Ship communication system based on directional very high frequency equipment

Abstract

The utility model discloses a ship communication system based on directional very high frequency (VHF) equipment, which comprises a plurality of independent VHF transmitters, and each VHF transmitter respectively covers different areas through three groups of yagi directional antennas. When information needs to be sent to ships in a certain area, the VHF transmitter covering the area can be selected for information sending, the VHF transmitter can directionally send signals to the area through the arranged directional antenna, and interference to ships in other areas is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of arrangement of marine instruments or navigation equipment, and in particular to a ship communication system based on directional very high frequency equipment. Background Art

[0002] VHF wireless communication is an important part of the marine safety communication system. It is a communication method between ships and shores, and between ships and ships in coastal waters specified by IMO. VHF communication equipment is an indispensable emergency response facility to ensure the safety of ship navigation, and is the most effective communication method between ships and shores, and ships on the water. The traditional VHF antenna is an omnidirectional antenna, and its power transmission angle is 360° omnidirectional transmission below the horizontal. When information is frequently pushed in the whole range near the bridge area, it is easy to cause channel occupation and interfere with ships in other areas. In order to avoid channel occupation and interference, the current conventional method is to reduce the transmission frequency of VHF communication equipment, thereby reducing the coverage range and avoiding interference with ships in other areas. However, this method has the risk of being interfered by signals emitted by VHF communication equipment on other ships. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the utility model proposes a ship communication system based on directional VHF equipment, which can select the VHF transmitter covering the corresponding area to send signals in a directional manner according to the area where the signal receiving ship is located, so as to avoid interference with ships in other areas. The specific technical solution is as follows:

[0004] A ship communication system based on directional very high frequency equipment is provided. In a first possible implementation, it includes multiple VHF transmitters, all of which are provided with Yagi antennas, and each VHF transmitter covers a different area.

[0005] In combination with the first possible implementation, in a second possible implementation, the transmission frequency band of the VHF transmitter is 156.050 MHz to 163.275 MHz.

[0006] In combination with the first possible implementation, in a third possible implementation, the spacing between the components of the Yagi antenna is set according to a set spacing range, and the spacing range matches the transmission frequency band of the VHF transmitter.

[0007] In combination with the first possible implementation, in a fourth possible implementation, the distance between the reflector and the active vibrator in the Yagi antenna is 0.3 m, the distance between the active vibrator and the adjacent director is 0.2 m, and the distance between two adjacent directors is 0.3 m.

[0008] In combination with the first possible implementation, in a fifth possible implementation, the lengths of the components of the Yagi antenna are set according to a set length range, and the length range matches the transmission frequency band of the VHF transmitter.

[0009] In combination with the first possible implementation, in a sixth possible implementation, the length of the reflector in the Yagi antenna is 1 m, the length of the active vibrator is 0.9 m, and the length of the director is 0.8 m.

[0010] Beneficial effect: With the ship communication system based on directional very high frequency equipment of the utility model, each VHF transmitter covers different areas around the ship. When it is necessary to send information to ships in a certain area, the VHF transmitter covering the area can be selected to send information. The VHF transmitter can send signals to the area in a direction through the set Yagi antenna, avoiding interference with ships in other areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the specific implementation of the utility model, the following will briefly introduce the drawings required for use in the specific implementation. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0012] Figure 1 A schematic diagram of the principle of a ship communication system based on directional VHF equipment provided by an embodiment of the utility model;

[0013] Figure 2 A structural side view of a Yagi antenna provided in one embodiment of the utility model;

[0014] Figure 3 A top view of the structure of a Yagi antenna provided in one embodiment of the utility model;

[0015] Figure 4 This is the receiving gain test spectrum when the directional antenna rotation angle is 0;

[0016] Figure 5 This is the receiving gain test spectrum when the directional antenna is rotated 180 degrees;

[0017] Figure 6 Field test data for all angles;

[0018] Figure 7 Simulation test data for all angles. DETAILED DESCRIPTION

[0019] The following embodiments of the technical solution of the utility model are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the utility model, and are therefore only used as examples, and cannot be used to limit the protection scope of the utility model.

[0020] like Figure 1 The schematic diagram of the principle of the ship communication system based on directional very high frequency equipment is shown, and the communication device includes multiple VHF transmitters, all of which are equipped with Yagi antennas, and each VHF transmitter covers different areas.

[0021] Specifically, the warning area on one side of the bridge can be divided into sectors of 60°, with a total of three warning sectors on one side to achieve 180° warning area coverage. The communication device includes three independent VHF transmitters and a very high frequency radio station. These three VHF transmitters respectively use three sets of two-element dipole directional array antennas to achieve complete communication coverage with an edge coverage overlap of about 9°. When it is necessary to send information to ships in a certain area, you can choose to send information from a VHF transmitter covering the area. The VHF transmitter can send signals to the area in a directional array antenna to avoid interference with ships in other areas.

[0022] For example, the alarm area covered by 1# VHF transmitter 4 is area 1#, the alarm area covered by 2# VHF transmitter 5 is area 2#, and the alarm area covered by 3# VHF transmitter 6 is area 3#. The early warning system can determine that the location of the alarm event corresponds to the alarm area, and select the corresponding VHF transmitter to send out the alarm. When the alarm event occurs in the overlapping area between area 1# and area 2# or area 2# and area 3#, the VHF transmitter used for the alarm is selected according to the idle state of the VHF transmitter.

[0023] In this embodiment, if Figure 2 As shown, the directional array element antenna can be a Yagi antenna, which is a passive directional antenna and can be composed of an active vibrator 1, a reflector 2 and five directors 3. The reflector 2, which is slightly longer than the active vibrator 1, plays a role in reflecting energy, and the director 3, which is slightly shorter than the active vibrator 1, plays a role in guiding energy. The reflectors 2 and directors 3 on both sides of the active vibrator 1 turn the original bidirectional radiation into unidirectional radiation to improve the gain of the antenna.

[0024] In this embodiment, optionally, the transmission frequency band of the VHF transmitter can be set to a communication frequency band of 156.050 MHz to 163.275 MHz commonly used by ships.

[0025] In this embodiment, optionally, Figure 3 As shown, the spacing between the components of the Yagi antenna is set according to a set spacing range, and the spacing range matches the transmission frequency band of the VHF transmitter. Designing the spacing between the components of the Yagi antenna based on the transmission frequency band of the VHF transmitter can improve the directivity and anti-interference ability of the transmission.

[0026] Specifically, after multiple simulation experiments, the inventor concluded that the distances between the components of the Yagi antenna can be set according to the following spacing ranges:

[0027]

[0028] Where, λ is the emission wavelength of the VHF transmitter, S1 is the distance between the active oscillator 1 and the adjacent director 3 in the Yagi antenna, S D is the distance between two adjacent directors 3, S R is the distance between the reflector 2 and the active oscillator 1.

[0029] In this embodiment, optionally, the length of each component of the Yagi antenna is set according to a set length range, and the length range matches the transmission frequency band of the VHF transmitter. Designing the length of each component of the Yagi antenna based on the transmission frequency band of the VHF transmitter can further improve the directivity and anti-interference ability of the transmission.

[0030] Specifically, after multiple simulation experiments, the inventor concluded that the lengths of the various components of the Yagi antenna can be set within the following length ranges:

[0031]

[0032] Among them, l0 is the length of the active oscillator 1, l R is the length of reflector 2, l D is the length of the director 3.

[0033] In this embodiment, optionally, the distance between the reflector 2 and the active vibrator 1 in the Yagi antenna is 0.3m, the distance between the active vibrator 1 and the adjacent director 3 is 0.2m, and the distance between two adjacent directors 3 is 0.3m. The length of the reflector 2 in the Yagi antenna is 1m, the length of the active vibrator 1 is 0.9m, and the length of the director 3 is 0.8m.

[0034] Through multiple experiments, the distance between the reflector 2 and the active vibrator 1 in the Yagi antenna is set to 0.3m, the distance between the active vibrator 1 and the adjacent director 3 is set to 0.2m, and the distance between two adjacent directors 3 is set to 0.3m. The length of the reflector 2 in the Yagi antenna is set to 1m, the length of the active vibrator 1 is set to 0.9m, and the length of the director 3 is set to 0.8m. This can not only make the communication device have good transmission gain and directional characteristics, but also reduce the size of the Yagi antenna and have strong wind resistance.

[0035] In order to verify the effect of the technical solution of this embodiment, the inventor selected a certain place for actual installation test. On the day of the test, the flow rate of the nearby waters was: 16900m 3 / s, water level: 171.05, wind speed 6 km / h, humidity 80%, ship density of about 10 ships / h, which are typical hydrological and meteorological conditions and ship density of this waterway. The test results have good reference value.

[0036] The test uses vertical polarization. The simulated gain when the antenna elevation angle is 0° is known. By comparing the gain data when the antenna elevation angle is 0° with the simulated data, the directional effect of the antenna design is verified.

[0037] During the test, ensure that the antenna under test and the auxiliary transmitting antenna are at the same height and have the same polarization. The distance D between the transmitting and receiving antennas is greater than 10λ. Considering the actual inland waterway conditions, D is selected as 500 meters.

[0038] The antenna frequency range is 156MHz to 164MHz, and the typical value 156.667MHz is selected as the test frequency. During the test, a set of test data is recorded each time the antenna angle is adjusted by 10° to verify the directional effect of the antenna.

[0039] Figure 4 , Figure 5 Test spectrum for directional antenna receiving gain, such as Figure 4 As shown in the figure, when the directional antenna rotation angle is 0 degrees, that is, when the transmitting antenna is facing the receiving antenna, the receiving antenna gain is -53.875dBm. Figure 5 As shown, the rotation angle of the directional antenna is 180°, that is, when the transmitting antenna is facing away from the receiving antenna, the receiving antenna gain is -61.375dBm.

[0040] Summarize the test data of all angles, such as Figure 6 As shown, the measured results are consistent with Figure 7 The simulation results shown are quite consistent. In this embodiment, the directional angle width of the Yagi directional antenna is about 60°, which has good directional characteristics. The main lobe gain amplitude is about -53dBm, the side lobe gain amplitude is about -63dBm, and the main and side lobe gain amplitudes differ by 10dBm, which proves that the ship communication system of the present invention has good directional effect in the common frequency band of VHF communication equipment in the field of active bridge collision prevention.

[0041] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A ship communication system based on directional very high frequency equipment, characterized in that: It includes multiple VHF transmitters, all of which are equipped with Yagi antennas, and each VHF transmitter covers different areas.

2. The ship communication system based on directional VHF equipment according to claim 1, characterized in that: The transmission frequency band of the VHF transmitter is 156.050 MHz to 163.275 MHz.

3. The ship communication system based on directional VHF equipment according to claim 1, characterized in that: The spacing between the components of the Yagi antenna is set according to a set spacing range, which matches the transmission frequency band of the VHF transmitter.

4. The ship communication system based on directional VHF equipment according to claim 1, characterized in that: In the Yagi antenna, the distance between the reflector and the active vibrator is 0.3m, the distance between the active vibrator and the adjacent director is 0.2m, and the distance between two adjacent directors is 0.3m.

5. The ship communication system based on directional VHF equipment according to claim 1, characterized in that: The lengths of the various components of the Yagi antenna are set according to a set length range, which matches the transmission frequency band of the VHF transmitter.

6. The ship communication system based on directional VHF equipment according to claim 1, characterized in that: The length of the reflector in the Yagi antenna is 1 m, the length of the active vibrator is 0.9 m, and the length of the director is 0.8 m.

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