CN108253934A - Bathymetric surveying emulation mode and its emulator - Google Patents

Abstract

The invention relates to the technical field of marine surveying and mapping, in particular to an underwater terrain surveying simulation method and a simulator thereof. The user changes the ship speed and rudder angle of the simulated survey ship through the survey ship simulation controller, calculates the position of the simulated survey ship through the position simulation algorithm; sends the GPS positioning signal to the host computer through the positioning signal simulation algorithm; generates The sound wave emission direction of the depth sounder of the ship's attitude; calculate the instantaneous tide water level height through the tide forecast algorithm, according to the period defined by the user; calculate the instantaneous water depth measurement result through the water depth simulation algorithm, and send it to the host computer installed with the underwater terrain measurement navigation acquisition software . Under the condition of not carrying out wading measurement, it provides measurement results similar to real bathymetry for hydrographic survey navigation acquisition software. The purpose of the present invention is to provide users with a realistic water depth measurement environment through the simulated underwater terrain measurement signal generated by the simulation system.

Description

Simulation Method and Simulator for Underwater Terrain Measurement

technical field

The invention relates to the technical field of marine surveying and mapping, in particular to an underwater terrain surveying simulation method and a simulator thereof.

Background technique

At present, with the full development of marine and inland water resources, the demand for underwater topographic survey has increased dramatically, requiring a large number of experienced underwater topographic surveyors. Underwater topographic survey requires a high level of work experience for surveyors. Experienced surveyors can perform correct surveys of various underwater targets according to hydrographic survey standards, and can also correctly handle the impact caused by changes in sea conditions and hydrological parameters during the survey process. influence on the measurement results. However, since the underwater topographic survey needs to be carried out by survey ships in the ocean or inland rivers, the cost is relatively high. General colleges and surveying and mapping training institutions can only demonstrate the measurement process to trainees indoors by playing back the measurement results when training surveyors. Although some units with better conditions can use survey boats for teaching on the water, it is difficult to find various typical underwater targets in the training waters at the same time. These conditions greatly limit the effectiveness and efficiency of bathymetry training. Indoor simulated training through simulators or simulated trainers is an effective way to improve training efficiency and effectiveness. At present, the closest realization scheme to the present invention is the sounding demonstration function carried by the sounding instrument. For example, the HD8000X single-beam depth sounder produced by my country Hi-Target Satellite Navigation Technology Co., Ltd. allows users to manipulate the simulated survey ship to move in the demo interface through the keyboard and generate fixed simulated water depth data. The disadvantage of the prior art is that it cannot simulate the real underwater environment. In the demonstration function that comes with the echo sounder, only fixed simulated water depth data can be generated. The purpose is to demonstrate the operation and use of the echo sounder. The underwater terrain in the measurement results is completely flat, does not contain any underwater targets, and has no Changes in sea state and hydrological parameters. Through this demonstration function, the user can only master the most basic operation method of the bathymetry system, and cannot learn the underwater terrain simulation method in the real underwater environment.

Contents of the invention

In view of the defects in the prior art, the technical problem to be solved by the present invention is how to provide hydrographic survey navigation acquisition software with measurement results similar to real bathymetry without wading measurement. The purpose of the present invention is to provide users with a realistic water depth measurement environment through the simulated underwater terrain measurement signal generated by the simulation system.

In order to achieve the above object, the technical solution of the present invention provides a simulation method for underwater terrain surveying on the one hand, and its specific steps include:

Step 1: The user changes the speed and rudder angle of the simulated survey ship through the simulated manipulator of the survey ship, and the underwater terrain survey simulator is controlled by the internal clock of the system according to the ship speed and rudder angle input from the simulated manipulator of the survey ship. Calculate the position of the simulated survey ship through the position simulation algorithm at a user-defined period;

Step 2: The underwater terrain measurement simulator generates a GPS positioning signal with a delay effect according to the position of the simulated survey ship through the positioning signal simulation algorithm, and sends the GPS positioning signal to the upper computer;

Step 3: Under the control of the internal clock of the system, the underwater terrain measurement simulator generates the sound wave emission of the echo sounder corresponding to the attitude of the measurement ship at the current moment according to the sea state level set by the user through the measurement ship attitude simulation algorithm, and in the period defined by the user. direction;

Step 4: The underwater topographic measurement simulator calculates the instantaneous tide water level height according to the tidal harmonic constant stored in the database through the tide forecast algorithm, and displays it on the screen of the underwater topographic measurement simulator according to the period defined by the user.

Step 5: The underwater terrain measurement simulator uses the depth simulation algorithm to calculate the measurement results of the instantaneous water depth according to the position of the simulated survey ship, the sound wave emission direction of the depth sounder, and the basic data of the underwater terrain simulation stored in the database. The format and period defined by the user send the instantaneous water depth measurement results to the host computer installed with the underwater terrain survey navigation acquisition software.

Further, the position simulation algorithm is based on the simulated measurement of the position (X0, Y0) and course angle β0 of the ship at T0, the ship speed V0 and rudder angle α0 input by the user, the tidal current velocity Vr set by the user, and the tidal current direction , the change speed of the tidal current direction ω, the random disturbance value of the tidal current direction Rt, the steering sensitivity S of the simulated survey ship, and calculate the position (X1, Y1) of the simulated survey ship at T1 time, the specific algorithm is as follows:

β1=(β0+V0*△t*α0*S)Mod 360;

Among them: T0 and T1 are the two adjacent simulation times, T1=T0+△t, △t is the clock period defined by the user, the default is 0.1 seconds;

The default value of steering sensitivity S is 0.5, which can be set by the user to any value between {0.1, 0.3, 0.5, 0.7, 0.9, 1.0};

The default value of tidal current direction change speed ω is 0.1 degree/second, which can be set by the user to any value in {0.1, 0.3, 0.5};

The random disturbance value Rt of the tidal current direction takes a random number uniformly distributed between -2.0 degrees and +2.0 degrees.

Further, the positioning signal simulation algorithm is to generate a GPS positioning signal with a delay effect according to the delay time set by the user and the current position of the measuring ship. The specific algorithm is as follows:

Step 2.1: Define a one-way linked list to store the position of the survey ship, and each item in the linked list is the position of the survey ship (X, Y);

Step 2.2: The system calculates the position of the survey ship (X, Y) according to the position simulation algorithm every time a custom clock period △t passes, and inserts it into the head of the linked list;

Step 2.3: If the length of the linked list is greater than N=Td/△t, delete the last node of the linked list;

Step 2.4: The system takes out the last node of the linked list according to the positioning signal period set by the user, and converts the position of the survey ship (X, Y) contained in it into the format required by the host computer and outputs it from serial port 1.

Further, the underwater terrain database includes a water depth data table, a tidal harmonic constant table, and an underwater sound velocity profile table; wherein the water depth data table stores the underwater topographic point cloud data of the simulated survey area; the tidal harmonic constant table stores It is the 11 tidal harmonic constants of the simulated survey area; the sound velocity profile table stores the sound wave propagation velocity at different depths of the simulated survey area. The specific structure of each data table is as follows:

(1) Depth data table

(2) Table of tidal harmonic constants

(3) Underwater sound velocity profile table

Field Name type of data Remark ID Int self-increment water depth Int Depth value speed of sound Decimal Underwater sound velocity value

Further, through the tide forecasting algorithm, according to the tidal harmonic constant stored in the database, the instantaneous tide water level height is calculated, and displayed on the screen of the underwater terrain survey simulator according to the period defined by the user.

Further, the attitude simulation algorithm of the measuring ship is to calculate the plane coordinates of the center of the seabed irradiation range of the sound waves emitted by the simulated depth sounder according to the sea state level set by the user and the position of the simulated measuring ship. The specific algorithm is as follows:

Step 3.1: Define the position coordinates of the simulated survey ship as (Xc, Yc, 0), query a sounding point P with the smallest distance from the (Xc, Yc) plane from the sounding data table in the database, and take out the sounding value Zp of this point;

Step 3.2: Take the location of the simulated survey ship (Xc, Yc, 0) as the coordinate origin, and calculate the center of the seabed exposure range of the sound waves emitted by the simulated depth sounder when the survey ship rolls and pitches under the influence of waves according to the following formula position Xr, Yr, Zr;

In the formula, Roll is the roll angle of the measuring ship, and the value is a random number evenly distributed in the interval [-3*G,+3*G]; Pitch is the pitch angle of the measuring ship, and the value is in the interval [-2*G] *G,+2*G] A uniformly distributed random number; G is the sea state level set by the user, the value is any number in [0,1,2,3,4,5], the default value is 0 ;

Step 3.3: Calculate the plane position coordinates (Xcent, Ycent) of the sound wave emitted by the depth sounder in the center of the seabed irradiation area according to the following formula

Where Th is the tide height at the current moment, which is calculated by the tide forecast algorithm according to the harmonic constant in the database.

Further, the water depth simulation method is to calculate and measure the instantaneous water depth measurement result data based on the center position of the sound wave emitted by the depth sounder in the seabed exposure range, the basic data of the underwater terrain, and the sound wave beam angle set by the user. The specific algorithm is as follows :

Step 5.1: According to the beam angle θ set by the user, the water depth Zp at the position of the measuring ship, and the instantaneous tide height Th, calculate the radius of the sound wave emitted by the analog echo sounder on the seabed R=(Zp+Th)*tan(θ );

Step 5.2: Select 4 candidate points P1 (X _P1 , Y _{P1 ), P2 (X P2 , Y P2} ), P3 (X _{P3 ,} Y _P3 ), P4 (X _P4 , Y _P4 ) with (Xcent, _Ycent ) as the center ),in:

Step 5.3: In the sounding data table of the database, search for all neighboring sounding points whose planar distance to each candidate point is less than R/2, and calculate the planar distance between the candidate point and each neighboring sounding point, and finally pass the distance inverse ratio The weighted interpolation algorithm calculates the water depth Z1, Z2, Z3, Z4 of the four candidate points P1, P2, P3, and P4;

Step 5.4: According to the plane coordinates and water depth of the four candidate points, calculate the distances between them and the position (Xc, Yc, 0) of the analog echo sounder i=1, 2, 3, 4; and select the smallest Di as the current position water depth value D;

Step 5.5: Calculate the total propagation time T of the sound wave corresponding to the water depth D from emission to reception according to the underwater sound velocity data stored in the database, Among them, i corresponds to the serial number of the water depth calculated from the sea surface, m is the serial number of the water depth corresponding to the water depth D; △Hi is the distance between the i-th layer and the i+1-th layer, through the corresponding depth correlation of the two layers in the database Subtracted; V _i and V _i+1 are the underwater sound velocity of the i-th layer and the i+1-th layer respectively;

Step 5.6: Calculate the instantaneous bathymetry results Where Vs is the average underwater sound velocity set by the user.

On the other hand, the technical solution provided by this application is an underwater terrain survey simulator, which logically includes underwater terrain survey simulation software, underwater terrain simulation database, underwater terrain survey simulation equipment, and survey ship simulation control device.

The underwater topography measurement simulation software is installed in the underwater topography measurement simulation equipment, and is used to receive the ship speed and rudder angle data sent by the user through the survey ship simulation controller, and based on these data and the basic data stored in the underwater topography simulation database, real-time Calculate the instantaneous water depth signal and satellite positioning signal, and send it to the underwater terrain survey navigation acquisition system through the serial port on the device;

The underwater terrain simulation database is used to provide various basic data for calculating simulation data for the underwater terrain measurement simulation software, including the underwater terrain point cloud data of the simulated survey area, the tidal harmonic constant of the simulated survey area, and the underwater sound velocity profile data;

The underwater terrain measurement simulation equipment is used to install the underwater terrain measurement simulation software and the underwater terrain simulation database. The equipment includes an LCD screen, three USB interfaces, four serial interfaces and one RJ-45 network interface. The equipment contains A motherboard and a hard disk, the motherboard is integrated with CPU, memory and graphics card; the underwater topographic measurement simulation equipment is used to run the underwater topographic measurement simulation software and provide an interface for sending data to the outside; the liquid crystal display is used to display the speed of the ship in real time, Heading, rudder angle, beam angle, tidal current velocity, tidal current direction, tidal height, simulator working status information;

The survey ship simulation manipulator is a standard windows game joystick (steering wheel), which is used to provide users with a platform to manipulate the simulated survey ship, and is connected to the underwater terrain survey simulation device through a USB transmission line; the user can use the survey ship simulation manipulator to The buttons on the controller can be used to change the speed and rudder angle of the simulated measurement ship, and various parameters of the simulator can also be set through the buttons on the controller.

Explanation of terms in the present invention:

Underwater topographic survey: also known as bathymetry, hydrographic survey. The survey ship sails on the water surface according to the planned route, and measures the water depth and plane position at the current position through the echo sounder and satellite locator installed on the survey ship, and at the same time conducts tide observation at specific places in the survey area. Finally, the observed water depth, plane position and tidal height are input into the underwater topography data processing software to obtain the underwater topography in the measurement area.

Board parameters: Before underwater topographic surveying, firstly, a board corresponding to the measurement area needs to be established in the underwater topographic survey navigation collection software. Plate projection type.

Planning survey line: before underwater topographic surveying, it is necessary to lay out several auxiliary lines on the drawing board created by the underwater topographical surveying navigation collection software to represent the route. When conducting underwater topographic surveys, surveyors need to steer the survey ship along the planned survey line.

Single-beam echo sounder: An instrument that uses ultrasound to measure water depth. The instrument transmits a cone-shaped sound wave beam with a certain opening angle to the water through the transducer, and the sound wave is reflected by the seabed/river bed and then received by the transducer on the instrument. The depth sounder calculates the water depth at the current location based on the sound wave round-trip time and the underwater sound velocity.

Inverse distance weighted interpolation algorithm: a commonly used spatial point interpolation algorithm. Suppose the point to be interpolated in space is P(Xp, Yp, Zp), and there are known scattered points Qi(Xi, Yi, Zi) in the neighborhood of point P, i=1, 2,...n. Use the inverse distance weighting method to interpolate the attribute value Zp of point P. Zp is the weighted average of the attribute values Zi of scattered points in the neighborhood of point P, namely: Where Di is the distance between point P and the i-th point in its neighborhood.

Underwater topographic survey navigation acquisition software: the navigation acquisition software used in the underwater topographic survey system, runs on the computer, receives the survey raw data sent by the underwater topographic survey system, mainly includes position and water depth data, and is formatted as an independent file The form saves the measurement results when the survey ship sails on each planned route in the computer for use by the underwater terrain survey data analysis software. Currently, the commonly used underwater topographic survey and navigation acquisition software in our country are: hydrographic survey and navigation acquisition system, HYPACK navigation and acquisition system.

Host computer: a computer installed with underwater topographic survey navigation acquisition software, with multiple serial interfaces, capable of receiving data sent by depth sounders and satellite locators.

Sea state level: Also known as the sea state level, it mainly refers to the wind and waves on the water surface and the undercurrent in the water. The wind and waves on the water surface will cause the measuring ship to sway in the left and right direction (rolling) or in the forward and backward direction (pitching), which will cause the sound wave beam emitted by the depth sounder fixed on the measuring ship to deviate from the correct direction, and the correct measurement cannot be obtained result. my country stipulates that the sea state level is divided into 10 levels. The wave height of level 0 is 0 meters, the sea is calm, and the roll angle and pitch angle of ordinary survey ships are both 0; the wave height of level 5 is about 2.5-4 meters. The ship can roll up to 15 degrees and pitch up to 10 degrees. In underwater topographic survey, in order to ensure the measurement quality, the sea state level is generally required to be less than 3; when the sea state level is greater than 3, a large number of invalid sounding points will appear in the measurement results.

Measurement raw data: measurement records output from depth sounder, GPS and other equipment. The depth sounder outputs measurement results through the serial port, and the format of the result is specified by the depth sounder manufacturer, and is generally given in the depth sounder technical manual. The GPS outputs the measurement results in the common NAME 0183 format through the serial port.

Positioning signal with time delay: When positioning according to the signal transmitted by the GPS satellite, it takes about △T time from the locator receiving the satellite signal to the locator outputting the positioning result, (△T can generally reach 0.1-0.5S). Since the survey ship is always in motion when surveying at sea, the positioning signal received by the underwater topographic survey navigation acquisition system corresponds to the position of the survey ship before the △T time during the underwater topographic survey. This phenomenon is called is the time delay of the positioning signal.

Underwater sound velocity profile: The underwater sound velocity profile refers to the speed of sound at different depths starting from the sea surface. Affected by underwater temperature, salinity, pressure and other factors, the speed of sound underwater changes with the depth of the water. In seawater, the speed of sound underwater varies from about 1400-1700 m/s.

Tidal harmonic constant: The average amplitude and delay angle of each partial tide decomposed from the measured tide data. Also known as the tidal harmony constant. Referred to as the harmonic constant. After the tidal harmonic constant is calculated, the tide forecasting algorithm can be used to forecast the ocean tide, judge the tide type and calculate the bathymetry depth datum.

Tide forecasting algorithm: The ocean tide phenomenon can be regarded as a series of imaginary celestial bodies with different tidal periods superimposed. The expression of the tidal height of each minute tide can be derived by using the lunar equilibrium tidal height formula and the solar equilibrium tidal height formula:

h＝Rcos[ωt+(Vo+U)]

In the formula, h is the tidal height; R is the theoretical amplitude of the tidal (i.e. semi-tidal range); ω is the angular rate of the tidal; t is the longitude of the station, and ωt is the phase angle of the time measurement; Vo+U is the astronomical initial phase angle of the tidal equinox, which is calculated based on 0:00 GMT solar time on January 1 every year.

According to the equilibrium tide theory, the climax of any equinox should occur at the upper (lower) mid-heaven moment of the imaginary celestial body, that is, when the phase angle [ωt+(Vo+U)]=0, due to seabed friction, seawater inertia, etc., the nearshore The high tides of the actual tides occur some time after the Moon's upper (lower) eclipse (i.e., the high tide gap). To obtain the high tide at a certain time in a certain place, it is necessary to add a correction angle K, that is, assuming that the phase angle of each equinox has a K value hysteresis, that is, the time when the actual tidal climax appears lags behind the equilibrium tidal high tide time K/omega hours. K is called the local delay angle or delay angle. The above formula should be:

h＝Rcos[ωt+(Vo+U)－K]

In the formula, R is a variable, if it is replaced by the multi-year average value (average amplitude), R=fH. f is the correction value of the amplitude of the tidal, which is called node factor or amplitude factor; f is a function of time, which is usually taken at 12:00 on July 2, Green in the middle of the year (0:00 in leap years), and is calculated year by year for each tidal . [ωt+(Vo+U)－K] is the sub-tidal phase angle, which is expressed in the local time of the longitude where the station is located (for the conversion of Green Time, District Time and Local Time, see Time and District Time System), the sub-tidal height The final expression is:

h＝fHcos[ωt+(Vo+U)－K]

That is: the tidal height h of a certain place at a certain time t can be calculated by H and K of each tidal, and H and K are harmonic constants.

To determine the tide height according to the harmonic constant, 4 diurnal equinoxes, 4 semidiurnal equinoxes and 3 shallow water equinoxes are usually selected for observation, and a cosine curve is drawn for each equinox, h=Rcos(ωt－ Q), R and Q are the actual amplitude and delay angle, and the superimposed curve can reflect the complex actual tidal process. The tidal harmonic constant varies from place to place, but it is constant for a fixed station.

Tide observation: Tidal observation is usually called water level observation, also known as tide inspection. The purpose of tide observation is to understand the nature of local tides, apply the obtained tide observation data, calculate the tidal harmonic constant, mean sea level, depth datum, tide forecast and provide water level corrections at different times, etc. Military, transportation, aquatic products, surveying and mapping and other departments use. Tide observation usually records the tide value at a certain moment as the tide correction data. Two hours before and after high tide and low tide, the recording time interval is shorter, generally every 10 minutes. When the tide is low, the recording time interval can be extended appropriately. The most commonly used tide observation method for underwater topographic surveys at sea is to manually record the tide height through a water gauge erected on the seashore.

The beneficial effects of the present invention are: the simulated underwater terrain measurement signal generated by the simulator provides the user with a realistic water depth measurement simulation environment and simulated measuring instruments, which is convenient for the operator to perform simulated measurement on the survey area, and the simulated measurement results can be used by general The water depth data analysis software is processed, so as to realize the simulation training function of the underwater terrain measurement method; in addition, scientific research institutions can also verify the underwater terrain data processing algorithm according to the simulated measurement results generated by the simulator.

Description of drawings

Fig. 1 is a work flow chart of the present invention;

Fig. 2 is a schematic diagram of the simulation process of simulating the position of the survey ship;

Fig. 3 is a schematic diagram of a satellite positioning signal simulation algorithm;

Fig. 4 is the schematic diagram of the simulation algorithm of the water depth measurement signal;

Fig. 5 is a connection structure diagram of the underwater terrain measurement simulator.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the following will be described in conjunction with the accompanying drawings and specific examples of the description.

The purpose of the present invention is to simulate the whole process of underwater topography measurement, to be able to steer and simulate the navigation of the survey ship, and to provide real-time data on the position of the survey ship and the water depth at the location for the upper computer installed with the underwater topography survey navigation acquisition software. A simulation method for underwater terrain surveying, the specific steps comprising:

Step 1: The user changes the simulated ship speed and rudder angle of the simulated survey ship through the simulated manipulator of the survey ship, and the underwater terrain survey simulator is controlled by the internal clock of the system according to the speed and rudder angle input from the survey ship simulated manipulator. The position simulation algorithm calculates the position of the simulated survey ship;

Step 2: The underwater terrain measurement simulator generates a GPS positioning signal with a delay effect according to the position of the simulated survey ship through the positioning signal simulation algorithm, and sends the GPS positioning signal to the upper computer;

Step 3: Under the control of the internal clock of the system, the underwater terrain measurement simulator generates the sound wave emission direction of the depth sounder corresponding to the current moment of measuring the ship's attitude according to the sea state level set by the user through the ship's attitude simulation algorithm; Step 4: The underwater topographic survey simulator calculates the instantaneous tide water level height according to the tidal harmonic constant stored in the database through the tide forecast algorithm, and displays it on the screen of the underwater topographic survey simulator according to the period defined by the user.

Step 5: The underwater terrain measurement simulator uses the depth simulation algorithm to calculate the measurement results of the instantaneous water depth according to the position of the simulated survey ship, the sound wave emission direction of the depth sounder, and the basic data of the underwater terrain simulation stored in the database. The format and period defined by the user send the instantaneous water depth measurement results to the host computer installed with the underwater terrain survey navigation acquisition software.

Further, the position simulation algorithm is based on the simulated measurement of the position (X0, Y0) and course angle β0 of the ship at T0, the ship speed V0 and rudder angle α0 input by the user, the tidal current velocity Vr set by the user, and the tidal current direction , the change speed of the tidal current direction ω, the random disturbance value of the tidal current direction Rt, the steering sensitivity S of the simulated survey ship, and calculate the position (X1, Y1) of the simulated survey ship at T1 time, the specific algorithm is as follows:

β1=(β0+V0*△t*α0*S)Mod 360;

Among them: T0 and T1 are the two adjacent simulation times, T1=T0+△t, △t is the clock period defined by the user, the default is 0.1 seconds;

The default value of steering sensitivity S is 0.5, which can be set by the user to any value between {0.1, 0.3, 0.5, 0.7, 0.9, 1.0};

The default value of tidal current direction change speed ω is 0.1 degree/second, which can be set by the user to any value in {0.1, 0.3, 0.5};

The random disturbance value Rt of the tidal current direction takes a random number uniformly distributed between -2.0 degrees and +2.0 degrees.

Further, the positioning signal simulation algorithm is to generate a GPS positioning signal with a delay effect according to the delay time set by the user and the current position of the measuring ship. The specific algorithm is as follows:

Step 2.1: Define a one-way linked list to store the position of the survey ship, and each item in the linked list is the position of the survey ship (X, Y);

Step 2.2: The system calculates the position X, Y of the measuring ship according to the position simulation algorithm every time a custom clock period △t passes, and inserts it into the head of the linked list;

Step 2.3: If the length of the linked list is greater than N=Td/△t, delete the last node of the linked list;

Step 2.4: The system takes out the last node of the linked list according to the positioning signal period set by the user, and converts the position of the survey ship (X, Y) contained in it into the format required by the host computer and outputs it from serial port 1.

Further, the underwater terrain database includes a water depth data table, a tidal harmonic constant table, and an underwater sound velocity profile table; wherein the water depth data table stores the underwater topographic point cloud data of the simulated survey area; the tidal harmonic constant table stores It is the 11 tidal harmonic constants of the simulated survey area; the sound velocity profile table stores the sound wave propagation velocity at different depths of the simulated survey area. The specific structure of each data table is as follows:

(1) Depth data table

(2) Table of tidal harmonic constants

(3) Underwater sound velocity profile table

Field Name type of data Remark ID Int self-increment water depth Int Depth value speed of sound Decimal Underwater sound velocity value

Further, through the tide forecasting algorithm, according to the tidal harmonic constant stored in the database, the instantaneous tide water level height is calculated, and displayed on the screen of the underwater terrain survey simulator according to the period defined by the user.

Further, the attitude simulation algorithm of the measuring ship is to calculate the plane coordinates of the center of the seabed irradiation range of the sound waves emitted by the simulated depth sounder according to the sea state level set by the user and the position of the simulated measuring ship. The specific algorithm is as follows:

Step 3.1: Define the position coordinates of the simulated survey ship as (Xc, Yc, 0), query a sounding point P with the smallest distance from the (Xc, Yc) plane from the sounding data table in the database, and take out the sounding value Zp of this point;

Step 3.2: Take the location of the simulated survey ship (Xc, Yc, 0) as the coordinate origin, and calculate the center of the seabed exposure range of the sound waves emitted by the simulated depth sounder when the survey ship rolls and pitches under the influence of waves according to the following formula position Xr, Yr, Zr;

In the formula, Roll is the roll angle of the measuring ship, and the value is a random number evenly distributed in the interval [-3*G,+3*G]; Pitch is the pitch angle of the measuring ship, and the value is in the interval [-2*G] *G,+2*G] A uniformly distributed random number; G is the sea state level set by the user, the value is any number in [0,1,2,3,4,5], the default value is 0 ;

Step 3.3: Calculate the plane position coordinates (Xcent, Ycent) of the center of the seabed irradiation area where the echo sounder emits sound waves according to the following formula

Where Th is the tide height at the current moment, which is calculated by the tide forecast algorithm according to the harmonic constant in the database.

Further, the water depth simulation method is to calculate and measure the instantaneous water depth measurement result data based on the center position of the sound wave emitted by the depth sounder in the seabed exposure range, the basic data of the underwater terrain, and the sound wave beam angle set by the user. The specific algorithm is as follows :

Step 5.1: According to the beam angle θ set by the user, the water depth Zp at the position of the measuring ship, and the instantaneous tide height Th, calculate the radius of the sound wave emitted by the analog echo sounder on the seabed R=(Zp+Th)*tan(θ );

Step 5.2: Select 4 candidate points P1 (X _P1 , Y _P1 ), P2 (X P2 , Y P2 ), P3 (X _{P3 ,} Y _P3 ), P4 (X _P4 , Y _P4 ) with (Xcent, _Ycent ) as the center ),in:

Step 5.3: In the sounding data table of the database, search for all neighboring sounding points whose planar distance to each candidate point is less than R/2, and calculate the planar distance between the candidate point and each neighboring sounding point, and finally pass the distance inverse ratio The weighted interpolation algorithm calculates the water depth Z1, Z2, Z3, Z4 of the four candidate points P1, P2, P3, and P4;

Step 5.4: According to the plane coordinates and water depth of the four candidate points, calculate the distances between them and the position (Xc, Yc, 0) of the analog echo sounder i=1, 2, 3, 4; and select the smallest Di as the current position water depth value D;

Step 5.5: Calculate the total propagation time T of the sound wave corresponding to the water depth D from emission to reception according to the underwater sound velocity data stored in the database, Among them, i corresponds to the serial number of the water depth calculated from the sea surface, m is the serial number of the water depth corresponding to the water depth D; △Hi is the distance between the i-th layer and the i+1-th layer, through the corresponding depth correlation of the two layers in the database Subtracted; V _i and V _i+1 are the underwater sound velocity of the i-th layer and the i+1-th layer respectively;

Step 5.6: Calculate the instantaneous bathymetry results Where Vs is the average underwater sound velocity set by the user.

On the other hand, the technical solution provided by this application is an underwater terrain survey simulator, which logically includes underwater terrain survey simulation software, underwater terrain simulation database, underwater terrain survey simulation equipment, and survey ship simulation control device.

The underwater topography measurement simulation software is installed in the underwater topography measurement simulation equipment, and is used to receive the ship speed and rudder angle data sent by the user through the survey ship simulation controller, and based on these data and the basic data stored in the underwater topography simulation database, real-time Calculate the instantaneous water depth signal and satellite positioning signal, and send it to the underwater terrain survey navigation acquisition system through the serial port on the device;

The underwater terrain simulation database is used to provide various basic data for calculating simulation data for the underwater terrain measurement simulation software, including the underwater terrain point cloud data of the simulated survey area, and the tidal harmonic constant of the simulated survey area;

The underwater terrain measurement simulation equipment is used to install the underwater terrain measurement simulation software and the underwater terrain simulation database. The equipment includes an LCD screen, three USB interfaces, four serial interfaces and one RJ-45 network interface. The equipment contains A motherboard and a hard disk, the motherboard is integrated with CPU, memory and graphics card; the underwater topographic measurement simulation equipment is used to run the underwater topographic measurement simulation software and provide an interface for sending data to the outside; the liquid crystal display is used to display the speed of the ship in real time, Heading, rudder angle, beam angle, tidal current velocity, tidal current direction, tidal height, simulator working status information;

The survey ship simulation manipulator is a standard windows game joystick (steering wheel), which is used to provide users with a platform to manipulate the simulated survey ship, and is connected to the underwater terrain survey simulation device through a USB transmission line; the user can use the survey ship simulation manipulator to The buttons on the controller can be used to change the speed and rudder angle of the simulated measurement ship, and various parameters of the simulator can also be set through the buttons on the controller.

The technical scheme of the underwater terrain measurement simulator is as follows:

As shown in Figure 1, the simulator includes a survey ship simulation control module, a survey ship position simulation module, a survey ship attitude simulation module, a tide simulation module and a water depth simulation module in terms of software structure. All modules work together to output water depth and position data according to the period specified by the user.

When working, first connect the water depth measurement simulator with the host computer installed with the underwater terrain survey navigation acquisition software through the serial port line. Then, the ship speed and rudder angle of the simulated survey ship are generated in real time by the simulated manipulator of the survey ship, and the simulated survey ship is controlled to sail according to the planned survey line. The position simulation module automatically generates the corresponding GPS positioning signal according to the position of the simulated survey ship. The attitude simulation module calculates the irradiation area of the sound wave emitted by the simulated depth sounder on the seabed according to the sea conditions set by the user. The tide simulation module stores the tide in the database. The harmonic constant calculation corresponds to the current tide height. The water depth simulation module calculates the corresponding measurement water depth according to the aforementioned simulation results, and finally sends the water depth signal and GPS signal to the navigation acquisition system at the same time to complete the water depth measurement simulation.

The functions of each software module are as follows:

(1) Survey ship simulation control module: The main function of the survey ship simulation control module is to control the simulated survey ship to advance in the direction specified by the user in the simulated survey area under certain sea conditions, and output the instantaneous position of the simulated survey ship. The simulation principle and process of the simulated survey ship position are shown in Fig. 2.

(2) Survey ship position simulation module: The core of the survey ship position simulation module is to correctly reflect the set GPS signal delay time in the output simulation signal. For a survey ship in motion, due to the calculation capability of the GPS device itself, the given GPS position will always be delayed for a period of time, about 0.1 to 0.5 seconds. The GPS signal simulation module stores the received position of the measuring ship in a fixed-length linked list according to the time sequence. When the signal is output every second, the delayed GPS coordinates are searched according to the linked list. The principle is shown in Figure 3.

(3) Measurement ship attitude simulation module: The main function of the measurement ship attitude simulation module is to simulate the range of the beam emitted by the echo sounder on the seabed under the influence of wind and waves on the sea surface. The simulator calculates the instantaneous roll angle and pitch angle of the sound waves emitted by the simulated depth sounder according to the sea conditions set by the user, and then calculates the range of the beam emitted by the depth sounder on the seabed according to the current position of the simulated survey ship

(4) Tidal simulation module: The role of the tidal simulation module is to simulate the instantaneous tide height corresponding to the current moment. The tide simulation module calculates the instantaneous tide height through the tide forecast algorithm and the tide harmonic constant stored in the database.

(5) Water depth measurement signal simulation module: The principle of the water depth measurement signal simulation module is to first determine the direction of the simulated ultrasonic beam according to the current sea conditions, and then calculate the beam range illuminated by it on the bottom of the water according to the position of the survey ship, and determine within the beam range 4 candidate points, calculate the water depth at the position of the candidate point through the distance inverse weighted interpolation algorithm according to the water depth points in the neighborhood of each candidate point, and then calculate the slope distance from each candidate point to the transducer and select the smallest one, plus Current tide height as measured water depth. Its principle is shown in Figure 4.

The feature of this embodiment is that the water depth and position signals output by the depth sounder and the GPS receiver in the underwater topographic survey are simulated and generated by the underwater topographic survey simulator, and the maneuvering control of the survey ship is simulated. Specifically include: (1) Manipulate the navigation of the simulated survey ship through the control equipment of the simulated survey ship; (2) Continuously output the position signal of the simulated survey ship during the navigation of the simulated survey ship through a self-defined algorithm; Continuously output water depth signal during navigation.

An underwater terrain measurement simulator, which logically includes underwater terrain measurement simulation software, an underwater terrain simulation database, underwater terrain measurement simulation equipment and a survey ship simulation manipulator.

The underwater topography measurement simulation software is installed in the underwater topography measurement simulation equipment, and is used to receive the ship speed and rudder angle data sent by the user through the survey ship simulation controller, and based on these data and the basic data stored in the underwater topography simulation database, real-time Calculate the instantaneous water depth signal and satellite positioning signal, and send it to the underwater terrain survey navigation acquisition system through the serial port on the device;

The underwater terrain simulation database is used to provide various basic data for calculating simulation data for the underwater terrain measurement simulation software, including underwater terrain point cloud data in the simulated survey area, tidal harmonic constant in the simulated survey area; used for underwater terrain survey simulation equipment It is used to install underwater terrain measurement simulation software and underwater terrain simulation database. The equipment includes an LCD screen, three USB interfaces, two serial interfaces and one RJ-45 network interface. The equipment contains a motherboard and a hard disk. It integrates CPU, memory and graphics card; the underwater topographic measurement simulation equipment is used to run the underwater topographic measurement simulation software, and provides an interface for sending data to the outside world; the LCD screen is used to display the ship's speed, heading, rudder angle, and beam angle in real time , tidal flow velocity, tidal current direction, tidal height, and simulator working status information; the survey ship simulation control device is used for the user to manipulate the simulated survey ship to sail according to the planned survey line; the simulated survey ship control device is a WINDOWS game joystick in the form of a steering wheel , in the present invention, the functions of each button on the rocker are as follows: button 1: reduce the beam angle of the sound wave; button 2: increase the sea state level of the simulated survey area; button 3: decrease the sea state level of the simulated survey area; button 4: increase the sound wave Beam angle; button 5: increase the speed of the simulated measurement ship; button 6: decrease the speed of the simulated measurement ship; button 7: stop the simulation; button 8: start the simulation; button 9: reduce the delay time of the GPS signal; button 10: increase the GPS signal Delay time; the upper button of the visual helmet: increase the tidal current speed of the simulated survey area; the lower button of the visual helmet: decrease the tidal current speed of the simulated survey area; the left button of the visual helmet: decrease the tidal current direction of the simulated survey area; the right button of the visual helmet: increase the simulated survey area Trend direction; left button on the steering wheel: the rudder angle increases to port; right button on the steering wheel: the rudder angle increases to starboard.

During the simulation, the user changes the rudder angle of the simulated survey ship through the steering wheel on the manipulator, and sets the speed of the simulated survey ship through the gear lever on the manipulator, so as to control the simulated survey ship to sail along the route designed by the user. Other buttons are used to set system simulation parameters.

The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Those skilled in the art make some simple modifications, equivalent changes or modifications by using the technical content disclosed above, all of which fall within the scope of the present invention. within the scope of protection of the invention.

Claims (8)

1. bathymetric surveying emulation mode, it is characterised in that：

Step 1：User changes the ship's speed and rudder angle of analogue measurement ship, bathymetric surveying emulation by surveying vessel analog manipulation device Device under the control of internal system clock, according to the user-defined period, passes through position according to the ship's speed and rudder angle of analogue measurement ship Put simulation algorithm calculating simulation surveying vessel position；

Step 2：Bathymetric surveying emulator is generated to carry according to analogue measurement ship position and be prolonged by positioning signal simulation algorithm The GPS positioning signal of slow effect, and with user-defined locating periodically, GPS positioning signal is sent to by serial ports by host computer；

Step 3：Bathymetric surveying emulator, according to the scale of state of sea set by user, is being by surveying vessel Attitude Simulation algorithm It unites under the control of internal clocking, according to the user-defined period, generates the sounding instrument sound wave of corresponding current time surveying vessel posture The direction of the launch；

Step 4：Bathymetric surveying emulator is reconciled normal by tide prediction algorithm according to the tide of storage in the database Number, calculates instantaneous tidal level height, is shown according to the user-defined period on the screen of bathymetric surveying emulator；

Step 5：Bathymetric surveying emulator is by depth of water simulation algorithm, according to analogue measurement ship position, analogue measurement ship appearance The underwater topography Math data of state and storage in the database, calculate the measurement result of the instantaneous depth of water, are pressed by serial ports Instantaneous water-depth measurement result is sent to installation bathymetric surveying navigation acquisition software according to user-defined form and period Host computer.

2. bathymetric surveying emulation mode according to claim 1, it is characterised in that：The position simulation algorithm is root According to analogue measurement ship in the position at T0 moment (X0, Y0) and course angle β 0, ship's speed V0 input by user, rudder angle α 0, Yong Hushe Fixed strength of current Vr, direction of tideDirection of tide pace of change ω, direction of tide random perturbation value Rt, analogue measurement ship turn To sensitivity S, analogue measurement ship is calculated at the position at T1 moment (X1, Y1), specific algorithm is as follows：

β 1=(β 0+V0* △ t* α 0*S) Mod 360；

Wherein：T0 and T1 is the adjacent emulation moment twice, and T1=T0+ △ t, △ t are the user-defined clock cycle, are given tacit consent to 0.1 second；

Steering sensitivity S default values take 0.5, can be arbitrary between { 0.1,0.3,0.5,0.7,0.9,1.0 } by user setting One numerical value；

Direction of tide pace of change ω default values are 0.1 degrees second, can be any one in { 0.1,0.3,0.5 } by user setting A numerical value；

Direction of tide random perturbation value Rt takes one in -2.0 degree to equally distributed random number between+2.0 degree.

3. bathymetric surveying emulation mode according to claim 1, it is characterised in that：The positioning signal simulation algorithm According to delay time Td set by user and current measurement ship position, to generate the GPS positioning signal with delay effect；Specifically Algorithm is as follows：

Step 2.1：Define the storage of single-track link table and measure ship position, in chained list each single item content be measure ship position (X, Y)；

Step 2.2：By a self-defined clock cycle △ t, one-shot measurement accommodation often is calculated according to position simulation algorithm for system (X, Y) is put, is inserted into the head of chained list；

Step 2.3：If the length of chained list is more than N=Td/ △ t, the last one node of deletion chained list；

Step 2.4：System according to the positioning signal period set by user take out chained list the last one node, by it includes survey The form that amount ship position (X, Y) is converted into host computer requirement is exported from serial ports 1.

4. bathymetric surveying emulation mode according to claim 1, it is characterised in that：The underwater topography database packet Include bathymetric data table, harmonic constant of tide table, Sound speed profile table；What is wherein stored in bathymetric data table is that the underwater of area is surveyed in simulation Landform point cloud data；The storage of harmonic constant of tide table is to simulate 11 harmonic constants of tide for surveying area；Sound speed profile table is stored Be simulation survey area's different depth under acoustic wave propagation velocity.

5. bathymetric surveying emulation mode according to claim 1, it is characterised in that：The surveying vessel Attitude Simulation is calculated Method is according to the scale of state of sea set by user and analogue measurement ship position, and calculating simulation sounding instrument emits sound wave and irradiates model in seabed The plane coordinates at center is enclosed, specific algorithm is as follows：

Step 3.1：It is (Xc, Yc, 0) to define analogue measurement ship position coordinate, from the bathymetric data table in database inquiry with One depth of water point P of (Xc, Yc) plan range minimum takes out the water depth value Zp of the point；

Step 3.2：With analogue measurement ship position (Xc, Yc, 0) be coordinate origin, according to equation below calculate surveying vessel by When wave influences to occur roll and pitch, simulation sounding instrument emits center Xr, Yr of the sound wave in seabed range of exposures, Zr；

Roll is the roll angle of surveying vessel in formula, and value is an equally distributed random number in section [- 3*G ,+3*G]； Pitch is the pitch angle of surveying vessel, and value is an equally distributed random number in section [- 2*G ,+2*G]；G is set for user The scale of state of sea, value be [0,1,2,3,4,5] in any one number, default value 0；

Step 3.3：Plan-position coordinate of the sounding instrument transmitting sound wave at seabed irradiation area center is calculated according to equation below (Xcent,Ycent)；

Wherein Th is current time tidal height, and the harmonic constant in database is calculated by tide prediction algorithm.

6. bathymetric surveying emulation mode according to claim 1, it is characterised in that：The depth of water emulation mode is root Emit sound wave in the center of seabed range of exposures, underwater topography basic data, acoustic wave beam set by user according to sounding instrument Angle, calculates the instantaneous water-depth measurement result data for measuring and obtaining, and specific algorithm is as follows：Step 5.1：According to wave beam set by user Angle θ, the depth of water Zp of surveying vessel position, instantaneous tidal height Th, calculating simulation sounding instrument emit sound wave in seabed range of exposures Radius R=(Zp+Th) * tan (θ)；

Step 5.2：4 candidate point P1 (X are chosen centered on (Xcent, Ycent)_P1, Y_P1), P2 (X_P2, Y_P2), P3 (X_P3, Y_P3), P4 (X_P4, Y_P4), wherein：

Step 5.3：The plan range of retrieval and each candidate point is less than the whole of R/2 respectively in the bathymetric data table of database Neighborhood depth of water point, and the plan range of candidate point and each of which neighborhood depth of water point is calculated, finally by apart from inverse ratio weighted interpolation Algorithm calculates the depth of water Z1, Z2, Z3, Z4 of this four candidate points of P1, P2, P3, P4；

Step 5.4：They and simulation sounding instrument position are calculated according to the plane coordinates of four candidate points and the depth of water respectively The distance between (Xc, Yc, 0)I=1,2,3,4；And choose minimum one A Di is as current location water depth value D；

Step 5.5：The corresponding sound waves of depth of water D are calculated from being emitted to reception according to storage underwater sound velocity data in the database Total propagation time T,Wherein i corresponds to the depth of water sequence number calculated since sea, and m is right for depth of water D The depth of water sequence number answered；△ Hi, the distance between to i+1 layer, pass through two layers of corresponding depth phase in the database for i-th layer Subtract to obtain；V_iAnd V_i+1Respectively i-th layer and the underwater velocity of sound of i+1 layer；

Step 5.6：Calculate instantaneous water-depth measurement resultWherein Vs is underwater bulk sound velocity set by user.

7. bathymetric surveying emulator, it is characterised in that：

Bathymetric surveying emulator includes bathymetric surveying simulation software, underwater topography emulation data in logical construction Library, bathymetric surveying emulator and surveying vessel analog manipulation device；

Bathymetric surveying simulation software is mounted in bathymetric surveying emulator, for receiving user by measuring ship model Intend ship's speed, the rudder angle data that control device is sent, according to the basic data stored in these data and underwater topography simulation data base Instantaneous water signal and satellite positioning signal are calculated in real time, and being sent to bathymetric surveying navigation by the serial ports in equipment adopts In collecting system；

Underwater topography simulation data base is used to provide all kinds of basic numbers of computer sim- ulation data for bathymetric surveying simulation software According to underwater topography point cloud data, simulation including simulation survey area survey area's harmonic constant of tide, the underwater Sound speed profile number in area is surveyed in simulation According to；

Bathymetric surveying emulator is used to install bathymetric surveying simulation software and underwater topography simulation data base, equipment Comprising a liquid crystal display, three USB interfaces, four serial line interfaces and a RJ-45 network interface, one is included inside equipment Block mainboard and a hard disk are integrated with CPU, memory and video card on mainboard；Bathymetric surveying emulator is underwater for running Topographic survey simulation software, and the interface of external transmission data is provided；Liquid crystal display is for real-time display ship's speed, course, rudder Angle, field angle, tidal current speed, trend flow direction, tidal height, emulator work state information；

Surveying vessel analog manipulation device is used for the equipment for providing control simulation surveying vessel to the user, and water is connected to by USB transmission line On lower topographic survey emulator；User changes the speed and rudder of analogue measurement ship by the button on surveying vessel analog manipulation device Angle passes through the parameters of the button settings emulator on control device.

8. bathymetric surveying emulator according to claim 7, it is characterised in that：The surveying vessel analog manipulation device is Rocking bar, steering wheel or keyboard.