A self-powered edge node device for monitoring the wear state of an axial piston pump

Abstract

The present invention relates to the wear state monitoring of an axial piston pump, and particularly to a self-powered edge node device for monitoring the wear state of an axial piston pump. It includes a CPU; a power supply module, which includes a generator and an energy storage power supply circuit to supply power to the sensing module and the CPU; a sensing module, which includes a sensing motor and a Hall current sensor. The sensing motor is arranged on the piston pump and generates a current signal containing wear state information. The Hall current sensor is connected to the sensing motor and converts the current signal into a voltage signal; an analysis module, which includes an A / D conversion and a wear state conversion recognition algorithm. The A / D conversion is connected to the Hall current sensor to convert the voltage signal into a digital signal, and the analysis module runs the wear state conversion recognition algorithm to identify the wear state; a transmission module, which uploads the recognition result of the analysis module. An edge node is set on the piston pump to directly monitor the state of the piston pump, reducing the latency and bandwidth requirements.

Description

Technical Field

[0001] The present invention relates to the wear state monitoring of axial piston pumps, and particularly to a self-powered edge node device for monitoring the wear state of axial piston pumps. Background Art

[0002] As the heart of hydraulic transmission and control systems, axial piston pumps are widely used in high-end equipment fields such as aerospace, marine vessels, and construction machinery. Affected by manufacturing process defects, high-pressure and high-speed working conditions, and harsh working environments, axial piston pumps are extremely prone to wear, resulting in reduced efficiency, economic losses, and even casualties. Therefore, it is very important to monitor the wear state of axial piston pumps.

[0003] Existing methods for monitoring the wear state of axial piston pumps install vibration sensors and eddy current sensors on the axial piston pumps, and transmit the collected vibration signals and vibration displacement signals to the cloud platform for time-domain, frequency-domain, and time-frequency domain analysis to identify the wear state. There are two problems with such methods: on the one hand, the amount of data transmitted to the cloud platform is huge, consuming a large amount of computing and storage resources of the cloud platform and bringing a certain delay; on the other hand, vibration sensors and eddy current sensors require additional installation space, and the signal transmission path is long, and the signals are easily interfered by noise.

[0004] Although edge computing distributes the functions of the cloud platform to edge nodes, it can reduce the transmission bandwidth, relieve the computing and storage pressure, and improve the real-time performance, but it still faces the problems of sensor installation and long signal transmission paths. At the same time, edge nodes that work in real time require continuous and stable energy supply, and traditional batteries have problems such as high cost, difficult recycling, and environmental pollution, and are not the best solution for supplying energy to edge nodes in the context of the Internet of Things. Summary of the Invention

[0005] In view of the above deficiencies or defects in the prior art, the present invention provides a self-powered edge node device for monitoring the wear state of axial piston pumps, and the edge node can directly detect the working state of the piston pump at the piston pump.

[0006] A self-powered edge node device for monitoring the wear state of axial piston pumps includes a power supply module, a CPU, a sensing module, an analysis module, and a transmission module.

[0007] The power supply module includes a generator and an energy storage and power supply circuit, and powers the sensing module and the CPU.

[0008] The sensing module includes a sensing motor and a Hall current sensor. The sensing motor is arranged on the piston pump and generates a current signal containing wear state information, and the Hall current sensor is connected to the sensing motor and converts the current signal into a voltage signal.

[0009] The analysis module includes an A / D conversion and a wear state conversion recognition algorithm. The A / D conversion is connected to a Hall current sensor to convert the voltage signal into a digital signal, and the analysis module runs the wear state conversion recognition algorithm to identify the wear state.

[0010] The transmission module uploads the recognition result of the analysis module.

[0011] Preferably, the generator is a triboelectric nanogenerator; the generator includes a power supply film 1, a power supply film 2, a conductive electrode 1, and a conductive electrode 2. The power supply film 1 and the conductive electrode 1 are laminated and pasted together, and the power supply film 2 and the conductive electrode 2 are pasted together; the conductive electrode 1 and the conductive electrode 2 are electrically connected to an energy storage power supply circuit. The diameters of the power supply film 1 and the power supply film 2 are 1 cm, the thickness is 100 μm, and the material is polytetrafluoroethylene. The sizes of the conductive electrode 1 and the conductive electrode 2 are the same as those of the power supply film 1 and the power supply film 2 respectively, and the thickness of both is 400 μm, and the material is aluminum.

[0012] Preferably, a pit is provided on the low-pressure side of the swash plate of the plunger pump, and the generator is arranged in the pit. A through hole penetrating the swash plate is provided at the bottom of the pit, and the generator wire is arranged in the through hole. There are two pits, and the power supply film 1 and the power supply film 2 of the generator are respectively arranged in the two pits. The diameter of the pit is the same as the diameter of the installed power supply film, and the depth of the pit is the same as the thickness after the power supply film and the conductive electrode are laminated.

[0013] Preferably, the sensing motor is a triboelectric nanogenerator. The sensing motor includes a sensing film 1, a sensing film 2, a conductive electrode 3, and a conductive electrode 4. The sensing film 1 and the conductive electrode 3 are laminated and pasted together, and the sensing film 2 and the conductive electrode 4 are pasted together; the power supply electrode 3 and the power supply electrode 4 are electrically connected to a Hall current sensor. The sizes of the sensing film 1 and the sensing film 2 are the same, with a diameter of 1 cm and a thickness of 100 μm, and the material is polyimide. The sizes of the conductive electrode 3 and the conductive electrode 4 are the same as those of the sensing film 1 and the sensing film 2 respectively, and the thickness of the conductive electrode 3 and the conductive electrode 4 is 400 μm, and the material is aluminum.

[0014] Preferably, a pit is provided on the high-pressure side of the swash plate of the plunger pump, and the sensing motor is arranged in the pit. A through hole penetrating the swash plate is provided at the bottom of the pit, and the sensing motor wire is arranged in the through hole. There are two pits, and the sensing film 1 and the sensing film 2 of the sensing motor are respectively arranged in the pits. The diameter of the pit is the same as the diameter of the installed sensing film, and the depth of the pit is the same as the thickness after the sensing film and the conductive electrode are laminated.

[0015] Preferably, the energy storage power supply circuit is electrically connected to the generator, and the energy storage power supply circuit includes a bridge rectifier circuit, a capacitor charging circuit, and a capacitor discharging circuit.

[0016] Preferably, the analysis module further includes a preprocessing algorithm. The A / D conversion converts the voltage signal into a digital signal, the preprocessing algorithm converts the digital signal into a preprocessed signal, and the wear state recognition algorithm realizes the wear state recognition based on the preprocessed signal. The preprocessing algorithm in the analysis module obtains the preprocessed signal by removing the bias value of the digital signal.

[0017] Preferably, the wear state recognition algorithm in the analysis module recognizes the wear state by comparing the root mean square value of the preprocessed signal and the wear threshold I 1 、 I 2 、 I 3 、 I 4 , and recognizes the wear state.

[0018] When 0 ≤ root mean square value < I 1 , the wear state recognition result is the normal state;

[0019] When I 1 ≤ root mean square value < I 2 , the wear state recognition result is slight wear;

[0020] When I 2 ≤ root mean square value < I 3 , the wear state recognition result is moderate wear;

[0021] When I 3 ≤ root mean square value < I 4 , the wear state recognition result is severe wear.

[0022] Preferably, the transmission module includes USART wired transmission and / or 4G / Wifi wireless transmission.

[0023] Preferably, the energy storage power supply circuit, the Hall current sensor, the CPU, the analysis module, and the transmission module are integrated on the same circuit board, and the circuit board is installed on the plunger pump to be monitored.

[0024] Through the above technical solution of the present invention, a self-powered edge node device for monitoring the wear state of an axial piston pump has the following effects:

[0025] A self-powered edge node device for monitoring the wear state of an axial piston pump converts the mechanical energy dissipated during the operation of the axial piston pump into electrical energy by installing a triboelectric nanogenerator for power supply on the axial piston pump, and powers the CPU and the sensing module without the need for external power supply. By installing a triboelectric nanogenerator for sensing on the axial piston pump, a current signal containing the wear state is generated using the triboelectric generation principle, which not only does not require additional installation space but also shortens the signal transmission path. Wear state recognition is achieved at the edge end closer to the axial piston pump, shortening the delay time and thus improving the real-time performance. Through the transmission module, only the wear state recognition result needs to be transmitted to other devices such as the cloud platform and the host computer, which not only reduces the transmission bandwidth but also alleviates the computing and storage pressure of the cloud platform and the host computer. Therefore, the present invention is particularly suitable for high-end equipment fields such as aerospace, marine vessels, and construction machinery that have high requirements for the stable and reliable operation of axial piston pumps.

[0026] Other features and advantages of the present invention will be described in detail in the following specific implementation section. Brief Description of the Drawings

[0027] Figure 1 is the overall block diagram of the edge node in the present invention;

[0028] Figure 2 is a schematic diagram of the generator and the induction motor in the present invention;

[0029] Figure 3 is the circuit diagram of the power supply module in the present invention;

[0030] Figure 4 is the flowchart of the analysis module in the present invention. Specific Embodiments

[0031] The following details the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only for illustrating and explaining the present invention and are not used to limit the present invention.

[0032] In the present invention, unless otherwise stated, the orientation terms such as "upper" and "lower" generally refer to the orientation in the assembled and used state. "Inner" and "outer" refer to the inside and outside relative to the contour of each component itself.

[0033] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances for the embodiments of the present invention described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion.

[0034] To solve the problem that the traditional plunger pump monitoring device referred to in the background art needs to send a large amount of data to the server, with high latency and large bandwidth occupation, the present invention provides a self-powered edge node device for monitoring the wear state of an axial plunger pump, as Figures 1 to 4 shown in, which includes a power supply module, a CPU, a sensing module, an analysis module, and a transmission module. The CPU controls the operation of the analysis module and the transmission module.

[0035] The power supply module includes a generator and an energy storage power supply circuit, which supplies power to the sensing module and the CPU.

[0036] The sensing module includes a sensing motor and a Hall current sensor. The sensing motor is arranged on the plunger pump and generates a current signal containing wear state information. The Hall current sensor is connected to the sensing motor and converts the current signal into a voltage signal.

[0037] The analysis module includes an A / D conversion and a wear state conversion recognition algorithm. The A / D conversion is connected to the Hall current sensor to convert the voltage signal into a digital signal. The analysis module runs the wear state conversion recognition algorithm to identify the wear state.

[0038] The transmission module uploads the recognition result of the analysis module.

[0039] Among them, the generator is a device that timely uses the rotation of the plunger pump itself to generate electricity for other devices. Therefore, the generator can be a traditional rotor generator, which can be installed on the plunger pump. However, considering that this setting method will change the contour of the plunger pump and occupy space on the one hand, and on the other hand, considering that the power consumption of the edge node itself is extremely small, specially setting a rotor motor is overkill and has a large mass. Therefore, preferably, as Figure 2 shown in, the generator adopts a triboelectric nanogenerator.

[0040] Specifically, the generator includes a power supply film 1, a power supply film 2, a conductive electrode 1, and a conductive electrode 2. The power supply film 1 and the conductive electrode 1 are adhered to each other, and the power supply film 2 and the conductive electrode 2 are adhered to each other. The conductive electrode 1 and the conductive electrode 2 are electrically connected to the energy storage power supply circuit, that is, the power supply film 1 and the conductive electrode 1 form an electrode. The power supply film 2 and the conductive electrode 2 form another electrode. When the power supply film rubs against other objects, a voltage will be generated. As Figure 2 shown in, the two electrodes of the generator are arranged on the track where the sliding shoes on the low-pressure side of the swash plate slide. When the sliding shoe passes through the electrode, a voltage will be generated.

[0041] The power supply film 1 and the power supply film 2 are both the same size, with a diameter of 1 cm and a thickness of 100 μm, and the material is polytetrafluoroethylene,

[0042] The sizes of the conductive electrode 1 and the conductive electrode 2 are the same as those of the power supply thin film 1 and the power supply thin film 2 respectively. Since the conductive electrode 1 and the power supply thin film 1 are laminated together, their sizes are the same. Similarly, the conductive electrode 2 and the power supply thin film 2 are laminated together, so their sizes are the same. The thickness of the conductive electrode 1 and the conductive electrode 2 is 400 μm, and the material is aluminum.

[0043] A concave pit is provided on the low-pressure side of the swash plate of the piston pump, and the generator is arranged in the concave pit, and the concave pit is located on the track where the slipper slides.

[0044] There are two such concave pits, and the power supply thin film 1 and the power supply thin film 2 of the generator are respectively arranged in the two concave pits. The diameter of the concave pit is the same as that of the power supply thin film 2, and the depth of the concave pit is 0.5 mm. The purpose of the concave pit is to install these two electrodes. Therefore, the size of the concave pit used to install the power supply thin film 1 is the same as that of the power supply thin film 1, and the size of the concave pit used to install the power supply thin film 2 is the same as that of the power supply thin film 2. During installation, the conductive electrode is at the bottom and the power supply thin film is on the surface, and the upper surface of the power supply thin film is flush with the surface of the swash plate. A through hole penetrating the swash plate is provided at the bottom of the concave pit, and the generator wire is arranged in the through hole.

[0045] The sensing motor is a triboelectric nanogenerator. The sensing motor includes a sensing thin film 1, a sensing thin film 2, a conductive electrode 3, and a conductive electrode 4. The sensing thin film 1 and the conductive electrode 3 are pasted to each other, and the sensing thin film 2 and the conductive electrode 4 are laminated and pasted to each other. The power supply electrodes 3 and 4 are electrically connected to the Hall current sensor. Similar to the generator, the two electrodes of the sensing motor are also arranged on the track passed by the slipper. When the working state or the wear degree of the piston pump changes, the current waveform generated by the sensing motor will change. Therefore, the information of the wear state is included in the current signal of the sensing motor.

[0046] Specifically, the sizes of the sensing thin film 1 and the sensing thin film 2 are the same, with a diameter of 1 cm and a thickness of 100 μm, and the material is polyimide.

[0047] The sizes of the conductive electrode 3 and the conductive electrode 4 are the same as those of the sensing thin film 1 and the sensing thin film 2. Since the conductive electrode 3 needs to be laminated with the sensing thin film 1 to form an electrode, their sizes are the same. The conductive electrode 4 needs to be laminated with the sensing thin film 2 to form an electrode, so their sizes are the same, with a thickness of 400 μm and the material is aluminum.

[0048] Such as Figure 2As shown in the right half of [Figure], a pit is provided on the high-pressure side of the swash plate of the plunger pump. The sensing motor is arranged in the pit. There are two pits. The sensing films 1 and 2 of the sensing motor are respectively arranged in the pits, and the pits are located on the sliding track of the slipper. The diameter of the pit is the same as the electrode installed in the pit, that is, the same as the size of the sensing film installed inside. The depth of the pit is 0.5 mm. Therefore, the size of the pit for installing the sensing film 1 is the same as that of the sensing film 1. The size of the pit for installing the sensing film 2 is the same as that of the sensing film 2. During installation, the conductive electrode is at the bottom, the sensing film is on the surface, and the upper surface of the sensing film is flush with the surface of the swash plate. A through hole penetrating the swash plate is provided at the bottom of the pit, and the generator wire is arranged in the through hole. A through hole penetrating the swash plate is provided at the bottom of the pit, and the sensing motor wire is arranged in the through hole.

[0049] As Figure 3 shown in [Figure], since the voltage generated by the triboelectric nanogenerator is not stable, a dedicated energy storage and power supply circuit with energy storage function needs to be set up. The energy storage and power supply circuit includes a bridge rectifier circuit, a capacitor charging circuit and a capacitor discharging circuit.

[0050] As Figure 1 shown in [Figure], the analysis module further includes a preprocessing algorithm. The A / D conversion converts the voltage signal into a digital signal. The preprocessing algorithm converts the digital signal into a preprocessing signal. The wear state recognition algorithm realizes the wear state recognition according to the preprocessing signal. The preprocessing algorithm in the analysis module obtains the preprocessing signal by removing the bias value of the digital signal.

[0051] The wear state recognition algorithm in the analysis module, by comparing the root mean square value of the preprocessing signal and the wear threshold I 1 , I 2 , I 3 , I 4 , recognizes the wear state, and the specific principle is as follows:

[0052] When 0 ≤ root mean square value < I 1 , the wear state recognition result is the normal state;

[0053] When I 1 ≤ root mean square value < I 2 , the wear state recognition result is slight wear;

[0054] When I 2 ≤ root mean square value < I3 When it is in this state, the wear state recognition result is moderate wear;

[0055] When I 3 ≤ root mean square value < I 4 When it is in this state, the wear state recognition result is severe wear.

[0056] The transmission module includes USART wired transmission and / or 4G / Wifi wireless transmission. The function of the transmission module is to send out the recognition result, so the specific module type can be determined according to the specific working conditions.

[0057] The energy storage power supply circuit, Hall current sensor, CPU, analysis module, and transmission module are integrated on the same circuit board, and the circuit board is installed on the plunger pump to be monitored.

[0058] Embodiment

[0059] The following combines the attached Figure 1 –4 to make a detailed description of the present invention. As Figure 1 As shown in Fig. –4, a self-powered edge node device for monitoring the wear state of an axial piston pump includes a CPU, a power supply module, a sensing module, an analysis module, and a transmission module.

[0060] The generator is a triboelectric nanogenerator for power supply, and the induction motor is a triboelectric nanogenerator for sensing.

[0061] Among them, the triboelectric nanogenerator for power supply includes power supply thin film 1 and power supply thin film 2 with a diameter of 1 cm, a thickness of 100 μm, and a material of polytetrafluoroethylene; conductive electrode 1 and conductive electrode 2 with a diameter of 1 cm, a thickness of 400 μm, and a material of aluminum. Power supply thin film 1 and conductive electrode 1 are pasted together. Power supply thin film 2 and conductive electrode 2 are pasted together. By machining two pits with a diameter of 1 cm and a depth of 0.5 mm on the low-pressure side of the swash plate of the axial piston pump, the triboelectric nanogenerator for power supply is installed, and through holes penetrating the swash plate of the axial piston pump are respectively machined at the bottoms of these two pits for arranging wires. Conductive electrode 1 and conductive electrode 2 are connected to the power supply module through wires. When the axial piston pump rotates, the cylinder block drives the piston-slider assembly to rotate, and the slider contacts and slides relative to the swash plate. When the bottom surface of the slider contacts power supply thin film 1, due to triboelectrification and electrostatic induction, induced charges begin to be generated on power supply thin film 1 and power supply thin film 2, and as the contact area between the bottom surface of the slider and power supply thin film 1 and power supply thin film 2 changes, the amounts of induced charges generated on power supply thin film 1 and power supply thin film 2 are also different, thereby generating a changing potential difference between power supply thin film 1 and power supply thin film 2. Since power supply thin film 1 is in contact with conductive electrode 1, power supply thin film 2 is in contact with conductive electrode 2, and conductive electrode 1 and conductive electrode 2 are connected to the power supply module through wires to form a loop, a changing current is generated. In the power supply module, when the switch is closed to the left, the capacitor charging circuit is turned on, and the current generated by the triboelectric nanogenerator for power supply charges the capacitor through the rectifying circuit; when the switch is closed to the right, the capacitor discharging circuit is turned on, and the capacitor supplies the stored electrical energy to the CPU and the sensing module.

[0062] The triboelectric nanogenerator for sensing includes sensing film 1 and sensing film 2 with a diameter of 1 cm, a thickness of 100 μm, and a material of polyimide, and conductive electrodes 3 and 4 with a diameter of 1 cm, a thickness of 400 μm, and a material of aluminum. Sensing film 1 and conductive electrode 3 are pasted together, and sensing film 2 and conductive electrode 4 are pasted together. By machining two pits with a diameter of 1 cm and a depth of 0.5 mm on the high-pressure side of the swash plate of the axial piston pump, the triboelectric nanogenerator for sensing is installed, and through holes penetrating the swash plate of the axial piston pump are machined at the bottoms of these two pits for arranging wires. Conductive electrodes 3 and 4 are connected to the sensing module through wires. When the axial piston pump rotates, the cylinder block drives the plunger-slide shoe assembly to rotate, and the slide shoe contacts and slides relative to the swash plate. When the bottom surface of the slide shoe touches sensing film 1, due to triboelectrification and electrostatic induction, induced charges begin to be generated on sensing film 1 and sensing film 2, and as the contact area between the bottom surface of the slide shoe and sensing film 1 and sensing film 2 changes, the induced charge amounts generated on sensing film 1 and sensing film 2 are also different, thus generating a changing potential difference between sensing film 1 and sensing film 2. Since sensing film 1 is in contact with conductive electrode 3, sensing film 2 is in contact with conductive electrode 4, and conductive electrodes 3 and 4 are connected to the sensing module through wires, a changing current is generated. The Hall current sensor in the sensing module collects the current signal and converts it into a voltage signal U ( t ), and transmits it to the analysis module.

[0063] The CPU is ARM ® Cortex ® -M7 core with an operating frequency of 480 MHz, which can control the analysis module and the transmission module to execute functions.

[0064] When the CPU runs and controls the analysis module and the transmission module to execute functions, the analysis module receives the voltage signal from the sensing module . First, the analysis module performs A / D conversion on the voltage signal to obtain a digital signal , where is the digital signal, is the i th value of the digital signal sequence, N is the number of sampling points, and the sampling frequency is 500 Hz, the sampling resolution is 16 bits, and the number of sampling points is 2048. Then, the preprocessing algorithm removes the bias from the digital signal to obtain a preprocessed signal , where is the preprocessed signal, is the i th value of the preprocessed signal sequence. Finally, the wear state recognition algorithm calculates the processed signal Root mean square value , by comparing the root mean square value of the preprocessed signal and the wear threshold I 1 、 I 2 、 I 3 、 I 4 , identify the wear state recognition, and the specific principle is as follows:

[0065] When 0 ≤ root mean square value < I 1 , the wear state recognition result is the normal state;

[0066] When I 1 ≤ root mean square value < I 2 , the wear state recognition result is slight wear;

[0067] When I 2 ≤ root mean square value < I 3 , the wear state recognition result is moderate wear;

[0068] When I 3 ≤ root mean square value < I 4 , the wear state recognition result is severe wear.

[0069] The analysis module transmits the wear state recognition result to the transmission module. The transmission module selects the wired transmission of USART or / and the wireless transmission of 4G / Wifi according to the control command of the CPU, and transmits the wear state recognition result to other devices such as the cloud platform and the host computer.

[0070] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0071] In addition, it should be noted that, in the case of no contradiction, the various specific technical features described in the above specific embodiments can be combined in any appropriate manner. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0072] Furthermore, any combination can be made between various different embodiments of the present invention, as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. A self-powered edge node device for monitoring the wear state of an axial piston pump, characterized in that, it includes a power supply module, a CPU, a sensing module, an analysis module and a transmission module; The power supply module includes a generator and an energy storage power supply circuit, which supplies power to the sensing module and the CPU; the generator is a triboelectric nanogenerator, and a pit is provided at the position corresponding to the sliding shoe on the low-pressure side of the swash plate of the piston pump, and the generator is arranged in the pit; The sensing module includes a sensing motor and a Hall current sensor. The sensing motor is arranged on the piston pump and generates a current signal containing wear state information. The Hall current sensor is connected to the sensing motor and converts the current signal into a voltage signal; the sensing motor is a triboelectric nanogenerator, and a pit is provided at the position corresponding to the sliding shoe on the high-pressure side of the swash plate of the piston pump, and the sensing motor is arranged in the pit; The analysis module includes an A / D conversion and a wear state conversion recognition algorithm. The A / D conversion is connected to the Hall current sensor to convert the voltage signal into a digital signal, and the analysis module runs the wear state conversion recognition algorithm to identify the wear state; The transmission module uploads the recognition result of the analysis module.

2. The self-powered edge node device for monitoring the wear state of an axial piston pump according to claim 1, characterized in that, The generator includes a power supply thin film 1, a power supply thin film 2, a conductive electrode 1 and a conductive electrode 2. The power supply thin film 1 and the conductive electrode 1 are overlapped and pasted, and the power supply thin film 2 and the conductive electrode 2 are pasted to each other; the conductive electrode 1 and the conductive electrode 2 are electrically connected to the energy storage power supply circuit; The diameters of the power supply thin film 1 and the power supply thin film 2 are 1 cm, the thickness is 100 μm, and the material is polytetrafluoroethylene, The sizes of the conductive electrode 1 and the conductive electrode 2 are the same as those of the power supply thin film 1 and the power supply thin film 2 respectively, and the thickness of both is 400 μm, and the material is aluminum.

3. The self-powered edge node device for monitoring the wear state of an axial piston pump according to claim 2, characterized in that, A through hole penetrating the swash plate is provided at the bottom of the pit, and the generator wire is arranged in the through hole; There are two pits, and the power supply thin film 1 and the power supply thin film 2 of the generator are respectively arranged in the two pits; The diameter of the pit is the same as the diameter of the installed power supply thin film, and the depth of the pit is the same as the thickness after the power supply thin film and the conductive electrode are overlapped.

4. The self-powered edge node device for monitoring the wear state of an axial piston pump according to claim 1, characterized in that, The sensing motor includes the generator including a sensing thin film 1, a sensing thin film 2, a conductive electrode 3 and a conductive electrode 4. The sensing thin film 1 and the conductive electrode 3 are overlapped and pasted, and the sensing thin film 2 and the conductive electrode 4 are pasted to each other; the power supply electrode 3 and the power supply electrode 4 are electrically connected to the Hall current sensor; The sizes of the sensing thin film 1 and the sensing thin film 2 are the same, the diameter is 1 cm, the thickness is 100 μm, and the material is polyimide, The sizes of the conductive electrode 3 and the conductive electrode 4 are the same as those of the sensing thin film 1 and the sensing thin film 2 respectively, and the thickness of the conductive electrode 3 and the conductive electrode 4 is 400 μm, and the material is aluminum.

5. The self-powered edge node device for monitoring the wear state of an axial piston pump according to claim 4, characterized in that, a through hole penetrating the swash plate is provided at the bottom of the pit, and the sensing motor wire is arranged in the through hole; two pits are provided, and the sensing films 1 and 2 of the sensing motor are respectively arranged in the pits; the diameter of the pit is the same as that of the installed sensing film, and the depth of the pit is the same as the thickness after the sensing film and the conductive electrode are laminated.

6. The self-powered edge node device for monitoring the wear state of an axial piston pump according to claim 1, characterized in that, the energy storage power supply circuit is electrically connected to the generator, and the energy storage power supply circuit includes a bridge rectification circuit, a capacitor charging circuit and a capacitor discharging circuit.

7. The self-powered edge node device for monitoring the wear state of an axial piston pump according to claim 1, characterized in that, the analysis module further includes a preprocessing algorithm, the A / D conversion converts the voltage signal into a digital signal, the preprocessing algorithm converts the digital signal into a preprocessing signal, and the wear state recognition algorithm realizes the wear state recognition according to the preprocessing signal; the preprocessing algorithm in the analysis module obtains the preprocessing signal by removing the bias value of the digital signal.

8. The self-powered edge node device for monitoring the wear state of an axial piston pump according to claim 7, characterized in that, The wear state recognition algorithm in the analysis module recognizes the wear state by comparing the root mean square value of the preprocessed signal with the wear threshold I 1 、 I 2 、 I 3 、 I 4 and When 0 ≤ root mean square value < I 1 the wear state recognition result is the normal state; When I 1 ≤ root mean square value < I 2 , the wear state recognition result is slight wear; When I 2 ≤ root mean square value < I 3 the wear state recognition result is moderate wear; When I 3 ≤ root mean square value < I 4 , the wear state recognition result is severe wear.

9. The self-powered edge node device for monitoring the wear state of an axial piston pump according to claim 1, characterized in that, the transmission module includes USART wired transmission and / or 4G / Wifi wireless transmission.

10. The self-powered edge node device for monitoring the wear state of an axial piston pump according to claim 1, characterized in that, the energy storage power supply circuit, the Hall current sensor, the CPU, the analysis module and the transmission module are integrated on the same circuit board, and the circuit board is installed on the piston pump to be monitored.

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