A method for measuring a radar blind area of a ship

Abstract

A kind of ship radar blind area measurement method, need to input the scale information of mother ship in workstation, take any point on the ship's waist line of mother ship as coordinate origin, along the direction of ship's waist line is X axis, ship width direction is Y axis, input the coordinate information of radar on mother ship, obtain the positioning data provided by ship differential DGPS, the heading data provided by compass and the positioning data of unmanned aerial vehicle, construct three-dimensional coordinate system.Unmanned aerial vehicle trajectory planning for radar bow blind area measurement longitudinal length and transverse width is carried out, unmanned aerial vehicle trajectory planning for radar stern blind area measurement longitudinal length and transverse width is carried out, finally generate radar bow blind area chart and radar stern blind area chart.The present application overcomes the shortcomings of high cost of tugboat, safety risk of collision between tugboat and mother ship, long test time and low test precision of existing test method.It has the advantages of low cost, short test time, not affected by sea waves, accurate positioning and high test precision.

Description

Technical Field

[0001] This invention belongs to the field of ship design and construction, specifically relating to a method for determining radar blind spots during ship navigation after the ship has been built. Background Technology

[0002] Before a ship is delivered after construction, its radar blind zone needs to be measured. Currently, this can only be done by tugboats or small boats circling the mother ship, which is time-consuming, labor-intensive, and inaccurate. Using tugboats is also very expensive and affects the ship's delivery schedule. Furthermore, during the measurement, tugboats need to navigate in the opposite direction of the ship or pass in front of it, posing a risk of collision. Therefore, there is an urgent need to develop a simple, convenient, safe, and low-cost method for measuring ship radar blind zones.

[0003] Specifically, the shortcomings of existing testing methods stem from tugboat operation, where the tugboat is used as a radar target for measurements in radar blind zones. Tugboat operation requires close-range navigation forward, side, and aft of the mother ship, and the tugboat's trajectory is easily affected by waves generated by the mother ship, leading to low testing accuracy. When the tugboat needs to navigate towards the mother ship, there is a risk of collision. Tugboat operation is also very expensive, costing approximately 20,000 yuan per test and lasting 4-8 hours. Furthermore, testing is impossible in adverse sea conditions. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for measuring the radar blind zone of a ship, aiming to achieve the goal of eliminating the need for tugboats or small boats and requiring no personnel to operate outside the mother ship. The technical solution adopted is as follows:

[0005] A method for measuring the radar blind zone of a ship, the specific measurement steps are as follows:

[0006] S1: Input the mother ship's dimensions in the workstation, take any point on the midship line of the mother ship as the origin of the coordinate system, take the direction along the midship line as the X-axis and the direction of the ship's width as the Y-axis, input the radar's coordinate information on the mother ship, obtain the positioning data provided by the ship's differential DGPS, the heading data provided by the compass, and the positioning data of the UAV, and construct a three-dimensional coordinate system including the ship's outline model, radar, and UAV.

[0007] S2: UAV trajectory planning for measuring longitudinal length of radar bow blind zone.

[0008] The starting point for UAV measurement is set 0.5 to 2 nautical miles directly forward of the bow of the ship along the midships line. The radar is turned on and its ARPA function is activated to lock onto the UAV. At this point, the UAV can be detected and tracked on the radar display. The UAV is then commanded to fly slowly along the midships line towards the stern. When the UAV target disappears from the radar display, the UAV's position A(Ax,Ay) is recorded. The distance between A(Ax,Ay) and the radar R(Rx,Ry) is the longitudinal length of the bow blind zone.

[0009] S3: UAV trajectory planning for measuring the lateral width of the radar bow blind zone.

[0010] Starting from any point between A(Ax,Ay) and radar R(Rx,Ry), plan the UAV to fly along the direction perpendicular to the midships line towards the starboard side of the ship. Turn on the radar and activate its ARPA function to lock onto the UAV. At this time, the UAV can be detected and tracked on the radar display. When the UAV target disappears from the radar display, record the UAV positioning data B(Bx,By).

[0011] The same operation causes the drone to fly perpendicular to the midships line towards the port side of the ship. When the drone target disappears from the radar display, the drone's positioning data C(Cx,Cy) is recorded. The distance between B(Bx,By) and C(Cx,Cy) is the lateral width of the bow blind zone at point S1(S1x,S1y) in front of the radar.

[0012] S4: UAV trajectory planning for measuring the longitudinal length of the radar stern blind zone.

[0013] The starting point for UAV measurement is set 0.5 to 2 nautical miles directly in front of the stern of the ship along the midships line. The radar is turned on and its ARPA function is activated so that the radar can lock onto the UAV. At this time, the UAV can be detected and tracked on the radar display. The UAV is commanded to fly slowly along the midships line towards the bow. When the UAV target disappears from the radar display, the UAV's position D(Dx,Dy) is recorded. The distance between D(Dx,Dy) and the radar R(Rx,Ry) is the longitudinal length of the stern blind zone.

[0014] S5: UAV trajectory planning for measuring the lateral width of the radar stern blind zone.

[0015] Starting from any point between point D(Dx,Dy) and radar R(Rx,Ry), take point S2(S2x,S2y). Plan the UAV to fly towards the starboard side of the ship in a direction perpendicular to the midship line. Turn on the radar and activate its ARPA function so that the radar can lock onto the UAV. At this time, the UAV can be detected and tracked on the radar display. When the UAV target disappears from the radar display, record the UAV's location data E(Ex,Ey). Perform the same operation to make the UAV fly towards the starboard side of the ship in a direction perpendicular to the midship line. When the UAV target disappears from the radar display, record the UAV's location data F(Fx,Fy). The distance between E(Ex,Ey) and F(Fx,Fy) is the lateral width of the bow blind zone at point S2(S2x,S2y) behind the radar.

[0016] S6: Generate the radar bow blind zone map based on points A(Ax,Ay), B(Bx,By), C(Cx,Cy), and R(Rx,Ry); generate the radar stern blind zone map based on points D(Dx,Dy), E(Ex,Ey), F(Fx,Fy), and R(Rx,Ry).

[0017] Furthermore, the aforementioned method for measuring the radar blind zone of a ship further incorporates theoretical values ​​of the ship's overall length, beam, depth, draft, and hull lines to form a ship profile model.

[0018] Furthermore, in the aforementioned method for measuring ship radar blind zones, the UAV is equipped with a radar corner reflector or Luneburg lens to reflect radar echoes. This allows the UAV to be identified and locked onto by the ship's S-band or X-band radar within a range of 1-2 nautical miles.

[0019] Furthermore, in the aforementioned method for measuring the radar blind zone of a ship, the mother ship is in a moored state during the measurement.

[0020] Furthermore, in the aforementioned method for measuring the blind zone of ship radar, the radar corner reflector can be replaced with a Luneburg lens or a radar signal generator.

[0021] This invention overcomes the shortcomings of existing testing methods, such as high tugboat usage costs, safety risks of collisions between tugboats and mother ships, long testing times, and low testing accuracy. It offers advantages such as extremely low cost of using drones, no need for tugboats (lower operating costs), shorter testing time (approximately one hour compared to existing solutions), drones being unaffected by sea waves, and significantly improved positioning accuracy. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the measurement method of the present invention. Detailed Implementation

[0023] A method for measuring the radar blind zone of a ship, the specific steps of which are as follows:

[0024] Step 1: With the mother ship in a moored state, input the mother ship's dimensional information, including overall length, beam, depth, draft, and hull lines, into the workstation to create a ship outline model. Take a point on the mother ship's midships line as the origin, with the midships line as the X-axis and the beam direction as the Y-axis. Input the radar's coordinate information on the mother ship. Acquire positioning data from the ship's differential DGPS, heading data from the compass, and positioning data from the UAV to construct a three-dimensional coordinate system including the ship outline model, radar, and UAV.

[0025] Step two: Plan the UAV trajectory for measuring the longitudinal length of the radar blind zone. Since the radar blind zone is usually within 1 nautical mile forward of the ship's bow, plan a point 1 nautical mile directly forward of the ship's midships as the UAV's measurement starting point. Turn on the radar and activate its ARPA function to lock onto the UAV. At this point, the radar display should be able to detect and track the UAV. Command the UAV to fly slowly towards the stern along the midships. When the UAV target disappears from the radar display, record the UAV's position A(Ax,Ay). The distance between A(Ax,Ay) and the radar R(Rx,Ry) is the longitudinal length of the bow blind zone.

[0026] Step 3: Plan the UAV trajectory for measuring the lateral width of the radar's bow blind zone. Starting from point S1(S1x,S1y) between point A(Ax,Ay) and radar point R(Rx,Ry), plan the UAV to fly perpendicular to the ship's midships line towards the starboard side. Turn on the radar and activate its ARPA function to lock onto the UAV. The UAV should then be detectable and tracked on the radar display. When the UAV disappears from the radar display, record its location data B(Bx,By). Repeat this process to make the UAV fly perpendicular to the ship's midships line towards the starboard side. When the UAV disappears from the radar display, record its location data C(Cx,Cy). The distance between B(Bx,By) and C(Cx,Cy) is the lateral width of the bow blind zone at point S1(S1x,S1y) in front of the radar.

[0027] Step four: Plan the UAV trajectory for measuring the longitudinal length of the radar stern blind zone. Since the radar blind zone is typically within 1 nautical mile forward of the ship's stern, plan a point 1 nautical mile directly ahead of the ship's midships as the starting point for the UAV measurement. Turn on the radar and activate its ARPA function to lock onto the UAV. At this point, the radar display should show and track the UAV. Command the UAV to fly slowly towards the bow along the midships. When the UAV target disappears from the radar display, record the UAV's current location D(Dx,Dy). The distance between D(Dx,Dy) and the radar's R(Rx,Ry) is the longitudinal length of the stern blind zone.

[0028] Step 5: Plan the UAV trajectory for measuring the lateral width of the radar stern blind zone. Starting from point S2(S2x,S2y) between point D(Dx,Dy) and radar R(Rx,Ry), plan the UAV to fly perpendicular to the ship's midships line towards the starboard side. Turn on the radar and activate its ARPA function to lock onto the UAV. The radar display should then be able to detect and track the UAV. When the UAV target disappears from the radar display, record the UAV's location data E(Ex,Ey). Repeat this process to make the UAV fly perpendicular to the ship's midships line towards the starboard side. When the UAV target disappears from the radar display, record the UAV's location data F(Fx,Fy). The distance between E(Ex,Ey) and F(Fx,Fy) is the lateral width of the bow blind zone at point S2(S2x,S2y) behind the radar.

[0029] Step 6: Generate the radar bow blind zone map based on points A(Ax,Ay), B(Bx,By), C(Cx,Cy), and R(Rx,Ry). Generate the radar stern blind zone map based on points D(Dx,Dy), E(Ex,Ey), F(Fx,Fy), and R(Rx,Ry).

Claims

1. A method for measuring the radar blind zone of a ship, characterized in that: The specific measurement steps are as follows: S1: Input the mother ship's dimensions in the workstation, take any point on the midship line of the mother ship as the origin of the coordinate system, take the direction along the midship line as the X-axis and the direction of the ship's width as the Y-axis, input the radar's coordinate information on the mother ship, obtain the positioning data provided by the ship's differential DGPS, the heading data provided by the compass, and the positioning data of the UAV, and construct a three-dimensional coordinate system including the ship's outline model, radar, and UAV. S2: UAV trajectory planning for measuring longitudinal length of radar bow blind zone. The starting point for UAV measurement is 0.5 to 2 nautical miles directly in front of the bow of the ship along the midships line. The radar is turned on and the ARPA function of the radar is activated so that the radar locks onto the UAV. At this time, the UAV can be detected and tracked on the radar display. The UAV is commanded to fly slowly along the midships line towards the stern. When the UAV target disappears from the radar display, the UAV position A(Ax,Ay) at this time is recorded. The distance between A(Ax,Ay) and the radar R(Rx,Ry) is the longitudinal length of the bow blind zone. S3: UAV trajectory planning for measuring the lateral width of the radar bow blind zone. Starting from any point between A(Ax,Ay) and radar R(Rx,Ry), take point S1(S1x,S1y) as the starting point. Plan the UAV to fly along the direction perpendicular to the midships line towards the starboard side of the ship. Turn on the radar and activate the radar's ARPA function so that the radar locks onto the UAV. At this time, the UAV can be detected and tracked on the radar display. When the UAV target disappears from the radar display, record the UAV's positioning data B(Bx,By). The same operation causes the drone to fly in a direction perpendicular to the midship line towards the port side of the ship. When the drone target disappears from the radar display, the drone's positioning data C(Cx,Cy) is recorded at this time. The distance between B(Bx,By) and C(Cx,Cy) is the lateral width of the bow blind zone at point S1(S1x,S1y) in front of the radar. S4: UAV trajectory planning for measuring the longitudinal length of the radar stern blind zone. The starting point for UAV measurement is set 0.5 to 2 nautical miles directly in front of the stern of the ship along the midships line. The radar is turned on and its ARPA function is activated so that the radar can lock onto the UAV. At this time, the UAV can be detected and tracked on the radar display. The UAV is commanded to fly slowly along the midships line towards the bow. When the UAV target disappears from the radar display, the UAV's position D(Dx,Dy) is recorded. The distance between D(Dx,Dy) and the radar R(Rx,Ry) is the longitudinal length of the stern blind zone. S5: UAV trajectory planning for measuring the lateral width of the radar stern blind zone. Starting from any point between point D(Dx,Dy) and radar R(Rx,Ry), take point S2(S2x,S2y). Plan the UAV to fly towards the starboard side of the ship in a direction perpendicular to the midship line. Turn on the radar and activate its ARPA function so that the radar can lock onto the UAV. At this time, the UAV can be detected and tracked on the radar display. When the UAV target disappears from the radar display, record the UAV positioning data E(Ex,Ey). Repeat the same operation to make the UAV fly towards the port side of the ship in a direction perpendicular to the midship line. When the UAV target disappears from the radar display, record the UAV positioning data F(Fx,Fy). The distance between E(Ex,Ey) and F(Fx,Fy) is the lateral width of the stern blind zone at point S2(S2x,S2y) behind the radar. S6: Generate the radar bow blind zone map based on points A(Ax,Ay), B(Bx,By), C(Cx,Cy), and R(Rx,Ry); generate the radar stern blind zone map based on points D(Dx,Dy), E(Ex,Ey), F(Fx,Fy), and R(Rx,Ry).

2. The method for measuring the blind zone of a ship's radar according to claim 1, characterized in that: The mother ship's dimensional information includes theoretical values ​​for the ship's overall length, beam, depth, draft, and hull lines, forming a ship outline model.

3. The method for measuring the blind zone of a ship's radar according to claim 1, characterized in that: Drones equipped with radar corner reflectors or Luneburg lenses can reflect radar echoes.

4. The method for measuring the blind zone of a ship's radar according to claim 1, characterized in that: The mother ship was moored during the measurement.

5. The method for measuring the blind zone of a ship's radar according to claim 3, characterized in that: Radar corner reflectors can be replaced with Luneburg lenses or radar signal generators.

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