A single-channel vibrating-wire sensor acquisition device

Abstract

The present invention discloses a single-channel vibrating string sensor acquisition device, which belongs to the technical field of data acquisition devices, and includes a data acquisition instrument 1, a main control gateway, a data acquisition instrument 2 and a monitoring platform. Both the data acquisition instrument 1 and the data acquisition instrument 2 are single-channel vibrating string sensor acquisition instruments, and the single-channel vibrating string sensor acquisition instruments include a communication module, a main control module and a data acquisition module. The communication module includes an RS485 communication interface, a 4G module and a LoRa module. The data acquisition instrument 1 is connected to the main control gateway through an RS485 communication interface or a LoRa module, and the main control gateway is connected to the monitoring platform through a wireless network or a wired network. The data acquisition instrument 1 is connected to the data acquisition instrument 2 through a LoRa module, and the data acquisition instrument 2 is connected to the monitoring platform through a 4G module. The data acquisition instrument 1 is connected to the monitoring platform through a 4G module. The present invention has a rich networking mode, which can solve the problem of limited networking mode of the existing single-channel vibrating string sensor acquisition instrument.

Description

Technical Field

[0001] The invention belongs to the technical field of data acquisition devices, and in particular relates to a single-channel vibrating-string sensor acquisition device. Background Art

[0002] The vibrating string sensor data acquisition instrument excites the vibrating string in the vibrating string sensor to vibrate, and then measures the frequency of the vibrating string vibration. Since there is a specific relationship between the frequency of the vibrating string and the physical quantity it is subjected to (such as pressure, strain, displacement, temperature, etc.), the data acquisition instrument converts the measured frequency into the corresponding physical quantity value according to a predetermined mathematical model.

[0003] Existing vibrating string sensor data collectors are of two types: single-channel and multi-channel. Multi-channel vibrating string sensor data collectors can connect multiple vibrating string sensors at the same time to obtain data from multiple monitoring points at one time, greatly improving the efficiency of data collection, but they are large in size and cumbersome to install. Single-channel vibrating string sensor data collectors are small in size and more flexible in installation, but can only obtain data from one monitoring point and require networking. Existing single-channel vibrating string sensor data collectors are difficult to achieve data sharing from multiple monitoring points due to their relatively simple communication methods and limited networking methods.

[0004] In addition, when the existing vibrating string sensor collector performs temperature acquisition, the temperature is generally calculated by measuring the resistance of the NTC thermistor. At present, the resistance detection circuit of the NTC thermistor is usually: a 10KΩ resistor is connected in series, and then the ADC is used to collect the voltage across the NTC thermistor, and then the current resistance of the thermistor is calculated. Among them, v is the voltage loaded in the entire circuit, r is the current resistance of the NTC thermistor, and v1 is the voltage across the NTC thermistor. According to the formula U=IR and v=((v-v1) / 10000)*r, it is derived that: r=10000*v / (v-v1). It can be seen that to calculate r, you need to know the values ​​of v and v1. v1 can be collected by ADC, while v is obtained through peripheral circuits (DC-DC step-down devices). Due to the consistency of peripheral circuit devices (such as the error of resistor values), the voltage v obtained by each device through the hardware circuit will have a certain deviation. However, when writing software, v often takes a fixed value, resulting in a large error between the final calculated r and the actual resistance value of the NTC thermistor. Summary of the invention

[0005] The present invention provides a single-channel vibrating string sensor acquisition device, which is equipped with WiFi and BLE modules, LoRa modules, and 4G modules, and has a variety of networking modes, so as to solve the problem that the networking modes of existing single-channel vibrating string sensor acquisition instruments are limited; when measuring temperature, the present invention does not need to measure the total voltage v of the measuring circuit, so as to solve the problem that the temperature monitoring error of existing vibrating string sensor acquisition instruments is large.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A single-channel vibrating string sensor acquisition device, comprising a data acquisition instrument 1, a main control gateway, a data acquisition instrument 2 and a monitoring platform; the data acquisition instrument 1 and the data acquisition instrument 2 are both single-channel vibrating string sensor acquisition instruments, and the single-channel vibrating string sensor acquisition instruments include a communication module, a main control module and a data acquisition module;

[0008] The communication module includes an RS485 communication interface, a 4G module, and a LoRa module; the main control module is connected to the RS485 communication interface, the 4G module, and the LoRa module for receiving and sending data, and is also connected to the data acquisition module to collect data through the data acquisition module;

[0009] The data acquisition instrument 1 is connected to the main control gateway through an RS485 communication interface or a LoRa module, and the main control gateway is connected to the monitoring platform through a wireless network or a wired network;

[0010] The data collector 1 is connected to the data collector 2 via the LoRa module, and the data collector 2 is connected to the monitoring platform via the 4G module;

[0011] The data acquisition instrument is connected to the monitoring platform via a 4G module.

[0012] Furthermore, the communication module also includes WiFi and BLE modules, and the WiFi and BLE modules are used for the mobile terminal and the PC to configure the single-channel vibrating string sensor collector.

[0013] Furthermore, the method for configuring the single-channel vibrating-wire sensor collector by the mobile terminal comprises the following steps:

[0014] Step 1: The operator registers the APP through the mobile terminal and provides the Bluetooth MAC address of the mobile terminal to the monitoring platform;

[0015] Step 2: The operator logs in to the APP through the mobile terminal, and the monitoring platform returns the operator token to the mobile terminal;

[0016] Step 3: The operator operates the APP on the mobile terminal to connect to the single-channel vibrating string sensor collector via Bluetooth, and the APP sends the operator token to the single-channel vibrating string sensor collector via Bluetooth;

[0017] Step 4: The single-channel vibrating string sensor collector obtains the Bluetooth MAC address of the mobile terminal through the Bluetooth connection;

[0018] Step 5: The single-channel vibrating string sensor collector sends the Bluetooth MAC address of the mobile terminal and the operator token to the monitoring platform;

[0019] Step 6: The monitoring platform verifies the received Bluetooth MAC address and operator token. If the operator is legitimate, the monitoring platform verifies successfully and sends a random password to the single-channel vibrating string sensor collector. If the operator is not legitimate, the monitoring platform verifies failed and the operation ends.

[0020] Step 7: After the monitoring platform is verified, the single-channel vibrating string sensor collector uses a random password to open the WiFi hotspot and sends the random password to the APP of the mobile terminal via Bluetooth;

[0021] Step 8: The mobile terminal APP connects to the WiFi hotspot of the single-channel vibrating string sensor collector according to the obtained random password;

[0022] Step 9: The operator configures the single-channel vibrating string sensor collector through the APP of the mobile terminal;

[0023] Step 10: The single-channel vibrating string sensor collector saves the configuration record and sends it to the monitoring platform;

[0024] Step 11: When the single-channel vibrating string sensor collector detects that there is no data exchange within the set time, the WiFi hotspot is automatically turned off;

[0025] Step 12: After the WiFi hotspot is automatically turned off, the single-channel vibrating string sensor collector disconnects the Bluetooth connection between it and the mobile terminal;

[0026] Among them, in steps 3 and 7, the mobile terminal is connected to the single-channel vibrating string sensor collector via Bluetooth, a fixed key is used for data exchange, and AES128bit encryption is used; in steps 5 and 6, the single-channel vibrating string sensor collector communicates with the monitoring platform using https.

[0027] Furthermore, the mobile terminal is a mobile phone or a laptop computer.

[0028] Furthermore, the data acquisition module includes an oscillation starting module, a vibration pickup module, a vibrating string sensor acquisition interface and an NTC resistance value acquisition module, all of which are connected to the main control module; the main control module generates PWM pulses of different frequencies, and after passing through the oscillation starting module, outputs +5V and -5V pulses, and performs frequency sweep excitation on the sensor through the vibrating string sensor acquisition interface. When the frequency of the excitation pulse is close to the frequency of the vibrating string in the sensor, the vibrating string vibrates and generates a sinusoidal wave signal of a specific frequency. After the sinusoidal wave signal enters the vibrating string sensor acquisition interface, the vibration pickup module performs operational amplifier and filtering operations, and converts the sinusoidal wave signal into a level pulse signal. The main control module obtains frequency information by capturing and calculating the level pulse signal; the main control module monitors the resistance of the NTC thermistor through the NTC resistance value acquisition module, and calculates the temperature value based on the specific relationship between the resistance of the NTC thermistor and the temperature.

[0029] Furthermore, the NTC resistance acquisition module includes a fixed resistor 1, a fixed resistor 2, an NTC thermistor, a switch module and a power supply module; the fixed resistor 1 and the NTC thermistor are connected in series to form a test circuit 1, and the fixed resistor 2 and the NTC thermistor are connected in series to form a test circuit 2; the power supply module and the main control module are both electrically connected to the switch module, and the switch module, under the control of the main control module, performs an on-off action to load the output voltage of the power supply module to the test circuit 1 or the test circuit 2; one end of the NTC thermistor connected to the fixed resistor 1 and the fixed resistor 2 is electrically connected to the signal acquisition end of the main control module, and the other end is grounded.

[0030] Furthermore, the resistance of the fixed-value resistor 1 is 10 kΩ, and the resistance of the fixed-value resistor 2 is 1 kΩ.

[0031] Furthermore, a bypass capacitor is provided between the switch module and the power module, and the capacitance value of the bypass capacitor is 100NF.

[0032] Furthermore, the single-channel vibrating string sensor collector also includes a channel selection module, which is used to control the designated collection channel to connect with the vibration module and the vibration pickup module according to the instructions issued by the main control gateway, and the connections of other channels will be disconnected.

[0033] Furthermore, the single-channel vibrating-wire sensor collector further comprises:

[0034] Debugging and burning module, used for program debugging and program burning;

[0035] A storage module, used for recording and storing monitoring data of sensors;

[0036] The LED indicator is used to indicate the working status. It flashes slowly when in standby mode and is always on when performing frequency acquisition and NTC resistor value detection.

[0037] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0038] 1. The single-channel vibrating string sensor data collector proposed in the present invention is equipped with WiFi and BLE modules, LoRa modules, and 4G modules, and has a variety of networking methods, which can be used in networking according to actual conditions. Among them, the data collector can be used alone, used as a master station after networking, and used as a slave station after networking, which can meet various work needs.

[0039] 2. The NTC resistance value acquisition module of the present invention does not need to measure the total voltage v of the measurement circuit, but can also measure the resistance value of the NTC thermistor, thus avoiding the problem of large detection error caused by using the total voltage v of the measurement circuit to calculate the NTC resistance value in the prior art, and effectively improving the accuracy of the NTC resistance value measurement. The NTC resistance value acquisition module proposed by the present invention also has the advantages of simple structure, low cost, strong stability, etc., and can be applied to application scenarios under various conditions, and has good practicality.

[0040] 3. The present invention also proposes a method for configuring a single-channel vibrating string sensor collector by cooperating with WiFi and Bluetooth, wherein the APP of the mobile terminal is assisted by Bluetooth to establish a WiFi connection with the single-channel vibrating string sensor collector, and a random WiFi password is used. By dynamically updating the WiFi password, the security of the WiFi connection is ensured, and the security risk of the device is reduced. Using WiFi for configuration ensures the speed of data transmission, has good convenience and real-time performance, and can bring a good user experience. During the configuration process of the single-channel vibrating string sensor collector, the operator needs to be verified at multiple levels: APP login verification, the platform verifies the legitimacy of the operator's mobile terminal (such as a mobile phone) and account, ensures the legitimacy of the operator, and further reduces the security risk of the device. After the single-channel vibrating string sensor collector is configured, the configuration record is saved and sent to the platform, and the operation is traceable. When a problem occurs, it is easy to investigate and determine the responsibility, and further reduces the security risk of the device. In addition, the WiFi hotspot is turned on when it is needed, and the WiFi hotspot is automatically turned off and the Bluetooth connection is disconnected when it is not needed, which can reduce the power consumption of the device and save electricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a system block diagram of the single-channel vibrating string sensor acquisition device provided by the present invention;

[0042] Figure 2 This is a flow chart of the data acquisition device provided by the present invention when used independently;

[0043] Figure 3 This is a flow chart of the data acquisition device provided by the present invention when used as a master station;

[0044] Figure 4 This is a flow chart of the data acquisition device provided by the present invention when used as a slave station;

[0045] Figure 5 It is a flow chart of configuring the single-channel vibrating-wire sensor acquisition instrument provided by the present invention;

[0046] Figure 6 It is a circuit schematic diagram of the NTC resistance value acquisition module provided by the present invention;

[0047] Figure 7 It is a circuit schematic diagram of the main control module provided by the present invention;

[0048] Figure 8 It is a circuit schematic diagram of the 4G module provided by the present invention;

[0049] Fig. 9 It is a circuit schematic diagram of the SIM card 1 module provided by the present invention;

[0050] Fig.10 It is a circuit schematic diagram of the SIM card 2 module provided by the present invention;

[0051] Fig.11 It is a circuit schematic diagram of the SIM card selection module provided by the present invention;

[0052] Fig.12 It is a circuit schematic diagram of the RS485 communication interface provided by the present invention;

[0053] Fig.13 It is a circuit schematic diagram of the RTC module provided by the present invention;

[0054] Fig.14 is a circuit schematic diagram of the power module provided by the present invention;

[0055] Fig.15 It is a circuit principle diagram of the storage module provided by the present invention. DETAILED DESCRIPTION

[0056] 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.

[0057] Example

[0058] like Figure 1As shown, a single-channel vibrating string sensor acquisition device includes a data acquisition device 1, a main control gateway, a data acquisition device 2 and a monitoring platform. Both the data acquisition device 1 and the data acquisition device 2 are single-channel vibrating string sensor acquisition devices, and the single-channel vibrating string sensor acquisition devices include a communication module, a main control module and a data acquisition module.

[0059] The communication module includes RS485 communication interface, 4G module and LoRa module. The main control module is connected to the RS485 communication interface, 4G module and LoRa module for receiving and sending data, and is also connected to the data acquisition module to collect data.

[0060] The data acquisition instrument is connected to the main control gateway through the RS485 communication interface or the LoRa module, and the main control gateway is connected to the monitoring platform through a wireless network or a wired network.

[0061] Data collector one is connected to data collector two via the LoRa module, and data collector two is connected to the monitoring platform via the 4G module.

[0062] The data collector is connected to the monitoring platform through a 4G module.

[0063] Among them, the 4G module is based on the SIM card, and is equipped with a SIM card 1 module, a SIM card 2 module, and a SIM card selection module. For details on the specific circuit design, see Figure 8-11 The RS485 communication interface has no lightning protection design. Compared with the RS485 interface of the multi-channel vibrating string sensor collector, its design is simpler and the cost is lower. For details on the circuit design, see Fig.12 .

[0064] like Figure 2 As shown, mode 1: when the data logger is used independently, the configuration is sent through the monitoring platform, and the data is directly sent to the monitoring platform after reading, and the 4G module is used to communicate with the monitoring platform. The specific steps are as follows:

[0065] 1. Start.

[0066] 2. The device establishes a connection with the monitoring platform through the 4G module.

[0067] 3. The monitoring platform sends configuration information such as collection start time and collection cycle to the device.

[0068] 4. When the collection time arrives, the device starts collecting sensor data.

[0069] 5. Oscillation: The main control module generates PWM pulses of different frequencies. After passing through the oscillation module, +5V and -5V pulses are output. The sensor is swept and excited through the vibrating string sensor acquisition interface. When the frequency of the excitation pulse is close to the vibrating string frequency in the sensor, the vibrating string will vibrate and generate a sine wave of a specific frequency.

[0070] 6. Vibration pickup: After the vibrating string sensor starts to vibrate, it will generate a sine wave of a specific frequency, but this sine wave signal is very weak. After entering the vibrating string sensor acquisition interface, the vibration pickup module will perform operations such as operational amplifier and filtering, and convert the sine signal into a level pulse signal. The main control module captures and calculates the frequency information through the pulse signal.

[0071] 7. Temperature measurement: Connect the temperature acquisition channel of the vibrating string sensor. The temperature sensor consists of a 3R NTC thermistor. The resistance of the thermistor decreases as the temperature increases. The main control module calculates the resistance of the NTC thermistor through the ADC acquisition function and obtains the current temperature based on the resistance.

[0072] 8. Return the read data to the monitoring platform.

[0073] like Figure 3 As shown in the figure, mode 2: when data collector 1 is used as the master station, it is networked with the slave station (data collector 2, the number can be one or more) through the LoRa module. The monitoring platform sends the configuration information to the master station, and the master station reads the sensor value of the device through the vibrating string acquisition module, reads the sensor value of the slave station device through the LoRa network, and finally sends the data to the monitoring platform through 4G. The specific steps are as follows:

[0074] 1. Start.

[0075] 2. The device establishes a connection with the monitoring platform through the 4G module.

[0076] 3. The monitoring platform sends configuration information such as collection start time and collection cycle to the device.

[0077] 4. When the collection time arrives, the device starts collecting sensor data.

[0078] 5. Start vibration.

[0079] 6. Pick up the vibration.

[0080] 7. Temperature measurement.

[0081] 8. Poll the slave station and send a read data request to the slave station.

[0082] 9. Return the data read by this device and the data read by the slave station to the monitoring platform.

[0083] like Figure 4 As shown in the figure, mode 3: when data logger 1 is used as a slave station, the master station can be data logger 2 or a master control gateway, which is networked with the master station through the LoRa module or RS485 communication interface, monitors the master station's instructions, and after receiving the instructions, reads the sensor value and sends it to the master station through LoRa, which then sends it to the monitoring platform. The specific steps are as follows:

[0084] 1. Start.

[0085] 2. Monitor the RS485 communication interface and LoRa interface, receive messages from the master station, and parse the message content to obtain the channel information to be read.

[0086] 3. A passage connecting the designated channel with the vibration starting module and the vibration picking module.

[0087] 4. Start vibration.

[0088] 5. Pick up the vibration.

[0089] 6. Temperature measurement.

[0090] 7. Return the read data to the master station.

[0091] The single-channel vibrating string sensor data collector proposed in the present invention is equipped with WiFi and BLE modules, LoRa modules, and 4G modules, and has a variety of networking methods, which can be used in networking according to actual conditions. Among them, the data collector can be used alone, as a master station after networking, and as a slave station after networking, which can meet various work needs.

[0092] In addition, the communication module also includes WiFi and BLE modules, which are used for mobile terminals and PCs to configure the single-channel vibrating string sensor collector.

[0093] like Figure 5 As shown, the method for configuring the single-channel vibrating string sensor collector by a mobile terminal includes the following steps:

[0094] Step 1: The operator registers the APP through the mobile terminal and provides the Bluetooth MAC address of the mobile terminal to the monitoring platform.

[0095] Step 2: The operator logs in to the APP through the mobile terminal, and the monitoring platform returns the operator token to the mobile terminal.

[0096] Step 3: The operator operates the APP on the mobile terminal to connect to the single-channel vibrating string sensor collector via Bluetooth, and the APP sends the operator token to the single-channel vibrating string sensor collector via Bluetooth.

[0097] Step 4: The single-channel vibrating string sensor collector obtains the Bluetooth MAC address of the mobile terminal through the Bluetooth connection.

[0098] Step 5: The single-channel vibrating string sensor collector sends the Bluetooth MAC address of the mobile terminal and the operator token to the monitoring platform.

[0099] Step 6: The monitoring platform verifies the received Bluetooth MAC address and operator token; if the operator is legitimate, the monitoring platform passes the verification and sends a random password to the single-channel vibrating string sensor collector; if the operator is not legitimate, the monitoring platform fails the verification and the operation ends.

[0100] Step 7: After the monitoring platform is verified, the single-channel vibrating string sensor collector uses a random password to open the WiFi hotspot and sends the random password to the APP of the mobile terminal via Bluetooth.

[0101] Step 8: The mobile terminal APP connects to the WiFi hotspot of the single-channel vibrating string sensor collector according to the obtained random password.

[0102] Step 9: The operator configures the single-channel vibrating string sensor collector through the APP of the mobile terminal.

[0103] Step 10: The single-channel vibrating string sensor collector saves the configuration record and sends it to the monitoring platform.

[0104] Step 11: When the single-channel vibrating string sensor collector detects that there is no data exchange within the set time, the WiFi hotspot is automatically turned off.

[0105] Step 12: After the WiFi hotspot is automatically turned off, the single-channel vibrating string sensor collector disconnects the Bluetooth connection between it and the mobile terminal.

[0106] Among them, in steps 3 and 7, the mobile terminal is connected to the single-channel vibrating string sensor collector via Bluetooth, a fixed key is used for data exchange, and AES128bit encryption is used; in steps 5 and 6, the single-channel vibrating string sensor collector communicates with the monitoring platform using https.

[0107] The mobile terminal is a mobile phone or a laptop computer. In this embodiment, the mobile terminal is a mobile phone.

[0108] In the prior art, operators usually connect to the device's WiFi through a mobile phone or PC to configure the device, but WiFi hotspots often use fixed passwords, and configuration changes cannot be traced, and the configuration personnel cannot be verified, so there is a great security risk. In addition, WiFi hotspots are always turned on, increasing the power consumption of the device.

[0109] The present invention proposes a method for configuring a single-channel vibrating string sensor collector by cooperating with WiFi and Bluetooth, establishing a WiFi connection between an APP of a mobile terminal and the single-channel vibrating string sensor collector through Bluetooth, and using a random WiFi password. By dynamically updating the WiFi password, the security of the WiFi connection is ensured, and the security risk of the device is reduced. Using WiFi for configuration ensures the speed of data transmission, has good convenience and real-time performance, and can bring a good user experience.

[0110] During the configuration of the single-channel vibrating string sensor collector, the operator needs to undergo multi-level verification: APP login verification, platform verification of the operator's mobile terminal (such as a mobile phone) and account legitimacy, to ensure the legitimacy of the operator and further reduce the security risks of equipment use.

[0111] After the single-channel vibrating string sensor collector is configured, the configuration record is saved and sent to the platform. The operation is traceable. When a problem occurs, it is easy to troubleshoot and determine responsibility, further reducing the safety risks of equipment use.

[0112] In addition, the WiFi hotspot is only turned on when it is needed, and automatically turned off and the Bluetooth connection is disconnected when it is not needed, which can reduce device power consumption and save electricity.

[0113] The data acquisition module includes an oscillating module, a vibration pickup module, a vibrating string sensor acquisition interface, and an NTC resistance acquisition module, all of which are connected to the main control module. The main control module generates PWM pulses of different frequencies. After passing through the oscillating module, it outputs +5V and -5V pulses, and sweeps the sensor through the vibrating string sensor acquisition interface. When the frequency of the excitation pulse is close to the frequency of the vibrating string in the sensor, the vibrating string vibrates and generates a sine wave signal of a specific frequency. After the sine wave signal enters the vibrating string sensor acquisition interface, the vibration pickup module performs op amp and filtering operations, and converts the sine wave signal into a level pulse signal. The main control module obtains frequency information by capturing and calculating the level pulse signal. The main control module monitors the resistance of the NTC thermistor through the NTC resistance acquisition module, and calculates the temperature value based on the specific relationship between the resistance of the NTC thermistor and the temperature.

[0114] like Figure 6 As shown, the NTC resistance value acquisition module includes fixed value resistor 1, fixed value resistor 2, NTC thermistor, switch module and power module. The power module is used to provide power to each module. The specific circuit design is detailed in Fig.14 .

[0115] The fixed resistor 1 and the NTC thermistor are connected in series to form the test circuit 1, and the fixed resistor 2 and the NTC thermistor are connected in series to form the test circuit 2. Among them, the resistance of the fixed resistor 1 is 10kΩ, marked as R15 in the figure. The resistance of the fixed resistor 2 is 1kΩ, marked as R16 in the figure.

[0116] The power module and the main control module are both electrically connected to the switch module. Under the control of the main control module, the switch module performs on-off actions to load the output voltage of the power module to test circuit 1 or test circuit 2. Among them, the switch module is an analog switch, and its model is TS5A3160DBVR, marked as U5 in the figure.

[0117] One end of the NTC thermistor connected to the fixed resistor 1 and the fixed resistor 2 is electrically connected to the signal acquisition end of the main control module, and the other end is grounded. The main control module collects the voltage at both ends of the NTC thermistor through the ADC.

[0118] In addition, a bypass capacitor is set between the switch module and the power module, marked as C4 in the figure, and the capacitance value of the bypass capacitor is 100NF. When high-frequency noise appears in the circuit, since the bypass capacitor presents low impedance to high-frequency signals, the noise current will flow to the ground through the bypass capacitor instead of entering U5, thereby ensuring that the power received by U5 is relatively stable and clean.

[0119] The working principle of the NTC resistance value acquisition module is:

[0120] First, the main control module controls the switch module to load the output voltage of the power module to the test circuit 1. At the same time, the main control module collects the voltage across the NTC thermistor through the ADC. Since the resistance of the fixed resistor 1 is 10kΩ=10000Ω, formula (1) is obtained:

[0121] v / (10000+r)=v1 / r, so: vr=v1(10000+r) (1)

[0122] Among them, v is the voltage value loaded on the entire circuit, r is the resistance value of the NTC thermistor, and v1 is the voltage value across the NTC thermistor resistance measured when a 10KΩ resistor is connected in series.

[0123] Then, the main control module controls the switch module to load the output voltage of the power module to the test circuit 2. At the same time, the main control module collects the voltage across the NTC thermistor through the ADC. Since the resistance of the fixed resistor 2 is 1kΩ=1000Ω, formula (2) is obtained:

[0124] v / (1000+r) = v2 / r, and we can deduce that: vr = v2(1000+r) (2)

[0125] Among them, v2 is the voltage value across the NTC thermistor measured when a 1KΩ resistor is connected in series.

[0126] Finally, from formula (1) and formula (2), we can derive formula (3), (4), (5), and (6):

[0127] v1(10000+r) =v2(1000+r) (3)

[0128] 10000*v1+v1*r=1000*v2+v2*r (4)

[0129] 10000*v1-1000*v2=(v2-v1)r (5)

[0130] Finally, we get: r = (10000*v1-1000*v2) / (v2-v1)(6)

[0131] It can be seen from formula (6) that v does not need to be introduced in the calculation process of r. The only variables are v1 and v2. Both v1 and v2 are acquired by the same main control module through ADC acquisition, avoiding the problem of device consistency.

[0132] The NTC resistance value acquisition module of the present invention does not need to measure the total voltage v of the measurement circuit, but can also measure the resistance value of the NTC thermistor, thereby avoiding the problem of large detection error caused by using the total voltage v of the measurement circuit to calculate the NTC resistance value in the prior art, and effectively improving the accuracy of the NTC resistance value measurement. The NTC resistance value acquisition module proposed by the present invention also has the advantages of simple structure, low cost, strong stability, etc., can be applied to application scenarios under various conditions, and has good practicality.

[0133] In addition, the single-channel vibrating string sensor data logger also includes a channel selection module, a debugging and burning module, a storage module, an RTC module, and an LED indicator. The RTC module is used to provide a clock signal. For details on its specific circuit design, see Fig.13 The channel selection module is used to control the specified acquisition channel to connect with the vibration module and the vibration pickup module according to the instructions issued by the master gateway, and the connections of other channels will be disconnected. The debugging and burning module is used for program debugging and program burning. The storage module is used to record and store the monitoring data of the sensor. Its circuit design is detailed in Fig.15 The LED indicator light is used to indicate the working status. It flashes slowly when in standby mode and stays on when performing frequency acquisition and NTC resistor value detection.

[0134] The above description is a detailed description of the preferred feasible embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modified changes completed under the technical spirit suggested by the present invention should fall within the patent scope covered by the present invention.

Claims

1. A single-channel vibrating-wire sensor acquisition device, characterized in that: It includes a data acquisition instrument 1, a main control gateway, a data acquisition instrument 2 and a monitoring platform; the data acquisition instrument 1 and the data acquisition instrument 2 are both single-channel vibrating string sensor acquisition instruments, and the single-channel vibrating string sensor acquisition instrument includes a communication module, a main control module and a data acquisition module; The communication module includes an RS485 communication interface, a 4G module, and a LoRa module; the main control module is connected to the RS485 communication interface, the 4G module, and the LoRa module for receiving and sending data, and is also connected to the data acquisition module to collect data through the data acquisition module; The data acquisition module includes an oscillating module, a vibration pickup module, a vibrating string sensor acquisition interface and an NTC resistance acquisition module, all of which are connected to the main control module; the main control module generates PWM pulses of different frequencies, and after passing through the oscillating module, outputs +5V and -5V pulses, and performs frequency sweep excitation on the sensor through the vibrating string sensor acquisition interface. When the frequency of the excitation pulse is close to the frequency of the vibrating string in the sensor, the vibrating string vibrates and generates a sine wave signal of a specific frequency. After the sine wave signal enters the vibrating string sensor acquisition interface, the vibration pickup module performs operational amplifier and filtering operations, and converts the sine wave signal into a level pulse signal. The main control module obtains frequency information by capturing and calculating the level pulse signal; the main control module monitors N through the NTC resistance acquisition module The resistance of the NTC thermistor is calculated, and the temperature value is calculated according to the specific relationship between the resistance of the NTC thermistor and the temperature; the NTC resistance acquisition module includes a fixed value resistor 1, a fixed value resistor 2, an NTC thermistor, a switch module and a power supply module; the fixed value resistor 1 and the NTC thermistor are connected in series to form a test circuit 1, and the fixed value resistor 2 and the NTC thermistor are connected in series to form a test circuit 2; the power supply module and the main control module are both electrically connected to the switch module, and the switch module performs an on-off action under the control of the main control module to load the output voltage of the power supply module to the test circuit 1 or the test circuit 2; one end of the NTC thermistor connected to the fixed value resistor 1 and the fixed value resistor 2 is electrically connected to the signal acquisition end of the main control module, and the other end is grounded; The data acquisition instrument 1 is connected to the main control gateway through an RS485 communication interface or a LoRa module, and the main control gateway is connected to the monitoring platform through a wireless network or a wired network; The data collector 1 is connected to the data collector 2 via the LoRa module, and the data collector 2 is connected to the monitoring platform via the 4G module; The data acquisition instrument is connected to the monitoring platform via a 4G module.

2. A single-channel vibrating-wire sensor acquisition device according to claim 1, characterized in that: The communication module also includes WiFi and BLE modules, and the WiFi and BLE modules are used for mobile terminals and PCs to configure the single-channel vibrating string sensor collector.

3. A single-channel vibrating-wire sensor acquisition device according to claim 2, characterized in that: The method for configuring the single-channel vibrating string sensor collector by the mobile terminal comprises the following steps: Step 1: The operator registers the APP through the mobile terminal and provides the Bluetooth MAC address of the mobile terminal to the monitoring platform; Step 2: The operator logs in to the APP through the mobile terminal, and the monitoring platform returns the operator token to the mobile terminal; Step 3: The operator operates the APP on the mobile terminal to connect to the single-channel vibrating string sensor collector via Bluetooth, and the APP sends the operator token to the single-channel vibrating string sensor collector via Bluetooth; Step 4: The single-channel vibrating string sensor collector obtains the Bluetooth MAC address of the mobile terminal through the Bluetooth connection; Step 5: The single-channel vibrating string sensor collector sends the Bluetooth MAC address of the mobile terminal and the operator token to the monitoring platform; Step 6: The monitoring platform verifies the received Bluetooth MAC address and operator token. If the operator is legitimate, the monitoring platform verifies successfully and sends a random password to the single-channel vibrating string sensor collector. If the operator is not legitimate, the monitoring platform verifies failed and the operation ends. Step 7: After the monitoring platform is verified, the single-channel vibrating string sensor collector uses a random password to open the WiFi hotspot and sends the random password to the APP of the mobile terminal via Bluetooth; Step 8: The mobile terminal APP connects to the WiFi hotspot of the single-channel vibrating string sensor collector according to the obtained random password; Step 9: The operator configures the single-channel vibrating string sensor collector through the APP of the mobile terminal; Step 10: The single-channel vibrating string sensor collector saves the configuration record and sends it to the monitoring platform; Step 11: When the single-channel vibrating string sensor collector detects that there is no data exchange within the set time, the WiFi hotspot is automatically turned off; Step 12: After the WiFi hotspot is automatically turned off, the single-channel vibrating string sensor collector disconnects the Bluetooth connection between it and the mobile terminal; Among them, in steps 3 and 7, the mobile terminal is connected to the single-channel vibrating string sensor collector via Bluetooth, a fixed key is used for data exchange, and AES128bit encryption is used; in steps 5 and 6, the single-channel vibrating string sensor collector communicates with the monitoring platform using https.

4. A single-channel vibrating-wire sensor acquisition device according to claim 3, characterized in that: The mobile terminal is a mobile phone or a laptop computer.

5. The single-channel vibrating-wire sensor acquisition device according to claim 1, characterized in that: The resistance of the fixed resistor 1 is 10 kΩ, and the resistance of the fixed resistor 2 is 1 kΩ.

6. A single-channel vibrating-wire sensor acquisition device according to claim 5, characterized in that: A bypass capacitor is provided between the switch module and the power module, and the capacitance value of the bypass capacitor is 100NF.

7. A single-channel vibrating-wire sensor acquisition device according to claim 1, characterized in that: The single-channel vibrating string sensor collector also includes a channel selection module, which is used to control the designated collection channel to connect with the vibration starting module and the vibration picking module according to the instructions issued by the main control gateway, and the connections of other channels will be disconnected.

8. A single-channel vibrating-wire sensor acquisition device according to claim 7, characterized in that: The single-channel vibrating-wire sensor collector also includes: Debugging and burning module, used for program debugging and program burning; A storage module, used for recording and storing monitoring data of sensors; The LED indicator is used to indicate the working status. It flashes slowly when in standby mode and is always on when performing frequency acquisition and NTC resistor value detection.

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