An acoustic positioning and communication integrated method for underwater multi-platform sensors

Abstract

The application provides an acoustic positioning and communication integrated method for underwater multi-platform sensors, which comprises three working modes of a same set of underwater acoustic hardware circuit and transducer: positioning and communication integrated mode, single positioning mode and single communication mode; when the working mode is the positioning and communication integrated mode, a spread spectrum code is directly used on the I branch, and the spread spectrum code is used to modulate communication information in the BPSK mode on the Q branch; after the two-way information spread spectrum, the two-way information is synthesized and modulated to the carrier; when the working mode is the single positioning mode, the spread spectrum code is directly used to modulate the carrier signal in the BPSK mode; when the working mode is the single communication mode, the spread spectrum code is used to modulate the communication information in the BPSK mode, and then the carrier signal is modulated in the BPSK mode; finally, the working mode is judged by the judgment criterion, the single or integrated service function of the underwater acoustic positioning and communication is realized, and technical support is provided for the development and progress of the underwater network information system.

Description

Technical Field

[0001] This invention relates to the field of underwater acoustic positioning and communication technology, and in particular to an integrated acoustic positioning and communication method for underwater multi-platform sensors. Background Technology

[0002] With the proposal of the deep-sea strategic goal, venturing into the deep sea and the open ocean is an essential path for developing maritime affairs and building a maritime power. Whether in the military or civilian sectors such as deep-sea scientific research, the development of advanced equipment and technology is indispensable. AUVs, underwater gliders, unmanned surface vessels, buoys, and seabed-based equipment are widely used in marine scientific research, deep-sea resource exploration, marine engineering, and strategic high-tech fields.

[0003] Underwater positioning and communication technologies provide underwater equipment with real-time identification, communication, control, and crucial information on its spatial position, speed, and other motion status in complex marine environments, thus effectively ensuring the safety of underwater equipment navigation and successful return. Because electromagnetic waves attenuate significantly when propagating in water, and sound waves are the only known form of energy capable of long-distance propagation in water, identification, communication, positioning, and navigation in the ocean are primarily achieved using sound waves. Currently, research on underwater acoustic communication, positioning, and identification technologies mainly focuses on single technologies, with communication primarily in a point-to-point manner. There is a lack of research on multifunctional systems integrating underwater acoustic positioning and communication functions for multiple underwater platforms / sensors. Summary of the Invention

[0004] In view of this, the present invention proposes an integrated acoustic positioning and communication method for underwater multi-platform sensors, which can realize the individual or integrated service functions of underwater acoustic positioning and underwater acoustic communication, and provide technical support for the research and development of underwater networked information systems.

[0005] The technical solution of this invention is implemented as follows:

[0006] An integrated acoustic positioning and communication method for underwater multi-platform sensors includes the following steps:

[0007] Step S1: Determine the working mode, which includes integrated positioning and communication mode, standalone positioning mode, and standalone communication mode;

[0008] Step S2: When the working mode is the integrated positioning and communication mode, the spreading code is directly used on the I branch, and the spreading code is used on the Q branch to modulate the communication information in BPSK mode. The two information channels are spread and combined and then modulated onto the carrier.

[0009] Step S3: When the working mode is standby mode, the carrier signal is directly modulated by BPSK using spreading code;

[0010] Step S4, when the working mode is the single communication mode, the BPSK mode modulation communication information on the spread spectrum code, and then the BPSK modulation on the carrier signal;

[0011] Step S5, constructing a judgment criteria, according to the judgment criteria on the working mode feasibility judgment.

[0012] Preferably, the working mode is the positioning communication integration mode, the i-th node transmits the positioning communication integration signal expression is:

[0013]

[0014] Wherein is the power of the positioning signal in the integrated signal; is the spread spectrum code corresponding to the positioning signal in the integrated signal; is the carrier frequency corresponding to the integrated signal; is the phase corresponding to the integrated signal; is the power of the communication signal in the integrated signal; is the spread spectrum code corresponding to the communication signal in the integrated signal; is the communication information of the communication signal in the integrated signal.

[0015] Preferably, the working mode is the single positioning mode, the i-th node transmits the positioning signal expression is:

[0016]

[0017] Wherein is the power of the positioning signal; is the spread spectrum code corresponding to the i-th positioning signal; is the carrier frequency corresponding to the i positioning signal; is the phase corresponding to the i positioning signal.

[0018] Preferably, the working mode is the single communication mode, the i-th node transmits the positioning signal expression is:

[0019]

[0020] Wherein, is the power of the communication signal; is the spread spectrum code corresponding to the i-th communication signal; is the communication information of the i communication signal; is the carrier frequency corresponding to the i communication signal; is the phase corresponding to the i communication signal.

[0021] Preferably, the judging criteria include:

[0022] A. User number judging criteria: the number of spread spectrum codes is less than the number of users:

[0023]

[0024] where r is the number of bits of the spread spectrum code, is the expected number of users;

[0025] B. Maximum effective distance judging criteria: the carrier center frequency satisfies the sonar equation:

[0026] Gain + SL-TL-NL ≥ 0

[0027] where the gain Gain provided by the signal design, SL is the sound source level of the transducer at the carrier center frequency, TL is the propagation loss at the carrier center frequency, and NL is the noise at the carrier center frequency;

[0028] C. Communication rate judging criteria: at least one complete spread spectrum code period is contained in each communication information code, and the communication rate formula needs to satisfy:

[0029]

[0030] where, is the communication rate, is the duty cycle of the signal, is the spread spectrum code rate, and r is the number of bits of the spread spectrum code;

[0031] D. Bit error rate judging criteria: the theoretical bit error rate of BPSK signal coherent demodulation is satisfied, and the bit error rate formula is:

[0032]

[0033] where, is the bit error rate of the communication signal, is the error function, is the signal-to-noise ratio, is the communication rate;

[0034] E. Positioning accuracy judging criteria: taking 1 / 2 of the system positioning accuracy as the spatial grid point, the system theoretical positioning accuracy satisfies that the confidence interval of the required system positioning accuracy is not less than 95%, and the theoretical positioning accuracy formula is:

[0035]

[0036] where, is the average sound speed, is the spread spectrum code rate, , , The definitions are as follows:

[0037]

[0038] The definitions are as follows:

[0039]

[0040] represent the spatial coordinate position of the mth transmitting beacon, represent the position of the mth receiving beacon. Preferably, the specific steps of the step S5 are as follows:

[0041] Step S51, when the working mode is the positioning and communication integrated mode, the feasibility is judged by using the judging criteria A, B, C, D and E.

[0042] Step S52, when the working mode is the single positioning mode, the feasibility is judged by using the judging criteria A, B, C and E.

[0043] Step S53, when the working mode is the single communication mode, the feasibility is judged by using the judging criteria A, B, C and D.

[0044] Preferably, the three working modes share the same set of underwater acoustic hardware circuit and transducer.

[0045] Preferably, the spread spectrum code uses Gold sequence code, chaotic sequence code or pseudo-random code.

[0046] Preferably, the method further comprises the step S6, after the feasibility is judged to be passed, clock synchronization is performed.

[0047] Compared with the prior art, the method has the beneficial effects that:

[0048] The method provides an acoustic positioning and communication integrated method for underwater multi-platform sensors, integrates underwater acoustic positioning and underwater acoustic communication technology from the system layer and the hardware layer, realizes underwater acoustic positioning and communication integrated function, independent underwater acoustic positioning function and independent underwater acoustic communication function based on the same set of hardware circuit and transducer equipment, saves underwater energy and space resources, avoids interference problems caused by independent working of underwater acoustic positioning and underwater acoustic communication, and guarantees the performance of single underwater acoustic positioning and underwater acoustic communication.

[0049] BRIEF DESCRIPTION OF DRAWINGS

[0050] ​In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments description. Obviously, the drawings in the following description only are the preferred embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0051] Figure 1 A flow chart of an acoustic positioning and communication integrated method for underwater multi-platform sensors according to the present application;

[0052] Figure 2 A 10ms signal simulation chart in the positioning and communication integrated mode;

[0053] Figure 3 A 10ms signal simulation chart in the single positioning mode;

[0054] Figure 4 A 10ms signal simulation chart in the single communication mode;

[0055] Figure 5 A communication error rate and signal-to-noise ratio simulation chart;

[0056] Figure 6 A positioning accuracy and beacon spatial topology simulation chart. DETAILED DESCRIPTION

[0057] In order to better understand the technical content of the present application, a specific embodiment is provided below, and the present application is further described in combination with the drawings.

[0058] Referring to Figure 1 The present application provides an acoustic positioning and communication integrated method for underwater multi-platform sensors, comprising the following steps:

[0059] Step S1, determining a working mode, the working mode comprising a positioning and communication integrated mode, a single positioning mode and a single communication mode, the three working modes sharing the same set of underwater acoustic hardware circuit and transducer, realizing the interoperation function of underwater acoustic positioning and underwater acoustic communication.

[0060] The present application combines underwater acoustic positioning and underwater acoustic communication together on the basis of realizing the single underwater acoustic positioning and single underwater acoustic communication function, creates a new integrated mode, integrates the underwater acoustic communication and underwater acoustic positioning together, saves the energy and space resources, and at the same time also has the independent underwater acoustic positioning and underwater acoustic communication function, ensures the performance of the single underwater acoustic positioning and underwater acoustic communication. In the future, the present application has certain advantages and prospects in the fields of ocean observation, military activities, emergency disposal, engineering operation and the like.

[0061] Step S2, when the working mode is the positioning and communication integrated mode, directly using the spread spectrum code on the I branch, using the spread spectrum code to modulate the communication information in the BPSK mode on the Q branch, synthesizing the spread spectrum of the two information and modulating to the carrier, the expression of the i-th node transmitting the positioning and communication integrated signal is:

[0062]

[0063] wherein is the power of the positioning signal allocated in the integrated signal; is the spread spectrum code corresponding to the positioning signal in the integrated signal; is the carrier frequency corresponding to the integrated signal; is the phase corresponding to the integrated signal; is the power of the communication signal allocated in the integrated signal; is the spread spectrum code corresponding to the communication signal in the integrated signal; is the communication information of the communication signal in the integrated signal.

[0064] Step S3, when the working mode is the single positioning mode, directly using the spread spectrum code to modulate the carrier signal in the BPSK mode, the expression of the i-th node transmitting the positioning signal is:

[0065]

[0066] wherein is the power of the transmitted positioning signal; is the spread spectrum code corresponding to the i-th positioning signal; is the carrier frequency corresponding to the i-th positioning signal; is the phase corresponding to the i-th positioning signal.

[0067] Step S4, when the working mode is the single communication mode, modulating the communication information on the spread spectrum code in the BPSK mode, and then modulating the carrier signal in the BPSK mode, the expression of the i-th node transmitting the positioning signal is:

[0068]

[0069] wherein, is the power of the transmitted communication signal; is the spread spectrum code corresponding to the i-th communication signal; is the communication information of the i-th communication signal; is the carrier frequency corresponding to the i-th communication signal; is the phase corresponding to the i-th communication signal.

[0070] Step S5, constructing a judgment criterion to judge the feasibility of the working mode according to the judgment criterion, the judgment criterion comprising:

[0071] A, the number of users to determine criteria: the number of spread spectrum code to be less than the number of users:

[0072]

[0073] where r is the number of bits of the spread spectrum code, the expected number of users;

[0074] B, the maximum range of the judgment criteria: the carrier center frequency to meet the equation of the sonar:

[0075] Gain + SL-TL-NL ≥ 0

[0076] Where the gain provided by the signal design, SL is the transducer located at the carrier center frequency of the sound source level, TL is the carrier center frequency of the propagation loss, NL is the carrier center frequency of the noise;

[0077] C, the communication rate determination criteria: to meet each communication information code contains at least one complete spread spectrum code period, the communication rate formula needs to meet:

[0078]

[0079] Where, the communication rate, the duty cycle of the signal, the spread spectrum code rate, r is the number of bits of the spread spectrum code;

[0080] D, the bit error rate determination criteria: to meet the theoretical bit error rate of BPSK signal coherent demodulation, the bit error rate formula is:

[0081]

[0082] Where, the bit error rate of the communication signal, the error function, the signal-to-noise ratio, the communication rate;

[0083] E, the positioning accuracy determination criteria: the 1 / 2 of the system positioning accuracy as a spatial grid point, the system theoretical positioning accuracy meets the requirement that the confidence interval of the system positioning accuracy is not less than 95%, the theoretical positioning accuracy formula is:

[0084]

[0085] Where, the average sound speed, the spread spectrum code rate, , , The definitions are as follows:

[0086]

[0087] The following definitions are given:

[0088]

[0089] representing the spatial coordinate position of the mthtransmitting beacon, representing the position of the mthreceiving beacon. The specific steps of step S5 are:

[0090] Step S51, when the working mode is the positioning and communication integrated mode, the feasibility is judged by using the judging criteria A, B, C, D and E.

[0091] Step S52, when the working mode is the single positioning mode, the feasibility is judged by using the judging criteria A, B, C and E.

[0092] Step S53, when the working mode is the single communication mode, the feasibility is judged by using the judging criteria A, B, C and D.

[0093] After the corresponding working mode is selected, the feasibility of the working mode is judged according to the set judging criteria. The judging criteria of the application include five A-E, and not all the judging criteria are needed in the three working modes. When the working mode is the positioning and communication integrated mode, the five judging criteria are needed, and when the working mode is the single positioning mode and the single communication mode, only four judging criteria are needed. Among them, the bit error rate is not considered in the single positioning mode, and the positioning accuracy is not considered in the single communication mode, so as to judge whether the working mode is available.

[0094] Step S6, after the feasibility judgment is passed, clock synchronization is performed.

[0095] In order to ensure high positioning accuracy and low bit error rate, all users need to be equipped with high-precision crystal oscillators or high-precision atomic clocks to ensure clock synchronization. The accuracy of clock synchronization is recommended to be not less than 1 ms.

[0096] The application is based on spread spectrum communication technology. The spread spectrum code adopts Gold sequence code, chaos sequence code or other pseudo-random codes with good autocorrelation characteristics and cross-correlation characteristics. The spread spectrum code has good autocorrelation characteristics and cross-correlation characteristics, and is mainly used as an identification code of different devices, and secondarily can be used as a ranging code to realize high-precision ranging function.

[0097]

[0098] ​From the system layer and hardware layer fusion of underwater acoustic positioning and underwater acoustic communication technology, based on the same set of hardware circuit and transducer equipment, according to different working modes, with the number of users, the action distance, the communication rate, the bit error rate, the positioning accuracy and other system indexes as the basis to design the acoustic positioning and communication integration method for underwater multi-platform sensor, the underwater acoustic positioning and communication integration function, the independent underwater acoustic positioning function and the independent underwater acoustic communication function are realized. Not only the underwater energy and space resources are saved, the interference problem caused by the independent work of underwater acoustic positioning and underwater acoustic communication is avoided, but also the performance of the single underwater acoustic positioning and underwater acoustic communication can be guaranteed, which provides technical support for the development and development of underwater network information system.

[0099] The beneficial effects of the present application are discussed by simulation experiment, the simulation conditions are as follows: code rate , 9-bit gold code is used, the carrier center frequency is , the positioning communication integrated signal simulation is as shown in Figure 2 , the positioning signal simulation is as shown in Figure 3 , and the communication signal simulation is as shown in Figure 4 .

[0100] Figure 5 The communication rate Under the condition, the curve diagram of the bit error rate when the signal-to-noise ratio is from-10dB to 10dB is given.

[0101] Figure 6 The simulation schematic diagram of the theoretical positioning progress when four transmitting beacons are located on the circular array with a radius of 2800m, the depth is 2000±10m, and one receiving beacon is located at the depth of 1000m is given.

[0102] The above only describes the preferred embodiments of the present application and does not limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An acoustic positioning and communication integrated method for underwater multi-platform sensors, characterized in that, The method comprises the following steps: Step S1, determining a working mode, which comprises a positioning-communication integrated mode, a single positioning mode and a single communication mode; Step S2, when the working mode is the positioning-communication integrated mode, directly using a spread spectrum code on the I branch and modulating communication information in a BPSK mode on the Q branch with the spread spectrum code, synthesizing the two information spread spectrums and modulating them to a carrier; Step S3, when the working mode is the single positioning mode, directly modulating the carrier signal in a BPSK mode with the spread spectrum code; Step S4, when the working mode is the single communication mode, modulating communication information in a BPSK mode on the spread spectrum code and then modulating the carrier signal in a BPSK mode; Step S5, constructing a judgment criterion to judge the feasibility of the working mode according to the judgment criterion.

2. The method of claim 1, wherein, When the working mode is the positioning-communication integrated mode, the signal expression of the i-th node for transmitting the positioning-communication integrated signal is: wherein is a power allocated to the positioning signal in the integrated signal; is a spreading code corresponding to the positioning signal in the integrated signal; is a carrier frequency corresponding to the integrated signal; is a phase corresponding to the integrated signal; is a power allocated to the communication signal in the integrated signal; is a spreading code corresponding to the communication signal in the integrated signal; is communication information of the communication signal in the integrated signal.

3. The method of claim 1, wherein, When the working mode is the single positioning mode, the signal expression of the i-th node for transmitting the positioning signal is: wherein is the power for transmitting the positioning signal; is the spreading code corresponding to the i-th positioning signal; is the carrier frequency corresponding to the i positioning signals; is the phase corresponding to the i positioning signals.

4. The method of claim 1, wherein, When the working mode is the single communication mode, the signal expression of the i-th node for transmitting the positioning signal is: wherein, is a power for transmitting the communication signal; is a spread spectrum code corresponding to the i-th communication signal; is communication information of the i communication signals; is a carrier frequency corresponding to the i communication signals; is a phase corresponding to the i communication signals.

5. The method of claim 1, wherein, The judgment criterion comprises: A, a user quantity judgment criterion: the number of spread spectrum codes is less than the number of users; where r is the number of bits of the spreading code, N is the number of desired users; B, a maximum action distance judgment criterion: the carrier center frequency satisfies the sonar equation: Gain + SL-TL-NL ≥ 0 wherein the gain Gain provided by the signal design, SL is the sound source level of the transducer at the carrier center frequency, TL is the propagation loss at the carrier center frequency, and NL is the noise at the carrier center frequency; C, a communication rate judgment criterion: at least one complete spread spectrum code period is contained in each communication information code, and the communication rate formula needs to satisfy: wherein, is the communication rate, is the duty cycle of the signal, is the spreading code rate, r is the number of bits of the spreading code; D, a bit error rate judgment criterion: the theoretical bit error rate of BPSK signal coherent demodulation is satisfied, and the bit error rate formula is: wherein BER is the bit error rate of the communication signal, erf is the error function, SNR is the signal-to-noise ratio, R is the communication rate; E, a positioning accuracy judgment criterion: taking 1 / 2 of the system positioning accuracy as a spatial grid point, the confidence interval of the system theoretical positioning accuracy satisfying the required system positioning accuracy is not less than 95%, and the theoretical positioning accuracy formula is: wherein is the average sound velocity, is the spreading code rate, , , are defined as follows: The following definitions apply: representing the spatial coordinate position of the mth transmitting beacon, representing the position of the mth receiving beacon.

6. The method of claim 5, wherein, The specific steps of the step S5 are: Step S51, when the working mode is the positioning-communication integrated mode, the judgment criteria A, B, C, D and E are used for the feasibility judgment; Step S52, when the working mode is the single positioning mode, the judgment criteria A, B, C and E are used for the feasibility judgment; Step S53, when the working mode is the single communication mode, the judgment criteria A, B, C and D are used for the feasibility judgment.

7. The method of claim 1, wherein, The three working modes share the same set of underwater acoustic hardware circuits and transducers.

8. The method of claim 1, wherein, The spread spectrum code adopts a Gold sequence code, a chaotic sequence code or a pseudo-random code.

9. The method of claim 1, wherein, The method further comprises a step S6 of performing clock synchronization after the feasibility judgment is passed.

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