阅读说明：本技术 一种基于深潜器无动力下潜实时信息的深海海流计算方法 (Deep sea current calculation method based on unpowered submergence real-time information of deep submergence device ) 是由 修宗祥 丁忠军 高伟 解秋红 孙永福 于 2021-09-01 设计创作，主要内容包括：本发明公开了一种基于深潜器无动力下潜实时信息的深海海流计算方法,涉及海洋工程技术领域,通过船载ADCP测量信息、深潜器无动力下潜实时信息以及深潜器搭载的ADCP测量信息,结合机器学习方法最终获得全海深范围的海流信息。本申请可以解决目前船载ADCP测流工作水深不能满足深海水深的问题。本发明通过深潜器常规下潜航次数据获得全海深范围内的海流信息,同时也可用于以往深潜器下潜数据的二次挖掘利用,无需额外的海上作业,是获得深海全海深范围海流数据的一种便利方法。(The invention discloses a deep sea current calculation method based on real-time unpowered submergence information of a deep submergence device, which relates to the technical field of ocean engineering. The problem that present shipborne ADCP current surveying operating water depth can not satisfy deep sea water depth can be solved in this application. The method obtains the ocean current information in the full sea depth range through the conventional diving voyage data of the deep submersible, can be used for secondary mining and utilization of the diving data of the conventional deep submersible without extra offshore operation, and is a convenient method for obtaining the ocean current data in the full sea depth range of the deep sea.)

1. A deep sea current calculation method based on real-time information of unpowered submergence of a deep submergence device is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: after the mother ship of the deep submergence device reaches a submergence position, starting a shipborne ADCP acoustic Doppler current profiler, wherein the water depth generally exceeds the maximum measurement depth of the ADCP, the bottom tracking function is invalid, and actual current information within the maximum working water depth range is obtained through vector separation according to the synchronous mother ship navigation positioning record;

step two: the method comprises the following steps that (1) the deep submersible vehicle is unpowered to dive, attitude, course, navigational speed and diving depth information of the deep submersible vehicle are obtained by means of a navigation and positioning system of the deep submersible vehicle in the diving process, and a carried ADCP system is started when the deep submersible vehicle dives to the near bottom surface to obtain ocean current information in the near bottom range;

step three: establishing a data set corresponding to the ocean current, the attitude, the course and the navigational speed of the deep submersible vehicle according to the depth by using the ocean current data with different depths obtained in the first step and the second step and the attitude, the course and the navigational speed of the deep submersible vehicle;

step four: carrying out standardization processing on each data set obtained in the step three, and dividing the corresponding data set in the effective working depth range of the shipborne ADCP into a training set and a testing set;

step five: designing and establishing a machine learning prediction model based on the recurrent neural network based on the training set data in the fourth step, training the prediction model, and checking the prediction model through a test set, wherein if the error is large, the prediction model is improved until the precision requirement is met;

step six: aiming at the depth range exceeding the ship-borne ADCP working water depth, adopting a qualified network prediction model, and calculating ocean current information at different depths according to the attitude, course and speed of the deep submergence device in real time;

step seven: and integrating the ocean current measurement information in the upper water depth range obtained by the shipborne ADCP, the ocean current information at the bottom of the sea obtained by the deep submersible vehicle carrying the ADCP and the middle section ocean current information obtained in the sixth step to obtain the ocean current information in the full sea depth range.

Technical Field

The invention relates to the technical field of ocean engineering, in particular to a deep sea current calculation method based on real-time unpowered submergence information of a deep submergence vehicle.

Background

The influence of ocean currents in a depth range of thousands of meters on the engineering structure safety of a mining system must be considered in the development of deep-sea mineral resources, and the mechanical characteristics of a conveying hose under the action of the deep-sea ocean currents must be considered to ensure the safety of the conveying hose system in the mining process, such as the currently proposed fluid mining method. In addition, silt stirred up by submarine mining and waste liquid generated by processing mineral liquid of sea-surface ships can influence the marine environment, and ocean currents are the main factors for controlling the space influence range. Therefore, acquiring flow velocity data of deep ocean currents in advance is an important environmental parameter for future deep ocean mining safety design and environmental impact evaluation.

The conventional fixed-point marine anchor system observation needs special laying and recovery, can generate higher offshore operation cost and faces certain loss risk. The maximum working depth of the shipborne ADCP flow velocity profile measuring system cannot meet the requirement of deep sea full-sea deep-sea current measurement. At present, the technology of the deep submersible vehicle at home and abroad is rapidly developed, the submergence depth almost covers all sea areas, and the submergence process of the deep submersible vehicle provides convenience for the whole-sea deep ocean current measurement of the deep sea areas. Taking a flood dragon manned deep submersible as an example, because unpowered diving is adopted, from the mechanical point of view, the posture and the navigational speed of the deep submersible are changed in the diving process, and are mainly influenced by the action of ocean currents except the self weight and the structural shape. Therefore, the real-time information such as the attitude, the navigational speed and the like of the deep submergence vehicle in the unpowered submerging process actually implies the information of the ocean current. Based on the real-time information of the unpowered submergence process of the deep submergence device, the ocean current information in the submergence process can be calculated through inversion of a mathematical model by combining certain auxiliary measurement, preliminary deep sea flow velocity information can be provided for future deep sea mining system design and environmental impact evaluation, and the method has obvious engineering practical significance.

Disclosure of Invention

The invention provides a deep sea current calculation method based on real-time unpowered submergence information of a deep submergence vehicle.

In order to achieve the purpose, the invention adopts the following technical scheme:

a deep sea current calculation method based on real-time information of unpowered submergence of a deep submergence device comprises the following steps:

the method comprises the following steps: after the mother ship of the deep submergence device reaches a submergence position, starting a shipborne ADCP acoustic Doppler current profiler, wherein the water depth generally exceeds the maximum measurement depth of the ADCP, the bottom tracking function is invalid, and actual current information within the maximum working water depth range is obtained through vector separation according to the synchronous mother ship navigation positioning record;

step two: the method comprises the following steps that (1) the deep submersible vehicle is unpowered to dive, attitude, course, navigational speed and diving depth information of the deep submersible vehicle are obtained by means of a navigation and positioning system of the deep submersible vehicle in the diving process, and a carried ADCP system is started when the deep submersible vehicle dives to the near bottom surface to obtain ocean current information in the near bottom range;

step three: establishing a data set corresponding to the ocean current, the attitude, the course and the navigational speed of the deep submersible vehicle according to the depth by using the ocean current data with different depths obtained in the first step and the second step and the attitude, the course and the navigational speed of the deep submersible vehicle;

step four: carrying out standardization processing on each data set obtained in the step three, and dividing the corresponding data set in the effective working depth range of the shipborne ADCP into a training set and a testing set;

step five: designing and establishing a machine learning prediction model based on the recurrent neural network based on the training set data in the fourth step, training the prediction model, and checking the prediction model through a test set, wherein if the error is large, the prediction model is improved until the precision requirement is met;

step six: aiming at the depth range exceeding the ship-borne ADCP working water depth, adopting a qualified network prediction model, and calculating ocean current information at different depths according to the attitude, course and speed of the deep submergence device in real time;

step seven: and integrating the ocean current measurement information in the upper water depth range obtained by the shipborne ADCP, the ocean current information at the bottom of the sea obtained by the deep submersible vehicle carrying the ADCP and the middle section ocean current information obtained in the sixth step to obtain the ocean current information in the full sea depth range.

The invention has the following advantages: according to the method, a circulating neural network model is adopted to carry out prediction calculation on the ocean current exceeding the working water depth range of the current shipborne ADCP flow velocity measurement system through navigation and attitude data in the unpowered diving process of the deep submersible vehicle, and the ocean current data in the full sea depth range is obtained through integration of the measurement data and shipborne ADCP and ADCP carried by the deep submersible vehicle. The problem that present shipborne ADCP current surveying operating water depth can not satisfy deep sea water depth can be solved in this application. The method obtains the ocean current information in the full sea depth range through the conventional diving voyage data of the deep submersible, can be used for secondary mining and utilization of the diving data of the conventional deep submersible without extra offshore operation, and is a convenient method for obtaining the ocean current data in the full sea depth range of the deep sea.

Drawings

FIG. 1 is a flow chart of the deep sea current measuring and calculating method of the present invention

FIG. 2 is a schematic diagram of an offshore implementation of the present invention;

FIG. 3 is an underwater navigation and attitude data set of the deep submersible vehicle of the present invention;

fig. 4 is a schematic structural diagram of an ocean current prediction network model according to the present invention.

In the figure: 1 mother ship, 2 deep submergence vehicles, 3 shipborne ADCP, 4 input layers, 5 hidden layers and 6 output layers.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

The invention relates to a deep sea ocean current information calculation method based on unpowered submergence real-time information of a deep submergence device 2, which has the main working flow shown in figure 1 and is implemented according to the following steps.

Step 1, offshore operation and data acquisition;

as shown in fig. 2 of the offshore implementation schematic diagram of the invention, after a mother ship 1 of a deep submersible vehicle 2 reaches a deep sea submerged position (the water depth is greater than the maximum working depth of a shipborne ADCP 3), a shipborne ADCP3 acoustic doppler current profiler is started, because the water depth exceeds the maximum measurement depth of the ADCP at the moment, a bottom tracking function is invalid, and the acquired current information needs to be corrected by navigation position data of the mother ship 1.

And acquiring real speed data of the mother ship 1 according to the synchronous mother ship 1 navigation positioning, performing vector separation, and correcting the flow speed and direction of the onboard ADCP3 to obtain actual ocean current information within the maximum working water depth range.

Step two: the deep submergence vehicle 2 submerges in an unpowered mode, power is recovered when the deep submergence vehicle submerges to the near seabed, an ADCP system carried by the deep submergence vehicle 2 is started, and information of the flow speed and the direction of ocean currents in the near seabed range of the deep sea is obtained. And acquiring navigation and attitude data such as the diving depth, the course, the navigational speed, the heading, the heeling, the trim and the like of the deep submersible vehicle 2 by depending on a navigation and positioning system of the deep submersible vehicle 2 in the diving process.

Step three: preprocessing the data within the working water depth range of the ship-borne ADCP3 obtained in the first step and the second step, removing invalid data in the acquired data, and smoothing the invalid data. Taking the water depth increase as a sequence identifier, as shown in fig. 3, preprocessing data elements of ocean current flow velocity, flow direction at different depths, heading, navigational speed, heading, heeling, trim and the like of the deep submersible vehicle 2 to form a data set;

step four: and 4, normalizing the data sets obtained in the step three, and dividing the corresponding data sets in the effective working depth range of the shipborne ADCP3 into a training set and a testing set. And dividing a data set in the working depth range of the ship-borne ADCP3 into a training set and a testing set according to a depth sequence, wherein the training set data accounts for 80% of the total samples, and the testing set data accounts for 20% of the total samples.

Step five: a machine learning prediction model based on a recurrent neural network (CNN) is established, and the model has three layers, as shown in fig. 4, a first layer is an input layer 4, a second layer is a hidden layer 5, and a third layer is an output layer 6. I denotes the input level 4 node element, H denotes the hidden level 5 node element, S denotes the hidden level 5 node element of the previous depth sequence, and O denotes the output node element.

Five input elements of the input layer 4 are respectively the navigational speed, the course, the heading, the heeling and the trim corresponding to the unpowered diving process of the deep diving device 2; the second layer is a hidden layer 5, which realizes the feature extraction of the input data, wherein the hidden state h of the nth neural node element_tMay be represented by formula (1):

h_t＝σ(Wx_t+Uh_t-1+b) (1)

in the formula (1), x_tAs input data at depth of water t, h_tRepresenting hidden layer 5 node, h, at depth of water t_t-1Representing the hidden layer 5 node at the previous water depth. W and U are input weight and a weight matrix of a hidden layer 5 node respectively, b is a bias vector of the hidden layer 5, and sigma is an activation function of a neuron; h is not only determined by this depth input, but is also influenced by the previous water depth t-1.

Output of a prediction o at a depth t of the layer 6_tCan be calculated from equation (2):

o_t＝Vh_t+c (2)

in the formula (2), V is a weight matrix from the hidden layer 5 to the output layer 6, and c is a bias parameter vector.

And training the constructed network model through an optimizer model and a loss function model according to training set data accounting for 80% of the total sample number. In the classical gradient descent method, all training data need to be traversed each time the model parameters are updated, and huge computing resources and computing time need to be consumed when the data volume is large. The optimizer model adopts a small-batch random gradient descent method, namely, during each iterative computation, a group of samples with fixed quantity is randomly extracted from the samples, m samples are updated once according to the gradient after training, then m samples are randomly extracted, the gradient is updated once, and the like, so that the optimal value is obtained. The loss function, J (theta), is calculated and constructed by adopting a square loss function, and the formula is as follows:

the model training effect was examined based on test set data that accounted for 20% of the total number of samples. Calculating the output element variable ocean current flow velocity o according to the input data of the test set₁To the flow direction o₂Corresponding predicted variableFlow direction ofAnd comparing with the actually measured data in the test set. The prediction accuracy adopts a maximum error method and an average error to carry out error evaluation, and an error threshold value is set according to actual engineering requirements. Wherein the maximum error mainly aims at the output error of a single element and can be expressed asThe average error represents the average of all test set data errors, and is calculated by

If the trained network model can not meet the set error requirement under the existing data, a scheme optimization method is set. Firstly, increasing the number of hidden layer 5 node elements H, and training again until the precision requirement is met. When the effect of simply increasing the number of nodes of the hidden layer 5 is not obvious, the hidden layer 5 of the layer 1 is added, and the model with the added hidden layer 5 is trained again until the precision requirement is met. The network model with the hidden layer 5 added can also consider to increase the number of nodes of the hidden layer 5 so as to improve the model precision.

Step six: and calculating by adopting a circulating network prediction model qualified by the five-step inspection for the water depth range from the working water depth of the ship-borne ADCP3 to the power recovery of the deep submersible vehicle 2. And the data of the input layer 4 still adopts the course, the navigational speed, the heading, the transverse inclination and the longitudinal inclination of the identification sequence of different water depth depths in the unpowered diving process of the deep submersible vehicle 2 obtained in the step two, and the normalization processing is carried out. The prediction output data is subjected to inverse normalization to obtain the current flow speed and the current direction in the water depth range

Step seven: and integrating and linking the ocean current measurement information in the upper water depth range obtained by the onboard ADCP3, the ocean current information at the bottom of the sea obtained by carrying the ADCP on the deep submersible vehicle 2 and the middle section ocean current information obtained in the sixth step, so as to obtain the ocean current flow speed and the flow direction profile in the whole sea depth range.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.