阅读说明：本技术 一种预制式低成本测斜仪监测系统 (Prefabricated low-cost inclinometer monitoring system ) 是由 唐国华 王辅宋 刘付鹏 谢镇 刘文峰 王辅元 黄斌斌 李婧 刘国勇 姚龙 吴龙彪 于 2019-08-13 设计创作，主要内容包括：本发明涉及一种预制式低成本测斜仪监测系统,本发明属于土木工程领域,应用于结构安全健康监测行业。测斜仪电路板固定于传感器不锈钢舱体外壳,并通过信号电缆将每个测斜仪传感器舱电气上连接成一组,同时使用电路板灌封胶将测斜仪传感器舱的顶面和底面密封,再通过传感器舱限位装置固定在分体式测斜管上,分体式测斜管通过抱箍紧固在一起,并通过卡箍将每段紧固好的测斜管连接在一起,电缆对接插座与电缆插头对接完成每个传感器舱组之间的电气连接,测斜管底盖安装在测斜管的最底部,防止泥沙进入。(The invention relates to a prefabricated low-cost inclinometer monitoring system, belongs to the field of civil engineering, and is applied to the structural safety and health monitoring industry. The inclinometer circuit board is fixed on the sensor stainless steel cabin shell, each inclinometer sensor cabin is electrically connected into a group through a signal cable, the top surface and the bottom surface of each inclinometer sensor cabin are sealed by using a circuit board pouring sealant, the sensor cabin limiting devices are fixed on the split inclinometer pipes through the circuit board pouring sealant, the split inclinometer pipes are fastened together through hoops, each section of fastened inclinometer pipes are connected together through a hoop, the cable butt socket is in butt joint with a cable plug to complete the electrical connection between each sensor cabin group, the bottom cover of each inclinometer pipe is installed at the bottom of each inclinometer pipe, and silt is prevented from entering.)

1. A prefabricated low-cost inclinometer monitoring system comprises an inclinometer circuit board (1), a sensor stainless steel cabin shell (2), a circuit board pouring sealant (3), a signal cable (4), a fastening screw (5), a digital MEMS low-gravity accelerometer (6), a through hole type pad group (7), an RS485 acquisition host (8), an isolation power supply (9), an isolation RS485 driver (10), a microcontroller (11), an EEPROM (12), a split inclinometer (13), a cable butt socket (14), a cable plug (15), an inclinometer sensor cabin (16), a sensor cabin limiting device (17), a hoop (18), a hoop (19) and an inclinometer bottom cover (20);

the method is characterized in that: inclinometer circuit board (1) is fixed in sensor stainless steel cabin body shell (2), and connect into a set ofly every inclinometer sensor cabin (16) electricity through signal cable (4), use circuit board casting glue (3) simultaneously with the top surface and the bottom surface sealing of inclinometer sensor cabin (16), rethread sensor cabin stop device (17) is fixed on split type inclinometer pipe (13), split type inclinometer pipe (13) are together fastened through staple bolt (18), and link together every section of fastened inclinometer pipe through clamp (19), cable butt joint socket (14) and cable plug (15) butt joint accomplish the electrical connection between every sensor cabin group, inclinometer pipe bottom cover (20) are installed at the bottommost of inclinometer pipe, prevent that silt from getting into.

2. A prefabricated low-cost inclinometer monitoring system according to claim 1, characterized in that: the inclinometer sensor cabins (16) are connected in series into a group through signal cables (4), and each group of supports can be in butt joint with a cable plug (15) through a cable butt joint socket (14).

3. A prefabricated low-cost inclinometer monitoring system according to claim 1, characterized in that: an inclinometer sensor cabin (16) is fixed on a sensor cabin limiting device (17) in the split inclinometer pipe (13), and the split inclinometer pipe (13) is fastened through a hoop (18).

4. A prefabricated low-cost inclinometer monitoring system according to claim 1, characterized in that: each section of the split inclinometer pipe (13) is connected through a hoop (19).

5. A prefabricated low-cost inclinometer monitoring system according to claim 1, characterized in that: the microcontroller (11) reads the data of the digital MEMS low-gravity accelerometer (6) through an I2C bus and converts the data into angle values, and meanwhile, the temperature coefficient in the EEPROM (12) is called for temperature compensation.

Technical Field

The invention relates to a prefabricated low-cost inclinometer monitoring system, belongs to the field of civil engineering, and is applied to the structural safety and health monitoring industry.

Background

The current inclinometer is mainly applied to internal displacement monitoring of a foundation pit support structure, slope landslide monitoring, a dam, a foundation wall and the like, and has the advantages of wide application range, large using amount and high requirement on monitoring points. The inclinometer is one of the most important sensors for monitoring the displacement in the structure diagram at present. The existing monitoring method mainly comprises two types of manual detection and automatic online monitoring, and according to the development trend in the future, the actual scene has an increasing demand for the automatic online monitoring, but the existing monitoring method has the problems that the online monitoring cost is very high, at least several to more than ten inclinometer sensors are required to be arranged in each inclinometer hole according to the national standard requirements, and the existing inclinometer sensors have complicated mechanical structure, high cost and high maintenance cost, so the popularization and application of the inclinometer as displacement monitoring equipment in a common structure are limited in the aspects of cost, field installation, maintenance and the like. Another technical limitation that limits the application is the complexity of the field installation process and the high labor cost, for example, the installation of the existing inclinometer requires that the inclinometer is prefabricated into concrete or drilled and then backfilled with expansive soil. After the deviational survey pipe installation was accomplished, the installation of inclinometer is carried out again, every inclinometer at first need be connected the equipment with supplementary materials such as connecting rod or lead screw, universal joint, transfer the sensor along the guide slot of deviational survey inside pipe wall after the completion again, when the quantity of sensor was more, the degree of difficulty and the work load of transferring of sensor all will greatly increased, and the weight of whole sensor group also can increase moreover, if the operation is improper, the sensor probably landing causes unnecessary troublesome to the deviational survey pipe bottom. After the traditional method is used, basically, the recovery value of the sensor is not high, because the sensor works in a working environment with water, silt and the like for a long time, a metal shell and a transmission structure of the sensor can be damaged correspondingly, even if the sensor is recovered, the sensor cannot be sold newly basically, and great cost waste is caused.

Disclosure of Invention

Aiming at the problems, the invention provides a prefabricated low-cost inclinometer monitoring system in order to solve the problem that the application of an inclinometer in automatic online monitoring is greatly limited by the limitations (complex installation, high cost and difficult maintenance) of an inclinometer sensor used in the internal displacement monitoring of a structural body and a soil body at present.

In order to achieve the purpose, the invention adopts the following technical scheme:

a prefabricated low-cost inclinometer monitoring system comprises an inclinometer circuit board, a sensor stainless steel cabin shell, a circuit board pouring sealant, a signal cable, a fastening screw, a digital MEMS low-gravity accelerometer, a through hole type pad group, an RS485 acquisition host, an isolation power supply, an isolation RS485 driver, a microcontroller, an EEPROM, a split type inclinometer pipe, a cable butt socket, a cable plug, an inclinometer sensor cabin, a sensor cabin limiting device, a hoop and an inclinometer pipe bottom cover;

the inclinometer circuit board is fixed on the sensor stainless steel cabin shell, each inclinometer sensor cabin is electrically connected into a group through a signal cable, the top surface and the bottom surface of each inclinometer sensor cabin are sealed by using a circuit board pouring sealant, the sensor cabin limiting devices are fixed on the split inclinometer pipes through the circuit board pouring sealant, the split inclinometer pipes are fastened together through hoops, each section of fastened inclinometer pipes are connected together through a hoop, the cable butt socket is in butt joint with a cable plug to complete the electrical connection between each sensor cabin group, the bottom cover of each inclinometer pipe is installed at the bottom of each inclinometer pipe, and silt is prevented from entering.

Furthermore, the inclinometer sensor cabins are connected in series into a group through signal cables, and each group of supports can be in butt joint with a cable plug through a cable butt joint socket.

Furthermore, the inclinometer sensor cabin is fixed on a sensor cabin limiting device in the split inclinometer pipe, and the split inclinometer pipe is fastened through a hoop.

Furthermore, each section of the split-type inclinometer pipe is connected through a hoop.

Further, the microcontroller reads the data of the digital MEMS low-gravity accelerometer through the I2C bus and converts the data into angle values, and meanwhile, the temperature coefficient in the EEPROM is adjusted to carry out temperature compensation.

The invention has the beneficial effects that:

according to the invention, the inclinometer sensor is simplified and designed into the sensor cabin, so that the cost, the weight and the volume are greatly reduced, key sensitive parts for measuring the displacement in the soil body are greatly simplified under the condition of no loss of performance, and a basic condition is provided for prefabricating an inclinometer system. Meanwhile, the split type inclinometer is adopted, the manufacturing and installation work of the sensor can be completely finished in a factory in a prefabricated mode, after the sensor is assembled, the sensor is packaged and transported according to each section, after the sensor is on site, only the inclinometer of each section needs to be electrically connected through a waterproof aviation plug, and each inclinometer is connected together through a hoop. The construction process on site is greatly simplified, and much cost is reduced. Meanwhile, the system is designed to be a non-recovery system due to low implementation cost, maintenance is not required to be considered, and the reliability of the system is high due to the self electrical isolation design, the simplified circuit system and the simple mechanical structure. If there is more important monitoring point, it can completely carry out redundancy design, namely when designing the monitoring point, it is enough to arrange one more monitoring point.

Drawings

FIG. 1 is a view of the internal structure of a sensor capsule of the inclinometer of the present invention;

in fig. 1: 1, an inclinometer circuit board, 2, a sensor stainless steel cabin shell, 3, a circuit board pouring sealant, 4 signal cables, 5 fastening screws, 6 digital MEMS low gravity accelerometers, and 7 through hole type pad groups;

FIG. 2 is a block diagram of a sensor circuit of the inclinometer of the present invention;

in fig. 2: 8 RS485 acquisition host, 9 isolation power supply, 10 isolation RS485 driver, 11 microcontroller, 12 EEPROM and 6 digital MEMS low gravity accelerometer;

FIG. 3 is an assembled view of the split inclinometer casing of the present invention;

in fig. 3: 13 split type inclinometer pipes, 14 cable butt joint sockets, 15 cable plugs, 16 inclinometer sensor cabins and 17 sensor cabin limiting devices;

FIG. 4 is a schematic view of an assembled inclinometer pipe of the present invention;

in fig. 4: 13 split type inclinometer pipe, 18 hoops, 19 hoops and 20 inclinometer pipe bottom covers;

FIG. 5 is a block diagram of an inclinometer monitoring system of the present invention.

In fig. 5: 8 RS485 gathers host computer, 16 inclinometer sensor cabin.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-5, the present invention provides a technical solution:

a prefabricated low-cost inclinometer monitoring system comprises an inclinometer circuit board 1, a sensor stainless steel cabin shell 2, a circuit board pouring sealant 3, a signal cable 4, a fastening screw 5, a digital MEMS low-gravity accelerometer 6, a through hole type pad group 7, an RS485 acquisition host 8, an isolation power supply 9, an isolation RS485 driver 10, a microcontroller 11, an EEPROM12, a split type inclinometer 13, a cable butt socket 14, a cable plug 15, an inclinometer sensor cabin 16, a sensor cabin limiting device 17, a hoop 18, a hoop 19 and an inclinometer bottom cover 20;

inclinometer circuit board 1 is fixed in sensor stainless steel cabin body shell 2 to connect into a set of in 4 electrical behavior with every inclinometer sensor cabin 16 through the signal cable, use circuit board casting glue 3 to seal the top surface and the bottom surface of inclinometer sensor cabin 16 simultaneously, rethread sensor cabin stop device 17 fixes on split type inclinometer pipe 13, split type inclinometer pipe 13 passes through staple bolt 18 fastening together, and link together every section of fastened inclinometer pipe through clamp 19, electrical connection between every sensor cabin group is accomplished in cable butt joint socket 14 and the butt joint of cable plug 15, inclinometer pipe bottom cover 20 is installed at the bottommost of inclinometer pipe, prevent that silt from getting into.

Further, the inclinometer sensor compartments 16 are connected in series into one group through the signal cables 4, and each group of brackets can be butted through the cable butting sockets 14 and the cable plugs 15.

Further, an inclinometer sensor cabin 16 is fixed on a sensor cabin limiting device 17 in the split type inclinometer pipe 13, and the split type inclinometer pipe 13 is fastened through a hoop 18.

Furthermore, each section of the split inclinometer pipe 13 is connected through a clamp 19.

Further, the microcontroller 11 reads the data of the digital MEMS low-gravity accelerometer 6 through the I2C bus and converts the data into an angle value, and at the same time, adjusts the temperature coefficient in the EEPROM12 for temperature compensation.

Aiming at the problems of high cost, inconvenience in installation and the like of the existing inclinometer, the invention adopts a prefabricated mode, namely an inclinometer and an inclinometer are prefabricated before installation, the inclinometer and the inclinometer are assembled together in advance and are independently assembled according to each section of the inclinometer, so that the inclinometer can be installed in place only once without complex steps and procedures on site. The invention simplifies the mechanical structure into a hollow cylinder, greatly simplifies the machining process and mechanical materials, and greatly lightens the weight of a single sensor.

Therefore, the system mainly comprises (1) a sensor cabin, (2) a detachable inclinometer pipe and (3) a waterproof navigation plug assembly.

(1) Inclinometer sensor bay: the device consists of an inclinometer circuit board, a signal cable, a sensor stainless steel cabin body shell and the like.

(1.1) inclinometer circuit board: as shown in figure 1, the circuit board of the acquisition instrument is arranged in the middle of the stainless steel metal cabin of the sensor, an installation step is reserved in the middle of the stainless steel metal cabin and mainly used for fixing the circuit board and providing a stable installation plane, and meanwhile, the grounding of the circuit board is connected with the stainless steel metal cabin of the sensor through fastening screws, so that the anti-interference capability of the sensor cabin is improved.

The circuit block diagram of the inclinometer circuit board is shown in fig. 2 and comprises a microcontroller, an isolation power supply, an isolation RS485 driver, an EEPROM and a digital MEMS inclination angle sensor. The isolation power supply and the isolation RS485 driver are used for electrically isolating the inclinometer sensor from the outside, so that the protection capability is improved, and the reliability is improved. The EEPROM is used for storing parameters of the sensor, such as temperature compensation fitting coefficients, sensor module numbers and the like. With the development of MEMS technology, more and more semiconductor companies provide digital MEMS accelerometers with higher accuracy for tilt measurement, and above all, lower cost and smaller size. Currently, most of the special tilt meter chips such as SCA10x series chips of village corporation are used, and the price of each chip is more than one hundred yuan. The MEMS chip used by the invention can provide 14bit precision, and the price is only ten yuan. In addition, the invention uses the digital MEMS accelerometer, and the chip directly outputs the gravity acceleration value, thus saving the cost and the volume of the analog-digital converter and the driving work of the microcontroller on the analog-digital converter. The microcontroller can use limited resources to do more other work, for example, the data precision can be further improved by an optimized weighting algorithm.

(1.2) signal cable, the inclinometer sensor group of the invention adopts a bus type topological structure (a series structure, a hand-in-hand mode of each sensor cabin), namely, each sensor cabin is cascaded together in an RS485 bus mode, compared with a star connection mode (or a parallel connection mode), the sensor group has the advantages of less cables, light system and no limitation of the number of sensors due to the diameter limitation of an inclinometer pipe. The signal cable adopts a 4-core shielding wire, wherein four cores are respectively a power supply positive end, a power supply negative end, an RS485 interface A end and an RS485 interface B end, the cable is divided into two sections in the sensor cabin, and the two sections are correspondingly welded together through two groups of through hole type welding discs on the top layer and the bottom layer of the circuit board.

And (1.3) the sensor cabin is made of stainless steel, and 304 stainless steel is actually adopted. The sensor cabin is designed into a hollow cylinder structure, meanwhile, installation steps of the circuit board are arranged in the sensor cabin, and the circuit board is fixed in the sensor cabin through four fastening screws. After the circuit board welded with the cable is fixed in the sensor cabin, the upper surface and the lower surface of the circuit board of the sensor cabin are sealed by using special circuit board pouring sealant, the top layer of the circuit board is sealed in practice, the bottom layer of the circuit board is sealed after the pouring sealant is solidified, and the pouring sealant mainly prevents water from contacting the circuit part and plays a role in protection.

(2) Can dismantle the deviational survey pipe: the detachable inclinometer pipe consists of a split inclinometer pipe, a hoop, a bottom cover and a sensor cabin limiting device.

The split inclinometer is a customized PVC pipe cut along the axial center line, and the split type aims to install the sensor cabin in the inclinometer in advance as shown in figure 3. The split type inclinometer pipe is generally a section of 2m, the diameter is generally 50mm, and the diameter which can be made by the split type inclinometer pipe is smaller because the inclinometer is made into a sensor cabin without mechanical structures such as guide wheels. After the sensor cabin is fixedly arranged on the limiting device on the inner wall of the split-type inclinometer pipe, the sensor can be further fastened on the inclinometer pipe by using resin or special structural adhesive. The two half inclinometer pipes are joggled together through a groove and a convex groove at the joint, and the split inclinometer pipes are further hooped and fastened firmly by using the hoops.

The prefabricated inclinometer pipe and the inclinometer pipe are connected through a groove, the two sections of inclinometer pipes are connected together through a hoop, and similarly, according to the designed depth requirement, a single inclinometer pipe with a corresponding length is used as a unit and connected together through the hoop, as shown in figure 4.

The inclinometer pipe bottom cover is used for preventing silt from entering the inclinometer pipe. The bottom opening of the underground inclinometer pipe is sealed by the bottom cover.

(3) The waterproof navigation plug is composed of a cable plug with an IP65 grade and a cable butt socket and is used for electrically connecting the sensor groups between each section of the inclinometer, and after the installation of the sensor cabin and the combination and fastening of the split inclinometer are finished, the signal wires of the two sections of the inclinometer are connected through the waterproof navigation plug.

The system has the specific implementation mode that:

the core part sensor cabin of this system only needs a machined part, hollow cylinder stainless steel protects a section of thick bamboo promptly, and inside mills out the step for fixed circular circuit board, the circuit board sets up 4 fixed screw holes of central symmetry, be used for with the stable smooth terminal surface of fixing at a metal protection section of thick bamboo of circuit board, systematically on the circuit board simultaneously through walking the line and be connected with mechanical mounting hole, mechanical mounting hole passes through fastening screw and connects on sensor stainless steel cabin body shell 2 simultaneously, plays the effect of electromagnetic shield.

The general prefabricated sensor cabin group is in a group of three (so that 4 signal cables are needed in a section of inclinometer), firstly, four signal cables are respectively sleeved on a sensor stainless steel cabin body shell 2 for standby, then two adjacent cables are welded together through a through hole type pad group 7 at the top layer and the bottom layer of a circuit board, so that the two adjacent cables are electrically connected in series, the operation of other cables is similar, after all the cables are welded, the circuit board is fixed on the sensor stainless steel cabin body shell 2 which is just pre-sleeved, and finally, the sealing of pouring sealant and the welding work of waterproof navigation plug are carried out.

The main devices of the sensor circuit part, such as a digital MEMS low gravity accelerometer, can adopt MMA8451Q of NXP company, have 14-bit precision and three mutually perpendicular measuring axes, and completely meet the measuring requirements of the system. The microcontroller can adopt a low-power MSP430 series single chip microcomputer or an STM32L series low-power single chip microcomputer of ST company.

There are several key steps to the implementation process that require attention:

(1) because the inclinometer system is introduced in a high-precision measurement environment, the sensor needs to carry out a temperature drift test so as to correct the influence of temperature on a measurement result, after the prefabrication of the sensor cabin is finished (generally three sensor cabins form a group), the sensor cabin is placed in a high-low temperature alternating test box through a special fixing tool, the temperature is in a range from minus 20 ℃ to 60 ℃, data reading is carried out at intervals of 10 ℃ and a curve is fitted to obtain a compensation correction coefficient. After obtaining the latitude correction coefficient, the operator writes the temperature coefficient and other related parameters into the EEPROM in the sensor cabin through special software, and the temperature coefficient can be automatically read from the EEPROM for compensation when the sensor carries out temperature measurement.

(2) Since the MEMS accelerometer chip is a vibration sensitive element, if the MEMS chip is mounted in the center of the PCB, the vibration of the PCB itself is not suppressed due to the point without support, which may cause a certain measurement error. Therefore, in the case of the MEMS accelerometer, attention is needed to refer to the chip to a position close to the fastening screw, as shown in fig. 1, the MEMS chip is close to the fastening screw on the left side, not in the middle of the PCB.

(3) The pouring sealant can be made of polyurethane, and is suitable for being used in the designed scene due to moderate hardness, low shrinkage rate, wide temperature range, high waterproof grade and the like of the pouring sealant collected by polyurethane.

(4) The interface finally provided for the outside by the prefabricated low-cost inclinometer monitoring system is in an RS485 form, so the acquisition host can be integrated as long as the acquisition host has the RS485 interface, for example, the system can be used as a subsystem in a centralized data acquisition system and can also be used as a single measuring point in a distributed acquisition system.

(5) The inclinometer pipe is generally connected by a section of pipe of about 2m, the arrangement number of the sensor cabins in each 2m pipe can refer to the requirements of national standards or design documents, and generally 3 sensor cabins are most suitable for being installed in 2m pipelines, so that the requirement on cost can be met, and the requirement on measuring density can also be met.

The technical scope of the present invention is not limited to the above embodiments, and any modifications, equivalent variations and modifications made to the above embodiments according to the technical spirit of the present invention still fall within the technical scope of the present invention.