Multi-source high-precision adaptive pulse timing control system and method

Abstract

The application provides a multi-source high-precision adaptive pulse timing control system and method, and solves the problems of poor underwater acoustic positioning accuracy of a towed detection system and fixed timing parameters that cannot adapt to environmental changes.The system comprises a towed platform, an underwater towed fish, a multi-reference source terminal, an environment sensing module, an optical-electric transmission module and a timing control unit.The towed platform is used for providing energy and power for the towed detection system.The multi-reference source terminal is used for providing timing reference for the timing control unit in different stages of task execution of the towed detection system.The environment sensing module is used for outputting environmental parameters of the system in real time.The optical-electric transmission module is used for transmitting RS-422 level pulse signals in the form of optical signals between the towed platform and the underwater towed fish.The timing control unit comprises a towed platform timing control unit and an underwater towed fish timing control unit.

Description

Technical Field

[0001] This invention relates to the field of timing control technology for underwater acoustic equipment in towed detection systems, specifically a multi-source high-precision adaptive pulse timing control system and method. Background Technology

[0002] Towed detection systems have become a significant research focus for major countries worldwide in recent years, particularly in military applications. These systems also possess non-combat capabilities such as deep-sea search and rescue and seabed exploration. A towed detection system primarily consists of a towed platform and an underwater towed fish, connected by an electro-optical composite tow cable. The system's main principle involves scanning and imaging a three-dimensional area from a certain depth to the seabed using side-scan sonar, synthetic aperture sonar, forward-looking sonar, and gap-filling sonar mounted on the towed fish. Underwater acoustic beacons are used for precise target localization within this three-dimensional space, supplemented by depth sensors, altimeters, and collision avoidance sonar for safety protection. However, the simultaneous operation of numerous underwater acoustic devices can lead to mutual interference due to uncontrolled sound emission sequences, resulting in degraded sonar imaging quality and impacting the performance of the towed detection system.

[0003] The existing solution involves first specifying that each type of underwater acoustic device uses the rising edge of a standard RS-422 level pulse as the sound control signal, and then installing a synchronization module on both the towed platform and the underwater towed fish to control the pulse timing of each device. However, this approach generally suffers from two problems: first, the control accuracy is not high. Traditional pulse control accuracy is typically at the millisecond level, while the underwater acoustic positioning error corresponding to each millisecond is approximately 1.5 meters, which significantly impacts the detection accuracy of the towed detection system; second, as factors such as different sonar range settings, the height of the towed platform and towed fish above the seabed, and the depth of the towed fish change, a fixed set of timing control parameters cannot meet the requirements, necessitating frequent manual issuance of different parameters to adapt to varying operating conditions. Summary of the Invention

[0004] To overcome these problems, this invention proposes a multi-source high-precision adaptive pulse timing control system and method, which solves the problems of poor underwater acoustic positioning accuracy and the inability of fixed timing parameters to adapt to environmental changes in towed detection systems.

[0005] The present invention is achieved through the following technical solution.

[0006] A multi-source high-precision adaptive pulse timing control system includes: a towed platform, an underwater towed fish, a multi-reference source terminal, an environmental sensing module, a photoelectric transmission module, and a timing control unit;

[0007] The towed platform provides energy and power to the towed detection system; the multi-reference source terminal provides timing references to the timing control unit at different stages of the towed detection system's task execution; the environmental sensing module outputs the system's environmental parameters in real time; and the photoelectric transmission module transmits RS-422 level pulse signals between the towed platform and the underwater towed fish using optical signals.

[0008] The timing control unit includes a towed platform timing control unit and an underwater towed fish timing control unit. The towed platform timing control unit has two input channels, which receive 1pps pulse signals from the Beidou terminal and the UUV, respectively. The output channel is connected to the pulse input interface of multiple underwater acoustic devices on the towed platform and the optical transceiver. The underwater towed fish timing control unit has one input channel, which is connected to the pulse signal output by the optical transceiver. The output channel is connected to multiple underwater acoustic devices on the underwater towed fish. The underwater towed fish timing control unit is used to calculate the pulse timing parameters of each output channel in real time according to the environmental parameters provided by the environmental sensing module, and control the sound emission timing of each underwater acoustic device according to the parameters.

[0009] as well as:

[0010] A multi-source high-precision adaptive pulse timing control method includes the following steps:

[0011] Step 1: Power on and initialize the drag system, and complete the configuration of the local clock, timer, and Ethernet interface;

[0012] Step 2: The timing control unit of the towing platform is configured with two input pulse detection ports, which are detected by rising edge triggering interrupt mode; it is configured with four output ports, which initially output a low level. The output signal of the fourth output channel is transmitted to the optical transceiver of the underwater fish tower through the photoelectric transmission module.

[0013] Step 3: The timing control unit for underwater fish towing is configured with one input pulse detection port, the output signal of the optical transceiver is used as the signal source, and the rising edge triggers the interrupt detection. It is configured with four output ports to connect to four underwater acoustic devices, and the initial output is low level.

[0014] Step 4: Initialize the timing control unit with default parameters, including the frequency, period, pulse width, and delay of each signal source channel and output channel;

[0015] Step 5: The environmental perception module acquires the environmental parameters of the system in real time, including the profile sound velocity, the height of the towed fish from the seabed, the towed fish depth, and the sonar setting range and frame rate, and transmits the environmental parameters to the towing platform timing control unit and the underwater towed fish timing control unit.

[0016] Step 6: Depending on the different stages of the task, the timing control unit of the towing platform determines whether to use the Beidou pulse signal or the UUV pulse signal as the system timing reference.

[0017] Step 7: The timing control unit of the towing platform and the timing control unit of the underwater towed fish calculate the signal coverage time domain range of each underwater acoustic device based on the acquired environmental parameters, and plan the occurrence order and delay of each underwater acoustic device within one second cycle, thereby obtaining the optimized control parameters of each output pulse.

[0018] Step 8: Continuously acquire environmental parameters and calculate output channel control parameters. When the control parameters change to the set threshold, change the output channel pulse timing according to the corrected parameters.

[0019] The beneficial effects of this invention are:

[0020] 1. This invention uses an interrupt method to detect multi-source pulse signals and uses CPU hardware to precisely calibrate the time t0, thereby improving initial accuracy;

[0021] 2. The present invention uses a photoelectric transmission module to synchronize the timing control unit of the towing platform and the timing control unit of the underwater towing body, with a timing accuracy better than 1µs;

[0022] 3. This invention uses a high-precision timer to control the pulse signals of each output channel, while optimizing the control logic to improve operating efficiency;

[0023] 4. This invention uses multiple signal sources as system reference pulses, and in different task modes of the towed detection system, it controls the timing of multiple channel pulse signals on the towed platform and the underwater towed fish with high precision.

[0024] 5. This invention monitors the environmental conditions of the entire system in real time, calculates the optimal control parameters based on parameters such as sonar range, frame rate, sound speed, tow distance from the seabed, and tow depth, and then adaptively controls multiple underwater acoustic devices to work in the most reasonable sequence to achieve autonomous control.

[0025] 6. The present invention uses an environmental perception module to obtain the environmental parameters of the entire system in real time, including the profile sound velocity, the height of the towed fish from the seabed, the towed fish depth, and the sonar setting range and frame rate, etc. The timing control unit calculates the optimal working timing of each underwater acoustic device in the entire system based on the real-time status parameters through modeling. Based on this timing, the frequency, period, pulse width, delay, etc. of the pulse signal of each output channel are controlled to ultimately eliminate or reduce mutual interference.

[0026] 7. This invention enables the towed detection system to achieve stable, efficient, and autonomous timing control of underwater acoustic equipment in complex and variable underwater environments. This innovative control system provides a technical route for towed detection system equipment and is expected to bring wider applications in deep-sea exploration, underwater military detection, and other fields. Attached Figure Description

[0027] Figure 1This is a structural diagram illustrating a specific embodiment of the multi-source high-precision adaptive pulse timing control system of the present invention.

[0028] Figure 2 This is a flowchart of a multi-source high-precision adaptive pulse timing control method according to the present invention;

[0029] Figure 3 This is a timing control example of a multi-source high-precision adaptive pulse timing control method according to the present invention. Detailed Implementation

[0030] Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that the embodiments shown and described in the drawings are merely exemplary and are intended to illustrate the principles and spirit of the present invention, and are not intended to limit the scope of the present invention.

[0031] like Figure 1 As shown, the present invention provides a multi-source high-precision adaptive pulse timing control system, which specifically includes: a towing platform, an underwater towed fish, a multi-reference source terminal, an environmental sensing module, a photoelectric transmission module, and a timing control unit.

[0032] The towing platform is used to provide energy and power for the towed detection system; in specific implementations, the towing platform can take various forms such as a towing mother ship and an underwater towing platform.

[0033] The multi-reference source terminal is used to provide timing references for the timing control unit at different stages of the towed detection system's mission. In specific implementation, the multi-reference source terminal adopts a Beidou terminal and a UUV, which are placed on the towed platform. Both can output a standard RS-422 level 1pps second pulse signal. The signal parameters are usually a frequency of 1Hz, a duty cycle of 50%, and a differential amplitude of 7V or more.

[0034] The environmental perception module is used to output the environmental parameters of the system in real time. In this embodiment, the environmental perception module includes a collision avoidance sonar, an underwater acoustic array, and an altimeter. The environmental parameters include the profile sound velocity, the distance of the towed fish from the seabed, the depth of the towed fish, and the sonar setting range and frame rate. The sound velocity varies with seawater temperature, salinity, and depth. The sound waves emitted by the sonar and the underwater acoustic positioning beacon are affected by the sound velocity, so the change in sound velocity must be considered. The distance of the towed fish from the seabed, the depth of the towed fish, and the sonar setting range and frame rate determine the target scale and position accuracy represented by the sonar image.

[0035] The photoelectric transmission module is used to transmit RS-422 level pulse signals between the towing platform and the underwater towed fish, ensuring that both use the same pulse reference as the control timing time t0. In specific implementation, the photoelectric transmission module adopts a photoelectric composite towing cable and is installed on a pair of optical transceivers on the towing platform and the underwater towed fish.

[0036] The timing control unit includes a towed platform timing control unit and an underwater towed fish timing control unit. The towed platform timing control unit has two input channels, receiving 1pps pulse signals from the Beidou terminal and the UUV respectively, and its output channel is connected to the pulse input interface of multiple underwater acoustic devices on the towed platform and the optical transceiver. The underwater towed fish timing control unit has one input channel, connected to the pulse signal output from the optical transceiver, and its output channel is connected to multiple underwater acoustic devices on the underwater towed fish. The underwater towed fish timing control unit is used to calculate the pulse timing parameters of each output channel in real time based on the environmental parameters provided by the environmental sensing module, and control the sound emission timing of each underwater acoustic device according to the parameters. In this embodiment, the pulse timing parameters include frequency, delay, pulse width, etc.; the underwater acoustic devices include side-scan sonar, forward-looking sonar, underwater acoustic positioning beacon, and altimeter.

[0037] like Figure 2 As shown, the multi-source high-precision adaptive pulse timing control method of the present invention specifically includes the following steps:

[0038] Step 1: Power on and initialize the towing system, and complete the configuration of the local clock, timer, and Ethernet interface; in this embodiment, the timer is set to 1µs.

[0039] Step 2: The timing control unit of the towed platform is configured with two input pulse detection ports. In this embodiment, the Beidou terminal is used as the signal source by default, and the rising edge triggers the interrupt method for detection. It is configured with four output ports, initially outputting a low level. The output signal of the fourth output channel is transmitted to the optical transceiver of the underwater fish tower through the photoelectric transmission module.

[0040] Step 3: The timing control unit for underwater fish towing is configured with one input pulse detection port, the output signal of the optical transceiver is used as the signal source, and the rising edge triggers the interrupt detection. It is configured with four output ports to connect to four underwater acoustic devices, and the initial output is low level.

[0041] Step 4: Initialize the timing control unit with default parameters, including the frequency, period, pulse width, and delay of each signal source channel and output channel;

[0042] Step 5: The environmental perception module acquires the environmental parameters of the system in real time, including the profile sound velocity, the height of the towed fish from the seabed, the towed fish depth, and the sonar setting range and frame rate, and transmits the environmental parameters to the towing platform timing control unit and the underwater towed fish timing control unit.

[0043] Step 6: Depending on the different stages of the task, the timing control unit of the towing platform determines whether to use the Beidou pulse signal or the UUV pulse signal as the system timing reference.

[0044] Step 7: The timing control unit of the towing platform and the timing control unit of the underwater towed fish calculate the signal coverage time domain of each underwater acoustic device based on the acquired environmental parameters, and plan the occurrence order and delay of each underwater acoustic device within a one-second cycle, thereby obtaining the optimized control parameters for each output pulse; in specific implementation, the standard for judging the rationality of the optimized control parameters is: during the time period after each underwater acoustic device emits its own sound wave and receives the echo, no echo from other devices arrives at the same time;

[0045] like Figure 3 As shown in this embodiment, after calculating the signal coverage time domain range of each underwater acoustic device, if the calculation results cannot satisfy that the signal coverage time domain ranges of each underwater acoustic device are completely staggered, the output channel parameters are determined according to the following priority order: collision avoidance sonar > side scan sonar > forward-looking sonar > underwater acoustic positioning beacon > underwater array > towed fish altimeter > towed platform altimeter.

[0046] Step 8: Continuously acquire environmental parameters and calculate output channel control parameters. When the control parameters change to the set threshold, change the output channel pulse timing according to the corrected parameters. This method can eliminate or reduce mutual interference between devices.

[0047] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A multi-source high-precision adaptive pulse timing control system, characterized in that, include: Towing platform, underwater fish towing, multi-reference source terminal, environmental sensing module, photoelectric transmission module, timing control unit; The towed platform provides energy and power to the towed detection system; the multi-reference source terminal provides timing references to the timing control unit at different stages of the towed detection system's mission; the environmental sensing module outputs real-time environmental parameters of the system, including collision avoidance sonar, underwater acoustic array, and altimeter; these environmental parameters include profile sound velocity, towed fish height from the seabed, towed fish depth, and sonar range and frame rate; the photoelectric transmission module transmits RS-422 level pulse signals between the towed platform and the underwater towed fish using optical signals; the timing control unit includes timing control for the towed platform. The system includes a timing control unit for the towed platform and an underwater towed fish. The timing control unit for the towed platform has two input channels, which receive 1pps pulse signals from the Beidou terminal and the UUV, respectively. The output channel is connected to the pulse input interface of multiple underwater acoustic devices and the optical transceiver on the towed platform. The timing control unit for the underwater towed fish has one input channel, which is connected to the pulse signal output from the optical transceiver. The output channel is connected to multiple underwater acoustic devices on the underwater towed fish. The timing control unit for the underwater towed fish is used to calculate the pulse timing parameters of each output channel in real time according to the environmental parameters provided by the environmental sensing module, and control the sound emission timing of each underwater acoustic device according to the parameters.

2. The multi-source high-precision adaptive pulse timing control system as described in claim 1, characterized in that, The multi-reference source terminal uses a Beidou terminal and a UUV, and is placed on the towing platform.

3. A multi-source high-precision adaptive pulse timing control system as described in claim 1 or 2, characterized in that, The photoelectric transmission module uses a photoelectric composite tow cable, which is installed between a pair of optical transceivers on the towing platform and the underwater towed fish.

4. A multi-source high-precision adaptive pulse timing control system as described in claim 1 or 2, characterized in that, The pulse timing parameters include frequency, delay, and pulse width; the underwater acoustic equipment includes side-scan sonar, forward-looking sonar, underwater acoustic positioning beacon, and altimeter.

5. A multi-source high-precision adaptive pulse timing control system as described in claim 1 or 2, characterized in that, The towing platform is either a towing mother ship or an underwater towing platform.

6. A multi-source high-precision adaptive pulse timing control method, characterized in that, Includes the following steps: Step 1: Power on and initialize the drag system, and complete the configuration of the local clock, timer, and Ethernet interface; Step 2: The timing control unit of the towing platform is configured with two input pulse detection ports, which are triggered by rising edge interrupts; it is also configured with four output ports, which initially output a low level. The output signal of the fourth output channel is transmitted to the optical transceiver of the underwater fish tower through the photoelectric transmission module. Step 3: The timing control unit for underwater fish towing is configured with one input pulse detection port, the output signal of the optical transceiver is used as the signal source, and the rising edge triggers the interrupt detection. It is configured with four output ports to connect to four underwater acoustic devices, and the initial output is low level. Step 4: Initialize the timing control unit with default parameters, including the frequency, period, pulse width, and delay of each signal source channel and output channel; Step 5: The environmental perception module acquires the environmental parameters of the system in real time, including the profile sound velocity, the height of the towed fish from the seabed, the towed fish depth, and the sonar setting range and frame rate, and transmits the environmental parameters to the towing platform timing control unit and the underwater towed fish timing control unit. Step 6: Depending on the different stages of the task, the towing platform timing control unit determines whether to use the BeiDou pulse signal or the UUV pulse signal as the system timing reference. Step 7: The timing control unit of the towing platform and the timing control unit of the underwater towed fish calculate the signal coverage time domain range of each underwater acoustic device based on the acquired environmental parameters, and plan the occurrence order and delay of each underwater acoustic device within one second cycle, thereby obtaining the optimized control parameters of each output pulse. Step 8: Continuously acquire environmental parameters and calculate output channel control parameters. When the control parameters change to the set threshold, change the output channel pulse timing according to the corrected parameters.

7. The multi-source high-precision adaptive pulse timing control method as described in claim 6, characterized in that, The criterion for judging the rationality of the optimized control parameters is: during the time period after each underwater acoustic device emits its own sound wave and receives the echo, no other device's echo arrives at the same time.

8. A multi-source high-precision adaptive pulse timing control method as described in claim 6 or 7, characterized in that, After calculating the time domain coverage of each underwater acoustic device, if the calculation results cannot satisfy that the time domain coverage of each underwater acoustic device is completely staggered, the output channel parameters are determined according to the following priority order: collision avoidance sonar > side scan sonar > forward look-ahead sonar > underwater acoustic positioning beacon > underwater array > towed fish altimeter > towed platform altimeter.

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