Self-organizing network acoustic emission acquisition device and system

Abstract

The present invention discloses a self-organizing network acoustic emission acquisition device and system. The acquisition device includes: a preprocessing module, a fault processing module, a feature frame management module, a signal feature processing module, and an evaluation and judgment module. Among them, the preprocessing module is used for preprocessing historical transmission information, the fault processing module is used for processing network connection faults, the feature frame management module is used for managing feature frames, the signal feature processing module is used for analyzing and calculating distance reference values, and the evaluation and judgment module judges whether the clocks of the acquisition devices are synchronized. Among them, the fault processing module includes a network detection unit, a cache management unit, and a network formation time period management unit. The signal feature processing module includes a signal decomposition unit, a feature frame parsing unit, and a distance analysis unit. The evaluation and judgment module includes a distance evaluation coefficient calculation unit, a reference distance calculation unit, and a time evaluation unit.

Description

Technical Field

[0001] The present invention relates to the technical field of network device management, and specifically to an ad-hoc acoustic emission acquisition device and system. Background Art

[0002] Ad-hoc networking technology allows a group of devices to communicate with each other without a fixed infrastructure. Such networks typically consist of mobile nodes, each of which can act as either an end device or a router. By forming an acoustic acquisition array with multiple acoustic acquisition devices, sound information of the same sound source can be acquired from different angles or distances, enabling more sound source information to be recorded.

[0003] In the acoustic acquisition array, it is necessary to synchronize the time of each acoustic acquisition device terminal in order to align the sound tracks of the sound source. In the actual application of the acoustic acquisition array, due to network fluctuations, individual acquisition device terminals may disconnect, and the remaining acquisition device terminals will re-form an ad-hoc network according to the routing information. After the ad-hoc network is formed, in order to ensure the unity of the time dimension of the acquired sound source, it is necessary to re-synchronize the clocks of the acoustic acquisition device terminals in the network. In the prior art, usually a time server in the network system is found for re-timing, which requires a long communication link and a relatively complex network time protocol. The acoustic acquisition array is often independently built, and the cost of deploying a time server alone is relatively high. Moreover, in the working state of high-speed sound acquisition, it is necessary to minimize the waiting time for network timing. Therefore, the traditional time synchronization scheme is difficult to apply. Summary of the Invention

[0004] The purpose of the present invention is to provide an ad-hoc acoustic emission acquisition device and system to solve the problems raised in the prior art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: An ad-hoc acoustic emission acquisition device, the acquisition device includes: a preprocessing module, a fault processing module, a feature frame management module, a signal feature processing module, and an evaluation and judgment module. Among them, the preprocessing module is used to preprocess the historical transmission information of the acquisition device, the fault processing module is used to handle the faults of the network connection, the feature frame management module is used to manage the feature frames inserted after caching the data, the signal feature processing module is used to analyze and calculate the distance reference value for the feature frames and the received signals, and the evaluation and judgment module calculates the reference record to judge whether the clocks of the acquisition devices are synchronized.

[0006] Further, the preprocessing module includes: a historical data management unit, a feature management unit, and a distance function management unit. Among them, the historical data management unit is used for the historical transmission records of the acquisition device, the feature management unit is used to obtain the signal features of the transmitted signals, and the distance function management unit is used to manage the first distance function and the second distance function.

[0007] Further, the fault handling module includes: a network detection unit, a cache management unit, and a networking time period management unit. Among them, the network detection unit is used to detect the network connection quality between the acquisition devices, the cache management unit is used to cache the data acquired by the acquisition devices, and the networking time period management unit is used to manage the networking time period between the acquisition devices.

[0008] Further, the signal feature processing module includes: a signal decomposition unit, a feature frame parsing unit, and a distance analysis unit. Among them, the signal decomposition unit is used to decompose the received signal, the feature frame parsing unit is used to obtain information from the feature frame, and the distance analysis unit is used to calculate a first distance reference value and a second distance reference value through a first distance function and a second distance function respectively.

[0009] Further, the evaluation and judgment module includes: a distance evaluation coefficient calculation unit, a reference distance calculation unit, and a time evaluation unit. Among them, the distance evaluation coefficient calculation unit is used to calculate the distance evaluation coefficient through a coefficient calculation function, the reference distance calculation unit is used to calculate the reference distance, and the time evaluation unit is used to evaluate whether the clocks of the acquisition devices are synchronized.

[0010] A self-organizing network acoustic emission acquisition system is used to execute a self-organizing network acoustic emission acquisition method. The method includes:

[0011] Obtain the historical data of the transmission signals of any two identical acquisition terminals, and according to the signal characteristics of the sending-end signal and the receiving-end signal, obtain a first distance function for the attenuation of the effective part of the signal with distance and a second distance function for the increase of the interference part of the signal with distance;

[0012] Three identical acquisition terminals are connected through a self-organizing network protocol. When a network connection fails between the first acquisition terminal and the second acquisition terminal, the first acquisition terminal caches the acquired data, and records the time period when the first acquisition terminal disconnects from the second acquisition terminal and connects to the third acquisition terminal as the networking time period;

[0013] At the end of the networking time period, the first acquisition terminal inserts a feature frame containing clock information and the signal characteristics of the transmitted signal, and sends the cached data, the feature frame, and the data acquired after the networking time period to the third acquisition terminal. The third acquisition terminal caches the received data and records the time from the start of receiving the data to receiving the feature frame;

[0014] The third acquisition terminal obtains the signal characteristics of the received signal, extracts the signal characteristics of the transmitted signal from the feature frame, obtains the first distance function and the second distance function, and calculates a first distance reference value and a second distance reference value through the feature values of the signal characteristics;

[0015] Obtain the average value of the signal-to-noise ratio of the received signal, calculate the weights of the first distance reference value and the second distance reference value through a coefficient calculation function, perform a weighted operation on the first distance reference value and the second distance to obtain the reference distance L, obtain the signal transmission speed to calculate the transmission time, and combine the time from the start of receiving data to the receipt of the characteristic frame to calculate the time difference between the clocks of the first acquisition terminal and the third acquisition terminal, and compare the time difference with the difference threshold to determine whether the clocks of the first acquisition terminal and the third acquisition terminal are synchronized.

[0016] Further, obtain the historical data of the signal transmission between two acquisition terminals, and use the signal transmitted in any piece of historical data as the target signal;

[0017] The distance from the sending end that sends the target signal to the receiving end that receives the target signal is recorded as the transmission distance, and the signal characteristic of the target signal at the sending end is recorded as the first target characteristic;

[0018] Obtain the signal of the target signal at the receiving end, decompose the signal into a first part and a second part, record the signal characteristic of the first part of the signal at the receiving end as the second target characteristic, and record the signal characteristic of the second part of the signal at the receiving end as the third target characteristic;

[0019] Obtain the eigenvalue r1 of the first target characteristic and the eigenvalue m21 of the second target characteristic, calculate the difference v1, v1 = r1 - m21, record the difference as the target difference, form the first data group (v1, d) with the target difference and the transmission distance d, obtain the eigenvalue m22 of the third target characteristic, and form the second data group (m22, d) with the eigenvalue of the third target characteristic and the transmission distance;

[0020] By adjusting the transmission distance, obtain several pieces of historical data of the signal transmission of the acquisition terminal, and respectively collect the first data group and the second data group of all historical data;

[0021] When the first target characteristic is a certain eigenvalue, obtain the functional relationship between the target difference and the transmission distance, and record the functional relationship as the first distance function F1(D), obtain the functional relationship between the eigenvalue of the third target characteristic and the transmission distance, and record the functional relationship as the second distance function F2(D), where F1 and F2 are respectively the functional relationships of the first distance function and the second distance function, and D represents the distance variable;

[0022] Establish the corresponding relationship between the eigenvalue of the first target characteristic and the first distance function and the second distance function.

[0023] Further, connect three identical acquisition terminals in a network line type. The three acquisition terminals are the first acquisition terminal, the second acquisition terminal, and the third acquisition terminal in sequence according to the connection order. The acquisition terminal is deployed with a self-organizing network protocol;

[0024] When the first acquisition terminal detects a network connection failure with the second acquisition terminal, the acquired data is cached in the first cache unit of the first acquisition terminal;

[0025] The time period from disconnecting the first acquisition terminal from the second acquisition terminal to successfully connecting the first acquisition terminal to the third acquisition terminal is recorded as the network formation period.

[0026] Further, the first acquisition terminal inserts a feature frame at the end moment of the network formation period. The feature frame includes the clock information of the first acquisition terminal and the signal characteristics of the transmitted signal. The first acquisition terminal sends the data cached in the first cache unit, the feature frame, and the data acquired after the network formation period to the third acquisition terminal;

[0027] After receiving the data sent by the first acquisition terminal, the third acquisition terminal stores the data in the second cache unit of the third acquisition terminal, and records the time from the start of receiving the data sent by the first acquisition terminal to receiving the feature frame as the cache period.

[0028] Further, the data transmission signal of the first acquisition terminal received by the third acquisition terminal during the cache period is recorded as the received signal. The received signal is decomposed into a first part and a second part, and the signal characteristics of the first part of the received signal and the signal characteristics of the second part of the received signal are obtained respectively;

[0029] The first part of the signal is the useful signal transmitted, and the second part is the noise signal of the signal. The transmission distance is estimated by calculating the attenuation amount of the signal with distance during transmission and the increase amount of the noise signal with distance;

[0030] The third acquisition terminal obtains the signal characteristics of the transmitted signal from the feature frame, obtains the signal characteristics of the transmitting-end signal that are the same as the signal characteristics of the transmitted signal, and obtains the first distance function F11(D) and the second distance function F21(D) corresponding to the characteristic values of the signal characteristics;

[0031] Obtain the characteristic value y1 of the signal characteristics of the transmitted signal and the characteristic value n21 of the signal characteristics of the first part of the received signal, calculate w1, w1 = y1 - n21, solve the equation w1 = F11(D) to obtain the first distance reference value h1, obtain the characteristic value n22 of the signal characteristics of the second part of the received signal, and solve the equation n22 = F21(D) to obtain the second distance reference value h2.

[0032] Further, obtain the average value of the signal-to-noise ratio of the received signal and record it as SNR, and calculate it through the coefficient calculation function G, The calculation result of the function is recorded as the distance evaluation coefficient α, where k and c respectively represent different parameters;

[0033] The recommended value of SNR in a general data transmission network is above 20 dB, that is, the power of the effective signal is more than 100 times that of the noise signal. Therefore, the predicted values of the transmission distance calculated based on the effective signal and the noise signal are not unified in accuracy. The larger the signal-to-noise ratio, the larger the proportion of the first part of the signal;

[0034] Therefore, by collecting the signal-to-noise ratio and using a coefficient calculation function to balance the distance data calculated by the two methods, the calculated reference distance has higher accuracy;

[0035] Calculate the reference distance L, L = α × h1 + β × h2, where β = 1 - α;

[0036] Set the signal transmission speed value cv and calculate the transmission time t tran , t tran = L / cv;

[0037] Set the difference threshold p and calculate T3 - T1 = δ. When |δ| > p, the clocks of the first acquisition terminal and the third acquisition terminal are not synchronized.

[0038] Compared with the prior art, the beneficial effects of the present invention are:

[0039] 1. Time calibration is performed from a terminal with a stable network state to a network terminal that reconnects after disconnection. In a data acquisition network with relatively simple network devices, the dependence on time server timing is reduced. At the same time, the timing process is simplified, enabling adjacent data acquisition terminals to achieve the synchronization function for rapid network recovery.

[0040] 2. Reduce data discard caused by network disconnection and time asynchronization during the timing process, and improve the data integrity of the data acquisition results. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic structural diagram of the self-organizing network acoustic emission acquisition device of the present invention;

[0042] Figure 2 It is a schematic diagram of an embodiment of the self-organizing network acoustic emission acquisition device and system of the present invention;

[0043] Figure 3 It is a schematic diagram of an embodiment of the self-organizing network acoustic emission acquisition device and system of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] Embodiment: As Figure 1 , Figure 2 and Figure 3 shown, the present invention provides a technical solution, a self-organizing network acoustic emission acquisition device;

[0046] The acquisition device includes: a preprocessing module, a fault processing module, a feature frame management module, a signal feature processing module, and an evaluation and judgment module;

[0047] Among them, the preprocessing module is used to preprocess the historical transmission information of the acquisition device. Among them, the preprocessing module includes: a historical data management unit, a feature management unit, and a distance function management unit. Among them, the historical data management unit is used for the historical transmission records of the acquisition device, the feature management unit is used to obtain the signal features of the transmission signal, and the distance function management unit is used to manage the first distance function and the second distance function;

[0048] Among them, the fault processing module is used to process the faults of the network connection. Among them, the fault processing module includes: a network detection unit, a cache management unit, and a network formation time period management unit. Among them, the network detection unit is used to detect the network connection quality between the acquisition devices, the cache management unit is used to cache the data collected by the acquisition device, and the network formation time period management unit is used to manage the network formation time period between the acquisition devices;

[0049] Among them, the feature frame management module is used to manage the feature frames inserted after caching the data;

[0050] Among them, the signal feature processing module is used to analyze and calculate the distance reference value for the feature frame and the received signal. Among them, the signal feature processing module includes: a signal decomposition unit, a feature frame parsing unit, and a distance analysis unit. Among them, the signal decomposition unit is used to decompose the received signal, the feature frame parsing unit is used to obtain information from the feature frame, and the distance analysis unit is used to calculate the first distance reference value and the second distance reference value respectively through the first distance function and the second distance function;

[0051] Among them, the evaluation and judgment module calculates reference records and determines whether the clocks of the acquisition devices are synchronized. The evaluation and judgment module includes: a distance evaluation coefficient calculation unit, a reference distance calculation unit, and a time evaluation unit. The distance evaluation coefficient calculation unit is used to calculate the distance evaluation coefficient through a coefficient calculation function. The reference distance calculation unit is used to calculate the reference distance. The time evaluation unit is used to evaluate whether the clocks of the acquisition devices are synchronized.

[0052] A self-organizing network acoustic emission acquisition system is used to execute a self-organizing network acoustic emission acquisition method. The method includes:

[0053] Obtain the historical data of the transmission signals of any two identical acquisition terminals. According to the signal characteristics of the transmitting-end signal and the receiving-end signal, obtain the first distance function of the effective part of the signal decaying with distance and the second distance function of the interference part of the signal increasing with distance.

[0054] Among them, obtain the historical data of the signal transmission between two acquisition terminals, and use the signal transmitted in any piece of historical data as the target signal.

[0055] The distance from the transmitting end that sends the target signal to the receiving end that receives the target signal is denoted as the transmission distance, and the signal characteristic of the target signal at the transmitting end is denoted as the first target characteristic.

[0056] Obtain the signal of the target signal at the receiving end, decompose the signal into a first part and a second part, denote the signal characteristic of the first part of the signal at the receiving end as the second target characteristic, and denote the signal characteristic of the second part of the signal at the receiving end as the third target characteristic.

[0057] Obtain the eigenvalue r1 of the first target characteristic and the eigenvalue m21 of the second target characteristic, calculate the difference v1, v1 = r1 - m21, denote the difference as the target difference, form the first data group (v1, d) with the target difference and the transmission distance d, obtain the eigenvalue m22 of the third target characteristic, and form the second data group (m22, d) with the eigenvalue of the third target characteristic and the transmission distance.

[0058] By adjusting the transmission distance, obtain several pieces of historical data of the signal transmission of the acquisition terminals, and respectively collect the first data groups and the second data groups of all the historical data.

[0059] When the first target characteristic is a certain eigenvalue, obtain the functional relationship between the target difference and the transmission distance, denote the functional relationship as the first distance function F1(D), obtain the functional relationship between the eigenvalue of the third target characteristic and the transmission distance, denote the functional relationship as the second distance function F2(D), where F1 and F2 are respectively the functional relationships of the first distance function and the second distance function, and D represents the distance variable.

[0060] Establish the correspondence between the eigenvalue of the first target feature and the first distance function and the second distance function.

[0061] Three identical acquisition terminals are connected through an ad-hoc network protocol. When a network connection fails between the first acquisition terminal and the second acquisition terminal, the first acquisition terminal caches the acquired data. The time period from disconnecting the first acquisition terminal from the second acquisition terminal to connecting the first acquisition terminal to the third acquisition terminal is recorded as the network formation time period.

[0062] Among them, the three identical acquisition terminals are connected in a network line type. The three acquisition terminals are, in order of connection, the first acquisition terminal, the second acquisition terminal, and the third acquisition terminal. The acquisition terminals are deployed with an ad-hoc network protocol.

[0063] When the first acquisition terminal detects a network connection failure with the second acquisition terminal, it caches the acquired data into the first cache unit of the first acquisition terminal.

[0064] The time period starting from disconnecting the first acquisition terminal from the second acquisition terminal until the first acquisition terminal successfully connects to the third acquisition terminal is recorded as the network formation time period.

[0065] At the end of the network formation time period, the first acquisition terminal inserts a feature frame containing clock information and the signal characteristics of the transmitted signal, and sends the cached data, the feature frame, and the data acquired after the network formation time period to the third acquisition terminal. The third acquisition terminal caches the received data and records the time from the start of receiving the data to receiving the feature frame.

[0066] In the embodiment, the signal characteristics of the target signal include: transmission power, transmission frequency, center frequency, waveform image characteristics of the time-domain signal, and waveform image characteristics of the frequency-domain signal.

[0067] Among them, the first acquisition terminal inserts a feature frame at the end moment of the network formation time period. The feature frame includes the clock information of the first acquisition terminal and the signal characteristics of the transmitted signal. The first acquisition terminal sends the data cached in the first cache unit, the feature frame, and the data acquired after the network formation time period to the third acquisition terminal.

[0068] After receiving the data sent by the first acquisition terminal, the third acquisition terminal stores the data in the second cache unit of the third acquisition terminal, and records the time from the start of receiving the data sent by the first acquisition terminal to receiving the feature frame as the cache time period.

[0069] The third acquisition terminal obtains the signal characteristics of the received signal, extracts the signal characteristics of the transmitted signal from the feature frame, obtains the first distance function and the second distance function, and calculates the first distance reference value and the second distance reference value through the eigenvalue of the signal characteristics.

[0070] Among them, the data transmission signal received by the third acquisition terminal from the first acquisition terminal during the caching period is denoted as the received signal. The received signal is decomposed into a first part and a second part, and the signal characteristics of the first part of the received signal and the signal characteristics of the second part of the received signal are respectively obtained;

[0071] The third acquisition terminal obtains the signal characteristics of the transmitted signal from the characteristic frame, obtains the signal characteristics of the transmitting end signal that are the same as the signal characteristics of the transmitted signal, and obtains the first distance function F11(D) and the second distance function F21(D) corresponding to the characteristic values of the signal characteristics;

[0072] Obtain the characteristic value y1 of the signal characteristics of the transmitted signal and the characteristic value n21 of the signal characteristics of the first part of the received signal, calculate w1, w1 = y1 - n21, solve the equation w1 = F11(D) to obtain the first distance reference value h1, obtain the characteristic value n22 of the signal characteristics of the second part of the received signal, and solve the equation n22 = F21(D) to obtain the second distance reference value h2.

[0073] Obtain the average value of the signal-to-noise ratio of the received signal, calculate the weights of the first distance reference value and the second distance reference value through the coefficient calculation function, perform a weighted operation on the first distance reference value and the second distance to obtain the reference distance L, obtain the signal transmission speed to calculate the transmission time, and combine the time from the start of receiving data to the receipt of the characteristic frame to calculate the time difference between the clocks of the first acquisition terminal and the third acquisition terminal, and compare the time difference with the difference threshold to determine whether the clocks of the first acquisition terminal and the third acquisition terminal are synchronized;

[0074] Among them, the average value of the signal-to-noise ratio of the received signal is denoted as SNR, and through the coefficient calculation function G, The calculation result of the function is denoted as the distance evaluation coefficient α, where k and c respectively represent different parameters;

[0075] In the embodiment, k takes 0.2197 and c takes 20;

[0076] When SNR = 20 (dB), α is approximately 0.5. When SNR = 30 (dB), α is approximately 0.9. In the actual calculation process, SNR is converted to the unit of dB and the numerical value is substituted into the formula for calculation;

[0077] Calculate the reference distance L, L = α×h1 + β×h2, where β = 1 - α;

[0078] Set the signal transmission speed value cv and calculate the transmission time t tran ,t tran = L / cv;

[0079] Set a difference threshold p, calculate T3 - T1 = δ, when |δ| > p, the clocks of the first acquisition terminal and the third acquisition terminal are out of sync.

[0080] In one embodiment, the ad-hoc acoustic emission acquisition terminal includes: a network connection unit, a connection detection unit, a clock management unit, a routing management unit, a time information management unit, a feedback unit, a cache module, a signal analysis module, a distance calculation module, and a delay detection module;

[0081] The network connection unit is used to manage the network connection of the acquisition device. Among them, the network connection unit includes a signal sending end and a signal receiving end. The signal sending end is used to send signals, and the signal receiving end is used to receive signals;

[0082] The connection detection unit is used to detect whether there is an abnormality in data transmission;

[0083] The clock management unit is used to manage the clock information of the acquisition device locally;

[0084] The routing management unit is used for ad-hoc networking and managing routing information;

[0085] The time information management unit is used to cache data and insert a feature frame between the current transmitted data. The feature frame includes clock information and the signal characteristics of the transmitted signal;

[0086] The feedback unit is used to send clock correction information to the signal sending section when the difference between the clock information of the received signal and the local clock information is greater than the difference threshold;

[0087] The cache module is used to save data;

[0088] Among them, the cache module includes a first cache unit and a second cache unit. The first cache unit is used to cache data. When there is an abnormality in the signal transmission of the sending end of the acquisition device, the acquired data is cached into the first cache unit; the second cache unit is used to cache data. When the acquisition device completes the network connection, the received data is cached into the second cache unit;

[0089] The signal analysis module is used to analyze the received signal to obtain the signal characteristics of the received signal;

[0090] Among them, the signal analysis module includes: a signal decomposition unit and a feature extraction unit. Among them, the signal decomposition unit is used to obtain a signal and decompose the signal into a first part and a second part. Among them, the first part is the effective part of the signal, and the second part is the remaining part of the signal after removing the first part. The feature extraction unit is used to obtain the signal characteristics of the first part and the second part of the signal respectively;

[0091] The distance calculation module is used to calculate the reference distance between the sending end and the receiving end through the signal received by the receiving end;

[0092] Among them, the distance calculation module includes a first transmission management unit, a second transmission management unit, a signal-to-noise ratio management unit, an evaluation coefficient calculation unit, and a reference distance calculation unit. Among them, the first transmission management unit is used to calculate the transmission distance of the signal according to the attenuation characteristics of the effective part of the signal, and record the transmission distance calculated by the first transmission management unit as the first distance reference value. The second transmission management unit is used to calculate the transmission distance of the signal according to the increasing characteristics of the second part of the signal, and record the transmission distance calculated by the second transmission management unit as the second distance reference value. The signal-to-noise ratio management unit is used to obtain the signal-to-noise ratio of the signal. The evaluation coefficient calculation unit is used to calculate the distance evaluation coefficient through a coefficient calculation function. The reference distance calculation unit is used to calculate the reference distance;

[0093] The time delay detection module is used to obtain the transmission time of the received signal for calculating the reference distance, and compare the clock information of the received signal with the local clock information of this acquisition device.

[0094] In the embodiment, there are three acquisition terminals, denoted as acquisition terminal A1, acquisition terminal A2, and acquisition terminal A3 respectively. In the initial network, acquisition terminal A1, acquisition terminal A2, and acquisition terminal A3 are connected in sequence;

[0095] Q1. When the acquisition terminal A1 detects network fluctuations at the signal sending end, cache the locally acquired data into the first cache unit;

[0096] Q2. After the acquisition terminal A1 disconnects the network connection with the acquisition terminal A2 and establishes a network connection with the acquisition terminal A3, the acquisition terminal A1 inserts a characteristic frame between the cached information and the current acquisition information and sends it to the acquisition terminal A3 in the order of acquisition time;

[0097] Q3. The acquisition terminal A3 stores the data sent by the acquisition terminal A1 into the second cache unit of the acquisition terminal A3. When receiving the characteristic frame, stop obtaining the connection information with the peer end, and obtain the time t when the acquisition terminal A3 stores the data into the second cache unit buffer ;

[0098] Q4. Obtain the signal at the signal receiving end of the acquisition terminal A3, decompose the signal into a first part and a second part, and respectively obtain the signal characteristics of the first part and the signal characteristics corresponding to the second part;

[0099] Q5. Obtain the signal characteristics of the transmitted signal from the characteristic frame, obtain the first target characteristic identical to the signal characteristics of the transmitted signal, obtain the corresponding first change rule and second change rule, and respectively calculate the first distance reference value h1 corresponding to the first change rule and the second distance reference value h2 corresponding to the second change rule;

[0100] Q6. Obtain the signal-to-noise ratio SNR of the signal at the signal receiving end of the acquisition terminal A3, and calculate the distance evaluation coefficient α through the coefficient calculation function;

[0101] Q7. Calculate the reference distance d, where d = α×h1 + β×h2, and β = 1 - α;

[0102] Q8. Obtain the signal transmission constant v and calculate the transmission time t tran , t tran = d / v;

[0103] Q9. When the acquisition terminal A3 receives the feature frame, record the clock information T2 of the acquisition terminal A3, obtain the clock information T1 of the acquisition terminal A1 from the feature frame, and calculate the comparison time T3, where T3 = T2 - (t tran + t buffer );

[0104] Q10. Obtain the difference threshold p, calculate T3 - T1 = δ, and when |δ| > p, the clocks of the acquisition terminal A1 and the acquisition terminal A3 are not synchronized;

[0105] Q11. When δ > 0, the clock of the acquisition terminal A1 is slower than that of the acquisition terminal A3; when δ < 0, the clock of the acquisition terminal A1 is faster than that of the acquisition terminal A3, and the acquisition terminal A3 sends clock correction information to the acquisition terminal A1.

[0106] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. The self-organizing network acoustic emission collection system is characterized by: The workflow of the system is as follows: Obtain historical data of transmission signals of any two identical acquisition terminals, and obtain a first distance function of the attenuation of the effective part of the signal with distance and a second distance function of the increase of the interference part of the signal with distance according to the signal characteristics of the transmitting end signal and the receiving end signal; Three identical collection terminals are connected through a self-organizing network protocol. When a network connection failure occurs between a first collection terminal and a second collection terminal, the first collection terminal caches the collected data, and a time period during which the first collection terminal is disconnected from the second collection terminal and the first collection terminal is connected to the third collection terminal is recorded as a networking time period. At the end of the networking period, the first acquisition terminal inserts a feature frame containing clock information and signal characteristics of the transmitted signal, and sends the cached data, the feature frame, and the data collected after the networking period to the third acquisition terminal, which caches the received data and records the time from the start of receiving the data to the receipt of the feature frame; The third acquisition terminal obtains the signal characteristics of the received signal, extracts the signal characteristics of the transmitted signal from the characteristic frame, obtains the first distance function and the second distance function, and calculates the first distance reference value and the second distance reference value through the characteristic values ​​of the signal characteristics; The average value of the signal-to-noise ratio of the received signal is obtained, and the weights of the first distance reference value and the second distance reference value are calculated through a coefficient calculation function. The first distance reference value and the second distance are weighted to obtain a reference distance L. The signal transmission speed is obtained to calculate the transmission time. The time difference between the clock of the first acquisition terminal and the clock of the third acquisition terminal is calculated by combining the time from the start of receiving data to the receipt of the characteristic frame. The time difference is compared with the difference threshold to determine whether the clocks of the first acquisition terminal and the third acquisition terminal are synchronized.

2. The ad hoc network acoustic emission collection system according to claim 1, characterized in that: The system executes the following workflow to obtain the first distance function and the second distance function based on the signal characteristics of the transmitting end signal and the receiving end signal: Obtain the historical data of signal transmission between two acquisition terminals, and use the signal transmitted in any piece of historical data as the target signal; The distance from the sending end that sends the target signal to the receiving end that receives the target signal is recorded as the transmission distance, and the signal feature of the target signal at the sending end is recorded as the first target feature; Acquire a signal of a target signal at a receiving end, decompose the signal into a first part and a second part, record a signal feature of the first part of the signal at the receiving end as a second target feature, and record a signal feature of the second part of the signal at the receiving end as a third target feature; Obtain the characteristic value r1 of the first target feature and the characteristic value m21 of the second target feature, calculate the difference v1, v1=r1-m21, record the difference as the target difference, combine the target difference and the transmission distance d into a first data group (v1, d), obtain the characteristic value m22 of the third target feature, and combine the characteristic value of the third target feature and the transmission distance into a second data group (m22, d); By adjusting the transmission distance, a plurality of historical data of the signal transmission of the acquisition terminal are obtained, and the first data group and the second data group of all the historical data are respectively collected; When the first target feature is a certain characteristic value, obtain the functional relationship between the target difference and the transmission distance, and record the functional relationship as the first distance function F1(D); obtain the functional relationship between the characteristic value of the third target feature and the transmission distance, and record the functional relationship as the second distance function F2(D), where F1 and F2 are the functional relationship between the first distance function and the second distance function respectively, and D represents the distance variable; A corresponding relationship between the feature value of the first target feature and the first distance function and the second distance function is established.

3. The ad hoc network acoustic emission collection system according to claim 2, characterized in that: The system executes the following workflow to obtain the networking time period: Connect three identical acquisition terminals through a network line type, the three acquisition terminals are a first acquisition terminal, a second acquisition terminal and a third acquisition terminal in order of connection, and the acquisition terminals are deployed with a self-organizing network protocol; When the first acquisition terminal detects that the network connection with the second acquisition terminal fails, the collected data is cached in the first cache unit of the first acquisition terminal; The time period from when the first acquisition terminal is disconnected from the second acquisition terminal to when the first acquisition terminal is successfully connected to the third acquisition terminal is recorded as the networking period.

4. The ad hoc network acoustic emission collection system according to claim 3, characterized in that: The system executes the management process of feature frames as follows: The first acquisition terminal inserts a feature frame at the end of the networking period, wherein the feature frame includes the clock information of the first acquisition terminal and the signal characteristics of the transmitted signal, and the first acquisition terminal sends the data cached in the first cache unit, the feature frame, and the data collected after the networking period to the third acquisition terminal; After receiving the data sent by the first collection terminal, the third collection terminal stores the data in the second cache unit of the third collection terminal, and records the time from the start of receiving the data sent by the first collection terminal to receiving the feature frame as the cache period.

5. The ad hoc network acoustic emission collection system according to claim 4, characterized in that: The system performs the calculation process of the first distance reference value and the second distance reference value as follows: Recording the data transmission signal sent by the first acquisition terminal and received by the third acquisition terminal during the buffer period as a received signal, decomposing the received signal into a first part and a second part, and respectively acquiring a signal feature of the first part of the received signal and a signal feature of the second part of the received signal; The third acquisition terminal obtains the signal feature of the transmission signal of the signal from the feature frame, obtains the signal feature of the transmission end signal that is the same as the signal feature of the transmission signal, and obtains the first distance function F11(D) and the second distance function F21(D) corresponding to the feature value of the signal feature; Obtain the characteristic value y1 of the signal characteristic of the transmitted signal and the characteristic value n21 of the signal characteristic of the first part of the received signal, calculate w1, w1=y1-n21, solve the equation w1=F11(D) to obtain the first distance reference value h1, obtain the characteristic value n22 of the signal characteristic of the second part of the received signal, solve the equation n22=F21(D) to obtain the second distance reference value h2.

6. The ad hoc network acoustic emission collection system according to claim 5, characterized in that: The process of the system executing to determine whether the clocks of the first acquisition terminal and the third acquisition terminal are synchronized is as follows: The average value of the signal-to-noise ratio of the received signal is recorded as SNR, and the function G is calculated by the coefficient. The calculation result of the function is recorded as the distance evaluation coefficient α, where k and c represent different parameters respectively; Calculate the reference distance L, L = α × h1 + β × h2, where β = 1-α; Set the signal transmission speed value cv and calculate the transmission time t tran , t tran =L / cv; Set the difference threshold p, calculate T3-T1=δ, when |δ|>p, the clock of the first acquisition terminal is not synchronized with the clock of the third acquisition terminal, where T3 represents the comparison time, T1 represents the clock information of the first acquisition terminal, where T3=T2-(t tran +t buffer ), T2 represents the clock information of the third acquisition terminal, t buffer Indicates the time when the data is stored in the second cache unit.

7. A self-organizing network acoustic emission collection device, used to implement the self-organizing network acoustic emission collection system according to any one of claims 1 to 6, characterized in that: The acquisition device includes: a preprocessing module, a fault processing module, a feature frame management module, a signal feature processing module and an evaluation and judgment module, wherein the preprocessing module is used to preprocess the historical transmission information of the acquisition device, the fault processing module is used to handle the network connection fault, the feature frame management module is used to manage the feature frames inserted after the cached data, the signal feature processing module is used to analyze the feature frames and the received signals to calculate the distance reference value, and the evaluation and judgment module calculates the reference record and determines whether the clock of the acquisition device is synchronized.

8. The ad hoc network acoustic emission collection device according to claim 7, characterized in that: The preprocessing module includes: a historical data management unit, a feature management unit and a distance function management unit, wherein the historical data management unit is used to collect historical transmission records of the device, the feature management unit is used to obtain signal characteristics of the transmission signal, and the distance function management unit is used to manage the first distance function and the second distance function; The fault handling module includes: a network detection unit, a cache management unit and a networking period management unit, wherein the network detection unit is used to detect the network connection quality between collection devices, the cache management unit is used to cache the data collected by the collection devices, and the networking period management unit is used to manage the networking period between collection devices.

9. The ad hoc network acoustic emission collection device according to claim 7, characterized in that: The signal feature processing module includes: a signal decomposition unit, a feature frame parsing unit and a distance analysis unit, wherein the signal decomposition unit is used to decompose the received signal, the feature frame parsing unit is used to obtain information from the feature frame, and the distance analysis unit is used to calculate the first distance reference value and the second distance reference value respectively through the first distance function and the second distance function.

10. The ad hoc network acoustic emission collection device according to claim 7, characterized in that: The evaluation and judgment module includes: a distance evaluation coefficient calculation unit, a reference distance calculation unit and a time evaluation unit, wherein the distance evaluation coefficient calculation unit is used to calculate the distance evaluation coefficient through a coefficient calculation function, the reference distance calculation unit is used to calculate the reference distance, and the time evaluation unit is used to evaluate whether the clock of the acquisition device is synchronized.

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