Integrated vibrating wire type stressometer

Abstract

The utility model discloses an integrated vibrating wire type stressometer, which comprises a main shell, a circuit board arranged in the main shell is provided with a minimum system unit, the minimum system unit is connected with an external communication unit, a simulation measurement unit and a power supply unit, the bottom of the main shell is provided with a battery cover plate, and the top of the main shell is provided with an upper cover. According to the utility model, the problems of inconvenient field power supply and high equipment failure rate of the vibrating wire type stress meter measuring equipment in the prior art are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of physical quantity vibrating string measurement, and in particular relates to an integrated vibrating string stress meter. Background Art

[0002] The integrated vibrating-wire strain gauge is a technology that uses a vibrating-wire surface stress sensor to convert the physical deformation of the target to be measured into a frequency signal, which is then collected and converted by the strain gauge. It is characterized by high measurement accuracy and the ability to monitor the deformation of the target equipment to be measured at the millimeter or even micron level. It has a miniaturized size, an integrated shell, and an IP66 waterproof and dustproof rating. It can be widely used in bridge construction, rail integration, oil and gas transportation, etc.

[0003] The vibrating-wire stress gauge can not only effectively obtain high-precision surface stress data information, but also perform high-precision measurements of other physical quantities such as pressure, stress, seepage pressure, settlement, tension and other parameters. The measurement of the above physical quantities is widely used in most infrastructure projects and environmental monitoring projects, and thus has significant social and economic benefits. This technology has broad application prospects and can be further promoted and applied in other fields in the future.

[0004] The products currently on the market require external AC and DC power supplies. They can be powered by solar energy in the wild, but outdoor lighting is inconvenient in some places. The equipment is exposed to complex high-temperature, high-humidity environments in the wild. When unpacking and maintaining the equipment, environmental variables (such as temperature or humidity) can easily penetrate into the equipment, causing it to malfunction. Utility Model Content

[0005] The utility model aims to provide an integrated vibrating-wire stress gauge, which solves the problems of inconvenient field power supply and high equipment failure rate of vibrating-wire stress gauge measuring equipment in the prior art.

[0006] The technical solution adopted by the utility model is an integrated vibrating-string strain gauge, comprising a main shell, a minimum system unit is provided on a circuit board built into the main shell, the minimum system unit is connected to an external communication unit, an analog measurement unit, and a power supply unit, a battery cover is provided at the bottom of the main shell, and an upper cover is provided at the top of the main shell.

[0007] The utility model is also characterized in that:

[0008] An indicator light board is provided on the upper cover, and a power light, a 4G communication light, and an operation or warning light are respectively provided on the indicator light board from top to bottom, and a light board cover is also provided on the indicator light board.

[0009] The main shell is also connected to the connector through the aviation plug mounting plate. The connector is used to connect the equipment and the fixed steel pipe below the equipment. The equipment and the outlet terminal are fixed on the connector, and the bottom of the connector is buckled with the fixed iron column. The indicator light board is connected to the minimum system unit through the FPC soft wire. The light board wire pressure plate is installed on the side of the indicator light board to fix the FPC soft wire. The vibrating string sensor passes through the connector and is connected to the analog measurement unit through the aviation connector on the aviation plug mounting plate. The wire pressure plate is installed on the side of the circuit board where the minimum system unit is located to fix the aviation plug mounting plate and the analog measurement unit.

[0010] The minimum system unit includes the MCU microcontroller, which is the brain of the device. It processes the acquired data according to the needs and sends it to the target unit through the external interface. The RTC is a real-time clock chip, which is connected to the MCU. The real-time clock chip RTC is connected to the MCU through the IIC or SPI bus. The MCU microcontroller is also connected to the storage FLASH / EEPROM, which is connected to the MCU microcontroller through the IIC or SPI bus. The MCU microcontroller is also connected to the IO / UART expansion chip, which is connected to the MCU microcontroller through the IIC or UART bus, and the other side of the IO / UART expansion chip is connected to the peripherals through the UART or IO bus.

[0011] The external communication unit includes a communication unit, RS232 / RS485 and a 10 / 100M 100M electrical port. The communication unit is connected to the MCU microcontroller or expansion chip. The 4G communication unit is connected to the MCU through the UART interface by default; the RS232 / RS485 communication unit is connected to the MCU or expansion chip through the UART bus; the 10 / 100M 100M electrical port communication unit is connected to the MCU or expansion chip through the RMII bus.

[0012] The communication unit is one of a 4G communication unit, a Lora communication unit, a WiFi communication unit, and a Beidou three short message communication unit.

[0013] The analog measurement unit includes 8 vibrating string analog measurement units and 1 pulse rain gauge test unit. One end of the vibrating string analog measurement unit is connected to the MCU single chip or expansion chip through UART / SPI or other buses, and the other end of the vibrating string analog measurement unit is connected to the vibrating string sensor through a 5-core wire. The 5 wires in the 5-core wire are: frequency +, frequency -, temperature +, temperature -, and protection ground.

[0014] The vibrating string analog measurement unit is composed of an excitation component, a conversion component, and a vibration pickup unit; the excitation component, the conversion component, and the vibration pickup unit are all connected to the MCU microcontroller. One end of the pulse rain gauge test unit is connected to the MCU through an ADC or other bus, and the other end of the pulse rain gauge test unit is connected to the pulse rain gauge through a 2-core wire.

[0015] The power supply unit includes a battery protection unit, an external 12V DC protection unit, a dual power automatic selection unit, and various levels of DCDC / LDO boost or buck units; the battery protection unit is connected to the ER34615 battery and the dual power automatic selection unit at the rear; the external 12VDC protection unit is connected to the dual power automatic selection unit; the dual power automatic selection unit is connected to the battery protection unit and the external 12VDC protection unit in the front, and to various levels of DCDC / LDO boost or buck units in the rear; various levels of DCDC / LDO boost or buck units are connected to the dual power automatic selection unit in the front stage, and to the power pins of various units of the equipment in the rear stage.

[0016] The beneficial effect of the utility model is that the integrated vibrating-wire stress gauge is very convenient to install and maintain due to its small size. The power supply adopts the coexistence of external power supply and lithium-manganese dioxide battery (Li MnO2) power supply. The external power supply is used first. When there is no external power supply, three lithium-manganese dioxide batteries (Li MnO2) ER34615M (power type) connected in series are used for external power supply. After the low-power design, the equipment can last for 3 years if it collects data twice and uploads data twice a day. The integrated appearance design is also convenient for engineering personnel to install and maintain, basically eliminating the influence of the external environment on the equipment, and can reach the IP66 level, which greatly increases the reliability and stability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of the integrated vibrating-wire stress meter of the utility model;

[0018] Figure 2 This is a working flow chart of the integrated vibrating-wire stress meter of the utility model;

[0019] Figure 3 This is a working flow chart of the vibrating wire simulation unit in the integrated vibrating wire stress gauge of the utility model;

[0020] Figure 4 This is a diagram showing the internal structure of the vibration pickup unit in the integrated vibrating-wire stress gauge of the utility model;

[0021] Figure 5 It is a schematic diagram of the vibrating wire frequency sweeping process in the integrated vibrating wire strain gauge of the utility model;

[0022] Figure 6This is the RJ45 pin assignment diagram of the integrated vibrating wire stress gauge of the utility model ( Figure 6 The pin names shown in the figure are all on this device).

[0023] Figure 7 It is a schematic diagram of NTC temperature in the integrated vibrating-wire stress gauge of the utility model.

[0024] In the figure, 1. upper cover, 2. light board cover, 3. main shell, 4. battery cover, 5. aviation plug mounting plate, 6. connector, 7. light board wire pressure plate, 8. wire pressure plate, 9. indicator light board, 10. minimum system unit, 11. external communication unit, 12. analog measurement unit, 13. power supply unit. DETAILED DESCRIPTION

[0025] The utility model is described in detail below with reference to the accompanying drawings and specific implementation modes.

[0026] The utility model is an integrated vibrating wire stress meter, the structure of which is as follows Figure 1 As shown, it includes a main shell 3, a minimum system unit 10 is provided on the built-in circuit board of the main shell 3, and the minimum system unit 10 is connected to the external communication unit 11, the analog measurement unit 12, and the power supply unit 13. A battery cover 4 is provided at the bottom of the main shell 3, and an upper cover 1 is provided on the top of the main shell 3.

[0027] An indicator light board 9 is provided on the upper cover 1 , and a power light, a 4G communication light, and an operation or warning light are respectively provided on the indicator light board 9 from top to bottom. A light board outer cover 2 is also provided on the indicator light board 9 .

[0028] The main shell 3 is also connected to the connector 6 through the aviation plug mounting plate 5. The connector 6 is used to connect the device to the fixed steel pipe below the device. The device and the outlet terminal are fixed on the top of the connector 6, and the bottom of the connector 6 is buckled with the fixed iron column. The indicator light board 9 is connected to the minimum system unit 10 through the FPC soft wire. The light board wire pressure plate 7 is installed on the side of the indicator light board 9 to fix the FPC soft wire. The vibrating string sensor passes through the connector 6 and is connected to the analog measurement unit 12 through the aviation connector on the aviation plug mounting plate 5. The wire pressure plate 8 is installed on the side of the circuit board where the minimum system unit 10 is located to fix the aviation plug mounting plate 5 and the analog measurement unit 12.

[0029] The minimum system unit 10 includes an MCU microcontroller, which is the brain of the device. It processes the acquired data according to the needs and sends it to the target unit through the external interface; the RTC is a real-time clock chip, which is connected to the MCU, and the real-time clock chip RTC is connected to the MCU through an IIC or SPI bus; the MCU microcontroller is also connected to the storage FLASH / EEPROM, and the storage FLASH / EEPROM is connected to the MCU microcontroller through an IIC or SPI bus; the MCU microcontroller is also connected to the IO / UART expansion chip, and the IO / UART expansion chip is connected to the MCU microcontroller through an IIC or UART bus, and the other side of the IO / UART expansion chip is connected to the peripheral through a UART or IO bus.

[0030] The external communication unit includes a communication unit, RS232 / RS485 and a 10 / 100M 100M electrical port. The communication unit is connected to the MCU microcontroller or expansion chip. The 4G communication unit is connected to the MCU through the UART interface by default; the RS232 / RS485 communication unit is connected to the MCU or expansion chip through the UART bus; the 10 / 100M 100M electrical port communication unit is connected to the MCU or expansion chip through the RMII bus.

[0031] The communication unit is one of a 4G communication unit, a Lora communication unit, a WiFi communication unit, and a Beidou three short message communication unit.

[0032] The analog measurement unit includes 8 vibrating string analog measurement units and 1 pulse rain gauge test unit. One end of the vibrating string analog measurement unit is connected to the MCU single chip or expansion chip through UART / SPI or other buses, and the other end of the vibrating string analog measurement unit is connected to the vibrating string sensor through a 5-core wire. The 5 wires in the 5-core wire are: frequency +, frequency -, temperature +, temperature -, and protection ground.

[0033] The vibrating string analog measurement unit is composed of an excitation component, a conversion component, and a vibration pickup unit; the excitation component, the conversion component, and the vibration pickup unit are all connected to the MCU single-chip computer, and the MCU single-chip computer sends a digital excitation signal, and the excitation component converts the digital excitation signal into an analog excitation signal through a power MOS tube; at this time, the conversion component controlled by the MCU single-chip computer outputs the analog excitation signal to the frequency + pin and the frequency - pin of the vibrating string sensor, and the vibrating string sensor receives the analog excitation signal and then feeds back a small resonance signal, and at this time, the MCU single-chip computer connects the frequency + and frequency - pins of the vibrating string sensor to the vibration pickup unit through the conversion component, and finally connects to the ADC interface of the MCU single-chip computer to complete the measurement closed loop, wherein the conversion component controls the double-pole double-throw relay or MOS tube through the MCU, and selects the frequency + pin and the frequency - pin of the vibrating string sensor to be connected to the excitation component or the vibration pickup unit;

[0034] One end of the pulse rain gauge test unit is connected to the MCU through ADC or other buses, and the other end of the pulse rain gauge test unit is connected to the pulse rain gauge through a 2-core wire.

[0035] The power supply unit includes a battery protection unit, an external 12V DC protection unit, a dual power automatic selection unit, and various levels of DCDC / LDO boost or buck units; the battery protection unit is connected to the ER34615 battery and the dual power automatic selection unit at the rear; the external 12VDC protection unit is connected to the dual power automatic selection unit; the dual power automatic selection unit is connected to the battery protection unit and the external 12VDC protection unit in the front, and to various levels of DCDC / LDO boost or buck units in the rear; various levels of DCDC / LDO boost or buck units are connected to the dual power automatic selection unit in the front stage, and to the power pins of various units of the equipment in the rear stage.

[0036] The minimum system unit in the utility model includes an MCU single-chip microcomputer, which is the brain of the device. The MCU single-chip microcomputer processes the acquired data according to the requirements and sends it to the target unit through the external interface. The MCU has various interface resources such as IIC\UART\SPI\IO\RGMII, etc.; the RTC is a real-time clock chip, which is used to ensure that the MCU can re-acquire the accurate clock when the system is powered on again and disconnected from the network; the real-time clock chip RTC is connected to the MCU, and the real-time clock chip RTC is connected to the MCU through the IIC or SPI bus; the MCU single-chip microcomputer is also connected to the storage FLASH / EEPROM, and the storage FLASH / EEPROM is connected to the MCU single-chip microcomputer through the IIC or SPI bus; the storage FLASH / EEPROM stores the data processed by the MCU into the unit and takes it out when needed. The MCU single-chip microcomputer is also connected to the IO / UART expansion chip, and the IO / UART expansion chip is connected to the MCU single-chip microcomputer through the IIC or UART bus, and the other side of the IO / UART expansion chip is connected to the peripheral through the UART or IO bus. IO / UART expansion chip: When the MCU interface resources are insufficient and the expansion interface speed requirement is not high, use the expansion chip to enhance the resource scalability of the MCU.

[0037] The external communication units include 4G communication unit / Lora communication unit / WiFi communication unit / Beidou 3 short message communication unit and RS232 / RS485 and 10 / 100M 100M electrical port. The 4G communication unit / Lora communication unit / WiFi communication unit / Beidou 3 short message communication unit is connected to the MCU microcontroller or expansion chip. By default, the 4G communication unit is connected to the MCU through the UART interface; the RS232 / RS485 communication unit is connected to the MCU or expansion chip through the UART bus; the 10 / 100M 100M electrical port communication unit is connected to the MCU or expansion chip through the RMII bus.

[0038] 4G communication unit / Lora communication unit / WiFi communication unit / Beidou 3 short message communication unit. The above four communication units are wireless communication units, and their main function is to serve as channels for information interaction between the device and the platform.

[0039] RS232 / RS485 communication unit, RS232 is the debugging serial port for on-site maintenance personnel, RS485 is the expansion interface, which has two functions: 1. Connecting to the handheld reader to read the instrument data through this interface; 2. Reserved for connecting to Lora communication equipment and Beidou 3 short message communication equipment;

[0040] The 10 / 100M electrical port communication unit is used to communicate with the platform when wired communication is available.

[0041] Combination Figure 3 to Figure 5 The vibrating string analog measurement unit is composed of an excitation component, a conversion component, and a vibration pickup unit; first, the MCU single-chip computer sends out a digital excitation signal, and the excitation component converts the digital excitation signal into an analog excitation signal through a power MOS tube; at this time, the conversion component controlled by the MCU single-chip computer outputs the analog excitation signal to the frequency + pin and the frequency - pin of the vibrating string sensor, and the vibrating string sensor receives the analog excitation signal and feeds back a small resonance signal. At this time, the MCU single-chip computer connects the frequency + and frequency - pins of the vibrating string sensor to the vibration pickup unit through the conversion component, and finally connects to the ADC interface of the MCU single-chip computer to complete the measurement closed loop, wherein the conversion component controls a double-pole double-throw relay or MOS tube through the MCU to select the frequency + pin and the frequency - pin of the vibrating string sensor to be connected to the excitation component or the vibration pickup unit, such as: when the MCU sends a high level through its IO, the excitation component is connected to the frequency + and frequency - pins of the sensor, and when the MCU sends a low level through its IO, the vibration pickup unit is connected to the frequency + and frequency - pins of the sensor.

[0042] The pulse rain gauge test unit is connected to the MCU via ADC or other buses, and the other end of the pulse rain gauge test unit is connected to the pulse rain gauge via a 2-core wire. The two wires in the 2-core wire are not distinguished.

[0043] The function of the vibrating wire analog measurement unit is to excite the sensor through high voltage or low voltage, and then calculate the stress through the frequency and temperature sent back by the sensor;

[0044] The pulse rain gauge test unit calculates the current rainfall by measuring the frequency and range of the pulse signal from the rain gauge;

[0045] Battery protection unit to protect the battery from short circuit and reverse high voltage shock;

[0046] The external 12VDC protection unit protects the subsequent circuit from interference from the external 12V power supply;

[0047] Dual power automatic selection unit, its function is to give priority to the external 12VDC power supply, and only use the battery power supply when there is no external power supply;

[0048] Each level of DCDC / LDO boost or buck unit has the function of supplying power to each level of the equipment;

[0049] The appearance structure of the utility model includes IP66 waterproof and dustproof design, miniaturized and integrated appearance design and DFx design;

[0050] The appearance structure, especially the IP66 design requirement, requires the use of a waterproof and dustproof casing, a sealed negative pressure rubber ring, a waterproof LED light, waterproof or touch-sensitive buttons, a waterproof aviation plug connector, and a PCB board that matches the appearance structure. In addition, the appearance of the equipment is miniaturized and integrated, which is convenient for installation, commissioning and on-site maintenance.

[0051] 1. The functions of IP66 design are: dust-tight, dust cannot enter at a low pressure of 20 mbar;

[0052] 2. The miniaturized integrated function is to facilitate installation and maintenance;

[0053] 3. DFX is a design for each link of the product life cycle, where X represents a certain link or feature of the product life cycle. It is a new design technology that considers product performance, quality, manufacturability, assemblability, testability, product service and price as early as possible in the design stage. DFX is a design for each link of the product life cycle, where X represents a certain link or feature of the product life cycle. It is a new design technology that considers product performance, quality, manufacturability, assemblability, testability, product service and price as early as possible in the design stage.

[0054] Example 1

[0055] The utility model is an integrated vibrating wire stress meter, the structure of which is as follows Figure 1As shown, it includes a main shell 3, a minimum system unit 10 is provided on the built-in circuit board of the main shell 3, and the minimum system unit 10 is connected to the external communication unit 11, the analog measurement unit 12, and the power supply unit 13. A battery cover 4 is provided at the bottom of the main shell 3, and an upper cover 1 is provided on the top of the main shell 3.

[0056] An indicator light board 9 is provided on the upper cover 1 , and a power light, a 4G communication light, and an operation or warning light are respectively provided on the indicator light board 9 from top to bottom. A light board outer cover 2 is also provided on the indicator light board 9 .

[0057] The main shell 3 is also connected to the connector 6 through the aviation plug mounting plate 5. The connector 6 is used to connect the device to the fixed steel pipe below the device. The device and the outlet terminal are fixed on the top of the connector 6, and the bottom of the connector 6 is buckled with the fixed iron column. The indicator light board 9 is connected to the minimum system unit 10 through the FPC soft wire. The light board wire pressure plate 7 is installed on the side of the indicator light board 9 to fix the FPC soft wire. The vibrating string sensor passes through the connector 6 and is connected to the analog measurement unit 12 through the aviation connector on the aviation plug mounting plate 5. The wire pressure plate 8 is installed on the side of the circuit board where the minimum system unit 10 is located to fix the aviation plug mounting plate 5 and the analog measurement unit 12.

[0058] The external communication unit includes a communication unit, RS232 / RS485 and a 10 / 100M 100M electrical port. The communication unit is connected to the MCU microcontroller or expansion chip. The 4G communication unit is connected to the MCU through the UART interface by default; the RS232 / RS485 communication unit is connected to the MCU or expansion chip through the UART bus; the 10 / 100M 100M electrical port communication unit is connected to the MCU or expansion chip through the RMII bus.

[0059] The communication unit is one of a 4G communication unit, a Lora communication unit, a WiFi communication unit, and a Beidou three short message communication unit.

[0060] The analog measurement unit includes 8 vibrating string analog measurement units and 1 pulse rain gauge test unit. One end of the vibrating string analog measurement unit is connected to the MCU single chip or expansion chip through UART / SPI or other buses, and the other end of the vibrating string analog measurement unit is connected to the vibrating string sensor through a 5-core wire. The 5 wires in the 5-core wire are: frequency +, frequency -, temperature +, temperature -, and protection ground.

[0061] The vibrating string analog measurement unit is composed of an excitation component, a conversion component, and a vibration pickup unit; the excitation component, the conversion component, and the vibration pickup unit are all connected to the MCU single-chip computer, and the MCU single-chip computer sends a digital excitation signal, and the excitation component converts the digital excitation signal into an analog excitation signal through a power MOS tube; at this time, the conversion component controlled by the MCU single-chip computer outputs the analog excitation signal to the frequency + pin and the frequency - pin of the vibrating string sensor, and the vibrating string sensor receives the analog excitation signal and then feeds back a small resonance signal, and at this time, the MCU single-chip computer connects the frequency + and frequency - pins of the vibrating string sensor to the vibration pickup unit through the conversion component, and finally connects to the ADC interface of the MCU single-chip computer to complete the measurement closed loop, wherein the conversion component controls the double-pole double-throw relay or MOS tube through the MCU, and selects the frequency + pin and the frequency - pin of the vibrating string sensor to be connected to the excitation component or the vibration pickup unit;

[0062] One end of the pulse rain gauge test unit is connected to the MCU through ADC or other buses, and the other end of the pulse rain gauge test unit is connected to the pulse rain gauge through a 2-core wire.

[0063] The power supply unit includes a battery protection unit, an external 12V DC protection unit, a dual power automatic selection unit, and various levels of DCDC / LDO boost or buck units; the battery protection unit is connected to the ER34615 battery and the dual power automatic selection unit at the rear; the external 12VDC protection unit is connected to the dual power automatic selection unit; the dual power automatic selection unit is connected to the battery protection unit and the external 12VDC protection unit in the front, and to various levels of DCDC / LDO boost or buck units in the rear; various levels of DCDC / LDO boost or buck units are connected to the dual power automatic selection unit in the front stage, and to the power pins of various units of the equipment in the rear stage.

[0064] Example 2

[0065] The utility model is an integrated vibrating wire stress meter, the structure of which is as follows Figure 1 As shown, it includes a main shell 3, a minimum system unit 10 is provided on the built-in circuit board of the main shell 3, and the minimum system unit 10 is connected to the external communication unit 11, the analog measurement unit 12, and the power supply unit 13. A battery cover 4 is provided at the bottom of the main shell 3, and an upper cover 1 is provided on the top of the main shell 3.

[0066] An indicator light board 9 is provided on the upper cover 1 , and a power light, a 4G communication light, and an operation or warning light are respectively provided on the indicator light board 9 from top to bottom. A light board outer cover 2 is also provided on the indicator light board 9 .

[0067] The main shell 3 is also connected to the connector 6 through the aviation plug mounting plate 5. The connector 6 is used to connect the device to the fixed steel pipe below the device. The device and the outlet terminal are fixed on the top of the connector 6, and the bottom of the connector 6 is buckled with the fixed iron column. The indicator light board 9 is connected to the minimum system unit 10 through the FPC soft wire. The light board wire pressure plate 7 is installed on the side of the indicator light board 9 to fix the FPC soft wire. The vibrating string sensor passes through the connector 6 and is connected to the analog measurement unit 12 through the aviation connector on the aviation plug mounting plate 5. The wire pressure plate 8 is installed on the side of the circuit board where the minimum system unit 10 is located to fix the aviation plug mounting plate 5 and the analog measurement unit 12.

[0068] The minimum system unit 10 includes an MCU microcontroller, which is the brain of the device. It processes the acquired data according to the needs and sends it to the target unit through the external interface; the RTC is a real-time clock chip, which is connected to the MCU, and the real-time clock chip RTC is connected to the MCU through an IIC or SPI bus; the MCU microcontroller is also connected to the storage FLASH / EEPROM, and the storage FLASH / EEPROM is connected to the MCU microcontroller through an IIC or SPI bus; the MCU microcontroller is also connected to the IO / UART expansion chip, and the IO / UART expansion chip is connected to the MCU microcontroller through an IIC or UART bus, and the other side of the IO / UART expansion chip is connected to the peripheral through a UART or IO bus.

[0069] The external communication unit includes a communication unit, RS232 / RS485 and a 10 / 100M 100M electrical port. The communication unit is connected to the MCU microcontroller or expansion chip. The 4G communication unit is connected to the MCU through the UART interface by default; the RS232 / RS485 communication unit is connected to the MCU or expansion chip through the UART bus; the 10 / 100M 100M electrical port communication unit is connected to the MCU or expansion chip through the RMII bus.

[0070] The analog measurement unit includes 8 vibrating string analog measurement units and 1 pulse rain gauge test unit. One end of the vibrating string analog measurement unit is connected to the MCU single chip or expansion chip through UART / SPI or other buses, and the other end of the vibrating string analog measurement unit is connected to the vibrating string sensor through a 5-core wire. The 5 wires in the 5-core wire are: frequency +, frequency -, temperature +, temperature -, and protection ground.

[0071] The vibrating string analog measurement unit is composed of an excitation component, a conversion component, and a vibration pickup unit; the excitation component, the conversion component, and the vibration pickup unit are all connected to the MCU single-chip computer, and the MCU single-chip computer sends a digital excitation signal, and the excitation component converts the digital excitation signal into an analog excitation signal through a power MOS tube; at this time, the conversion component controlled by the MCU single-chip computer outputs the analog excitation signal to the frequency + pin and the frequency - pin of the vibrating string sensor, and the vibrating string sensor receives the analog excitation signal and then feeds back a small resonance signal, and at this time, the MCU single-chip computer connects the frequency + and frequency - pins of the vibrating string sensor to the vibration pickup unit through the conversion component, and finally connects to the ADC interface of the MCU single-chip computer to complete the measurement closed loop, wherein the conversion component controls the double-pole double-throw relay or MOS tube through the MCU, and selects the frequency + pin and the frequency - pin of the vibrating string sensor to be connected to the excitation component or the vibration pickup unit;

[0072] One end of the pulse rain gauge test unit is connected to the MCU through ADC or other buses, and the other end of the pulse rain gauge test unit is connected to the pulse rain gauge through a 2-core wire.

[0073] The power supply unit includes a battery protection unit, an external 12V DC protection unit, a dual power automatic selection unit, and various levels of DCDC / LDO boost or buck units; the battery protection unit is connected to the ER34615 battery and the dual power automatic selection unit at the rear; the external 12VDC protection unit is connected to the dual power automatic selection unit; the dual power automatic selection unit is connected to the battery protection unit and the external 12VDC protection unit in the front, and to various levels of DCDC / LDO boost or buck units in the rear; various levels of DCDC / LDO boost or buck units are connected to the dual power automatic selection unit in the front stage, and to the power pins of various units of the equipment in the rear stage.

[0074] Example 3

[0075] The utility model is an integrated vibrating wire stress meter, the structure of which is as follows Figure 1 As shown, it includes a main shell 3, a minimum system unit 10 is provided on the built-in circuit board of the main shell 3, and the minimum system unit 10 is connected to the external communication unit 11, the analog measurement unit 12, and the power supply unit 13. A battery cover 4 is provided at the bottom of the main shell 3, and an upper cover 1 is provided on the top of the main shell 3.

[0076] An indicator light board 9 is provided on the upper cover 1 , and a power light, a 4G communication light, and an operation or warning light are respectively provided on the indicator light board 9 from top to bottom. A light board outer cover 2 is also provided on the indicator light board 9 .

[0077] The main shell 3 is also connected to the connector 6 through the aviation plug mounting plate 5. The connector 6 is used to connect the device to the fixed steel pipe below the device. The device and the outlet terminal are fixed on the top of the connector 6, and the bottom of the connector 6 is buckled with the fixed iron column. The indicator light board 9 is connected to the minimum system unit 10 through the FPC soft wire. The light board wire pressure plate 7 is installed on the side of the indicator light board 9 to fix the FPC soft wire. The vibrating string sensor passes through the connector 6 and is connected to the analog measurement unit 12 through the aviation connector on the aviation plug mounting plate 5. The wire pressure plate 8 is installed on the side of the circuit board where the minimum system unit 10 is located to fix the aviation plug mounting plate 5 and the analog measurement unit 12.

[0078] The minimum system unit 10 includes an MCU microcontroller, which is the brain of the device. It processes the acquired data according to the needs and sends it to the target unit through the external interface; the RTC is a real-time clock chip, which is connected to the MCU, and the real-time clock chip RTC is connected to the MCU through an IIC or SPI bus; the MCU microcontroller is also connected to the storage FLASH / EEPROM, and the storage FLASH / EEPROM is connected to the MCU microcontroller through an IIC or SPI bus; the MCU microcontroller is also connected to the IO / UART expansion chip, and the IO / UART expansion chip is connected to the MCU microcontroller through an IIC or UART bus, and the other side of the IO / UART expansion chip is connected to the peripheral through a UART or IO bus.

[0079] The external communication unit includes a communication unit, RS232 / RS485 and a 10 / 100M 100M electrical port. The communication unit is connected to the MCU microcontroller or expansion chip. The 4G communication unit is connected to the MCU through the UART interface by default; the RS232 / RS485 communication unit is connected to the MCU or expansion chip through the UART bus; the 10 / 100M 100M electrical port communication unit is connected to the MCU or expansion chip through the RMII bus.

[0080] The communication unit is one of a 4G communication unit, a Lora communication unit, a WiFi communication unit, and a Beidou three short message communication unit.

[0081] The analog measurement unit includes 8 vibrating string analog measurement units and 1 pulse rain gauge test unit. One end of the vibrating string analog measurement unit is connected to the MCU single chip or expansion chip through UART / SPI or other buses, and the other end of the vibrating string analog measurement unit is connected to the vibrating string sensor through a 5-core wire. The 5 wires in the 5-core wire are: frequency +, frequency -, temperature +, temperature -, and protection ground.

[0082] The power supply unit includes a battery protection unit, an external 12V DC protection unit, a dual power automatic selection unit, and various levels of DCDC / LDO boost or buck units; the battery protection unit is connected to the ER34615 battery and the dual power automatic selection unit at the rear; the external 12VDC protection unit is connected to the dual power automatic selection unit; the dual power automatic selection unit is connected to the battery protection unit and the external 12VDC protection unit in the front, and to various levels of DCDC / LDO boost or buck units in the rear; various levels of DCDC / LDO boost or buck units are connected to the dual power automatic selection unit in the front stage, and to the power pins of various units of the equipment in the rear stage.

[0083] The integrated vibrating wire stress gauge of the utility model has the following working principle: Figure 1 ,

[0084] 1. Vibration string information collection: The device periodically initiates a collection command to the vibration string signal unit according to the collection frequency received by the external communication unit; the specific process is as follows Figure 2 As shown, the details are as follows:

[0085] a. The excitation component in the vibrating string acquisition unit sends high-voltage or low-voltage excitation of the response frequency to the frequency lines (2 lines: frequency + and frequency -) of the vibrating string sensor;

[0086] b. Switch the interface of the docking frequency lines (2: frequency + and frequency -) from the excitation port to the frequency receiving port;

[0087] c. The response signal fed back by the vibrating string sensor enters the vibration pickup unit after passing through the protection unit at the frequency receiving port. The vibration pickup unit consists of four parts, namely, a primary amplifier, a bandpass filter, a terminal amplifier and a shaping circuit. The signal to be measured in the vibration pickup unit first passes through the primary amplifier to filter out the original response signal of about 2mV, and then passes through a capacitor greater than 1uF to filter out the DC component and allow the AC component to pass through, and then amplifies it by 6 times and passes through a positive feedback active bandpass filter. Since the feedback frequency of the vibrating string sensor is between 400 and 6000Hz, only the signal within the above frequency range is allowed to pass through the bandpass filter through the bandpass filter. The signal is amplified by 2 times in the bandpass filter, and then passes through the terminal amplifier to amplify the signal by 200 times, thus amplifying the initial mV level signal to a V level signal, which also provides a good precondition for the final shaping circuit, and finally enters the shaping circuit. The shaping circuit sets a threshold through the comparator. When the signal is higher than this threshold, it outputs a high potential, and when the signal is lower than this threshold, it outputs a low potential. In this way, the final output is a square wave signal, which is convenient for MCU to identify.

[0088] Not every time an excitation signal is sent out, a response signal will be fed back. If the frequency of the excitation signal is not near the natural frequency f0 of the device to be measured where the sensor is positioned, the response signal is basically zero. On the contrary, if the frequency of the excitation signal is near the natural frequency of the object where the sensor is positioned, the above-mentioned vibration pickup process will occur.

[0089] 2. Vibrating String Collection Sweep Frequency Process

[0090] After installing the vibrating string sensor for the first time, since the natural frequency f0 of the object to be measured is unknown, it is necessary to enter the sweep frequency range. If the range is within 400-6000Hz, the excitation sweep frequency is started. As shown in the figure above, starting from 400Hz, the sweep frequency is performed once every 10Hz, and each time takes 200ms. A total of 560 sweeps are required to complete the full frequency band scan, which takes less than 2 minutes in total. The natural frequency f0 of the object is finally measured, and then the voltage values ​​of temperature + and temperature - (the temperature sensitive resistor NTC in series on the vibrating string sensor) on the vibrating string sensor interface are used. The NTC temperature diagram is as follows Figure 7 As shown, the temperature T0 is calculated. The temperature T0 is calculated as follows Figure 6 As shown, by dividing the voltage of the NTC thermistor, the voltage value is tested by ADC, and then the resistance value of the NTC is calculated by the voltage value. Finally, the current temperature T0 is obtained through the comparison table of NTC resistance value and temperature.

[0091] In the subsequent tests, it is only necessary to compare the previous temperature T0. If the current temperature T is greater than T0, that is, the temperature rises, then the test starts from f0-10. On the contrary, if the current temperature T is less than T0, that is, the temperature drops, then the test starts from f0+10. The test frequency F and the current temperature T are obtained, and the stress change of the tested object is calculated according to the formula:

[0092] εm=k×△F+b′×△T=k×(F-F0)+(b-α)×(T-T0)

[0093] Where:

[0094] εm represents the stress and strain of the structure being measured, and the unit is 10 -6 ;

[0095] k represents the sensitivity coefficient of the surface strain gauge, the unit is 10 -6 / F;

[0096] b is the temperature correction coefficient of the surface strain gauge, in units of 10 -6 / ℃;

[0097] α represents the linear expansion coefficient of the structure being measured, in units of 10 -6 / ℃;

[0098] △T represents the change of the real-time temperature measurement value relative to the reference value, in °C;

[0099] T represents the real-time measurement value of temperature, in °C;

[0100] T0 represents the reference value of temperature, in °C;

[0101] α represents the linear expansion coefficient of the structure being measured, in units of 10 -6 / ℃;

[0102] The linear expansion coefficient of concrete is: α≈8~12×10 -6 / ℃;

[0103] σ=(k×(F-F0)+(b-α)×(T-T0))×E;

[0104] Where: σ represents the stress value of the measured structure, the unit is MPa;

[0105] E represents the elastic modulus of the structure under test, in MPa;

[0106] By reading the serial number and inherent parameters of the vibrating wire sensor: the stress value is calculated. The inherent parameters include the calibration coefficient k, the temperature correction coefficient b, the linear expansion coefficient α of the measured structure, and the elastic modulus E of the measured structure;

[0107] 3. Data processing

[0108] After the above calculation, the current stress change of the measured object can be obtained, which can be stamped with the RTC timestamp and stored in the storage FLASH / EEPROM. When the upload cycle is over, the new data, that is, the data that has not been uploaded, will be uploaded to the platform immediately; the data stored in the FLASH / EEPROM will be retained for 7 days and will be overwritten by the new data after 7 days;

[0109] 4. The device interacts with the platform through the 4G module

[0110] The platform and equipment can realize scheduled collection and reporting, online upgrade, remote parameter setting and telemetry functions; it is convenient for maintenance personnel to perform remote maintenance and save customer labor costs.

[0111] 5. Equipment working mode

[0112] The device has three working modes, and the acquisition frequency and upload frequency of the device are set as follows in the three modes:

[0113] a. When connected to an external power source, the device runs at full power and does not enter sleep mode;

[0114] b. When powered by battery, the device can upload less and enter sleep mode in spare time. At this time, the power consumption is within 50uA@3.3V;

[0115] c. When the collected data exceeds the alarm threshold, the device enters the alarm state, collects and reports once every minute (settable), until the collected data returns to below the threshold, or the battery runs out of power;

[0116] 6. Equipment power supply design

[0117] When both external power and battery are used for power supply, external power supply shall be used first. The external power supply only needs to provide stable DC power supply of 12V@2A. ER34615 is used as battery to ensure that the data is collected and uploaded twice a day. The battery shall be replaced after 3 years. The power consumption of sleep mode when powered by battery is below 50uA@3.3V. The battery voltage shall be collected and judged whether there is external power supply each time the device wakes up or is timed. If the battery is undervoltage, the platform shall be reported immediately to remind the maintenance personnel to replace the battery. If there is external power supply, the device shall enter full power state.

[0118] 7. RS232 interface and 10 / 100M 100M network port

[0119] RS232 and 10 / 100M share a RJ45 interface (such as Figure 5 As shown in the figure, RS232 is the debug serial port of the device. The device is debugged and burned through this port. The 10 / 100M electrical port is used to interact with the platform when the external environment is capable.

[0120] RS485 interface functions:

[0121] The default function of the RS485 interface is to automatically output the sorted data through RS485 after the device collects data, which can be directly connected to a handheld data reader. This port can also connect LORA and Beidou 3 short message devices as an alternative external communication solution when the 4G module cannot communicate.

[0122] 9. Pulse rain gauge interface function:

[0123] The pulse rain gauge interface has two wires, which are usually disconnected. When the fixed-scale bucket in the pulse rain gauge is full of rain, it will overturn, causing the two wires to be briefly connected for about 20ms. The pulse rain gauge only needs to measure the frequency of the short connection, and can calculate the amount of precipitation based on the scale of the bucket.

[0124] 10. Button functions

[0125] The device has 2 buttons,

[0126] One is a power switch with a self-locking function. The power switch controls the power switch by whether the G pin of the power MOS tube is grounded. Press the button to power on the device. Press the button again, the button pops up and the device is powered off.

[0127] The other button is an automatic pop-up button, which is connected to the IO pin of the MCU in front. It has two situations: short press and long press.

[0128] Short press:

[0129] a. When the device is in sleep mode, it wakes up the device, collects data immediately and then uploads it to the platform. b. When the device is in normal mode, it resets the device.

[0130] Long press for more than 6 seconds:

[0131] aThere is no function when the device is in sleep mode.

[0132] b. When the device is in normal state, it restores the device to factory settings.

Claims

1. Integrated vibrating wire strain gauge, It is characterized in that The invention comprises a main housing (3), wherein a minimum system unit (10) is arranged on a circuit board built into the main housing (3), and the minimum system unit (10) is connected to an external communication unit (11), an analog measurement unit (12), and a power supply unit (13); a battery cover plate (4) is arranged at the bottom of the main housing (3), and an upper cover (1) is arranged at the top of the main housing (3).

2. The integrated vibrating wire strain gauge according to claim 1, It is characterized in that The upper cover (1) is provided with an indicator light board (9), on which a power light, a 4G communication light and an operation or warning light are respectively provided from top to bottom, and a light board outer cover (2) is also provided on the indicator light board (9).

3. The integrated vibrating wire strain gauge according to claim 2, It is characterized in that The main housing (3) is also connected to a connector (6) via an aviation plug mounting plate (5); the connector (6) is used to connect the device to a fixed steel pipe below the device; the device is fixed to an outlet terminal on the top of the connector (6); the bottom of the connector (6) is interlocked with a fixed iron column; the indicator light board (9) is connected to a minimum system unit (10) via an FPC soft wire; a light board line pressure plate (7) is mounted on the side of the indicator light board (9) for fixing the FPC soft wire; the vibrating string sensor passes through the connector (6) and is connected to an analog measurement unit (12) via an aviation connector on the aviation plug mounting plate (5); and the line pressure plate (8) is mounted on the side of a circuit board where the minimum system unit (10) is located for fixing the aviation plug mounting plate (5) and the analog measurement unit (12).

4. The integrated vibrating wire strain gauge according to claim 3, It is characterized in that The minimum system unit (10) includes an MCU single-chip microcomputer, which is the brain of the device and processes the acquired data according to the requirements and sends it to the target unit through the external interface; the RTC is a real-time clock chip, which is connected to the MCU, and the real-time clock chip RTC is connected to the MCU through an IIC or SPI bus; the MCU single-chip microcomputer is also connected to a storage FLASH / EEPROM, and the storage FLASH / EEPROM is connected to the MCU single-chip microcomputer through an IIC or SPI bus; the MCU single-chip microcomputer is also connected to an IO / UART expansion chip, and the IO / UART expansion chip is connected to the MCU single-chip microcomputer through an IIC or UART bus, and the other side of the IO / UART expansion chip is connected to the peripheral through a UART or IO bus.

5. The integrated vibrating wire strain gauge according to claim 4, It is characterized in that The external communication unit includes a communication unit, RS232 / RS485 and a 10 / 100M 100M electrical port. The communication unit is connected to the MCU microcontroller or the expansion chip. The 4G communication unit is connected to the MCU through the UART interface by default; the RS232 / RS485 communication unit is connected to the MCU or the expansion chip through the UART bus; the 10 / 100M 100M electrical port communication unit is connected to the MCU or the expansion chip through the RMII bus.

6. The integrated vibrating wire strain gauge according to claim 5, It is characterized in that The communication unit is one of a 4G communication unit, a Lora communication unit, a WiFi communication unit, and a Beidou three short message communication unit.

7. The integrated vibrating wire strain gauge according to claim 6, It is characterized in that The analog measurement unit includes 8 vibrating string analog measurement units and 1 pulse rain gauge test unit. One end of the vibrating string analog measurement unit is connected to the MCU single chip or expansion chip through UART / SPI or other buses, and the other end of the vibrating string analog measurement unit is connected to the vibrating string sensor through a 5-core wire. The 5 wires in the 5-core wire are: frequency +, frequency -, temperature +, temperature -, and protection ground.

8. The integrated vibrating wire strain gauge according to claim 7, It is characterized in that The vibrating string analog measurement unit is composed of an excitation component, a conversion component, and a vibration pickup unit; the excitation component, the conversion component, and the vibration pickup unit are all connected to the MCU single-chip computer, and the MCU single-chip computer sends a digital excitation signal, and the excitation component converts the digital excitation signal into an analog excitation signal through a power MOS tube; at this time, the conversion component controlled by the MCU single-chip computer outputs the analog excitation signal to the frequency + pin and the frequency - pin of the vibrating string sensor, and the vibrating string sensor receives the analog excitation signal and then feeds back a small resonance signal, and at this time, the MCU single-chip computer connects the frequency + and frequency - pins of the vibrating string sensor to the vibration pickup unit through the conversion component, and finally connects to the ADC interface of the MCU single-chip computer to complete the measurement closed loop, wherein the conversion component controls a double-pole double-throw relay or a MOS tube through the MCU to select the frequency + pin and the frequency - pin of the vibrating string sensor to be connected to the excitation component or the vibration pickup unit; One end of the pulse rain gauge test unit is connected to the MCU through ADC or other buses, and the other end of the pulse rain gauge test unit is connected to the pulse rain gauge through a 2-core wire.

9. The integrated vibrating wire strain gauge according to claim 1, It is characterized in that The power supply unit includes a battery protection unit, an external 12V DC protection unit, a dual power automatic selection unit, and various levels of DCDC / LDO boost or buck units; the battery protection unit is connected to the ER34615 battery and the dual power automatic selection unit at the rear; the external 12VDC protection unit is connected to the dual power automatic selection unit; the dual power automatic selection unit is connected to the battery protection unit and the external 12VDC protection unit at the front, and to the DCDC / LDO boost or buck units at the rear; the DCDC / LDO boost or buck units at the front are connected to the dual power automatic selection unit at the rear, and to the power pins of the various units of the equipment at the rear.

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