Vibration self-powered acoustic emission wireless monitoring device and system

Abstract

The invention discloses a vibration self-powered acoustic emission wireless monitoring device and system, and relates to the technical field of self-powered, the vibration self-powered acoustic emission wireless monitoring device comprises a data collection module, a self-powered module, an acoustic emission monitoring module and a wireless communication module; the data collection module is used for collecting efficiency data of different power supply modes when the equipment is self-powered and vibration data when the equipment is abnormal in historical records; the self-powered module is used for converting mechanical energy of vibration into electric energy for storage by using different power supply modes, and self-powered by using the stored electric energy when the system works; the acoustic emission monitoring module is used for collecting acoustic emission signals generated in the working process of the equipment by using a piezoelectric ceramic sensor, judging whether the equipment has abnormal risks or not and performing early warning; and the wireless communication module is used for sending an abnormal early warning signal to a client of a user by using a wireless network when the system judges that the equipment has the abnormal risk and gives an early warning, so as to remind the user that the equipment has the abnormal risk for maintenance.

Description

Technical Field

[0001] The invention relates to the technical field of self-powered technology, in particular to a vibration self-powered acoustic emission wireless monitoring device and system. Background Art

[0002] In many industrial and engineering applications, the status of equipment or structures needs to be monitored for a long time. Traditional wired monitoring methods have problems such as complex wiring, high cost, and difficult maintenance, which limit the widespread application of monitoring systems. Wireless monitoring technology has the advantages of no wiring, easy installation, and high flexibility, and has become a development trend in the monitoring field. However, the power supply problem of wireless monitoring equipment has always been one of the key factors restricting its development. The traditional battery-powered method requires regular replacement of batteries, which not only increases maintenance costs, but may also cause monitoring interruptions; vibration is a widespread phenomenon in nature and engineering fields. Many equipment will generate vibration during operation, such as mechanical processing equipment, rotating machinery, bridges, buildings, etc. These vibrations contain abundant energy. If they can be effectively collected and converted into electrical energy to provide self-powered wireless monitoring equipment, the power supply problem of wireless monitoring equipment will be solved and long-term stable operation of the monitoring system will be achieved. Therefore, the use of mechanical energy from vibration to self-power the acoustic emission monitoring system has gradually begun to be used. However, when using piezoelectric ceramic sensors to self-power the acoustic emission monitoring system, the self-power supply cannot be sustained because the working time and frequency of the acoustic emission monitoring system are not fixed and the vibration of the equipment is unstable. In addition, the vibration of the equipment includes the vibration generated by itself during operation and the vibration caused by the environment. The two types of vibrations are quite different. A single piezoelectric ceramic sensor cannot adapt to all types of vibrations, resulting in low self-power efficiency. Summary of the invention

[0003] The purpose of the present invention is to provide a vibration self-powered acoustic emission wireless monitoring device and system to solve the problems raised in the prior art.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A vibration self-powered acoustic emission wireless monitoring system, the acoustic emission wireless monitoring system includes a data collection module, a self-powered module, an acoustic emission monitoring module and a wireless communication module;

[0006] The data collection module is used to collect efficiency data of different power supply modes when the device is self-powered in the historical records and vibration data when the device is abnormal;

[0007] The self-powered module is used to convert the mechanical energy of vibration into electrical energy by using different power supply modes for storage, and use the stored electrical energy for self-powering when the system is working;

[0008] The acoustic emission monitoring module is used to collect the acoustic emission signals generated during the operation of the equipment using a piezoelectric ceramic sensor, determine whether the equipment has abnormal risks and issue an early warning;

[0009] The wireless communication module is used to send an abnormal warning signal to the user's client using a wireless network when the system determines that the device has an abnormal risk and issues an early warning, reminding the user that the device has an abnormal risk and needs maintenance.

[0010] The self-powered module includes a piezoelectric self-powered unit, an electromagnetic self-powered unit, an intelligent switching unit and an electric energy storage unit;

[0011] The piezoelectric self-powered unit is used to collect the mechanical energy of the vibration of the equipment using the piezoelectric ceramic sensor. The vibration mechanical energy acts on the piezoelectric ceramic sensor to cause the piezoelectric ceramic to deform periodically. During the deformation process, the surface of the piezoelectric ceramic sensor continuously generates charges to form a potential difference and generate electrical energy. Before the piezoelectric ceramic sensor works, the working efficiency of the piezoelectric ceramic sensor in the historical records is used to calculate the self-powered vibration range of the piezoelectric ceramic sensor.

[0012] The specific steps of calculating the self-powered vibration range of the piezoelectric ceramic sensor are:

[0013] The vibration data and power supply efficiency of the device when the piezoelectric ceramic sensor is working in the historical records are collected, and the vibration data includes vibration frequency and vibration amplitude. The power supply efficiency of the piezoelectric ceramic sensor when working in the collected historical records is used as the vertical coordinate, and the vibration amplitude and vibration frequency of the device are used as the horizontal coordinates to draw scatter plots respectively, and the power supply efficiency scatter plots of the two piezoelectric ceramic sensors are obtained; the correlation between the two scatter plots of the vibration amplitude and the vibration frequency of the device and the power supply efficiency of the piezoelectric ceramic sensor is calculated respectively, and the correlation calculated for the vibration amplitude and the power supply efficiency is specifically:

[0014] First, calculate the average value of the vibration amplitude and power supply efficiency in the scatter plot. The formula is:

[0015]

[0016] In the formula, Av p Represents the average value of the vibration amplitude in the scatter plot, Av i Represents the vibration amplitude value at each point in the scatter plot, Ps p Represents the average value of power supply efficiency in the scatter plot, Ps i represents the power supply efficiency at each point in the scatter plot, n is the total number of points in the scatter plot, and i is from 1 to n;

[0017] Then the covariance of the vibration amplitude and power supply efficiency in the scatter plot is calculated as follows:

[0018]

[0019] In the formula, Cov(Av, Ps) is the covariance of the vibration amplitude and power supply efficiency in the scatter plot, and the standard deviation of the vibration amplitude is calculated using the average value of the vibration amplitude and power supply efficiency as Av st , the standard deviation of power supply efficiency is Ps st ; Finally, the correlation between vibration amplitude and power supply efficiency is calculated, and the formula is:

[0020]

[0021] In the formula, R(Av, Ps) represents the correlation between the calculated vibration amplitude and the power supply efficiency. The correlation between the vibration frequency and the power supply efficiency is calculated using the same method. The two correlations are compared to determine and select the vibration data with the largest correlation as the working characteristics of the piezoelectric self-power supply.

[0022] After calculating the working characteristics of the piezoelectric self-powered device, the scatter plots corresponding to the working characteristics are connected to form a curve, and the curve is derived to obtain the derivative curve of the working characteristics. The points where the derivative is 0 in the derivative curve are extracted, and the peaks and valleys adjacent to the derivative 0 point in the derivative curve are found. The points corresponding to the peaks and valleys adjacent to the derivative 0 point are used to construct the working characteristic interval as [G f , G d ] and the constructed working characteristic interval is taken as the optimal working interval of piezoelectric self-powering.

[0023] The electromagnetic self-powered unit is used to collect vibration data of the device, and utilize the vibration of the device to generate induced electromotive force through electromagnetic induction to generate electrical energy;

[0024] In the electromagnetic self-powered unit, the same method as in the piezoelectric self-powered unit is used to determine the working characteristics of the electromagnetic self-powered unit, and the working characteristic scatter plot is derived to obtain the derivative curve. The derivative curve is analyzed to find the point where the derivative is 0, and the adjacent peaks and valleys are extracted to construct the optimal working range of the electromagnetic self-powered unit as [F f , F d ].

[0025] By using the vibration data of the equipment in the historical records and the functional efficiency analysis to calculate the optimal functional range of the two functional modes, the energy conversion efficiency can be maximized, more input energy can be converted into usable electrical energy, and energy waste can be reduced; when the equipment is in the optimal functional range, the coordination of various related parameters is most appropriate, the internal and external interference of the equipment or system is relatively small, and the expected effect can be continuously and stably output;

[0026] The intelligent switching unit is used to collect vibration data of the device in real time, and use the vibration data to select and switch the self-powered mode of the device, specifically:

[0027] Collect the vibration data of the equipment in real time, including the real-time vibration amplitude and the real-time vibration frequency; determine the real-time working characteristic values ​​of the piezoelectric self-powered and inductive self-powered modes Gs and Fs respectively according to the two real-time vibration data;

[0028] The best working range of the two power supply modes is used to judge the real-time working characteristic value. f , G d ]and When the device is powered by the piezoelectric self-powered unit, it switches to the piezoelectric self-powered mode.

[0029] when And Fs∈[F f , F d ], the device selects the inductive self-powered unit for separate power supply and switches to the inductive self-powered mode;

[0030] When Gs∈[G f , G d ] and Fs∈[F f , F d ], the device selects bidirectional power supply from the piezoelectric self-powered unit and the inductive self-powered unit and switches to the hybrid power supply mode.

[0031] Freely switching between these two power supply modes according to the vibration of the device can better adapt to the energy acquisition needs of the device under various vibration conditions, ensuring that electrical energy can be continuously and stably collected in different vibration scenarios. Piezoelectric ceramics and electromagnetic induction each have their own advantages when facing the problem of intermittent vibration. After the vibration stops, piezoelectric ceramics may still be able to maintain a certain amount of electrical energy output for a certain period of time due to factors such as previously accumulated stress; electromagnetic induction can respond quickly and start collecting electrical energy when the vibration starts again. By freely switching between the two modes, the energy acquisition method can be flexibly adjusted when the vibration changes intermittently, ensuring the continuity of the power supply and avoiding power outages caused by vibration interruptions. And the mechanism of free switching according to the vibration situation can ensure that the vibration energy of the device is converted into electrical energy with the highest efficiency at any time, reducing energy loss during the conversion process and improving the overall energy conversion efficiency.

[0032] The electric energy storage unit includes a voltage stabilization control unit and a power distribution unit;

[0033] The voltage stabilization control unit is used to convert the unstable voltage into a fixed DC voltage after the two self-power supply units generate electric energy, and then store the electric energy of the fixed DC voltage;

[0034] The power distribution unit is used to collect the load of the monitoring system when the equipment is working. When the stored electric energy is insufficient to provide the electric energy required by the monitoring system, the electric energy generated in real time is directly input into the monitoring system for power supply; when the stored electric energy is sufficient to provide the electric energy required by the monitoring system, the electric energy generated in real time is input into the battery for storage without being input into the monitoring system.

[0035] When the monitoring system is self-powered, the generated electric energy is not stable due to the instability of vibration, and the monitoring system cannot be powered stably and continuously. Setting up an energy storage unit can integrate the generated electric energy to achieve stable and continuous power supply to the monitoring system. After setting up a battery to store electric energy, the device can rely on battery power to complete the startup operation during the period when no energy collection is performed, without waiting for the energy collection device to start collecting enough electric energy again to start, thereby improving the flexibility of the device operation and enabling it to better adapt to different working modes and needs.

[0036] The acoustic emission monitoring module includes a threshold calculation unit, an intelligent start unit and an early warning unit;

[0037] The threshold calculation unit includes a start threshold unit and a warning threshold unit;

[0038] The start threshold unit is used to collect the vibration frequency of the device when it is working and not working in the historical records by using the data collection module, calculate the average value and standard deviation of the vibration frequency when the device is not working and when it is working, and calculate the maximum vibration frequency limit when the device is not working. The formula is: Zw max =Zw p +Zw st , in the formula, Zw max Indicates the maximum vibration frequency limit when the calculated equipment is not working, Zw p Indicates the average value of the vibration frequency when the equipment is not working, Zw st Indicates the standard deviation of the vibration frequency when the equipment is not working; calculate the minimum vibration frequency limit when the equipment is working, the formula is: Zg min =Zg p -Zg st , in the formula, Zg min Indicates the minimum vibration frequency limit when the equipment is working, Zg p Indicates the average value of the vibration frequency of the equipment when it is working, Zg st Indicates the standard deviation of the vibration frequency when the equipment is working; the start threshold of the equipment is calculated using the maximum vibration frequency limit when the equipment is not working and the minimum vibration frequency limit when the equipment is working. The formula is: Zy=Zg min -Zw max , Zy represents the calculated startup threshold of the device;

[0039] The warning threshold unit is used to collect abnormal acoustic emission signals of the equipment when it is working in the historical records by using the data collection module, calculate the average value and standard deviation of the collected abnormal acoustic emission signals of the equipment when it is working, and then calculate the warning threshold of the equipment. The formula is: ZJ = H P -H st , ZJ represents the calculated warning threshold of the equipment, H P It represents the average value of the abnormal acoustic emission signal when the equipment is working. st It represents the standard deviation of the calculated acoustic emission signal when abnormalities occur during the operation of the equipment.

[0040] The intelligent starting unit is used to collect the vibration frequency of the equipment in real time, analyze the change amplitude of the real-time vibration frequency of the equipment, and obtain the change amplitude of the real-time vibration frequency of the equipment as Fzs; use the starting threshold to judge the change amplitude of the real-time vibration frequency, when Fzs≥Zy, it is judged that the equipment has started to work, and the monitoring system is started to monitor the equipment in real time; when Fzs<Zy, it is judged that the equipment has not started to work, and the monitoring system is not started, so that the monitoring system is in a dormant state.

[0041] The early warning unit is used to collect the acoustic emission signal of the equipment when it is working in real time. When the equipment starts to work and the monitoring system is started, the real-time acoustic emission signal of the equipment when it is working is judged by using the early warning threshold. The real-time acoustic emission signal of the equipment when it is working is set to be Pzs. When Pzs<ZJ, it is judged that there is no abnormal risk for the equipment; when Pzs≥ZJ, it is judged that there is an abnormal risk for the equipment, and the monitoring system issues an early warning; and the early warning signal of the monitoring system is transmitted to the user client by using the wireless communication module.

[0042] A vibration self-powered acoustic emission wireless monitoring device, the acoustic emission wireless monitoring device comprising a self-powered device, an acoustic emission monitoring device and a wireless communication device;

[0043] The self-powered device is used to collect the vibration mechanical energy of the equipment, convert the mechanical energy into electrical energy to self-power the acoustic emission monitoring equipment;

[0044] The acoustic emission monitoring device is used to monitor the real-time acoustic emission signals of the equipment when the equipment is working, and use the acoustic emission sensor to collect the acoustic emission signals of the equipment in real time when the equipment is working, to determine whether there is an abnormal risk of the equipment and issue an early warning;

[0045] The wireless communication device is used to send an abnormal warning signal to the user's client using a wireless network when the system determines that the equipment has an abnormal risk and issues an early warning, reminding the user that the equipment has an abnormal risk and needs maintenance.

[0046] The self-powered device includes a piezoelectric self-powered device, an electromagnetic self-powered device and an electric energy storage device;

[0047] The piezoelectric self-powered device is used to set a piezoelectric ceramic sensor to convert the vibration mechanical energy of the equipment, and use the vibration mechanical energy to act on the piezoelectric ceramic sensor to cause the piezoelectric ceramic to undergo periodic deformation. During the deformation process, the surface of the piezoelectric ceramic sensor continuously generates charges to form a potential difference and generate electrical energy;

[0048] The electromagnetic self-powered device is used to set a permanent magnet and an electromagnetic induction coil, and when the device vibrates, the set permanent magnet is prompted to pass through the electromagnetic induction coil to generate electrical energy;

[0049] The electric energy storage device is used to set a voltage stabilizing circuit and a rechargeable battery, and the voltage stabilizing circuit is used to stabilize the voltage of the generated electric energy; and the battery is used to store the generated electric energy.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] 1. The present invention utilizes the vibration data of the equipment when it is working in the historical records and the functional efficiency analysis to calculate the optimal functional range of the two functional modes, which can maximize the energy conversion efficiency, convert more input energy into usable electrical energy, and reduce energy waste; when the equipment is in the optimal functional range, the coordination of various related parameters is most appropriate, the internal and external interference of the equipment or system is relatively small, and the desired effect can be continuously and stably output.

[0052] 2. The present invention can freely switch between the two power supply modes according to the vibration of the device, which can better adapt to the energy acquisition needs of the device under various vibration conditions and ensure that electric energy can be continuously and stably collected in different vibration scenarios. By freely switching between the two modes, the energy acquisition method can be flexibly adjusted when the vibration changes intermittently, ensuring the continuity of the power supply and avoiding power supply interruptions caused by vibration interruptions. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a module distribution diagram of the vibration self-powered acoustic emission wireless monitoring system of the present invention;

[0054] Figure 2 This is a device connection diagram of the vibration self-powered acoustic emission wireless monitoring device of the present invention. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] Example: Figure 1-Figure 2 As shown, the present invention provides a technical solution.

[0057] A vibration self-powered acoustic emission wireless monitoring system, the acoustic emission wireless monitoring system includes a data collection module, a self-powered module, an acoustic emission monitoring module and a wireless communication module;

[0058] The data collection module is used to collect efficiency data of different power supply modes when the device is self-powered in the historical records and vibration data when the device is abnormal;

[0059] The self-powered module is used to convert the mechanical energy of vibration into electrical energy by using different power supply modes for storage, and use the stored electrical energy for self-powering when the system is working;

[0060] The acoustic emission monitoring module is used to collect the acoustic emission signals generated during the operation of the equipment using a piezoelectric ceramic sensor, determine whether the equipment has abnormal risks and issue an early warning;

[0061] The wireless communication module is used to send an abnormal warning signal to the user's client using a wireless network when the system determines that the device has an abnormal risk and issues an early warning, reminding the user that the device has an abnormal risk and needs maintenance.

[0062] The self-powered module includes a piezoelectric self-powered unit, an electromagnetic self-powered unit, an intelligent switching unit and an electric energy storage unit;

[0063] The piezoelectric self-powered unit is used to collect the mechanical energy of the vibration of the equipment using the piezoelectric ceramic sensor. The vibration mechanical energy acts on the piezoelectric ceramic sensor to cause the piezoelectric ceramic to deform periodically. During the deformation process, the surface of the piezoelectric ceramic sensor continuously generates charges to form a potential difference and generate electrical energy. Before the piezoelectric ceramic sensor works, the working efficiency of the piezoelectric ceramic sensor in the historical records is used to calculate the self-powered vibration range of the piezoelectric ceramic sensor.

[0064] The specific steps of calculating the self-powered vibration range of the piezoelectric ceramic sensor are:

[0065] The vibration data and power supply efficiency of the device when the piezoelectric ceramic sensor is working in the historical records are collected, and the vibration data includes vibration frequency and vibration amplitude. The power supply efficiency of the piezoelectric ceramic sensor when working in the collected historical records is used as the vertical coordinate, and the vibration amplitude and vibration frequency of the device are used as the horizontal coordinates to draw scatter plots respectively, and the power supply efficiency scatter plots of the two piezoelectric ceramic sensors are obtained; the correlation between the two scatter plots of the vibration amplitude and the vibration frequency of the device and the power supply efficiency of the piezoelectric ceramic sensor is calculated respectively, and the correlation calculated for the vibration amplitude and the power supply efficiency is specifically:

[0066] First, calculate the average value of the vibration amplitude and power supply efficiency in the scatter plot. The formula is:

[0067]

[0068] In the formula, Av p Represents the average value of the vibration amplitude in the scatter plot, Av i Represents the vibration amplitude value at each point in the scatter plot, Ps p Represents the average power supply efficiency in the scatter plot, Ps i represents the power supply efficiency at each point in the scatter plot, n is the total number of points in the scatter plot, and i is from 1 to n;

[0069] Then the covariance of the vibration amplitude and power supply efficiency in the scatter plot is calculated as follows:

[0070]

[0071] In the formula, Cov(Av, Ps) is the covariance of the vibration amplitude and power supply efficiency in the scatter plot, and the standard deviation of the vibration amplitude is calculated using the average value of the vibration amplitude and power supply efficiency as Av st , the standard deviation of power supply efficiency is Ps st ; Finally, the correlation between vibration amplitude and power supply efficiency is calculated, and the formula is:

[0072]

[0073] In the formula, R(Av, Ps) represents the correlation between the calculated vibration amplitude and the power supply efficiency. The correlation between the vibration frequency and the power supply efficiency is calculated using the same method. The two correlations are compared to determine and select the vibration data with the largest correlation as the working characteristics of the piezoelectric self-power supply.

[0074] After calculating the working characteristics of the piezoelectric self-powered device, the scatter plots corresponding to the working characteristics are connected to form a curve, and the curve is derived to obtain the derivative curve of the working characteristics. The points where the derivative is 0 in the derivative curve are extracted, and the peaks and valleys adjacent to the derivative 0 point in the derivative curve are found. The points corresponding to the peaks and valleys adjacent to the derivative 0 point are used to construct the working characteristic interval as [G f , G d ] and the constructed working characteristic interval is taken as the optimal working interval of piezoelectric self-powering.

[0075] The electromagnetic self-powered unit is used to collect vibration data of the device, and utilize the vibration of the device to generate induced electromotive force through electromagnetic induction to generate electrical energy;

[0076] In the electromagnetic self-powered unit, the same method as in the piezoelectric self-powered unit is used to determine the working characteristics of the electromagnetic self-powered unit, and the working characteristic scatter plot is derived to obtain the derivative curve. The derivative curve is analyzed to find the point where the derivative is 0, and the adjacent peaks and valleys are extracted to construct the optimal working range of the electromagnetic self-powered unit as [F f , F d ].

[0077] By using the vibration data of the equipment in the historical records and the functional efficiency analysis to calculate the optimal functional range of the two functional modes, the energy conversion efficiency can be maximized, more input energy can be converted into usable electrical energy, and energy waste can be reduced; when the equipment is in the optimal functional range, the coordination of various related parameters is most appropriate, the internal and external interference of the equipment or system is relatively small, and the expected effect can be continuously and stably output;

[0078] The intelligent switching unit is used to collect vibration data of the device in real time, and use the vibration data to select and switch the self-powered mode of the device, specifically:

[0079] Collect the vibration data of the equipment in real time, including the real-time vibration amplitude and the real-time vibration frequency; determine the real-time working characteristic values ​​of the piezoelectric self-powered and inductive self-powered modes Gs and Fs respectively according to the two real-time vibration data;

[0080] The best working range of the two power supply modes is used to judge the real-time working characteristic value. f , G d ]and When the device is powered by the piezoelectric self-powered unit, it switches to the piezoelectric self-powered mode.

[0081] when And Fs∈[F f , F d ], the device selects the inductive self-powered unit for separate power supply and switches to the inductive self-powered mode;

[0082] When Gs∈[G f , G d ] and Fs∈[F f , F d ], the device selects bidirectional power supply from the piezoelectric self-powered unit and the inductive self-powered unit and switches to the hybrid power supply mode.

[0083] Freely switching between these two power supply modes according to the vibration of the device can better adapt to the energy acquisition needs of the device under various vibration conditions, ensuring that electrical energy can be continuously and stably collected in different vibration scenarios. Piezoelectric ceramics and electromagnetic induction each have their own advantages when facing the problem of intermittent vibration. After the vibration stops, piezoelectric ceramics may still be able to maintain a certain amount of electrical energy output for a certain period of time due to factors such as previously accumulated stress; electromagnetic induction can respond quickly and start collecting electrical energy when the vibration starts again. By freely switching between the two modes, the energy acquisition method can be flexibly adjusted when the vibration changes intermittently, ensuring the continuity of the power supply and avoiding power outages caused by vibration interruptions. And the mechanism of free switching according to the vibration situation can ensure that the vibration energy of the device is converted into electrical energy with the highest efficiency at any time, reducing energy loss during the conversion process and improving the overall energy conversion efficiency.

[0084] The electric energy storage unit includes a voltage stabilization control unit and a power distribution unit;

[0085] The voltage stabilization control unit is used to convert the unstable voltage into a fixed DC voltage after the two self-power supply units generate electric energy, and then store the electric energy of the fixed DC voltage;

[0086] The power distribution unit is used to collect the load of the monitoring system when the equipment is working. When the stored electric energy is insufficient to provide the electric energy required by the monitoring system, the electric energy generated in real time is directly input into the monitoring system for power supply; when the stored electric energy is sufficient to provide the electric energy required by the monitoring system, the electric energy generated in real time is input into the battery for storage without being input into the monitoring system.

[0087] When the monitoring system is self-powered, the generated electric energy is not stable due to the instability of vibration, and the monitoring system cannot be powered stably and continuously. Setting up an energy storage unit can integrate the generated electric energy to achieve stable and continuous power supply to the monitoring system. After setting up a battery to store electric energy, the device can rely on battery power to complete the startup operation during the period when no energy collection is performed, without waiting for the energy collection device to start collecting enough electric energy again to start, thereby improving the flexibility of the device operation and enabling it to better adapt to different working modes and needs.

[0088] The acoustic emission monitoring module includes a threshold calculation unit, an intelligent start unit and an early warning unit;

[0089] The threshold calculation unit includes a start threshold unit and a warning threshold unit;

[0090] The start threshold unit is used to collect the vibration frequency of the device when it is working and not working in the historical records by using the data collection module, calculate the average value and standard deviation of the vibration frequency when the device is not working and when it is working, and calculate the maximum vibration frequency limit when the device is not working. The formula is: Zw max =Zw p +Zw st , in the formula, Zw max Indicates the maximum vibration frequency limit when the calculated equipment is not working, Zw p Indicates the average value of the vibration frequency when the equipment is not working, Zw st Indicates the standard deviation of the vibration frequency when the equipment is not working; calculate the minimum vibration frequency limit when the equipment is working, the formula is: Zg min =Zg p -Zg st , in the formula, Zg min Indicates the minimum vibration frequency limit when the equipment is working, Zg p Indicates the average value of the vibration frequency of the equipment when it is working, Zg st Indicates the standard deviation of the vibration frequency when the equipment is working; the start threshold of the equipment is calculated using the maximum vibration frequency limit when the equipment is not working and the minimum vibration frequency limit when the equipment is working. The formula is: Zy=Zg min -Zw max , Zy represents the calculated startup threshold of the device;

[0091] The warning threshold unit is used to collect abnormal acoustic emission signals of the equipment when it is working in the historical records by using the data collection module, calculate the average value and standard deviation of the collected abnormal acoustic emission signals of the equipment when it is working, and then calculate the warning threshold of the equipment. The formula is: ZJ = H P -H st , ZJ represents the calculated warning threshold of the equipment, H P It represents the average value of the abnormal acoustic emission signal when the equipment is working. st It represents the standard deviation of the calculated acoustic emission signal when abnormalities occur during the operation of the equipment.

[0092] The intelligent starting unit is used to collect the vibration frequency of the equipment in real time, analyze the change amplitude of the real-time vibration frequency of the equipment, and obtain the change amplitude of the real-time vibration frequency of the equipment as Fzs; use the starting threshold to judge the change amplitude of the real-time vibration frequency, when Fzs≥Zy, it is judged that the equipment has started to work, and the monitoring system is started to monitor the equipment in real time; when Fzs<Zy, it is judged that the equipment has not started to work, and the monitoring system is not started, so that the monitoring system is in a dormant state.

[0093] The early warning unit is used to collect the acoustic emission signal of the equipment when it is working in real time. When the equipment starts to work and the monitoring system is started, the real-time acoustic emission signal of the equipment when it is working is judged by using the early warning threshold. The real-time acoustic emission signal of the equipment when it is working is set to be Pzs. When Pzs<ZJ, it is judged that there is no abnormal risk for the equipment; when Pzs≥ZJ, it is judged that there is an abnormal risk for the equipment, and the monitoring system issues an early warning; and the early warning signal of the monitoring system is transmitted to the user client by using the wireless communication module.

[0094] A vibration self-powered acoustic emission wireless monitoring device, the acoustic emission wireless monitoring device comprising a self-powered device, an acoustic emission monitoring device and a wireless communication device;

[0095] The self-powered device is used to collect the vibration mechanical energy of the equipment, convert the mechanical energy into electrical energy to self-power the acoustic emission monitoring equipment;

[0096] The acoustic emission monitoring device is used to monitor the real-time acoustic emission signals of the equipment when the equipment is working, and use the acoustic emission sensor to collect the acoustic emission signals of the equipment in real time when the equipment is working, to determine whether there is an abnormal risk of the equipment and issue an early warning;

[0097] The wireless communication device is used to send an abnormal warning signal to the user's client using a wireless network when the system determines that the equipment has an abnormal risk and issues an early warning, reminding the user that the equipment has an abnormal risk and needs maintenance.

[0098] The self-powered device includes a piezoelectric self-powered device, an electromagnetic self-powered device and an electric energy storage device;

[0099] The piezoelectric self-powered device is used to set a piezoelectric ceramic sensor to convert the vibration mechanical energy of the equipment, and use the vibration mechanical energy to act on the piezoelectric ceramic sensor to cause the piezoelectric ceramic to undergo periodic deformation. During the deformation process, the surface of the piezoelectric ceramic sensor continuously generates charges to form a potential difference and generate electrical energy;

[0100] The electromagnetic self-powered device is used to set a permanent magnet and an electromagnetic induction coil, and when the device vibrates, the set permanent magnet is prompted to pass through the electromagnetic induction coil to generate electrical energy;

[0101] The electric energy storage device is used to set a voltage stabilizing circuit and a rechargeable battery, and the voltage stabilizing circuit is used to stabilize the voltage of the generated electric energy; and the battery is used to store the generated electric energy.

[0102] Embodiment: A self-powered acoustic emission monitoring system is now designed. According to the vibration data and power supply efficiency of the monitored object equipment in the historical records, the working characteristics of the piezoelectric sensor are calculated to be the vibration frequency, and the working characteristics of the electromagnetic induction self-power supply are the vibration amplitude; the optimal working range of the vibration frequency of the piezoelectric sensor is [30, 60], and the optimal working range of the vibration amplitude of the electromagnetic induction self-power supply is [10, 18]; according to the working conditions of the equipment in the historical records, the start threshold of the acoustic emission monitoring system is 20, and the warning threshold is 25;

[0103] The vibration frequency of the real-time acquisition device is 32 and the vibration amplitude is 15. According to the judgment, the piezoelectric sensor and the electromagnetic induction self-power supply are both in the optimal working range, and the hybrid power supply mode is implemented to generate electricity using the vibration of the device and then store it;

[0104] And it is judged that the real-time vibration frequency of the equipment is greater than the starting threshold, the acoustic emission monitoring system is started, and the acoustic emission signal of the equipment is monitored, and the real-time acoustic emission signal is assumed to be 26; it is judged that there is an abnormal risk in the equipment, and an early warning is issued; and the wireless communication device is used to transmit the early warning signal to the user client to remind the user that there is an abnormal risk in the equipment.

[0105] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. Vibration self-powered acoustic emission wireless monitoring system, characterized by: The acoustic emission wireless monitoring system includes a data collection module, a self-powered module, an acoustic emission monitoring module and a wireless communication module; The data collection module is used to collect efficiency data of different power supply modes when the device is self-powered in the historical records and vibration data when the device is abnormal; The self-powered module is used to convert the mechanical energy of vibration into electrical energy by using different power supply modes for storage, and use the stored electrical energy for self-powering when the system is working; The acoustic emission monitoring module is used to collect the acoustic emission signals generated during the operation of the equipment using a piezoelectric ceramic sensor, determine whether the equipment has abnormal risks and issue an early warning; The wireless communication module is used to send an abnormal warning signal to the user's client using a wireless network when the system determines that the device has an abnormal risk and issues an early warning, reminding the user that the device has an abnormal risk and needs maintenance.

2. The vibration self-powered acoustic emission wireless monitoring system according to claim 1 is characterized in that: The self-powered module includes a piezoelectric self-powered unit, an electromagnetic self-powered unit, an intelligent switching unit and an electric energy storage unit; The piezoelectric self-powered unit is used to collect the mechanical energy of the vibration of the equipment using the piezoelectric ceramic sensor. The vibration mechanical energy acts on the piezoelectric ceramic sensor to cause the piezoelectric ceramic to deform periodically. During the deformation process, the surface of the piezoelectric ceramic sensor continuously generates charges to form a potential difference and generate electrical energy. Before the piezoelectric ceramic sensor works, the working efficiency of the piezoelectric ceramic sensor in the historical records is used to calculate the self-powered vibration range of the piezoelectric ceramic sensor. The specific steps of calculating the self-powered vibration range of the piezoelectric ceramic sensor are: The vibration data and power supply efficiency of the device when the piezoelectric ceramic sensor is working in the historical records are collected, and the vibration data includes vibration frequency and vibration amplitude. The power supply efficiency of the piezoelectric ceramic sensor when working in the collected historical records is used as the vertical coordinate, and the vibration amplitude and vibration frequency of the device are used as the horizontal coordinates to draw scatter plots respectively, and the power supply efficiency scatter plots of the two piezoelectric ceramic sensors are obtained; the correlation between the two scatter plots of the vibration amplitude and the vibration frequency of the device and the power supply efficiency of the piezoelectric ceramic sensor is calculated respectively, and the correlation calculated for the vibration amplitude and the power supply efficiency is specifically: First, calculate the average value of the vibration amplitude and power supply efficiency in the scatter plot. The formula is: In the formula, Av p Represents the average value of the vibration amplitude in the scatter plot, Av i Represents the vibration amplitude value at each point in the scatter plot, Ps p Represents the average power supply efficiency in the scatter plot, Ps i represents the power supply efficiency at each point in the scatter plot, n is the total number of points in the scatter plot, and i is from 1 to n; Then the covariance of the vibration amplitude and power supply efficiency in the scatter plot is calculated as follows: In the formula, Cov(Av, Ps) is the covariance of the vibration amplitude and power supply efficiency in the scatter plot, and the standard deviation of the vibration amplitude is calculated using the average value of the vibration amplitude and power supply efficiency as Av st , the standard deviation of power supply efficiency is Ps st ; Finally, the correlation between vibration amplitude and power supply efficiency is calculated, and the formula is: In the formula, R(Av, Ps) represents the correlation between the calculated vibration amplitude and the power supply efficiency. The correlation between the vibration frequency and the power supply efficiency is calculated using the same method. The two correlations are compared to determine and select the vibration data with the largest correlation as the working characteristics of the piezoelectric self-power supply. After calculating the working characteristics of the piezoelectric self-powered device, the scatter plots corresponding to the working characteristics are connected to form a curve, and the curve is derived to obtain the derivative curve of the working characteristics. The points where the derivative is 0 in the derivative curve are extracted, and the peaks and valleys adjacent to the derivative 0 point in the derivative curve are found. The points corresponding to the peaks and valleys adjacent to the derivative 0 point are used to construct the working characteristic interval as [G f , G d ] and the constructed working characteristic interval is taken as the optimal working interval of piezoelectric self-powering.

3. The vibration self-powered acoustic emission wireless monitoring system according to claim 2 is characterized in that: The electromagnetic self-powered unit is used to collect vibration data of the device, and utilize the vibration of the device to generate induced electromotive force through electromagnetic induction to generate electrical energy; In the electromagnetic self-powered unit, the same method as in the piezoelectric self-powered unit is used to determine the working characteristics of the electromagnetic self-powered unit, and the working characteristic scatter plot is derived to obtain the derivative curve. The derivative curve is analyzed to find the point where the derivative is 0, and the adjacent peaks and valleys are extracted to construct the optimal working range of the electromagnetic self-powered unit as [F f , F d ].

4. The vibration self-powered acoustic emission wireless monitoring system according to claim 2 is characterized in that: The intelligent switching unit is used to collect vibration data of the device in real time, and use the vibration data to select and switch the self-powered mode of the device, specifically: Collect the vibration data of the equipment in real time, including the real-time vibration amplitude and the real-time vibration frequency; determine the real-time working characteristic values ​​of the piezoelectric self-powered and inductive self-powered modes Gs and Fs respectively according to the two real-time vibration data; The best working range of the two power supply modes is used to judge the real-time working characteristic value. f , G d ]and When the device is powered by the piezoelectric self-powered unit, it switches to the piezoelectric self-powered mode. when And Fs∈[F f , F d ], the device selects the inductive self-powered unit for separate power supply and switches to the inductive self-powered mode; When Gs∈[G f , G d ] and Fs∈[F f , F d ], the device selects bidirectional power supply from the piezoelectric self-powered unit and the inductive self-powered unit and switches to the hybrid power supply mode.

5. The vibration self-powered acoustic emission wireless monitoring system according to claim 2 is characterized in that: The electric energy storage unit includes a voltage stabilization control unit and a power distribution unit; The voltage stabilization control unit is used to convert the unstable voltage into a fixed DC voltage after the two self-power supply units generate electric energy, and then store the electric energy of the fixed DC voltage; The power distribution unit is used to collect the load of the monitoring system when the equipment is working. When the stored electric energy is insufficient to provide the electric energy required by the monitoring system, the electric energy generated in real time is directly input into the monitoring system for power supply; When the stored electric energy is sufficient to provide the electric energy required by the monitoring system, the electric energy generated in real time is input into the battery for storage without being input into the monitoring system.

6. The vibration self-powered acoustic emission wireless monitoring system according to claim 1 is characterized in that: The acoustic emission monitoring module includes a threshold calculation unit, an intelligent start unit and an early warning unit; The threshold calculation unit includes a start threshold unit and a warning threshold unit; The startup threshold unit is used to collect the vibration frequencies of the device when it is working and not working in the historical records by using the data collection module, calculate the average value and standard deviation of the vibration frequencies when the device is not working and when it is working, and calculate the maximum vibration frequency limit when the device is not working. The formula is: Z max =Zw p +Zw st , in the formula, Zw max Indicates the maximum vibration frequency limit when the calculated equipment is not working, Zw p Indicates the average value of the vibration frequency when the equipment is not working, Zw st Indicates the standard deviation of the vibration frequency when the equipment is not working; calculate the minimum vibration frequency limit when the equipment is working, the formula is: Zg min =Zg p -Zg st , in the formula, Zg min Indicates the minimum vibration frequency limit when the equipment is working, Zg p Indicates the average value of the vibration frequency of the equipment when it is working, Zg st Indicates the standard deviation of the vibration frequency when the equipment is working; the start threshold of the equipment is calculated using the maximum vibration frequency limit when the equipment is not working and the minimum vibration frequency limit when the equipment is working. The formula is: Zy=Zg min -Zw max , Zy represents the calculated startup threshold of the device; The warning threshold unit is used to collect abnormal acoustic emission signals of the equipment when it is working in the historical records by using the data collection module, calculate the average value and standard deviation of the collected abnormal acoustic emission signals of the equipment when it is working, and then calculate the warning threshold of the equipment. The formula is: ZJ = H P -H st , ZJ represents the calculated warning threshold of the equipment, H P It represents the average value of the abnormal acoustic emission signal when the equipment is working. st It represents the standard deviation of the calculated acoustic emission signal when abnormalities occur during the operation of the equipment.

7. The vibration self-powered acoustic emission wireless monitoring system according to claim 6 is characterized in that: The intelligent starting unit is used to collect the vibration frequency of the equipment in real time, analyze the change amplitude of the real-time vibration frequency of the equipment, and obtain the change amplitude of the real-time vibration frequency of the equipment as Fzs; use the starting threshold to judge the change amplitude of the real-time vibration frequency, when Fzs≥Zy, it is judged that the equipment has started to work, and the monitoring system is started to monitor the equipment in real time; when Fzs<Zy, it is judged that the equipment has not started to work, and the monitoring system is not started, so that the monitoring system is in a dormant state.

8. The vibration self-powered acoustic emission wireless monitoring system according to claim 6 is characterized in that: The early warning unit is used to collect the acoustic emission signal of the equipment when it is working in real time. When the equipment starts to work and the monitoring system is started, the real-time acoustic emission signal of the equipment when it is working is judged by using the early warning threshold. The real-time acoustic emission signal of the equipment when it is working is set to be Pzs. When Pzs<ZJ, it is judged that there is no abnormal risk for the equipment; when Pzs≥ZJ, it is judged that there is an abnormal risk for the equipment, and the monitoring system issues an early warning; and the early warning signal of the monitoring system is transmitted to the user client by using the wireless communication module.

9. A vibration self-powered acoustic emission wireless monitoring device, characterized in that: The acoustic emission wireless monitoring device includes a self-powered device, an acoustic emission monitoring device and a wireless communication device; The self-powered device is used to collect the vibration mechanical energy of the equipment, convert the mechanical energy into electrical energy to self-power the acoustic emission monitoring equipment; The acoustic emission monitoring device is used to monitor the real-time acoustic emission signals of the equipment when the equipment is working, and use the acoustic emission sensor to collect the acoustic emission signals of the equipment in real time when the equipment is working, to determine whether there is an abnormal risk of the equipment and issue an early warning; The wireless communication device is used to send an abnormal warning signal to the user's client using a wireless network when the system determines that the equipment has an abnormal risk and issues an early warning, reminding the user that the equipment has an abnormal risk and needs maintenance.

10. The vibration self-powered acoustic emission wireless monitoring device according to claim 9, characterized in that: The self-powered device includes a piezoelectric self-powered device, an electromagnetic self-powered device and an electric energy storage device; The piezoelectric self-powered device is used to set a piezoelectric ceramic sensor to convert the vibration mechanical energy of the equipment, and use the vibration mechanical energy to act on the piezoelectric ceramic sensor to cause the piezoelectric ceramic to undergo periodic deformation. During the deformation process, the surface of the piezoelectric ceramic sensor continuously generates charges to form a potential difference and generate electrical energy; The electromagnetic self-powered device is used to set a permanent magnet and an electromagnetic induction coil, and when the device vibrates, the set permanent magnet is prompted to pass through the electromagnetic induction coil to generate electrical energy; The electric energy storage device is used to set up a voltage stabilizing circuit and a rechargeable battery, and the voltage stabilizing circuit is used to stabilize the generated electric energy voltage; The generated electrical energy is stored in batteries.

Images