CN-121995082-A - Hydrologic observation sensor data real-time correction method based on unmanned ship motion gesture

CN121995082ACN 121995082 ACN121995082 ACN 121995082ACN-121995082-A

Abstract

The invention discloses a real-time correction method of hydrological observation sensor data based on unmanned ship motion gestures, which comprises the following steps of S1, collecting unmanned ship real-time gesture data and static installation position vector data in real time, determining an equivalent sound velocity profile of an ADCP wave beam pointing region, S2, outputting the actual longitude of a sampling point with acoustic line bending and gesture coupling errors eliminated Latitude and longitude Depth and depth S3 based on instantaneous incident angle Geometrically correcting ADCP wave beam to generate normalized echo intensity S4, calculating dynamic signal to noise ratio And S5, carrying out weighted least square calculation and outputting a finally corrected speed vector to be calculated. The invention effectively eliminates systematic deviation of sound ray tracking by generating the equivalent sound velocity profile matched with the actual pointing region of the ADCP beam.

Inventors

DING QIAN
ZHAO JING
LIU LIN
ZHAO YUE
ZHAO JIATING
JIANG YE
ZHENG SHUAIQIANG
YIN JIANG
ZHOU WEI
HUANG HAIBIN
ZHANG YINGYING
Ju Bolun
CHEN RUI

Assignees

华能澜沧江水电股份有限公司
哈尔滨工业大学（威海）
华软科技股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260326

Claims (9)

1. The real-time correction method for the hydrological observation sensor data based on the unmanned ship movement posture is characterized by comprising the following steps of: s1, acquiring real-time attitude data and static installation position vector data of an unmanned ship in real time, and constructing a rotation matrix from the ship body to a geographic coordinate system; S2, layering the water body and calculating the instantaneous incident angle by combining the real-time attitude angle Calculating the accumulated actual skew and horizontal offset of sound rays in each layer, and outputting the actual longitude of the sampling point without the coupling error of sound ray bending and posture Latitude and longitude Depth and depth ; S3 based on instantaneous incident angle Geometrically correcting ADCP wave beam to eliminate effective scattering volume change caused by ship inclination and generate normalized echo intensity ; S4, normalizing echo intensity according to S3 output And S2 output actual skew Calculating dynamic signal to noise ratio Comparing the dynamic signal-to-noise ratio with a preset threshold value to generate a quality zone bit Q; S5 actual longitude output according to S2 Latitude and longitude Depth of And carrying out weighted least square calculation on the mass zone bit and the equivalent sound velocity profile, and outputting a finally corrected speed vector to be calculated.
2. The method for correcting the data of the hydrological observation sensor based on the motion gesture of the unmanned ship according to claim 1, wherein the specific steps of S1 are as follows: S1.1, acquiring a roll angle, a pitch angle and a bow angle of a ship body in real time through an inertial measurement unit carried by the unmanned ship at a fixed sampling frequency, and simultaneously calculating draft; s1.2, inputting static installation position vectors of the CTD sensor and the ADCP transducer in a ship body coordinate system in advance in a memory ; S1.3, constructing a three-dimensional rotation matrix from a ship body coordinate system to a geographic coordinate system according to three attitude angles acquired in real time The method is used for describing the instantaneous attitude of the ship body in space at any moment; s1.4, static installation vectors and three-dimensional rotation matrix Multiplying to generate a relative position vector; s1.5, carrying out projection processing on the relative position vector, and only keeping the relative position vector under a geographic coordinate system Coordinate difference between the axis and the y axis so as to obtain a horizontal displacement vector between the actual water inlet point of the CTD sensor at the moment t and the center point of the ADCP transducer ; S1.6, calculating a horizontal sound velocity gradient estimated value based on real-time differential values of a main CTD sensor and a sound velocity sensor carried by the unmanned aerial vehicle Combining with horizontal displacement vector And depth weighting function Correcting the vertical sound velocity profile measured by the CTD sensor into the equivalent sound velocity profile of the ADCP beam pointing region 。
3. The method for correcting the data of the hydrographic observation sensor based on the motion gesture of the unmanned ship according to claim 2, wherein the specific content of S1.6 is that firstly, the sound velocity measurement value of the main CTD sensor at the current water inlet point is synchronously acquired Then according to the auxiliary sound velocity probe installed on the other side of the ship body, the horizontal distance is obtained Is a measurement of the speed of sound at another point of measurement Further calculate the horizontal sound velocity gradient estimation value The calculation formula is as follows: Wherein, the The unit vector is the connecting line direction of the two measuring points; Recombined horizontal displacement vector And depth weighting function Correcting the vertical sound velocity profile measured by the CTD sensor into the equivalent sound velocity profile of the ADCP beam pointing region Equivalent sound velocity profile The calculation formula of (2) is as follows: Wherein, the At the CTD sensor Raw sound velocity data measured at the moment, For the current moment Is included in the horizontal displacement vector of (a).
4. The real-time correction method for the data of the hydrological observation sensor based on the unmanned ship motion gesture according to claim 1, wherein the specific content of S2 is as follows: 1) Dividing the water body into N uniform thin layers along the depth direction; 2) Reading the fixed emission angle and azimuth angle parameters of the ADCP wave beam, combining the real-time attitude angle data, and calculating the instantaneous incident angle of the wave beam under a geographic coordinate system through coordinate transformation The calculation formula is as follows: Wherein, the Is that The roll angle of the moment in time, Is that The pitch angle of the moment in time, For a fixed emission angle of the beam in the hull coordinate system, The azimuth angle of the beam in the ship coordinate system; 3) According to the first Sound velocity and ray parameter back-push sound ray glancing angle of layer Calculating the sound wave at the first position according to the glancing angle and the thickness of the water layer The horizontal displacement component and the vertical displacement component of the layer are accumulated to obtain sound wave to be transmitted to the first stage Actual pitch of the layers And accumulated horizontal offset ; 4) Based on accumulated horizontal offset And geographical azimuth angle Outputting the actual longitude Latitude and longitude Depth and depth The calculation formula is as follows: Wherein, the Is the average radius of the earth, is used for converting plane displacement into spherical angle, The layer index corresponding to the current distance door meets the following requirements = , At the moment of unmanned ship Is used for the real-time draft of (c), At the current moment for unmanned ship Is provided.
5. The method for correcting hydrological observation sensor data based on unmanned ship motion gesture according to claim 1, wherein the normalized echo intensity The calculation formula of (2) is as follows; Wherein, the In ADCP sensor The first time of direct measurement output without geometric correction of the gesture The echo signal strength of the individual range gates, In order to fix the angle of emission, Is the instantaneous angle of incidence.
6. The method for real-time correction of hydrological observation sensor data based on unmanned ship motion gesture according to claim 1, wherein when the dynamic signal-to-noise ratio is compared with a preset threshold, if the dynamic signal-to-noise ratio is Above the threshold, the quality flag bit =1, Judges that the layered data of the current depth is valid, marks as valid data, if the dynamic signal to noise ratio Below the threshold, the quality flag bit =0, Marked as invalid data.
7. The method for correcting the data of the hydrological observation sensor based on the motion gesture of the unmanned ship according to claim 1, wherein the specific step of S5 is as follows: S5.1 receiving the actual longitude of S2 Latitude and longitude Depth and depth And S1, calculating the k-th wave beam Radial flow rate of stratification of each depth; S5.2, mapping radial flow velocity observation values of N wave beams to three geographic components of east, north and vertical based on a weighted least square method to obtain a to-be-solved speed vector; and S5.3, binding the speed vector to be solved with the absolute geographic coordinates and the time stamp provided by the step S2 to generate a final hydrological sensor data set.
8. The method for correcting hydrological observation sensor data based on unmanned ship motion gesture according to claim 7, wherein the radial flow velocity The calculation formula of (2) is as follows: Wherein, the Is an equivalent sound velocity profile, For the frequency of the transmitted ultrasonic waves of the ADCP transducer, In order to fix the angle of emission, Is the first The beam is at the first Multiple depths of layered received echo signal frequency and transmit frequency And (3) a difference.
9. The method for correcting the data of the hydrological observation sensor based on the motion gesture of the unmanned ship according to claim 1, wherein the dynamic signal-to-noise ratio The calculation formula is as follows: Wherein, the The initial intensity constant of the emitted sound wave for the ADCP transducer, as determined by factory calibration of the device, At the position of The background ambient noise intensity at the moment in time, In order to accumulate the actual slant distance, Is a preset absorption coefficient.

Description

Hydrologic observation sensor data real-time correction method based on unmanned ship motion gesture Technical Field The invention relates to the technical field of sensor data correction, in particular to a real-time correction method for hydrologic observation sensor data based on unmanned ship motion gestures. Background Unmanned Ship (USV) is widely applied to hydrological observation tasks of inland rivers, estuaries and coastal areas due to flexible maneuvering and low cost. The measurement of the water flow velocity profile from an acoustic Doppler flow profiler (ADCP) mounted is the core of the operation. The ADCP transducer emits sound pulses with fixed frequency to the water body, the sound waves are scattered after encountering suspended particles moving along with water flow in the water body, and a part of scattered signals are returned to the transducer along the original path to be received. Due to the relative motion between the particles and the transducer, a frequency shift, i.e., doppler shift, is created between the frequency of the received signal and the frequency of the transmitted signal. By measuring the frequency shift and combining the propagation speed of the sound wave in the water, the movement speed of the particulate matters along the beam direction can be calculated, and then the water flow speed is obtained through inversion. When an unmanned ship carries an acoustic Doppler flow profiler (ADCP) for hydrological observation, sensor data correction is a key link for guaranteeing data precision. Existing sensor data correction mainly focuses on the influence of hull motion (roll, pitch, yaw) on the sensor coordinate system, and the flow velocity data measured under the instrument coordinate system are converted into the geodetic coordinate system through a rotation matrix. However, in practical operation, especially in complex hydrologic environments such as inland estuary and coastal, unmanned ships can generate high-frequency rolling, pitching and bowing motions under the influence of wind and wave currents, and further have the following problems: 1. It is generally assumed that the sound velocity profile (measured by CTD or SVP) is uniform in the horizontal direction and that the profile is directly applied to ADCP beam path computation. In fact, when the pose of the unmanned ship is changed, a thermal salt depth detector (CTD) sensor and an ADCP transducer beam emission point are displaced relatively in the horizontal direction. In a water area with a significant horizontal sound velocity gradient (such as a estuary salt wedge frontal surface), the relative displacement can cause sound velocity data used by ADCP not to be the sound velocity of a path actually passed by a wave beam, and further refraction calculation deviation caused by sound velocity sampling space mismatch exists; 2. The unmanned ship attitude change can change the included angle between the wave beam of the transducer and the water surface and the effective scattering cross section, so that the echo signal intensity dynamically fluctuates. In the prior art, the signal-to-noise ratio is directly calculated by using the original strength, and the data is removed, so that the normal attenuation signal can be mistakenly removed, and further the assessment distortion of the echo signal-to-noise ratio of the attitude influence is caused. Disclosure of Invention Therefore, the invention provides a real-time correction method for hydrological observation sensor data based on unmanned ship motion gestures, which aims to solve the problems that in the prior art, a temperature and salt depth meter (CTD) sensor and an ADCP transducer have acoustic velocity profile use errors caused by asynchronous spatial positions, and the unmanned ship gestures influence echo signal to noise ratio evaluation distortion. In order to achieve the above object, the present invention provides the following technical solutions: the real-time hydrological observation sensor data correction method based on the unmanned ship movement gesture comprises the following steps: s1, acquiring real-time attitude data and static installation position vector data of an unmanned ship in real time, and constructing a rotation matrix from the ship body to a geographic coordinate system; S2, layering the water body, calculating the instantaneous incident angle by combining the real-time attitude angle, calculating the accumulated actual inclined distance and horizontal offset of the sound ray in each layer, and outputting the actual longitude of the sampling point with the sound ray bending and attitude coupling error eliminated Latitude and longitudeDepth and depth; S3 based on instantaneous incident angleGeometrically correcting ADCP wave beam to eliminate effective scattering volume change caused by ship inclination and generate normalized echo intensity; S4, normalizing echo intensity according to S3 outputAnd S2 output actual skewCalculating dyna