A micro vibration acceleration Internet of Things sensor node and application method

Abstract

The present invention relates to a micro vibration acceleration Internet of Things sensor node and an application method. The node is connected to an Internet of Things server. The node includes a three-axis MEMS acceleration sensor, a temperature and humidity sensor, a microprocessor, a LoRa wireless module and a battery. The microprocessor is respectively connected to the three-axis MEMS acceleration sensor, the temperature and humidity sensor, the LoRa wireless module and the battery. The battery is respectively connected to the three-axis MEMS acceleration sensor, the temperature and humidity sensor and the LoRa wireless module. The three-axis MEMS acceleration sensor, the temperature and humidity sensor and the battery transmit the collected data to the microprocessor. After the microprocessor analyzes and processes the data, the data is sent to the Internet of Things server through the LoRa wireless module. The battery provides energy for all modules. Compared with the prior art, the present invention has the following advantages: compact structure and small volume, significantly reducing the amount of data transmission, and improving the node battery life.

Description

Technical Field

[0001] The present invention relates to the field of vibration acceleration acquisition, and in particular to a micro vibration acceleration Internet of Things sensor node and an application method. Background Art

[0002] Vibration acceleration is a signal that is widely present in nature. Collecting and analyzing it can obtain a lot of useful information. For example, the vibration signal of rolling bearings can be used to analyze its wear and other faults; the vibration signal of motors can be used to analyze its main shaft eccentricity, rotor and other faults; in geological exploration, the collected signals of sensor arrays are used to analyze geological structures; in the security field, the analysis of signals collected by buried vibration sensors can obtain information such as the type of passing vehicles.

[0003] Currently, vibration signal acquisition typically uses piezoelectric or MEMS vibration accelerometers connected to a data acquisition instrument. This approach presents drawbacks such as cumbersome on-site wiring and the need for a power supply. To address these shortcomings, battery-powered vibration accelerometers have been developed that utilize IoT wireless technology to transmit data. However, in practical applications, to effectively extract information from vibration signals, the sampling frequency must be greater than twice the signal's maximum frequency, according to the Nyquist sampling theorem. This typically requires sampling rates of several kilohertz, and a single piece of collected data contains millions of vibration acceleration values. For example, a 30-second sample of triaxial vibration acceleration data at a sampling frequency of 10 kHz yields approximately 2 megabits of data. IoT wireless transmission rates are typically less than 1 kbps, with each packet containing approximately 100 bytes. It is estimated that transmitting this data requires approximately 2,000 packets, or 4,000 seconds (at a 50% duty cycle). Transmitting large amounts of raw vibration data is not only extremely time-consuming and prone to packet loss and data errors, but also consumes significant power, resulting in a short lifespan for the vibration accelerometer. Therefore, these vibration accelerometers present drawbacks in practical applications. Summary of the Invention

[0004] The purpose of the present invention is to provide a micro vibration acceleration Internet of Things sensor node and application method in order to overcome the defects of the above-mentioned prior art.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A micro vibration acceleration Internet of Things sensor node, which is connected to an Internet of Things server and includes a three-axis MEMS acceleration sensor, a temperature and humidity sensor, a microprocessor, a LoRa wireless module, and a battery. The microprocessor is respectively connected to the three-axis MEMS acceleration sensor, the temperature and humidity sensor, the LoRa wireless module, and the battery. The battery is respectively connected to the three-axis MEMS acceleration sensor, the temperature and humidity sensor, and the LoRa wireless module.

[0007] The three-axis MEMS acceleration sensor, temperature and humidity sensor and battery transmit the collected data to the microprocessor. After the microprocessor analyzes and processes the data, it sends it to the Internet of Things server through the LoRa wireless module. The battery provides energy for all modules.

[0008] Preferably, the microprocessor includes an A / D conversion circuit, and the microprocessor converts the analog voltage signal input by the MEMS sensor into a digital signal according to a set sampling frequency and stores the digital signal in a memory.

[0009] Preferably, the analysis and processing of the collected signal by the microprocessor includes: extracting the maximum value, minimum value, peak-to-peak value, mean value, variance and the frequency point and intensity at the peak in the frequency domain, and then forming a data packet to be sent.

[0010] Preferably, the node enters a receiving mode after sending data, and the microprocessor receives the data packet sent by the Internet of Things server through the LoRa wireless module, and modifies the sampling frequency and single sampling duration parameters according to the requirements of the data packet.

[0011] Preferably, the microprocessor calculates the remaining power through the data of the temperature and humidity sensor and the battery voltage, and sends it to the Internet of Things server.

[0012] Preferably, the node further includes an antenna, a housing, a circuit board and a mounting nut. The microprocessor, the three-axis MEMS vibration acceleration sensor, the LoRa wireless module and the temperature and humidity sensor are arranged on the circuit board. The antenna, the battery and the circuit board are fixed in the housing from top to bottom in sequence. A mounting nut is provided at the bottom of the outside of the housing.

[0013] Preferably, the shell is cylindrical and comprises an upper shell and a lower shell, and the upper shell and the lower shell are fixed by threads.

[0014] Preferably, the upper shell is made of ABS engineering plastic, and the lower shell is made of metal material.

[0015] Preferably, the node further includes a circuit board fixing column and a circuit board fixing screw. The circuit board fixing column is arranged at the inner bottom of the shell, and the circuit board is fixed to the circuit board fixing column by the circuit board fixing screw.

[0016] An application method using the micro vibration acceleration Internet of Things sensor node, the method comprising the following steps:

[0017] Step 1: After the node is powered on, it sends a network access request to the IoT server. If it receives a network access response from the IoT server, it enters sleep mode. Otherwise, it sends a network access request again.

[0018] Step 2: When the A / D interface input of the microprocessor exceeds the set threshold, the node is stimulated to enter the sampling mode from the sleep mode, and starts to collect vibration acceleration data at high frequency, converting the sensing data of the three-axis MEMS acceleration sensor into a digital signal and storing it in the node memory;

[0019] Step 3: When the A / D interface input of the microprocessor is continuously lower than the set threshold, the node ends the sampling mode, extracts the maximum value, minimum value, peak-to-peak value, mean value, and mean square error of the raw vibration acceleration data collected this time, and generates a data packet to be sent according to the node transmission data frame format one; the node performs a fast discrete Fourier transform on the collected data this time, extracts the frequency points and intensities of the peaks in the signal frequency domain, arranges them from high to low according to the frequency domain intensity, and generates a data packet to be sent according to the node transmission data frame format two;

[0020] Step 4: The node enters the sending mode and sends the data to be sent to the IoT server;

[0021] Step 5: After sending, the node enters the receiving mode and receives the data packet sent by the IoT server. The node parses the received data frame format and modifies the sampling frequency and single sampling duration parameters according to the data packet requirements.

[0022] Step 6: After completing data transmission and reception, the node re-enters the sleep mode.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. The node of the present invention only sends valid information and no longer sends original vibration data, which significantly reduces the amount of data sent and improves the battery life of the node.

[0025] 2. The node of the present invention processes the collected vibration acceleration data to obtain the frequency point and intensity value at the peak of the frequency domain, the maximum value, the minimum value, the average value, the mean square error and other parameters.

[0026] 3. The node of the present invention is generally in sleep mode. When the vibration acceleration is detected to exceed the set threshold, the microprocessor is triggered to exit sleep mode and start collecting acceleration data at a high frequency to save power.

[0027] 4. The antenna of the present invention adopts a built-in design with a compact structure and small size.

[0028] 5. The node of the present invention calculates the remaining power based on the monitored battery voltage and temperature. The Internet of Things server can monitor the power of the node in real time and provide timely reminders and replacements. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the node principle of the present invention;

[0030] Figure 2 Schematic diagram of the structure of the node of the present invention;

[0031] Figure 3 It is the workflow diagram of the method of the present invention;

[0032] 1 is the antenna, 2 is the battery, 3 is the housing, 4 is the circuit board, 5 is the mounting nut, 6 is the circuit board fixing column, 7 is the circuit board fixing screw, 31 is the upper housing, and 32 is the lower housing. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0034] like Figure 1 As shown, a miniature vibration acceleration Internet of Things sensor node includes a three-axis MEMS acceleration sensor, a temperature and humidity sensor, a microprocessor, a LoRa wireless module and a battery 2. The three-axis MEMS acceleration sensor, temperature and humidity sensor and battery transmit the collected data to the microprocessor. After the microprocessor analyzes and processes the data, it is sent to the Internet of Things server through the LoRa wireless module. The battery provides energy for all modules.

[0035] The microprocessor has an A / D conversion function. The microprocessor converts the analog voltage signal input by the MEMS sensor into a digital signal according to a set sampling frequency and stores the digital signal in the memory.

[0036] The analysis and processing of the collected signal by the microprocessor includes: extracting the maximum value, minimum value, peak-to-peak value, mean value, variance and the frequency point and intensity of the peak value in the frequency domain, and then forming a data packet to be sent.

[0037] The node enters the receiving mode after sending the data. The microprocessor receives the data packet sent by the Internet of Things server through the LoRa wireless module and modifies the sampling frequency and single sampling duration parameters according to the data packet requirements.

[0038] The microprocessor calculates the remaining power through the data of the temperature and humidity sensor and the battery voltage, and sends it to the Internet of Things server.

[0039] like Figure 2As shown, the node also includes an antenna 1, a housing 3, a circuit board 4 and a mounting nut 5. The microprocessor, three-axis MEMS vibration acceleration sensor, LoRa wireless module and temperature and humidity sensor are arranged on the circuit board 4. The antenna 1, battery 2 and circuit board 4 are fixed in the housing from top to bottom. A mounting nut 5 is provided at the bottom of the outside of the housing.

[0040] The housing 3 is cylindrical and includes an upper housing 31 and a lower housing 32. The upper housing 31 is made of ABS engineering plastic, and the lower housing 32 is made of metal. The upper housing 31 and the lower housing 32 are fixed by threads.

[0041] The node further includes a circuit board fixing column 6 and a circuit board fixing screw 7 . The circuit board fixing column 6 is provided at the inner bottom of the housing 3 , and the circuit board 4 is fixed to the circuit board fixing column 6 by the circuit board fixing screw 7 .

[0042] like Figure 3 As shown, an application method using the micro vibration acceleration Internet of Things sensor node includes the following steps:

[0043] Step 1: After the node is powered on, it sends a network access request to the IoT server. If it receives a network access response from the IoT server, it enters sleep mode. Otherwise, it sends a network access request again.

[0044] Step 2: When the microprocessor A / D interface input exceeds the set threshold, the node is stimulated to enter the sampling mode from the sleep mode, and start collecting vibration acceleration data at high frequency, converting the sensing data of the three-axis MEMS acceleration sensor into a digital signal and storing it in the node memory;

[0045] Step 3: When the input of the microprocessor A / D interface is continuously lower than the set threshold, the node ends the sampling mode, extracts the maximum value, minimum value, peak-to-peak value, mean value, and mean square error of the raw vibration acceleration data collected this time, and generates a data packet to be sent according to the node transmission data frame format one; the node performs a fast discrete Fourier transform on the collected data this time, extracts the frequency points and intensities of the peaks in the signal frequency domain, arranges them from high to low according to the frequency domain intensity, and generates a data packet to be sent according to the node transmission data frame format two;

[0046] Step 4: The node enters the sending mode and sends the data to be sent to the IoT server;

[0047] Step 5: After sending, the node enters the receiving mode and receives the data packet sent by the IoT server. The node parses the received data frame format and modifies the sampling frequency and single sampling duration parameters according to the data packet requirements.

[0048] Step 6: After completing data transmission and reception, the node re-enters the sleep mode.

[0049] Table 1 shows the first format of the data frame sent by the node of the present invention; Table 2 shows the second format of the data frame sent by the node of the present invention; and Table 3 shows the format of the data frame received by the node of the present invention.

[0050] Table 1

[0051]

[0052] Table 2

[0053]

[0054] Table 3

[0055] Frame Content Node ID Frame Number Sampling frequency Sampling duration length 2 bytes 1 byte 2 bytes 2 bytes

[0056] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. An application method using a micro vibration acceleration Internet of Things sensor node, the node is connected to an Internet of Things server, characterized in that: The node comprises a three-axis MEMS acceleration sensor, a temperature and humidity sensor, a microprocessor, a LoRa wireless module and a battery (2), wherein the microprocessor is respectively connected to the three-axis MEMS acceleration sensor, the temperature and humidity sensor, the LoRa wireless module and the battery (2), and the battery (2) is respectively connected to the three-axis MEMS acceleration sensor, the temperature and humidity sensor and the LoRa wireless module; The three-axis MEMS acceleration sensor, temperature and humidity sensor and battery transmit the collected data to the microprocessor. After the microprocessor analyzes and processes the data, the data is sent to the Internet of Things server via the LoRa wireless module. The battery (2) provides energy for all modules. The method comprises the following steps: Step 1: After the node is powered on, it sends a network access request to the IoT server. If it receives a network access response from the IoT server, it enters sleep mode. Otherwise, it sends a network access request again. Step 2: When the A / D interface input of the microprocessor exceeds the set threshold, the node is stimulated to enter the sampling mode from the sleep mode, and the vibration acceleration data is collected at high frequency, and the sensing data of the three-axis MEMS acceleration sensor is converted into a digital signal and stored in the node memory; Step 3, when the A / D interface input of the microprocessor is continuously lower than the set threshold, the node ends the sampling mode, and the node extracts the maximum value, minimum value, peak-to-peak value, mean value and mean square error of the original vibration acceleration data collected this time, and generates a data packet to be sent according to the node sending data frame format one; the node performs a fast discrete Fourier transform on the data collected this time, extracts the frequency point and intensity at the peak in the signal frequency domain, arranges them from high to low according to the frequency domain intensity, and generates a data packet to be sent according to the node sending data frame format two; Step 4: The node enters the sending mode and sends the data to be sent to the IoT server; Step 5: After sending, the node enters the receiving mode and receives the data packet sent by the IoT server. The node parses the received data frame format and modifies the sampling frequency and single sampling duration parameters according to the data packet requirements. Step 6: After completing data transmission and reception, the node re-enters the sleep mode.

2. The application method according to claim 1, characterized in that: The microprocessor comprises an A / D conversion circuit. The microprocessor converts the analog voltage signal input by the MEMS sensor into a digital signal according to a set sampling frequency and stores the digital signal in a memory.

3. The application method according to claim 1, characterized in that: The analysis and processing of the collected signal by the microprocessor includes: extracting the maximum value, minimum value, peak-to-peak value, mean value, variance and the frequency point and intensity at the peak value in the frequency domain, and then forming a data packet to be sent.

4. The application method according to claim 1, characterized in that: The node enters the receiving mode after sending the data. The microprocessor receives the data packet sent by the Internet of Things server through the LoRa wireless module and modifies the sampling frequency and single sampling duration parameters according to the requirements of the data packet.

5. The application method according to claim 1, characterized in that: The microprocessor calculates the remaining power through the data of the temperature and humidity sensor and the battery voltage, and sends it to the Internet of Things server.

6. The application method according to claim 1, characterized in that: The node also includes an antenna (1), a housing (3), a circuit board (4) and a mounting nut (5); the microprocessor, the three-axis MEMS vibration acceleration sensor, the LoRa wireless module and the temperature and humidity sensor are arranged on the circuit board (4); the antenna (1), the battery (2) and the circuit board (4) are fixed in the housing in sequence from top to bottom; and a mounting nut (5) is provided at the lower part of the outer shell.

7. The application method according to claim 6, characterized in that: The shell (3) is cylindrical and comprises an upper shell (31) and a lower shell (32). The upper shell (31) and the lower shell (32) are fixed by threads.

8. The application method according to claim 7, characterized in that: The upper shell (31) is a shell made of ABS engineering plastics, and the lower shell (32) is a shell made of metal material.

9. The application method according to claim 6, characterized in that: The node further comprises a circuit board fixing column (6) and a circuit board fixing screw (7) inside, wherein the circuit board fixing column (6) is arranged at the inner bottom of the housing (3), and the circuit board (4) is fixed to the circuit board fixing column (6) by the circuit board fixing screw (7).

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