CN102540224A - Fishing net tracker based on automatic ship identification technology and method thereof - Google Patents

Abstract

The invention provides a fishing net tracker based on ship automatic identification technology, which is characterized in that it includes a digital baseband system connected to a GPS antenna and connected to an AIS antenna through a high-frequency modulator and a power amplifier; The management module supplies power to the digital baseband system, high frequency modulator and power amplifier respectively. Adopt an AIS-compatible communication protocol, and represent itself as an AIS vessel, work with a longer transmission interval, and transmit AIS standard messages to fishing boats and surrounding ships, and fishing boats can use any AIS-compatible equipment already equipped to realize their position The monitoring realizes the long-distance tracking of the fishing net, even if the fishing net leaves the line of sight, it can be recovered.

Description

Fishing net tracker and its method based on ship automatic identification technology

technical field

The invention relates to the fields of pelagic fishery production and maritime safety, and mainly serves for the tracking of fishing nets in salvage operations of pelagic fishing boats.

Background technique

Ocean fishing operations are intensive and dangerous. With the improvement of various fishery regulations, trawling operations are gradually replaced by free netting operations. Every time an ocean fishing boat goes out to sea, an ocean fishing boat will carry 5 to 8 large fishing nets. The net range reaches 3 to 5 nautical miles. Fishing nets float on their own with ocean currents, and it is easy to lose fishing nets. However, the price of fishing nets is becoming more and more expensive. Fishermen spend most of their working time at sea on guarding the fishing nets. The main way of guarding is the original "watching", and at night, it is assisted by the light of fishing net lights. In bad weather, the traditional "watch" and lights cannot meet the demand. Once the fishing net floats out of the line of sight, it is very easy to lose.

At the same time, the coastal traffic is getting more and more busy, often passing through the fishing grounds, and it is often difficult for large ships to notice the fishing nets when they pass by. Fishing nets are often towed, and fishing nets entangle the propellers, which brings great economic losses to fishermen and passing ships, causing disputes .

Based on the above requirements, ocean fishing urgently needs a technology and equipment that can reduce the intensity of fishing net guarding operations, implement equipment for tracking fishing nets, and realize simultaneous visibility of passing ships, thereby reducing the occurrence of incidents of ships dragging fishing nets.

Contents of the invention

The technical problem to be solved by the present invention is to provide a fishing net tracker based on ship automatic identification technology and its method, which sends the current position of the fishing net to fishing boats and other passing ships, so that these ships can know the current position of the fishing net through standard AIS equipment information.

The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a fishing net tracker based on automatic ship identification technology, characterized in that it includes a digital baseband system connected to a GPS antenna, and through a high-frequency modulator 1. The power amplifier is connected with the AIS antenna; the battery supplies power to the digital baseband system, the high-frequency modulator and the power amplifier respectively through the power management module.

According to the above scheme, the digital baseband system includes: a GPS module for receiving position and speed information; a microcontroller and a baseband processor for packaging position, speed tracker identification number and name to generate AIS baseband data packets; The microcontroller controls the high-frequency modulator to generate the required high-frequency carrier signal, and at the same time controls the baseband processor to generate the baseband signal. After the baseband signal and the carrier signal are mixed and amplified by the power amplifier, they are transmitted through the AIS antenna; The device obtains position, speed and direction information from the GPS module.

According to the above solution, the baseband processor, GPS module, high frequency modulator and power amplifier are respectively controlled by the microprocessor through the triode.

According to the above solution, the digital baseband system, high-frequency modulator, power amplifier, battery and power management module are all arranged in a sealed casing and installed on the supporting floating equipment of the fishing net.

According to the above-mentioned scheme, the described microprocessor selects low-power consumption processor STM32F103RBT6 for use.

The fishing net tracking method based on the ship automatic identification technology is characterized in that: it comprises the following steps:

1) Set the sleep clock, and only keep the current location information in the sleep state;

2) Judging whether the voltage is too low, if it is too low, continue to sleep;

3) Send a frequency locking command to the VCO locking part, instructing it to lock the frequency on the AIS dedicated frequency, and perform voltage bias on the power amplifier to make the power amplifier work;

4) GPS positioning search, after successful positioning, transmit GPS signal to receive position and speed information;

5) Pack the position and speed information received by the GPS module to generate AIS baseband data packets, and send them through the AIS network.

The sleep clock is 32.768KHZ.

The working process of the present invention is as follows: the GPS module provides position and speed information to the microcontroller, and the microcontroller and the baseband processor package the above information with static information such as the tracker identification number and name to generate AIS baseband data packets, which are then modulated by high frequency The modulation of the device generates a high-frequency signal of 161.975/162.025MHZ, which is amplified by the power amplifier and radiated by the AIS antenna to realize long-distance transmission. The power management module supplies power to each module starting from battery power supply.

After the fishing net tracker system is started, first judge whether the power supply voltage is too low, if it is too low, the system will be hibernated to protect the battery and prevent the battery from being over-discharged; if the battery voltage meets the requirements, the frequency will be adjusted through the VCO Lock, lock the frequency on the AIS dedicated frequency (162MHz); then perform voltage bias on the power amplifier to make the power amplifier work; then the GPS module starts to search for location, if the location is successful, it will transmit GPS information, if the location fails, it will relocate ; After the launch is successful, the system sleeps for 3 minutes, and then restarts.

The beneficial effects of the present invention are:

1. The present invention adopts a communication protocol compatible with AIS, and represents itself as an AIS ship, works with a longer transmission interval, and transmits AIS standard messages to fishing boats and surrounding ships, and fishing boats can use any AIS compatible equipment that has been equipped Realize the monitoring of its position, and realize the long-distance tracking of the fishing net, even if the fishing net is out of the line of sight, it can be recovered.

2. The microcontroller uses a low-power processor STM32F103RBT6. Except for the microcontroller, all other electrical components are powered by triodes. In sleep mode, the power is completely cut off; the microcontroller enters sleep mode regularly, using 32.768KHZ As a sleep clock, a small amount of current position information is kept, and the power consumption is reduced to 50uA.

3. The VCO frequency generation circuit uses the LMX2332 chip to quickly lock it, which can reduce the VCO lock time to 500us, thereby reducing the lock power consumption.

3. Compatible with the existing AIS equipment on the fishing boat, which reduces the difficulty of configuring the whole system.

4. It can reflect the position of fishing nets to passing ships and reduce the risk of navigation.

Description of drawings

FIG. 1 is a system composition diagram of an embodiment of the present invention.

Figure 2 is a schematic diagram of the microcontroller circuit.

Figure 3 is a circuit diagram of the baseband processor.

Figure 4 is a circuit diagram of a high frequency modulator.

Figure 5 is a circuit diagram of the GPS module.

Figure 6 is a circuit diagram of a power amplifier.

FIG. 7 is a circuit diagram of the power management module.

Fig. 8 is a working example diagram of the present invention.

Fig. 9 is a flowchart of the present invention.

Detailed ways

As shown in Figure 1, this embodiment includes a digital baseband system, the digital baseband system is connected to the GPS antenna, and is connected to the AIS antenna through a high-frequency modulator and a power amplifier; power amplifiers and power amplifiers. The digital baseband system includes: a GPS module for receiving position and speed information; a microcontroller and a baseband processor for packaging position, speed tracker identification number and name to generate AIS baseband data packets; the GPS antenna, GPS module , a microcontroller, a baseband processor and the high frequency modulator are connected in sequence.

Figure 2 is the schematic diagram of the microcontroller circuit, which uses a low-power processor STM32F103RCT6, in low-power mode, the power consumption can be reduced to 3uA, while maintaining 20 bytes of memory storage space. As shown in the figure, STM32F103RCT6 pins 5 and 6 need to be connected to a special crystal oscillator. Usually, a 10P characteristic impedance 32768KHZ is used. Here, a 6P characteristic impedance 32768KHZ crystal oscillator is used, which can reduce the standby power consumption from 100uA to 1uA, thus prolonging the service life of the device. Adverse effects are: 1 to 2 startup failures in 100 startups, but it does not affect the overall use of the machine.

Figure 3 is the circuit diagram of the baseband processor. The baseband processor used is dedicated to this field. It has high power consumption and is prone to errors in sleep mode. In order to effectively reduce its power consumption, a dedicated power-off circuit is specially designed to ensure In mode it consumes no power at all. As shown in Figure 3, the system power supply network is cmx7042_3.3V_, which is controlled by the Q6SI2301i P-type FET in Figure 7. Special attention is that the clock frequency of the main chip CMX7042L4 must use an active crystal oscillator to achieve the 3PPM stability required by AIS. But in sleep mode, the active crystal oscillator of CMX7042L4 must be powered off together with the main chip to reduce power consumption. The power consumption of the active crystal oscillator is about 1mA, and it must be powered off during sleep.

Figure 4 is a circuit diagram of a high-frequency modulator, using a typical VCO circuit. In order to reduce power consumption, in addition to designing a sleep power switch, a special matching value is used in the circuit so that even in normal working conditions, the power consumption can reach the lowest . As shown in Figure 4, the main oscillation tube is Q25, the model is NXP's BFR540, R274 and R180 are clamping diodes, so that Q25 is in the amplified state, by increasing the value of R274 and R180, the VCO locking current is reduced, but the VCO is extended Since the VCO is mainly in a dormant working state, this improvement does not affect the actual work, but additional processing is required in the program to wait for the VCO to be locked before launching.

Figure 5 is a circuit diagram of the GPS module, which uses a low-power GPS module and adds a power switch. When the GPS module is in use, special technical means are required to reduce its power consumption. In the system, the power consumption of GPS positioning accounts for 80% of the power consumption of the whole system. Under normal circumstances, GPS power consumption is divided into two states, 25mA for satellite search state, and 10mA for normal work after search. For fishnet trackers that work intermittently, the GPS is mostly in a broken state. Starting from the power-off state, GPS is divided into cold start and hot start. The cold start time is longer, about 2 minutes; the hot start is faster, about 30 seconds. There are two situations in which hot start can be realized. One is that the power-off time is short, about 20 seconds, and it will enter cold start after 20 seconds; start state. In order to make it enter the hot start, the MCU can read the ephemeris status output by the GPS module after GPS positioning, and save it in the 20-byte backup space mentioned above; If the ephemeris is input into the GPS module, the GPS module can quickly enter the hot start state, thereby reducing the search time and power consumption.

Figure 6 is the circuit diagram of the power amplifier. The RF5110G radio frequency power amplifier module is used. The independent power switch makes it completely powered off in sleep mode. The module starts only when the transmission is about to start and the VCO is completely locked, which minimizes the power consumption. its power consumption.

FIG. 7 is a circuit diagram of the power management module.

When in use, the digital baseband system, high-frequency modulator, power amplifier, battery and power management module are all arranged in a sealed casing and installed on the supporting floating equipment of the fishing net.

Fig. 9 is a flow chart of the present invention, and it comprises the following steps:

1) Set the sleep clock to 32.768KHZ, and only keep the current location information in the sleep state;

2) Judging whether the voltage is too low, if it is too low, continue to sleep;

3) Issue a frequency locking command to lock the frequency on the AIS dedicated frequency, and perform voltage bias on the power amplifier to make the power amplifier work;

4) GPS positioning search, after successful positioning, transmit GPS signal to receive position and speed information;

5) Pack the position and speed information received by the GPS module to generate AIS baseband data packets, and send them through the AIS network.

As shown in Figure 8, the working mode of the fishnet tracker has the following components: several fishnet trackers, AIS terminals carried by fishing boats and AIS terminals carried by other ships.

The specific working process is as follows:

1. The fishing net tracker adopts the same working mode as the AIS ship, adopts the standard login network mode to enter the AIS communication system, and sends the No. 19 message including the name, length and width, position and speed to other ships, and only the position and speed Message No. 18 of the message.

2. The terminal of the fishing boat receives the signal of the tracker, analyzes its position and name, so as to prevent confusion with its non-own fishing net, and know its exact distance and movement speed, and judge whether it drifts.

3. Passing ships can resolve the fishing net into a specific ship, so as to achieve avoidance.

Claims (7)

1. A fishing net tracker based on ship automatic identification technology, characterized in that: it includes a digital baseband system, the digital baseband system is connected with the GPS antenna, and is connected with the AIS antenna by a high-frequency modulator, a power amplifier; The modules power the digital baseband system, high frequency modulator and power amplifier respectively. 2. the fishing net tracker based on ship automatic identification technology according to claim 1, is characterized in that: described digital baseband system comprises: be used for receiving the GPS module of position and speed information; Be used for position, speed tracker The identification number and name are packaged to generate the microcontroller and baseband processor of the AIS baseband data packet; the microcontroller controls the high-frequency modulator to generate the required high-frequency carrier signal, and simultaneously controls the baseband processor to generate the baseband signal, and the baseband After the signal and carrier signal are mixed and amplified by the power amplifier, they are transmitted through the AIS antenna; the microcontroller obtains position, speed, and direction information from the GPS module. 3. The fishing net tracker based on ship automatic identification technology according to claim 2, characterized in that: said baseband processor, GPS module, high-frequency modulator and power amplifier are controlled by a microprocessor through a triode respectively. 4. the fishing net tracker based on ship automatic identification technology according to claim 1, is characterized in that: described digital baseband system, high-frequency modulator, power amplifier, battery and power management module are all arranged in the sealed casing and Installed on the flotation equipment supporting the fishing net. 5. The fishing net tracker based on ship automatic identification technology according to claim 3, characterized in that: said microprocessor selects low power consumption processor STM32F103RBT6. 6. the fishing net tracking method based on the automatic identification technology of ships, is characterized in that: it comprises the following steps: 1) Set the sleep clock, and only keep the current location information in the sleep state; 2) Judging whether the voltage is too low, if it is too low, continue to sleep; 3) Issue a frequency lock command to lock the frequency on the AIS dedicated frequency, and make a voltage bias to the power amplifier to make the power amplifier work; 4) GPS positioning search, after successful positioning, transmit GPS signal to receive position and speed information; 5) Pack the position and speed information received by the GPS module to generate AIS baseband data packets, and send them through the AIS network. 7. The fishing net tracking method based on ship automatic identification technology according to claim 6, characterized in that: the sleep clock is 32.768KHZ.

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