CN109932701B - Target ship echo 2D imaging method for simulating ship radar - Google Patents
Target ship echo 2D imaging method for simulating ship radar Download PDFInfo
- Publication number
- CN109932701B CN109932701B CN201910261744.1A CN201910261744A CN109932701B CN 109932701 B CN109932701 B CN 109932701B CN 201910261744 A CN201910261744 A CN 201910261744A CN 109932701 B CN109932701 B CN 109932701B
- Authority
- CN
- China
- Prior art keywords
- radar
- ship
- coordinate system
- scanning
- scanning line
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The invention relates to a target ship echo 2D imaging method for simulating a ship radar, which comprises the steps of setting radar echo imaging parameters and simulating a radar echo in a scanning line mode; constructing a ship navigation simulation unit, and providing a ship simulation motion state in a multicast communication mode; preprocessing radar simulation data; resolving the relative position relation between each point on the radar scanning line and the target ship, and determining the amplitude of each point on the scanning line; and visualizing radar echo imaging information. The ship course simulation unit and the radar echo simulator are designed, the simulated target ship echo imaging information is sent in real time through network communication, a man-machine interaction interface is arranged, the number, the size, the position and the posture of echo imaging are set in a user-defined mode, dynamic echo imaging signals are customized flexibly, and universal verification imaging test signals are provided for a bridge radar display control console.
Description
Technical Field
The invention relates to a 2D imaging method, in particular to a target ship echo 2D imaging method for simulating a ship radar, and belongs to the technical field of communication information simulation.
Background
The marine radar is a target detection tool which is installed on a ship and used for monitoring a certain area around the ship in real time, and provides important information sources for tasks such as positioning of the ship, auxiliary obstacle avoidance, dangerous situation estimation and the like, so a radar display and control console used for displaying echo imaging information in real time is usually configured on a bridge, imaging information of surrounding target ships, islands and other target objects is provided for ship driving and controlling personnel, particularly the target ship is in a dynamic change state in real time, and the imaging information of the target ship is extremely important for the ship. And under the condition of not connecting hardware facilities such as radar antenna, the formation of image effect of radar display and control platform usually can't be tested, even connect radar hardware, also very difficult echo formation of image information for the display and control platform provides different operating modes in a flexible way.
When no radar hardware exists, in order to flexibly test the performance of the radar display and control console, a mode of simulating echo signals of a target ship by a computer can be adopted. Compare formation of image such as island, static buoy and large tracts of land, the target ship around this ship is in real-time motion state, and quantity can be many can be few, utilize virtual simulation mode to simulate its echo formation of image, can provide the echo formation of image of developments, quantity adjustable for radar display control platform, more be fit for testing the imaging performance of radar display control platform, greatly reduced connects the input on manpower and the material resources that the radar entity brought, also can shorten the research and development and the test cycle of radar display control platform simultaneously. Some scholars have also done research work in this respect, for example, in the document "double-station synthetic aperture radar imaging simulation of large-size targets on sea surface", by zhao, say, wei, and the like, the principle of imaging large-size targets on sea surface is researched, and a double-station synthetic aperture radar imaging model is established; guoding et al in the literature "polarimetric synthetic aperture radar sea surface imaging simulation and analysis" simulate the imaging effect of a marine scene target through a velocity bunching model and a Bragg scattering model, and other scholars mostly adopt similar methods to develop the research of radar imaging. However, the previous studies have the following problems: on one hand, the echo imaging is usually developed from the digital signal processing angle of the radar to carry out mechanism analysis and modeling, and can not directly provide information such as longitude and latitude, course and the like of a target ship for a radar display and control console; on the other hand, the radar signal simulation method is difficult to rapidly and flexibly provide real-time indexes such as scanning periods, physical distances corresponding to scanning points and the like for the radar display control console.
Disclosure of Invention
Aiming at the prior art, the technical problem to be solved by the invention is to provide a target ship echo 2D imaging method for simulating a ship radar, which is used for providing a flexible target ship echo imaging signal capable of setting multiple working conditions for a bridge radar display and control console and assisting in testing relevant functions such as signal processing and the like of the radar display and control console.
In order to solve the technical problem, the invention provides a target ship echo 2D imaging method for simulating a ship radar, which comprises the following steps:
the method comprises the following steps: setting radar echo imaging parameters and a coordinate system, and simulating radar echoes in a scanning line mode;
step two: constructing a ship navigation simulation unit, and providing a ship simulation motion state in a multicast communication mode:
establishing a ship kinematics model under a ground coordinate system, wherein the ship motion state comprises a position (x)t,yt) Velocity v, angular velocity ω, heading θtSpecifically, the following is shown:
in the above formula: x is the number of0And y0Is the horizontal and vertical coordinates theta of the ship and the target ship at the moment0The course angle of the ship at the last moment is delta t, and the delta t is a simulation step length;
step three: preprocessing radar simulation data:
(1) coordinate transformation
Converting the position of the target ship from the ground coordinate system to the position of the target ship in the radar coordinate system
Satisfies the following conditions:
wherein the ship is positioned at the lower position of the ground coordinate system as (x)O,yO) The course of the ship is thetaOThe position of the target ship in the ground coordinate system is (x)T,yT)；
(2) Target vessel two-dimensional shape construction
Scaling factor k defining the imaging length and width of the target vesselxAnd kyLet L be the actual length and width of the target vesselTxAnd LTyCourse of the target ship is thetaTThe method comprises the steps of representing echo imaging information of the position and the posture of a target ship by utilizing a pentagon, wherein the pentagon has an inner angle which is an acute angle, a vertex corresponding to the inner angle of the acute angle of the pentagon represents the course of the target ship, and the coordinate of one point in the pentagon is set as (x)TS,yTS) Transforming the coordinate point from radar coordinate system to ground coordinate system, and transforming the coordinate (x)TS_g,yTS_g) Satisfies the following conditions:
step four: the method for resolving the relative position relation between each point on the radar scanning line and a target ship and determining the amplitude value of each point on the scanning line comprises the following steps:
step 1: constructing a scanning line coordinate system, and determining the relative position relationship between the scanning line and the target ship:
establishing a scanning line coordinate system, wherein the scanning line coordinate system is to rotate a radar coordinate system to enable a currently processed scanning line to point to the x-axis direction of a ground coordinate system, converting coordinate points of the pentagon of the outline of the target ship from the ground coordinate system to the scanning line coordinate system, and converting a post-coordinate (x-coordinate) if an included angle between the radar scanning line and the heading direction of the ship is phiTS_p,yTS_p) Satisfies the following conditions:
after the processing of the formula, obtaining the relative relation between the scanning line currently processed and the pentagons of each target ship, namely determining whether the scanning line and the pentagons have intersection points;
step 2: and solving the coordinates of the intersection point of the scanning line being processed and the target ship pentagon:
by passing
Two adjacent vertex coordinates of the pentagon are obtained as (x)TS_p1,yTS_p1) And (x)TS_p2,yTS_p2) If the edge intersects with the scanning line, the abscissa x of the intersection pointpsSatisfies the following conditions:
xps＝xTS_p1-yTS_p1·(xTS_p2-xTS_p1)/(yTS_p2-yTS_p1)
regardless of the fact that the scan line passes through only one vertex of the pentagon and the scan line coincides with one side of the pentagon, when the scan line intersects with the pentagon, there are only two intersections, and in the scan line coordinate system, x is usedps＝xTS_p1-yTS_p1·(xTS_p2-xTS_p1)/(yTS_p2-yTS_p1) Obtaining the abscissa value x of the two intersection points of the scanning line and the target shipps_maxAnd xps_min，xps_maxAnd xps_minRespectively representing a larger abscissa value and a smaller abscissa value;
and 3, step 3: and (3) updating the amplitude of each point on the scanning line:
by xps＝xTS_p1-yTS_p1·(xTS_p2-xTS_p1)/(yTS_p2-yTS_p1) Can determine x on the scan line currently being processedps_minAnd xps_maxAll the scanning points in between are used for imaging the echo occupied by the target ship, and the amplitude values of all the points on the scanning line are updated, [ x ]ps_min,xps_max]The amplitude of each point outside the interval is 0, [ x ]ps_min,xps_max]The amplitude of each point in the interval is 255;
step five: simulating and sending radar echo imaging information, and intercepting imaging data;
step six: radar echo imaging information visualization comprises the following steps:
step 1: extracting imaging data in data channel, and sampling to obtain imaging information
Setting the multicast communication period of a ship navigation simulation unit as TmtsockThe scanning time of the radar display and control console is TscanRadar simulated echo refresh period TsimuSatisfies the following conditions:
Tsimu＝0.4·Tscan
for TmtsockSampling in a frequency reducing mode, and meanwhile refreshing the frequency higher than that of a radar display and control console;
step 2: selecting a full black picture as a background picture, and drawing radar echo imaging information according to pixels
Selecting a pre-made square all-black picture as a background picture for radar echo imaging, wherein the side length of the picture is LBKSetting a scene display zoom ratio kBTRFor representing the number of the screen display pixels corresponding to 1 radar echo image pixel, the maximum number of pixels N that can be displayed in the radar original imagepmaxComprises the following steps:
Npmax＝LBK/(2*kBTR+0.5)
in [0, N ]pmax]In the interval, traversing each radar pixel point, solving the coordinate value of each pixel point relative to the center of the background picture by using (x)pix,ypix) Is represented by (x)pix,ypix) Satisfies the following conditions:
wherein xBKAnd yBKRespectively representing the coordinates of the central point of the background picture on a screen coordinate system, wherein i is the ID number of the traversed pixel point;
calculating the offset D of the radar echo imaging pixel corresponding to the background pictureoffset，DoffsetSatisfies the following conditions:
Doffset＝3·(LBK·(LBK-ypix-1)+xpix)
by adjusting DoffsetDetermining the corresponding pixel position of each radar scanning line on a background picture, drawing imaging information on a black background picture according to the amplitude data of each scanning point, if the amplitude of the scanning point is 0, keeping the RGB three values of the pixel at the position of the picture to be 0, if the amplitude of the scanning point is 255, making the pixel at the position of the picture to be R255, R255 and B0, enabling the target ship to present a yellow pentagonal pattern, and adjusting k to adjust the position of the pixelBTRAnd enlarging or reducing the display radius of the radar visible area.
The invention also includes:
the parameters in the first step comprise:
(1) number of scanning line angle equivalences Nd；
(2) Time T of one circle of radar simulation echo scanningc；
(3) Azimuth angle theta of current scan linecs；
(4) The number of points N contained in each scanning linesp；
(5) Physical distance D represented by each scanning pointpp；
(6) Timer simulation step length Tsimu；
Sending echo imaging data to a radar display and control console in a timing sending mode, wherein the number of updated scanning lines in each simulation step is Nd·Tsimu/TcThe scan lines being processed in azimuthal increments, one by one, i.e. thetacs＝k·2π/NdThe unit is radian, wherein k is the serial number of a scanning line; according to the distance N of the target ship relative to the shipspAnd DppDetermining the crossing condition of all scanning points on a scanning line and a target ship, wherein the amplitude of the scanning point of echo imaging is in two states of 0 or 255, the amplitude of the scanning point without a target is 0, the amplitude of the scanning point with the target is 255, and the amplitudes of all the scanning points are all 0 during initialization;
the coordinate system in the first step is defined as:
(1) radar coordinate system: the coordinate system is the superposition of a dynamic plane rectangular coordinate system and a polar coordinate system, the origin of the coordinate system is the real-time central position of the ship, the y axis of the rectangular coordinate system is the real-time heading direction of the ship, the x axis of the rectangular coordinate system points to the starboard of the ship, the 0-degree line of the polar coordinate system is superposed with the y axis of the rectangular coordinate system, and the clockwise direction of the radar scanning direction is positive when the coordinate system is overlooked; under the coordinate system, each point has 4 variables, namely the position (x, y) under a plane rectangular coordinate system, the angle theta and the distance d under a polar coordinate system, and the initial scanning line of one circle of radar scanning is calculated from the line of 0 degree of the polar coordinate;
(2) a ground coordinate system: the coordinate system is a plane rectangular coordinate system, the origin of the coordinate system is fixed as the initial position of the ship, the x axis points to the east, the y axis points to the north
The invention has the beneficial effects that: in order to provide imaging test signals for the radar display and control console, the invention provides a method for simulating marine radar echo imaging, a ship course simulation unit is designed to provide a related virtual ship motion state, simulated target ship echo imaging information is sent in real time through network communication, a man-machine interaction interface is arranged, and a universal verification imaging test signal is provided for the bridge radar display and control console. Compared with the prior similar method, the method provided by the invention can directly provide information such as simulated longitude and latitude, course and the like of the target ship for the radar display and control console on one hand, can more easily provide self-defined setting and the like for the radar display and control console on the other hand, and can quickly and flexibly provide indexes such as scanning period, echo imaging quantity, size, position, attitude and the like for the radar display and control console.
Drawings
FIG. 1 is a flow chart of echo imaging calculations;
FIG. 2 is a schematic diagram of a radar coordinate system;
FIG. 3 is a schematic view of a pentagon of the ship profile;
FIG. 4 is a schematic view of a target vessel in a radar coordinate system;
FIG. 5 is a schematic diagram of a target vessel transformed from a radar coordinate system to a scan line coordinate system;
FIG. 6 shows a case where two intersections exist between the scan line and the target vessel;
FIG. 7 is a radar echo simulator visualization interface;
FIG. 8 is an interface for receiving echo information by a bridge radar display and control console;
FIG. 9 is a graph of the effect of the test of the scanning period of the radar display and control console
Detailed Description
The following further describes the embodiments of the present invention with reference to the drawings.
The echo imaging calculation flow of the target ship of the marine radar is shown in figure 1. The method comprises the steps of formulating radar echo imaging parameters, determining a radar echo form simulated in a scanning line mode, utilizing an established ship navigation simulation unit to calculate and output motion states of a ship and a target ship in real time, converting the motion states into contour coordinates of the target ship through a radar simulation data preprocessing module, resolving relative position coordinates of the scanning line and the target ship in real time by combining radar scanning line information, and determining amplitude values of all points of the scanning line. On the basis, the visualization work of multicast-based packet communication and simulated radar echo imaging is carried out simultaneously.
The specific process of the invention is as follows:
the method comprises the following steps: setting imaging parameters and coordinate system of radar echo, and simulating radar echo in scan line mode
The method comprises the following steps of defining relevant general parameters for formulating a simulation radar echo process aiming at radar hardware information needing simulation, wherein the parameters comprise the following variables:
(1) number of scanning line angle equivalences Nd；
(2) Time T of one circle of radar simulation echo scanningc；
(3) Azimuth angle theta of current scan linecs；
(4) The number of points N contained in each scanning linesp；
(5) Physical distance D represented by each scanning pointpp；
(6) Timer simulation step length Tsimu。
The invention adopts a timing transmission mode to transmit echo imaging data to the radar display and control console, and the number of the updated scanning lines in each simulation step is Nd·Tsimu/TcThe scan lines being processed in azimuthal increments, one by one, i.e. thetacs＝k·2π/NdThe unit is radian, wherein k is the serial number of the scanning line. According to the distance N of the target ship relative to the shipspAnd DppThe intersection condition of all scanning points on a scanning line and a target ship can be determined, the scanning points of echo imaging exist in two states of 0 or 255, namely the amplitude of the scanning point without a target is 0, the amplitude of the scanning point with the target is 255, and the amplitudes of all the scanning points are all 0 during initialization. The invention realizes the basic simulation function of radar echo imaging through the variables.
The coordinate system is defined as follows:
(1) radar coordinate system: the coordinate system is the superposition of a dynamic plane rectangular coordinate system and a polar coordinate system, the origin of the coordinate system is the real-time central position of the ship, the y axis of the rectangular coordinate system is the real-time heading direction of the ship, the x axis of the rectangular coordinate system points to the starboard of the ship, the 0-degree line of the polar coordinate system is superposed with the y axis of the rectangular coordinate system, and the clockwise direction of the radar scanning direction is positive when the coordinate system is overlooked. Note that: in this coordinate system, each point has 4 variables, which are a position (x, y) in a rectangular plane coordinate system, and an angle θ and a distance d in a polar coordinate system. The initial scan line for one cycle of radar scan is calculated starting from the polar 0 deg. line, see figure 2 for details.
(2) A ground coordinate system: the coordinate system is a plane rectangular coordinate system, the origin of the coordinate system is fixed as the initial position of the ship, the x axis points to the east, and the y axis points to the north.
Step two, constructing a ship navigation simulation unit, and providing a ship simulation motion state in a multicast communication mode
Establishing a simple ship kinematic model under a ground coordinate system, wherein the ship motion state comprises a position (x)t,yt) Velocity v, angular velocity ω, heading θtSpecifically, the following is shown:
in the above formula: x is a radical of a fluorine atom0And y0Is a time abscissa, theta, on the vessel0And the delta t is a course angle of the ship at a moment and is a simulation step length.
By establishing the ship navigation simulation unit in the above way, simulating the real-time state information of the ship and other target ships, and designing the man-machine interaction interface, the method can complete newly-built expected course information of all ships, adjusting the ship motion state, increasing/decreasing/suspending simulation speed and the like through a mouse and a keyboard, and simulate the self-defined ship motion state for the radar. The formula is used as a core, a ship navigation simulation unit is established, and motion state data of the ship and the target ship are provided for the radar echo simulator in a multicast communication mode. The invention adopts a multicast mode to send data for the radar echo simulator at fixed time, and the communication mode can utilize one navigation simulation unit to provide ship navigation state information for a plurality of radar echo simulators at the same time.
Providing motion state data of the ship and a target ship by using a ship navigation simulation unit in a multicast communication mode, wherein a communication protocol comprises the following contents:
(1) ship ID number
(2) Ship x, y position
(3) Course of ship
(4) Size of ship
The target ships and the ship are distinguished through the ship ID numbers, the ship position and posture information is obtained through the formula (1), and the ship size is static input data and is used for displaying the size of radar echo imaging. Considering that a certain period of time is needed for a circle of simulated radar echo scanning, the multicast communication simulation step length needs to be coordinated with a radar scanning period, and the radar scanning period is TscanThrough the joint debugging experience with the radar display and control console, the multicast communication step length T of the ship navigation simulation unit is setmtsockSatisfies the following formula:
Tmtsock≤0.04·Tscan (2)
the ship navigation simulation unit can be guaranteed to provide a timely ship motion state by using the above formula.
Step three, radar simulation data preprocessing
According to the position and attitude information of the ship transmitted by multicast communication and the setting condition of the radar echo imaging parameters in the 'set radar echo imaging parameters and coordinate system', preprocessing work is firstly carried out on the data, so that the subsequent echo imaging calculation is facilitated.
(1) Coordinate transformation
Converting the position of the target ship from a ground coordinate system to a radar coordinate system, and setting the position of the ship as (x) in the ground coordinate systemO,yO) The course of the ship is thetaOThe target ship position is (x)T,yT) Then the position of the target ship under the radar coordinate system
Can be represented by the following formula:
if the target vessel is calculated by the above formula
Above the actual length of the ship, which is often not justified in reality for non-high speed boats, the invention therefore discards this situation.
(2) Target vessel two-dimensional shape construction
In order to provide echo imaging signals with reasonable length-width ratio for a radar display and control console, the invention defines a scaling factor k of the imaging length and width of a target shipxAnd kyThe two variables are specially used for changing the imaging scale of the radar echo in a man-machine interaction mode, so that the imaging effect of the radar display and control console can be conveniently tested, and the imaging size suitable for observation can be determined in an assisting mode. The present invention uses a pentagon to represent the echo imaging information of the position and attitude of the target ship, as shown in fig. 3, the present invention sets the unit length as L, wherein AB ═ AE ═ L, BC ═ DE ═ 1.5L, CD ═ 0.5L, the midpoint F of the line segment BE represents the center of gravity of the ship, and the direction of FA represents the heading of the ship.
Let L be the actual length and width of the target vesselTxAnd LTyCourse of the target ship is thetaTThe coordinate of one point in the pentagon is (x)TS,yTS) Transforming the coordinate point from the radar coordinate system to the ground coordinate system by using the following formula, wherein the transformed coordinate is represented by the following formula:
according to the formula, the position and course state condition of each target ship can be determined under the polar coordinate system determined by the position and course of the ship.
Step four, resolving the relative position relation between each point on the radar scanning line and the target ship, and determining the amplitude value of each point on the scanning line
Considering factors such as the number of lines of a circle scanned by the radar, the number of points on each scanning line, the number of target ships in a simulation scene and the like, if traversing all the scanning points and judging whether each point is positioned in a pentagon representing each target ship one by one, the calculated amount is huge, imaging information provided for a display and control console by radar simulation echoes is seriously influenced, and even a simulation process is caused to be stuck.
In order to solve the problems, the invention provides a boundary data calculation method based on coordinate transformation, which reduces the calculation amount of the process and mainly comprises the following implementation steps:
step 1: and constructing a scanning line coordinate system, and determining the relative position relation between the scanning line and the target ship.
The present invention proposes the concept of a scanning line coordinate system, which is to rotate a radar coordinate system to make the currently processed scanning line point to the x-axis direction of a ground coordinate system, and fig. 4 is the radar coordinate system, and to rotate the radar coordinate system clockwise to obtain the scanning line coordinate system shown in the following fig. 5.
Taking a target ship in the scene as an example, the coordinate point of the pentagon of the outline of the target ship is transformed from the ground coordinate system to the scanning line coordinate system, and then the transformed coordinate (x) isTS_p,yTS_p) Can be calculated by the following formula:
in the above formula, phi is the included angle between the radar scanning line and the bow direction of the ship.
After the processing of the formula, the relative relationship between the scanning line currently processed and the pentagons of each target ship can be obtained, and whether the intersection points exist between the scanning line and the pentagons or not can be determined.
Step 2: and solving the coordinates of the intersection point of the scanning line being processed and the target vessel pentagon.
The coordinates of two adjacent vertexes of the pentagon are (x) obtained by the formula (5)TS_p1,yTS_p1) And (x)TS_p2,yTS_p2) If the edge intersects with the scanning line, the abscissa x of the intersection pointpsCan be represented by the following formula:
xps＝xTS_p1-yTS_p1·(xTS_p2-xTS_p1)/(yTS_p2-yTS_p1) (6)
note that: the invention does not consider the condition that the scanning line only passes through one vertex of the pentagon and is superposed with one edge of the pentagon, and when the scanning line is intersected with the pentagon, only two intersection points exist, as shown in the intersection condition under the scanning line coordinate system of figure 6.
In the manner of FIG. 5, in the scan line coordinate system, the abscissa values of the two intersection points A and B of the scan line with the target vessel are obtained using the above formula, where x is usedps_maxAnd xps_minRespectively, the abscissa (larger value) of the point B and the abscissa (smaller value) of the point a.
Step 3: updating the amplitude of each point on the scan line
The x on the scanning line currently processed can be determined by the formula (6)ps_minAnd xps_maxAll the scanning points in between are used for imaging the echo occupied by the target ship, and the amplitude values of all the points on the scanning line are updated, [ x ]ps_min,xps_max]The amplitude of each point outside the interval is 0, [ x ]ps_min,xps_max]The amplitude of each point in the interval is 255.
Through the steps 1 to 3, the relative position relation between each scanning line and all the target ships can be calculated, the two-dimensional space relation between all the scanning points and all the pentagons of the target ships does not need to be traversed, only two intersection points of the scanning lines and the pentagons need to be calculated from one-dimensional angles, the calculated amount is greatly reduced, and meanwhile, the calculation accuracy is guaranteed.
Step five, the imaging information of the radar echo is sent in a simulated mode, imaging data are intercepted, and it is guaranteed that network communication does not lose data packets
It should be noted that, in addition to the amplitude information of the scanning point described in the above step, the communication information provided by the method of the present invention for the radar display and control console further includes other real-time states such as a noise floor value, a scanning line time, a sampling distance, etc., so that the actual communication traffic is large. Considering that each network communication packet contains 1472 bytes and below, under the condition that the problem of losing the communication data packet does not usually occur, the invention intercepts the scanning line amplitude and other state information, each communication packet contains 1471 bytes of data packet, and a \ n byte is added as the ending byte of the data packet. Through the communication mode, on one hand, the influence on the communication speed caused by the fact that the received data need to be checked like TCP network communication can be avoided, on the other hand, the invention can provide echo imaging information for a plurality of display control consoles and ensure that data packets are not lost.
Step six, radar echo imaging information visualization
Besides providing echo imaging information for a radar display and control console, the invention designs a visualization function for simulating the radar echo information, the function can provide a corresponding imaging effect for the display and control console, and is also convenient for testing the real-time states of a ship and a target ship output by an echo imaging and ship navigation simulation unit, and the functions are realized by adopting the following steps:
step 1: extracting imaging data in data channel, and sampling to obtain imaging information
The multicast communication cycle of the ship navigation simulation unit is TmtsockMeanwhile, the scanning time of the radar display and control console for one week is considered as TscanThe radar of the invention simulates an echo refresh period TsimuSatisfies the following formula:
Tsimu＝0.4·Tscan (7)
the above formula realizes the pair TmtsockThe frequency of the down-sampling is higher than that of the radar display and control console, and a timely reference imaging effect can be provided for the radar display and control console.
Step 2: selecting a full-black picture as a background picture, and drawing radar echo imaging information according to pixels
The method selects a pre-made square all-black picture as a background picture of radar echo imaging, and the side length of the picture is LBKSetting a scene display scaling kBTRFor representing the number of the screen display pixels corresponding to 1 radar echo image pixel, the maximum number of pixels N that can be displayed in the radar original imagepmaxRepresented by the formula:
Npmax＝LBK/(2*kBTR+0.5) (8)
at [0, Npmax]In the interval, traversing each radar pixel point, and solving the central coordinate value of each pixel point relative to the background picture, wherein (x) is usedpix,ypix) Represented by the formula:
in the above formula: x is a radical of a fluorine atomBKAnd yBKAnd i is the traversed pixel point ID number.
The offset D of the radar echo imaging pixel corresponding to the background picture can be calculated by the following formulaoffsetNote that each pixel is determined by R, G, B values.
Doffset＝3·(LBK·(LBK-ypix-1)+xpix) (10)
By adjusting DoffsetDetermining the corresponding pixel position of each radar scanning line on the background picture, drawing imaging information on the black background picture according to the amplitude data of each scanning point on the black background picture, if the amplitude of the scanning point is 0, keeping the RGB three values of the pixel at the position of the picture to be 0, if the amplitude of the scanning point is 255, keeping the pixel at the position of the picture to be R (255), R (255) and B (0), and finally enabling the target ship to present a yellow pentagonal pattern. And by adjusting kBTRThe display radius of the radar visible area can be enlarged or reduced.
Algorithm validation examples and illustrations
In order to verify the validity and accuracy of the method of the present invention, two verification operations are performed below. The radar display control station comes from an actual bridge, radar simulation echo imaging information is provided by the method provided by the invention, and imaging visualization is realized.
1. Ship echo imaging pose comparison
The target ship imaging of the radar simulation imaging information visualization interface provided by the method of the invention and the target ship imaging received by the actual bridge radar display control console are shown in fig. 7 and 8:
comparing the two figures shows that: on one hand, the echo imaging information of the target ship generated by the method is consistent with the position and the posture of the bridge radar display control station receiving the imaging, and on the other hand, the echo imaging method provided by the invention can be used for randomly setting the imaging size of the target ship, so that the display control station can observe and debug the observation effect conveniently.
2. Scanning period verification of radar display and control console
The scanning period of the radar display and control console is 2.4 seconds, the method of the invention is utilized to continuously send simulation data of 10 different circles, the time for drawing 10 circles by the radar display and control console for imaging is counted, and the interface of the display and control console in the test process is shown in figure 9.
The results of 10 trials were counted as above and the data are shown in the following table:
TABLE 1 imaging scanning time statistical table of radar display unit
According to the data, the time of each scanning circle is 2.394 seconds and is basically consistent with the expected scanning period of 2.4 seconds, and the simulated target ship imaging method provided by the invention can provide more accurate radar simulation data for the radar display and control console.
Claims (2)
1. A target ship echo 2D imaging method for simulating a ship radar is characterized by comprising the following steps:
the method comprises the following steps: setting radar echo imaging parameters and a coordinate system, and simulating radar echoes in a scanning line mode;
step two: constructing a ship navigation simulation unit, and providing a ship simulation motion state in a multicast communication mode:
establishing a ship kinematics model under a ground coordinate system, wherein the ship motion state comprises a position (x)t,yt) Velocity v, angular velocity ω, heading θtSpecifically, the following are shown:
in the above formula: x is a radical of a fluorine atom0And y0Is a horizontal and vertical coordinate theta of the ship and the target ship at a moment0A course angle at the moment on the ship is shown, and delta t is a simulation step length;
step three: radar simulation data preprocessing:
(1) coordinate transformation
Converting the position of the target ship from the ground coordinate system to the position of the target ship in the radar coordinate system
Satisfies the following conditions:
wherein the ship is positioned at (x) in the ground coordinate system0,y0) The course of the ship is theta0The position of the target ship in the ground coordinate system is (x)T,yT)；
(2) Target vessel two-dimensional shape construction
Scaling factor k defining the imaging length and width of the target vesselxAnd kyLet L be the actual length and width of the target vesselTxAnd LTyCourse of the target ship is thetaTThe echo imaging information of the position and the posture of the target ship is represented by utilizing a pentagon, wherein the pentagon has an acute angle as an internal angle, a vertex corresponding to the internal angle of the acute angle of the pentagon represents the course of the target ship, and the coordinate of one point in the pentagon is set as (x)TS,yTS) Transforming the coordinate point from radar coordinate system to ground coordinate system, and transforming the coordinate (x)TS_g,yTS_g) Satisfies the following conditions:
step four: resolving the relative position relation between each point on a radar scanning line and a target ship, and determining the amplitude of each point on the scanning line, wherein the method comprises the following steps of:
step 1: constructing a scanning line coordinate system, and determining the relative position relation between the scanning line and the target ship:
establishing a scanning line coordinate system, wherein the scanning line coordinate system is to rotate a radar coordinate system to enable a currently processed scanning line to point to the x-axis direction of a ground coordinate system, converting coordinate points of the pentagon of the outline of the target ship from the ground coordinate system to the scanning line coordinate system, and converting a post-coordinate (x-coordinate) if an included angle between the radar scanning line and the heading direction of the ship is phiTS_p,yTS_p) Satisfies the following conditions:
after the processing of the formula, obtaining the relative relation between the scanning line currently processed and the pentagons of each target ship, namely determining whether the scanning line and the pentagons have intersection points;
and 2, step: and solving the coordinates of the intersection point of the scanning line being processed and the target vessel pentagon:
by passing
Two adjacent vertex coordinates of the pentagon are obtained as (x)TS_p1,yTS_p1) And (x)TS_p2,yTS_p2) If the edge intersects with the scanning line, the abscissa x of the intersection pointpsSatisfies the following conditions:
xps＝xTS_p1-yTS_p1·(xTS_p2-xTS_p1)/(yTS_p2-yTS_p1)
regardless of the fact that the scan line passes through only one vertex of the pentagon and the scan line coincides with one side of the pentagon, when the scan line intersects the pentagon, there are only two intersections, and when the scan line intersects the pentagon, the scan line scansIn the line-tracing coordinate system, using xps＝xTS_p1-yTS_p1·(xTS_p2-xTS_p1)/(yTS_p2-yTS_p1) Obtaining the abscissa value x of the two intersection points of the scanning line and the target shipps_maxAnd xps_min，xps_maxAnd xps_minRespectively representing a larger abscissa value and a smaller abscissa value;
and 3, step 3: and updating the amplitude of each point on the scanning line:
by xps＝xTS_p1-yTS_p1·(xTS_p2-xTS_p1)/(yTS_p2-yTS_p1) Can determine x on the scan line currently being processedps_minAnd xps_maxAll the scanning points in between are used for imaging the echo occupied by the target ship, and the amplitude values of all the points on the scanning line are updated, [ x ]ps_min,xps_max]The amplitude of each point outside the interval is 0, [ x ]ps_min,xps_max]The amplitude of each point in the interval is 255;
step five: simulating and sending radar echo imaging information, and intercepting imaging data;
step six: radar echo imaging information visualization comprises the following steps:
step 1: extracting imaging data in data channel, and sampling to obtain imaging information
Setting the multicast communication period of a ship navigation simulation unit as TmtsockThe scanning time of the radar display and control console is TscanRadar simulated echo refresh period TupdataSatisfies the following conditions:
Tupdata＝0.4·Tscan
for TmtsockSampling in a frequency reducing mode, and meanwhile refreshing frequency is higher than that of a radar display and control console;
step 2: selecting a full black picture as a background picture, and drawing radar echo imaging information according to pixels
Selecting a pre-made square all-black picture as a background picture of radar echo imaging, wherein the side length of the picture is LBKSetting a scene display zoom ratio kBTRFor representing the number of the screen display pixels corresponding to 1 radar return image pixel,the maximum number of pixels N displayable in the original image of the radarpmaxComprises the following steps:
Npmax＝LBK/(2*kBTR+0.5)
in [0, N ]pmax]In the interval, traversing each radar pixel point, solving the coordinate value of each pixel point relative to the center of the background picture by using (x)pix,ypix) Is represented by (x)pix,ypix) Satisfies the following conditions:
wherein xBKAnd yBKRespectively the coordinates of the central point of the background picture on a screen coordinate system, and i is the ID number of the traversed pixel point;
calculating the offset D of the radar echo imaging pixel corresponding to the background pictureoffset，DoffsetSatisfies the following conditions:
Doffset＝3·(LBK·(LBK-ypix-1)+xpix)
by adjusting DoffsetDetermining the corresponding pixel position of each radar scanning line on a background picture, drawing imaging information on a black background picture according to the amplitude data of each scanning point, if the amplitude of the scanning point is 0, keeping the RGB three values of the pixel at the position of the picture to be 0, if the amplitude of the scanning point is 255, making the pixel at the position of the picture to be R255, R255 and B0, enabling the target ship to present a yellow pentagonal pattern, and adjusting k to adjust the position of the pixelBTRAnd enlarging or reducing the display radius of the radar visible area.
2. The method for 2D imaging of the ship echo of the simulated ship radar as recited in claim 1, wherein the step one of the parameters comprises:
(1) number of scanning line angle equivalences Nd；
(2) Time T of one circle of radar simulation echo scanningc；
(3) Azimuth angle theta of current scan linecs；
(4) The number of points N contained in each scanning linesp；
(5) Physical distance D represented by each scanning pointpp；
(6) Timer simulation step length Tsimu；
Sending echo imaging data to a radar display and control console in a timing sending mode, wherein the number of updated scanning lines in each simulation step is Nd·Tsimu/TcThe scan lines being processed in azimuthal increments, i.e. thetacs＝k·2π/NdThe unit is radian, wherein k is the serial number of a scanning line; according to the distance N of the target ship relative to the shipspAnd DppDetermining the crossing condition of all scanning points on a scanning line and a target ship, wherein the amplitude of the scanning point of echo imaging is in two states of 0 or 255, the amplitude of the scanning point without a target is 0, the amplitude of the scanning point with the target is 255, and the amplitudes of all the scanning points are all 0 during initialization;
step one, the coordinate system is defined as:
(1) radar coordinate system: the coordinate system is the superposition of a dynamic plane rectangular coordinate system and a polar coordinate system, the origin of the coordinate system is the real-time central position of the ship, the y axis of the rectangular coordinate system is the real-time heading direction of the ship, the x axis of the rectangular coordinate system points to the starboard of the ship, the 0-degree line of the polar coordinate system is superposed with the y axis of the rectangular coordinate system, and the clockwise direction of the radar scanning direction is positive when the coordinate system is overlooked; under the coordinate system, each point has 4 variables, namely the position (x, y) under a plane rectangular coordinate system, the angle theta and the distance d under a polar coordinate system, and the initial scanning line of one circle of radar scanning is calculated from the line of 0 degree of the polar coordinate;
(2) a ground coordinate system: the coordinate system is a plane rectangular coordinate system, the origin of the coordinate system is fixed as the initial position of the ship, the x axis points to the east, and the y axis points to the north.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910261744.1A CN109932701B (en) | 2019-04-02 | 2019-04-02 | Target ship echo 2D imaging method for simulating ship radar |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910261744.1A CN109932701B (en) | 2019-04-02 | 2019-04-02 | Target ship echo 2D imaging method for simulating ship radar |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109932701A CN109932701A (en) | 2019-06-25 |
| CN109932701B true CN109932701B (en) | 2022-07-15 |
Family
ID=66989003
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910261744.1A Active CN109932701B (en) | 2019-04-02 | 2019-04-02 | Target ship echo 2D imaging method for simulating ship radar |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109932701B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110361707B (en) * | 2019-08-09 | 2023-03-14 | 成都玖锦科技有限公司 | Dynamic simulation method for motion state of radiation source |
| CN111175744B (en) * | 2019-09-20 | 2023-08-15 | 中国船舶工业系统工程研究院 | Rapid generation and scaling method for radar image |
| CN110554407B (en) * | 2019-09-25 | 2023-05-09 | 哈尔滨工程大学 | Three-dimensional point cloud imaging method for simulating laser radar for ship |
| CN111260676B (en) * | 2020-01-10 | 2023-10-17 | 大连海事大学 | Sharing method of marine target space data of shipborne radar image |
| CN111273282B (en) * | 2020-02-20 | 2023-04-14 | 西安爱生技术集团公司 | Unmanned aerial vehicle airborne radar ground scanning coverage area calculation method |
| CN112857360B (en) * | 2021-03-22 | 2022-06-17 | 哈尔滨工程大学 | Ship navigation multi-information fusion method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102736078A (en) * | 2012-07-06 | 2012-10-17 | 宁波成电泰克电子信息技术发展有限公司 | Method for processing information in ARPA (automatic radar plotting aid) in radar for digital ship |
| CN107810430A (en) * | 2015-06-17 | 2018-03-16 | 纽威莱克公司 | Millimeter wave sensor system for auxiliary of stopping |
| CN108957447A (en) * | 2018-04-16 | 2018-12-07 | 长江水利委员会水文局长江下游水文水资源勘测局 | A kind of ship base radar water boundaries method for automatic measurement |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62157584A (en) * | 1985-12-30 | 1987-07-13 | Shipbuild Res Assoc Japan | Automatic one's own ship position corrector |
| JPH0627801B2 (en) * | 1988-06-01 | 1994-04-13 | 古野電気株式会社 | Wake display device |
| JP2005055257A (en) * | 2003-08-01 | 2005-03-03 | Furuno Electric Co Ltd | Harbor surveillance radar device |
| CN101449983B (en) * | 2007-11-29 | 2014-12-10 | 深圳迈瑞生物医疗电子股份有限公司 | Scanning changing interpolation method and device of ultrasonic linear-array deflexion imaging |
| CN105260524B (en) * | 2015-09-28 | 2018-05-15 | 大连理工大学 | Ship-navigation radar two dimension echo sequence is as emulation mode under a kind of scanning mode |
| CN106556825B (en) * | 2015-09-29 | 2019-05-10 | 北京自动化控制设备研究所 | A kind of combined calibrating method of panoramic vision imaging system |
| CN105699951B (en) * | 2016-03-09 | 2018-05-29 | 中国人民解放军镇江船艇学院 | Marine radar analogue echoes method based on dem data superposition |
| CN106199555A (en) * | 2016-08-31 | 2016-12-07 | 上海鹰觉科技有限公司 | A kind of unmanned boat navigation radar for collision avoidance detection method |
| CN106353745A (en) * | 2016-11-01 | 2017-01-25 | 北京北科天绘科技有限公司 | Two-dimensional scanning device of laser radar |
| CN108226891B (en) * | 2018-01-26 | 2021-09-03 | 中国电子科技集团公司第三十八研究所 | Scanning radar echo calculation method |
| CN109239709B (en) * | 2018-08-02 | 2022-06-17 | 哈尔滨工程大学 | Autonomous construction method for local environment map of unmanned ship |
-
2019
- 2019-04-02 CN CN201910261744.1A patent/CN109932701B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102736078A (en) * | 2012-07-06 | 2012-10-17 | 宁波成电泰克电子信息技术发展有限公司 | Method for processing information in ARPA (automatic radar plotting aid) in radar for digital ship |
| CN107810430A (en) * | 2015-06-17 | 2018-03-16 | 纽威莱克公司 | Millimeter wave sensor system for auxiliary of stopping |
| CN108957447A (en) * | 2018-04-16 | 2018-12-07 | 长江水利委员会水文局长江下游水文水资源勘测局 | A kind of ship base radar water boundaries method for automatic measurement |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109932701A (en) | 2019-06-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109932701B (en) | Target ship echo 2D imaging method for simulating ship radar | |
| CN102129795B (en) | Airborne weather radar teaching simulation system | |
| US9330504B2 (en) | 3D building model construction tools | |
| KR101229283B1 (en) | Method and system for visualising virtual three-dimensional objects | |
| CN102346922B (en) | Space remote sensing load imaging geometric distortion three-dimensional visualization simulation method | |
| CN111459132A (en) | Evaluation method and system for navigation function of ship | |
| CN105260524B (en) | Ship-navigation radar two dimension echo sequence is as emulation mode under a kind of scanning mode | |
| CN106556822A (en) | Spaceborne Sliding spotlight SAR pointing accuracy Orbital detection method | |
| CN108109460A (en) | Equipment is visited in a kind of teaching with augmented reality chemical plant | |
| CN112286079A (en) | High fidelity unmanned aerial vehicle avionics semi-physical scene simulation system | |
| CN105467368A (en) | Multi-receiver equidistant rectangular distribution-based SAR deception jamming method and system | |
| CN106067160B (en) | Large screen merges projecting method | |
| US11548598B2 (en) | Image generating device and method of generating image | |
| CN110471061A (en) | A kind of emulation mode and its system for realizing airborne synthetic aperture radar imaging | |
| CN106772324A (en) | A kind of method of underwater sound signal simulation, underwater sound signal simulator and Imaging sonar | |
| JP2011102736A (en) | System and method of tracking diastrophism | |
| CN105427371B (en) | The method that the elemental areas such as Drawing Object are shown is kept in a kind of three-dimensional perspective projection scene | |
| WO2019012315A1 (en) | Method of generating an augmented reality environment | |
| Kalman | An underdetermined linear system for gps | |
| Im et al. | A Script Hook-based Ultra-Low Cost Driving Simulator for Development of Self-Driving Algorithms | |
| RU124021U1 (en) | DEVICE FOR PREPARING OPERATORS FOR SEARCHING AND CLASSIFICATION OF SUNWATED OBJECTS | |
| CN115035270B (en) | Swivel bridge simulation system and detection method for unmanned aerial vehicle lidar | |
| Naus et al. | Dynamic perspective projection for presentation of the geometrical information about the geographical environment | |
| CN115880973B (en) | Flight simulator view generation method, device and equipment of pseudo spherical coordinate system | |
| JPH04267284A (en) | Simulated visibility device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |