laser point cloud data and sonar water depth point cloud data, the laser point cloud data and the sonar water depth point cloud data are subjected to spatial registration to form point cloud data, and the laser point cloud data and the sonar water depth point cloud data are unified to the same coordinate system through the spatial registration; s22, performing gridding treatment on the point cloud data to generate the heterologous water depth grids, wherein the heterologous water depth grids comprise laser water depth grids and sonar water depth grids; S23, calculating a topography gradient vector of each grid unit in the heterologous water depth grid, wherein the topography gradient vector comprises a laser gradient vector and a sonar gradient vector; S24, calculating a confidence index of each grid unit in the heterologous water depth grid based on the consistency degree of the terrain gradient vector, and carrying out fusion processing on the heterologous water depth grid and the confidence index to generate the preliminary terrain curved surface.
4. The method for measuring underwater topography in lakes based on environmental features as set forth in claim 3, wherein the calculating of the confidence index comprises calculating an angle cosine value of the laser gradient vector and the sonar gradient vector, and mapping the angle cosine value to a value in a range of 0-1 as the confidence index of the grid unit.
5. The method for measuring underwater topography of a lake based on environmental characteristics of claim 1, wherein the identifying and planning process includes identifying a low confidence region, the low confidence region being a region with the confidence index lower than a preset threshold, dividing the low confidence region to form a block to be measured, measuring a priority of the block to be measured, and planning a measuring line for the block to be measured according to the priority to form the dynamic measurement path.
6. The method for measuring the underwater topography of the lake based on the environmental characteristics of claim 1, wherein the refined complement measurement processing comprises controlling the underwater robot to navigate along the dynamic measurement path, the underwater robot performs density data acquisition in a low confidence region of the preliminary topography surface to acquire the newly-added sensing data set, the density data acquisition comprises acquiring the navigation speed of the underwater robot, the sampling frequency of the laser radar and the sampling frequency of the multi-beam sonar, the navigation speed of the underwater robot is 0.5 m/s-1.0 m/s, the sampling frequency of the laser radar is 100 Hz-200 Hz, and the sampling frequency of the multi-beam sonar is 10 Hz-20 Hz.
7. The method for measuring underwater topography of a lake based on environmental features of claim 1 wherein said iteratively performing control includes performing a data assimilation process on said newly added sensing dataset and said multi-source sensing dataset to form a new multi-source sensing dataset, re-performing said heterologous data fusion process on said new multi-source sensing dataset to generate a new preliminary topography surface and a new confidence index, said data assimilation process employing a Kalman filter based sequence update algorithm.
8. The method for measuring underwater topography of lakes based on environmental features as set forth in claim 1, wherein said predetermined requirements are determined by a global average confidence level of said preliminary topography surfaces and a low confidence area of said preliminary topography surfaces.
9. The method for measuring underwater topography of lakes based on environmental features as set forth in claim 1, wherein the model of underwater topography of lakes comprises topography geometry data and quality confidence data.
10. A visual system for measuring underwater topography of a lake based on environmental characteristics, comprising: The data access and processing module receives and processes a multi-source sensing data set from the underwater robot, wherein the multi-source sensing data set comprises laser point cloud data, sonar water depth data and space pose data; the terrain modeling and confidence coefficient generation module performs heterologous data fusion processing on the multi-source sensing data set to generate a preliminary terrain curved surface; the dynamic path planning module analyzes and processes the confidence index on the preliminary terrain curved surface to generate a dynamic measurement path; The task control and complement testing module controls the underwater robot to execute fine complement testing according to the dynamic measurement path to acquire a newly-added sensing data set; The iterative optimization control module feeds the newly added sensing data set back to the data access and processing module, and the iterative optimization control module controls the terrain modeling and confidence degree generating module, the dynamic path planning module and the task control and complement testing module to repeatedly execute the heterologous data fusion processing, the analysis processing and the refined complement testing to generate a lake underwater terrain model; And the three-dimensional visualization module performs three-dimensional rendering and visual display on the lake underwater topography model.

Description

Lake underwater topography measurement method and visualization system based on environmental characteristics Technical Field The invention relates to the technical field of lake underwater topography measurement and three-dimensional visualization, in particular to a lake underwater topography measurement method and a visualization system based on environmental characteristics. Background The current lake underwater topography measurement mainly adopts a ship-borne single-beam or multi-beam sonar measurement system, the measurement ship sails along a preset survey line to collect underwater point cloud data, a GPS or Beidou positioning system obtains a plane position, a sound wave reflection principle calculates a water depth value, an interpolation algorithm generates an underwater topography model, and the method becomes a standard flow of channel and reservoir survey. Advanced systems integrate inertial measurement units that compensate for measurement vessel attitude errors. Unmanned survey vessels and automatic route planning techniques have been gradually popularized in recent years, and the field labor intensity is reduced. The airborne laser sounding technology starts to be tried in a clear water area, and blue-green laser penetrates through the water body to directly acquire the water bottom elevation. The satellite-borne optical remote sensing inversion method utilizes the correlation between the spectral characteristics of the water body and the water depth, and the empirical model realizes the topographic reckoning of the shallow water area in a large range. These techniques acquire underwater topography data under specific conditions. In the prior art, the inherent contradiction between the measurement efficiency and the data coverage density exists, the on-board sonar measurement depends on densely laying the measuring lines to ensure the data coverage, and only the narrow strip data below the measuring lines is obtained in a single operation. Large area lake measurement requires extremely long field periods and huge resource investment. The complex lake basin terrain areas are obviously contradictory, and the abrupt change area of the lake shore zone and the dense area of the underwater obstacle are obvious. The sparse line data seriously leaks key terrain features, and the generated terrain model generates systematic deviation. The rapid flow or bad weather shortens the operation window period, and high-density measurement is more difficult to realize. The fundamental contradiction restricts the practical effect and achievement reliability of the underwater topography measurement of the lake. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a lake underwater topography measurement method and a visualization system based on environmental characteristics, which aims to solve the technical problems of topography characteristic missing measurement and systematic deviation caused by low measurement efficiency and insufficient data coverage in lake underwater topography measurement in the prior art by a multisource data fusion, dynamic path planning and iterative optimization control method. In order to achieve the purpose, the invention is realized by the following technical scheme that the lake underwater topography measuring method based on the environmental characteristics comprises the following steps: S1, performing synchronous trigger control on an underwater robot carrying a laser radar and a multi-beam sonar to obtain a multi-source sensing data set; S2, carrying out data gridding on the multi-source sensing data set to form a heterogeneous water depth grid, carrying out heterogeneous data fusion processing on the heterogeneous water depth grid to form a preliminary topographic curved surface, wherein the preliminary topographic curved surface is provided with a confidence index, and calculating the confidence index of the heterogeneous water depth grid by adopting a topographic gradient consistency algorithm in the heterogeneous data fusion processing; S3, identifying and planning the confidence index to form a dynamic measurement path; s4, controlling the underwater robot to conduct fine complement on the complement area according to the dynamic measurement path to obtain a newly-added sensing data set; S5, feeding the newly added sensing data set back to the multi-source sensing data set, repeatedly executing the heterologous data fusion processing, the identification and planning processing and the refined complement processing to form iterative execution control, and generating a lake underwater topography model when the confidence index of the whole area meets the preset requirement. Preferably, the synchronous trigger control includes sending a synchronous clock pulse signal to a hardware trigger interface of the laser radar and the multi-beam sonar. Preferably, the step of the topography gradient consistency algorithm is as follows: S21, the