CN102095407A - Device and method for detecting tilting degree of tubular pile - Google Patents

Abstract

The invention discloses a device for detecting the inclination degree of pipe piles and a pipe pile inclination detection method. The command input unit is connected with the main control unit, the sensor unit is connected with the signal conditioning unit, and the electronic compass in the sensor unit is directly connected with the main control unit. The electronic compass is connected to the main control unit, the temperature sensor is connected to the main control unit, the sensor unit is connected to the main control unit through the signal conditioning unit and the A/D conversion unit, the display unit is connected to the main control unit, and the communication interface is connected to the main control unit. connected. Its steps: A, device self-inspection. B. Read the electronic compass. C. Sample X-axis and Z-axis acceleration. D. Calculate the pitch angle from the X-axis and Z-axis acceleration. E. Sampling Y-axis and Z-axis acceleration. F. Calculate the roll angle from the Y-axis and Z-axis acceleration. G. Synthesize the vertical tilt angle from the pitch angle and roll angle. H. Temperature compensation correction. High measurement accuracy, convenient and fast operation, economical and practical.

Description

A device for detecting the degree of inclination of pipe piles and a method for detecting the inclination of pipe piles

technical field

The invention relates to the field of foundation testing for geotechnical engineering, and more specifically relates to a device for detecting the inclination degree of prefabricated pipe piles, and at the same time relates to a method for detecting the inclination degree of prefabricated pipe piles, which is suitable for construction acceptance of prefabricated pipe piles.

Background technique

In foundation construction, pipe pile construction is the most basic and important step. Prefabricated piles are a method commonly used in pipe pile construction. Prefabricated piles are usually made in factories or construction sites. During construction, pile sinking equipment is used to drive, press or vibrate the piles into the soil. There are wooden piles, concrete piles, steel piles, etc., which are mainly used in China's construction field. There are two types of concrete piles and steel piles. Commonly used concrete piles include concrete solid square piles and prestressed concrete hollow pipe piles, and commonly used steel piles include steel pipe piles and H-shaped steel piles. Among them, concrete hollow pipe piles (hereinafter referred to as pipe piles) are the most common. The pipe piles are right cylinders, the axis is a straight line, and the outer contour of any section perpendicular to the axis is the same circle. It is widely used for bearing large loads.

At present, in addition to being widely used in industrial and civil buildings, pipe piles are also widely used in railways, highways, ports, bridges, water conservancy projects and other fields. Pipe pile products have a relatively complete standard system, such as "GB 13476-1999 Pretensioned Prestressed Concrete Pipe Piles", "03SG409 Prestressed Concrete Pipe Piles", "JC 888-2001 Pretensioned Prestressed Concrete Thin-walled Pipe Piles" Pile", "JC/T 947-2005 End Plates for Pre-tensioned Prestressed Concrete Pipe Pile", "JC/T 950-2005 Silica Sand Powder for Prestressed High Strength Concrete Pipe Pile", "JC/T 948-2005 Concrete Products Release agent", "JC/T540-2006 low carbon cold-drawn steel wire for concrete products", etc. There are also clear normative requirements for the construction acceptance of pipe piles, such as "GB/T 19496-2004 Test Method for the Compressive Strength of Centrifugal High-Strength Concrete by Core Drilling", "GB50202-2002 Specification for Construction Quality Acceptance of Building Foundation Engineering", "DB42/489- 2008 Technical Specifications for Prestressed Concrete Pipe Pile Foundations (Local Specifications of Hubei Province), etc.

In the construction of pipe piles, the pipe piles are often inclined due to geological conditions, construction conditions, construction technology and other factors, making the pipe piles vulnerable to damage during the construction process. At the same time, the deviation of the vertical inclination angle of the pipe pile will also affect the vertical bearing capacity or horizontal shear resistance of the pipe pile, leaving hidden dangers for the superstructure. The above-mentioned specifications have clear requirements for the verticality of the pipe pile, that is, the deviation of the vertical inclination angle. Therefore, the inclination degree of the pipe pile should be detected in time during the construction process, and the verticality of the deviation should be controlled and corrected.

Due to the very regular external geometric shape of pipe piles, detecting the degree of inclination is actually detecting the vertical inclination angle of the axis of pipe piles during or after construction. The inclination of the pipe pile will affect the stress state of the upper building structure. This effect is not only related to the inclination of the axis of the pipe pile relative to the vertical line, but also related to the inclination of the axis of the pipe pile. That is to say, the degree of inclination of the pipe pile is detected. Two angles should be detected at the same time: vertical inclination angle B - the angle of the axis of the pipe pile from the top of the pipe pile to the bottom of the pipe pile relative to the vertical line and the horizontal azimuth A - from the top of the pipe pile to the pipe pile The angle of the projection of the pipe pile axis at the bottom on the horizontal plane relative to the north orientation.

The traditional method of detecting the inclination of pipe piles is to use a digital level to measure. Not only is the operation complicated, the efficiency is low, and the accuracy is poor, but also the vertical inclination angle of the pipe pile cannot be directly measured, and it is only measured in one direction, and it is impossible to measure two The angle of the direction can no longer meet the actual needs. In the prior art, there is no fast and effective method for detecting the inclination degree of pipe piles, and there is no professional device for measuring the inclination degree of pipe piles, and only a general-purpose inclinometer device can be used for measurement.

The electronic inclinometer devices in the prior art are mostly aimed at the lateral displacement monitoring of landslide areas and deep tunnel excavation, as well as the deformation monitoring of embankment structures and stratum displacement monitoring, etc., and are not specially developed for pipe piles. Among them, there are not many that can be used to measure the inclination of pipe piles, such as the domestic LS160 level ruler, the Swiss Leica D5 laser range finder, etc. The domestic LS160 level is used to measure the angle between the surface of the level and the horizontal plane. Although the price is cheap, the accuracy is low and can only reach 0.1°, and it can only measure the vertical inclination angle B, not the horizontal azimuth A. In addition, its Using segment digital tubes to display measurement results requires manual data recording, which increases the workload of operators, so it is not suitable for pipe pile inclinometer work. The Swiss Leica D5 laser rangefinder has comprehensive functions, the main function is laser distance measurement, and it also has the function of inclinometer, which can be used to measure the angle between the surface of the instrument and the horizontal plane, and has analysis software, but it can only measure vertical The inclination angle B cannot measure the horizontal azimuth A, and the accuracy can only reach 0.1°, and its price is relatively expensive, and it is not a professional inclinometer tool, and it is not suitable for pipe pile inclinometer work. In addition, none of the electronic inclinometer devices in the prior art has a reporting function, requiring operators to manually prepare reports, and the post-workload is relatively cumbersome. Therefore, it is necessary to develop a device and method for detecting and measuring the inclination degree of pipe piles, which can accurately, economically, conveniently and quickly perform inclination and correction of pipe piles during construction.

Contents of the invention

The technical problem to be solved by the present invention is: the purpose of the present invention is to provide a device for detecting the inclination of pipe piles, the device has a simple structure and low cost, and the price is only 1/3 of the price of the imported Swiss Lycra D5 , to achieve accurate, economical, convenient and fast requirements.

Another object of the present invention is to provide a detection method for detecting the inclination of pipe piles, which is easy to implement and easy to operate, and can accurately, economically, conveniently and quickly detect the vertical inclination angle B and horizontal azimuth A of pipe piles .

In order to achieve the above object, the present invention adopts the following technical measures:

The present invention uses a vertical inclination sensor such as a two-axis accelerometer to measure the vertical inclination angle B of the pipe pile, and a horizontal inclination sensor such as an electronic compass to measure the horizontal azimuth A of the pipe pile. On the one hand, the principle of measuring the vertical tilt angle B is: when a static object is tilted, its gravitational acceleration will have a component in the tilt direction. The magnitude of this component is measured on each known axis, and the inclination angle of each axis relative to the horizontal plane can be obtained by performing calculations related to the value of this component and the acceleration of gravity. When an axis of the inclination sensor in the vertical direction of the pipe pile inclinometer is guaranteed to be parallel to the busbar of the pipe pile to be measured, the vertical inclination angle B of the pipe pile can be easily measured. On the other hand, the principle of measuring the horizontal azimuth angle A is: due to the effect of the earth's magnetic field, the output values of the magnetoresistive chip in different directions are different. The electronic compass uses the principle of detecting the geomagnetic field to detect the angle between the compass itself and the geomagnetic North Pole, which is the horizontal azimuth A of the pipe pile.

A device for detecting the inclination degree of a pipe pile, the pipe pile inclination detection device is composed of a main control unit, a command input unit, a sensor unit, a signal conditioning unit, an A/D conversion unit, a storage unit, a display unit, and a communication interface, Wherein the sensor unit, the signal conditioning unit and the storage unit also include subunits. Specifically, the sensor unit includes an accelerometer, an electronic compass, and a temperature sensor; the signal conditioning unit includes an amplitude conversion unit and a low-pass filter unit; the storage unit includes an SD card and a Flash memory. It is characterized in that: the command input unit is connected with the main control unit, the sensor unit is connected with the signal conditioning unit, the electronic compass (DCM220) in the sensor unit is directly connected with the main control unit, the accelerometer in the sensor unit is connected with the signal conditioning unit, the acceleration The meter (SCA100TD02) is connected to the main control unit after passing through the amplitude conversion unit (amplifier OPA2340), low-pass filter unit and A/D conversion unit (C8051F350) in the signal conditioning unit, and the electronic compass (DCM220) is directly connected to the main control unit The temperature sensor (DS18B20) is directly connected to the main control unit. The accelerometer in the sensor unit is not directly connected to the main control unit, but passes through the signal conditioning unit (amplifier OPA2340) and the A/D conversion unit (C8051F350) in turn. Connected to the main control unit. The A/D conversion unit is connected with the signal conditioning unit and the main control unit, and the storage unit includes SD card and Flash memory, which are all connected with the main control unit. The display unit 114 is connected to the main control unit 102 , and the communication interface 116 (USB) is connected to the main control unit 102 . Each component performs various functions respectively: the command input unit is used to input operation instructions; the sensor unit is used to collect various useful information at the measuring point of the pipe pile under test, convert these information into electrical signals, and transmit them to the main control unit; The accelerometer is used to measure the vertical inclination angle B of the pipe pile, the electronic compass is used to measure the horizontal azimuth A of the pipe pile, and the temperature sensor is used to provide multi-point temperature compensation when the inclination angle of the pipe pile is finally synthesized.

A detection method for detecting the degree of inclination of pipe piles, the steps of which are:

A. Device self-test. The components of the pipe pile inclination detection device include a main control unit, a command input unit, a sensor unit, a signal conditioning unit, an A/D conversion unit, a storage unit, a display unit, and a communication interface. The device is ready for work.

B. Read the electronic compass. The main control unit directly reads the output value of the electronic compass.

C. Sampling X-axis acceleration, sampling Z-axis acceleration. The analog voltage signal output by the accelerometer needs to be processed by the main control unit after amplitude conversion and low-pass filtering by the signal conditioning unit, and then converted into digital quantities by the A/D conversion unit.

D. Calculate the pitch angle from the X-axis acceleration and Z-axis acceleration, and perform Kalman filtering to obtain the longitudinal angle between the accelerometer plane and the horizontal plane, that is, the pitch angle (Pitch).

E. Sampling Y-axis acceleration, sampling Z-axis acceleration.

F. Calculate the roll angle from the Y-axis acceleration and the Z-axis acceleration, and perform Kalman filtering to obtain the lateral angle between the accelerometer plane and the horizontal plane, that is, the roll angle (Roll).

G. The vertical tilt angle is synthesized from the pitch angle (Pitch) and the roll angle (Roll).

H. Obtain the temperature of 3-6 measuring points (3-6 measuring points evenly distributed on the circuit board), and perform multi-point temperature compensation.

I. Display and store the results.

Compared with the prior art, the present invention has the following advantages: first, the measurement precision and accuracy are significantly improved, for example, the accuracy of the vertical inclination angle B of the device of the present invention can reach 0.01° or 0.01%, and the accuracy of the horizontal azimuth angle A can reach 1°, while the domestic LS160 level can only reach 0.1°. Second, the operation is more convenient and fast. For example, the device of the present invention can directly display the vertical inclination angle B and the horizontal azimuth angle A through the LCD screen, and automatically generate reports, while the domestic LS160 level requires operators to manually record the detection results and organize the reports. . Third, the operation is humanized. For example, the device of the present invention can automatically perform a sound alarm and an alarm under low power conditions when the detection result exceeds the warning value (such as a vertical tilt angle of 0.6° or a percentage of 1%). Fourth, it is more economical and practical. Since the present invention is positioned as a special-purpose pipe pile inclination detection device, it improves the special performance while simplifying the structure and reducing the cost. The price is only 1/3 of the price of the imported Swiss Lycra D5. Therefore, the requirements of accuracy, economy, convenience and speed mentioned above are fully realized.

Description of drawings

Fig. 1 is a schematic structural block diagram of a device for detecting the inclination degree of pipe piles.

Among them: 102-main control unit (MCU STM32); 104-command input unit (keyboard, touch screen); 106-sensor unit (including accelerometer, electronic compass, temperature sensor); 108-signal conditioning unit (amplitude conversion unit, low-pass filter unit); 110-A/D conversion unit (single chip microcomputer C8051F350); 112-storage unit (SD card, FLASH memory); 114-display unit (320*240TFT, liquid crystal drive module HX8347); 116-communication interface ( USB to serial port CP2102; RS232 interface ST3232ECTR); 120-accelerometer (SCA100TD02); 122-electronic compass (DCM220); 124-amplitude conversion unit (amplifier OPA2340); 126-low-pass filter unit; 128-SD card; 130 -FLASH memory; 132-temperature sensor.

Fig. 2 is a flow chart of a detection method for detecting the inclination degree of pipe piles.

Fig. 3 is a schematic diagram of the coordinates for calculating the vertical inclination angle in the pipe pile inclination detection method shown in Fig. 2 .

Fig. 4 is a schematic diagram of the coordinates for calculating the horizontal azimuth in the pipe pile inclination detection method shown in Fig. 2 .

Detailed ways

Embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. While the invention will be described in conjunction with examples, it will be understood that it is not intended to limit the invention to these examples. On the contrary, alternatives, modifications and equivalents are defined within the various scopes of the present invention. The technical solution of the present invention will be described in detail with reference to the drawings and specific embodiments, so as to make the characteristics and advantages of the present invention more obvious.

Embodiments described herein will be described in conjunction with generally conceptual computer-executable instructions. Computer-executable instructions refer to computer-usable media, such as program modules, that can be executed by one or more computers or other similar devices. Generally, program modules include routines, objects, components, data structures, etc. that perform particular tasks or operate on particular abstract data types. The functions of the program modules can be combined or divided according to the requirements of different embodiments.

By way of example, and not limitation, computer-usable media may comprise computer storage media and communication media. Computer storage media includes volatile and nonvolatile, removable and non-removable media that may be implemented in any method or technology for storing information such as computer readable instructions, data structures, programs modules and other data. Computer storage media include, but are not limited to, Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), Flash memory and other memory technologies, Compact Disc Read Only (CD - ROM), digital versatile disc (DVD) and other optical storage technologies, magnetic tape cassettes, magnetic disk storage and other magnetic storage, and other media that can be used to store information.

Communication media can be computer readable instructions, data structures, program modules and other data in a modulated data signal including any information delivery media such as carrier waves or other transport mechanisms. The term "modulated data signal" means that one or more characteristics of a signal are set or changed in order to impart information on the signal. For example, and not limitation, communication media may include wired media and wireless media. Wired media such as wired network, direct line connection. Wireless media such as acoustic, radio frequency (RF), infrared, and others. Combinations of any of the above should also be included within the scope of computer readable media.

Furthermore, in the following detailed description of the invention, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In some other instances, well-known schemes, processes, components and circuits are not described in detail in order to highlight the gist of the present invention.

Please refer to FIG. 1 , which is a schematic block diagram of the hardware structure of a preferred embodiment of the pipe pile inclinometer of the present invention. As shown in Figure 1, a kind of device that is used to detect the inclination degree of pipe pile, this pipe pile inclination detection device 100 is made up of main control unit 102 (MCU STM32), command input unit 104 (button), sensor unit 106, signal conditioning unit 108, an A/D conversion unit 110, a storage unit 112, a display unit 114, and a communication interface 116, wherein the sensor unit 106, the signal conditioning unit 108, and the storage unit 112 also include subunits. Specifically, the sensor unit 106 includes an accelerometer 120 , an electronic compass 122 , and a temperature sensor 132 ; the signal conditioning unit 108 includes an amplitude conversion unit 124 and a low-pass filter unit 126 ; the storage unit 112 includes an SD card 128 and a Flash memory 130 . The command input unit 104 (operating button) is connected with the main control unit 102 (MCU STM32), the electronic compass 122 (DCM220) in the sensor unit 106 is directly connected with the main control unit 102, and the accelerometer 120 (SCA100TD02) in the sensor unit 106 is connected with the main control unit 102. The signal conditioning unit 108 is connected, and the accelerometer 120 (SCA100TD02) passes through the amplitude conversion unit 124 (amplifier OPA2340) in the signal conditioning unit 108, the low-pass filter unit 126 and the A/D conversion unit 110, and the main control unit 102 (MCU) successively. STM32), and the temperature sensor 132 is directly connected to the main control unit 102. A/D conversion unit 110 links to each other with signal conditioning unit 108 and main control unit 102, and storage unit 112 comprises the SD card 128 of storing measurement data and the Flash memory 130 (FLASH) that stores Chinese character font library and temporary cache usefulness, all with main control unit 102 is directly connected. The display unit 114 is connected to the main control unit 102 , and the communication interface 116 is connected to the main control unit 102 to perform various functions respectively. The main control unit 102 is the core part of the pipe pile inclination detection device 100, and is used to control the operation of the entire pipe pile inclination detection device 100. For example, the main control unit can be an STM32 series microcontroller (MCU) with an ARM7 core. The command input unit 104 is connected to the main control unit 102 for inputting operation commands. For example, the command input unit 104 can be a common 8-key matrix keyboard, or a touch screen. When the operator presses the start button, the sensor 106 starts to collect the inclination information, and the main control unit 102 reads the data, calculates the vertical inclination angle B and the horizontal azimuth A; when the operator presses the storage button, the main control unit 102 will cache The data on the chip is stored in the SD card 128 according to a predetermined format.

The sensor unit 106 includes an accelerometer 120, an electronic compass 122 and a temperature sensor 132, wherein the accelerometer 120 is connected to the signal conditioning unit 108, the electronic compass 122 and the temperature sensor 132 are directly connected to the main control unit 102, and the use process is directly connected to the pipe pile under test. Contact with a certain measuring point of the pipe pile under test, collect relevant information at the measuring point of the pipe pile under test, convert the information into an electrical signal, and transmit it to the signal conditioning unit 108 or the main control unit 102 .

The accelerometer 120 is a tilt sensor (SCA100TD02) in the vertical direction, such as the ±90° range 2-axis accelerometer SCA100TD02 produced by VTI Technology in Finland. The output signal of the accelerometer 120 passes through the amplitude conversion unit 124, the low-pass The filter unit 126 and the A/D conversion unit 110 are connected to the main control unit 102 for measuring the vertical inclination angle B of the pipe pile. The output mode of SCA100TD02 accelerometer 120 can be SPI and analog quantity, and the analog quantity output mode is adopted in the present invention, and its output resolution is 0.0025°.

The electronic compass 122 is a horizontal tilt sensor (magnetoresistive chip), such as the two-dimensional electronic compass DCM220 produced by Shenzhen Ruifen Technology. The electronic compass 122 is directly connected to the main control unit 102 for measuring the horizontal azimuth A of the pipe pile. DCM220 type electronic compass 122 includes a single chip microcomputer (Atmel8L) and compensation circuit (magnetic declination compensation and hard iron compensation), no need to filter and compensate the output data, only obtain the corresponding data according to the output format of the communication protocol and re- It can be zeroed to the zero degree of true north. The DCM220 electronic compass 122 outputs data in I ² C or SCI format, and the output result is an angle of 0-360°. The I ² C or SCI format is directly received by the main control unit 102 and converted into inclination angle and azimuth angle, without further analog-to-digital conversion.

The temperature sensor 132 (DS18B20) is directly connected to the main control unit 102, and is not used for inclination detection, but for providing multi-point temperature compensation when finally synthesizing the inclination angle of pipe piles. Since the temperature has an impact on the 0° reference output and sensitivity of the accelerometer 120, for example, the temperature curve of the SCA100TD02 accelerometer 120 can be found in its data sheet, and the main control unit 102 will use an appropriate algorithm in combination with the temperature measured by the temperature sensor 132 Correct drift error and temperature error, perform temperature compensation and zero calibration.

As shown in FIG. 1 , the accelerometer 120 in the sensor unit 106 is not directly connected to the main control unit 102 , but is connected to the main control unit 102 after passing through the signal conditioning unit 108 and the A/D conversion unit 110 in sequence. The signal conditioning unit 108 includes an amplitude conversion unit 124 and a low-pass filter unit 126. The amplitude conversion unit 124 converts the output of the accelerometer 120 into an amplitude range suitable for the processing of the A/D conversion unit 110. For example, if the SCA100T type accelerometer is adopted Accelerometer 120, its output signal is 0-5V, and the signal input range of A/D conversion unit 110 is 0-2.5V, then the amplitude conversion unit 124 should attenuate the output of accelerometer 120 to 1/2 of the original. For example, the amplitude conversion unit 124 can be constructed by using the amplifier OPA2340, which can be understood by those of ordinary skill in the art and will not be repeated here. The low-pass filter unit 126 can use a conventional RC filter to filter high-frequency clutter in the signal. The signal collected by the accelerometer 120 is transmitted to the A/D conversion unit 110 after passing through the amplitude conversion unit 124 and the low-pass filter unit 126 .

The A/D conversion unit 110 is connected with the signal conditioning unit 108 and the main control unit 102 , and is used to convert the collected and conditioned analog signals into digital signals for the convenience of the main control unit 102 to process. For example, the A/D conversion unit 110 may adopt an integrated mixed-signal system-on-chip MCU C8051F350. What the applicant used was the on-chip 24-bit A/D of the C8051F350 MCU, with a sampling rate of 1kHz, including a programmable gain amplifier (PGA), and an on-chip calibration function. UART communication can be used between the A/D conversion unit 110 and the main control unit 102. For example, when C8051F350 communicates with STM32, the baud rate can be set to 115200, and the communication frame format can be set as shown in Table 1. The data is cached in the internal RAM of the main control unit 102. When calculating the inclination, the main control unit 102 takes out the data in the buffer and performs filtering processing first, and then performs algebraic operation to obtain the inclination value.

Table 1C8051F350 and STM32 communication frame format

The storage unit 112 includes an SD card 128 and a Flash memory 130 , both of which are directly connected to the main control unit 102 . The SD card 128 is used to store the final test results and related information. When the operator inputs a storage command through the command input unit 104, such as pressing the storage button, the main control unit 102 stores the data buffered in its on-chip Flash in the SD card 128 according to a predetermined data recording format. The main control unit 102 constructs a file system for the SD card 128, directly stores the pile data in a pre-established folder, and stores it in TXT format, which can be directly read in the future and generate a report file, which is convenient for general use. Transplanting the file system in the SD card 128 can greatly simplify the operation of the data in the SD card 128, and various operations can be performed on the files only by calling the most basic functions. The operation code of SD card 128 has already been completed by someone, and the SD card 128 can be read and written after simple transplantation. The common file systems include UC/FS of UCOS2 company, ZLG/FS used by Zhou Ligong for teaching, open source The file systems efsl and FatFs. What is transplanted in this embodiment is the improved version TFF (Tiny FATFile system) 0.06 of FatFs. TFF is an improved FAT32 file system for ARM7 series microcontrollers, which can be obtained on the Internet. The storage capacity of the SD card 128 is large. For example, assuming that each group of data occupies 20 bytes after packing, the storage capacity is 999 piles, and each pile has 100 data, then a total of 1000*100*20=2M byte space is required. At present, the common SD card 128 has a capacity of 2G or 4G, which is enough for use. The SD card 128 communicates with the main control unit 102 through SPI.

The pipe pile data format stored in SD card 128 can be preset according to detection needs, for example, the pipe pile data storage format as shown in Table 2 can be adopted:

Table 2 Pipe pile data storage format

Flash memory 130 is also used to store Chinese character fonts for text display. For example, the 220*240 liquid crystal display unit 114 usually adopts 8*16 dot matrix and 16*24 dot matrix Chinese character fonts. Arrange the font library according to the internal code of the Chinese characters, and burn it into the Flash memory 130 through the SPI interface of the main control unit 102 . When displaying, according to the inner code of the Chinese character to be displayed, search for the first address of the corresponding character library in the Flash memory 130, read the buffer, and call it for the liquid crystal display unit 114.

The display unit 114 is connected with the main control unit 102 and is used for real-time display of test results and related information, such as vertical inclination angle B, horizontal azimuth angle A, test serial number, test time and so on. The display interface can be written according to actual needs, using GUI design. For example, the display unit 114 may be composed of a 2.8-inch TFT liquid crystal display with a resolution of 220*240 and its driver. The display screen can display all measurement parameters on one screen. The TFT controller adopts the commonly used HX8347, which has rich control code resources and is easy to transplant. In addition, R6150V, SSD1289, etc. can also be used.

The communication interface 116 is connected with the main control unit 102, and the communication interface 116 is an interface for the PC to communicate with the pipe pile inclination detection device 100, so that the PC can access the pipe pile data stored in the SD card 128 and the data currently collected, including RS232 interface and USB to serial port interface. The main control unit 102 (STM32) itself has a USB full-speed controller, which can provide USB slave function, and can be designed according to the USB library file provided by ST company. In this preferred embodiment, the CP2102 chip provided by SALAB is used to convert one of the UART interfaces of the main control unit 102 (STM32) into a USB interface. When the pipe pile inclination detection device 100 is connected to the USB port, a serial port will be automatically added in the device manager of the PC, and the host computer software will access it as the serial port of the PC. In addition, it provides conventional RS232 interface, which is controlled by ST3232ECTR chip.

Fig. 2 is a detailed flowchart of a preferred embodiment of the pipe pile inclination detection method of the present invention. This method is applicable to the pipe pile inclination detection device 100 shown in Fig. 1, and is used to detect the vertical inclination angle B and the horizontal azimuth A of the pipe pile, But not limited. On the contrary, those skilled in the art can understand that the method is also applicable to other tilt detection devices. Fig. 3 is the coordinate schematic diagram of calculating the vertical inclination angle in the pipe pile inclination detection method, and Fig. 4 is the coordinate schematic diagram of calculating the horizontal azimuth angle in the method, and the preferred embodiment of the pipe pile inclination detection method is described below in conjunction with Fig. 3 and Fig. 4 .

As shown in FIG. 3 , the block is a schematic accelerometer 120 . In fact, the SCA100TD02 accelerometer 120 produced by Finland VTI Technology mentioned above is the block shape shown. Among Fig. 3, X, Y, Z represent 3 mutually orthogonal axes preset on the accelerometer 120, take the starting pin (pin 1, SCK) of the accelerometer 120 chip SCA100TD02 as the center, make the accelerometer 120 One side of the chip, such as the short side, is the X axis, the side perpendicular to it, such as the long side, is the Y axis, and the direction perpendicular to the chip surface of the accelerometer 120 is the Z axis. When the accelerometer 120 is tilted, ρ, Φ, θ respectively represent the angles between the X-axis, Y-axis, Z-axis and the horizontal plane. When the accelerometer 120 is static, the accelerometer 120 outputs components A _X , A _Y , A _Z of the acceleration of gravity on each axis. It can be seen that:

$\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}{\sqrt{{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; Y</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; Z</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; \&phi;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; Y</span>}}}{\sqrt{{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; Z</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\frac{\sqrt{{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; Y</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; Z</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

The SCA100TD02 accelerometer 120 is a 2-axis accelerometer, which needs to use its output V _OUTX , V _OUTY , OffsetX, OffsetY, and Sensitivity, where V _OUTX and V _OUTY are the pins of SCA100TD02 to directly output analog quantities, OffsetX, OffsetY, and Sensitivity It is an inherent parameter of SCA100TD02, which floats within a certain range and can be found in its data sheet. From the formulas (1)(2)(3), it can be seen that the expression of the corresponding inclination angle is:

$\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}{\sqrt{{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; Y</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; Z</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arcsin</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; OUTX</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; OffsetX</span>}}{\mathrm{<span\; class="notranslate">\; Sensitivity</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; \&phi;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; Y</span>}}}{\sqrt{{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; Z</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arcsin</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; OUTY</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; OffsetY</span>}}{\mathrm{<span\; class="notranslate">\; Sensitivity</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

As shown in FIG. 4 , the circle is a schematic electronic compass 122 , and the output is the angle between the positive direction of the electronic compass 122 and the true north direction, which is the horizontal azimuth A of the pipe pile to be detected by the pipe pile inclination detection method of the present invention.

Due to the monotonicity of the sine function, the inclination output of the accelerometer 120 has the highest accuracy near 0°, and the lowest accuracy near 90°, and the pipe pile is usually vertical to the ground. Therefore, when the accelerometer 120 chip is installed horizontally, the pipe pile inclination detection device 100 is the most accurate. When the pipe pile inclination detection device 100 is installed, the chip plane of the accelerometer 120 should be kept perpendicular to the generatrix of the pipe pile. In formula (3), θ is the inclination angle of the pipe pile to be measured. The main innovation of the present invention is to calculate the θ angle quickly and accurately according to the static measurement of the two-axis inclination angles ρ and Φ by the accelerometer 120, so as to improve the measurement accuracy.

根据公式(4)、公式(5)，可以推算出：Let tan ² ρ=m;

According to formula (4) and formula (5), it can be deduced that:

$\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\sqrt{\frac{\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; no</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; the\; tan</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; arcsin</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; outx</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; OffsetX</span>}}{\mathrm{<span\; class="notranslate">\; Sensitivity</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>$

in $\mathrm{no}={\mathrm{the\; tan}}^2\left(\arcsin \left(\frac{V_{\mathrm{outy}}-\mathrm{OffsetY}}{\mathrm{Sensitivity}}\right)\right)$

Since the tan() value is very small near 0°, and the tan() value is very large near 90°, the squared value will be smaller or larger. Therefore, in order to prevent errors caused by computer word length, in the present invention, tanθ is enlarged by a certain factor near θ=0°, and tanθ is reduced by a certain factor for operation near θ=90°. There are a large number of floating-point inverse trigonometric operations in the operation process of formula (6), and the calculation amount is relatively large. Therefore, the sin() and tan() involved in the present invention are respectively made into function tables and stored in the on-chip Flash of the main control unit 102 in advance. For example, to ensure the accuracy of the pipe pile inclination detection device 100 is 0.01°, if the increment of the angle variable is set to 0.005°, 72K on-chip Flash is required. It can be seen that the STM32 type main control unit 102 can meet the requirements.

Returning to Fig. 2, the steps performed by the preferred embodiment of the pipe pile inclination detection method of the present invention.

A detection method for detecting the degree of inclination of pipe piles, the steps of which are:

A. Device self-test 202. In the device self-inspection 202 step, each component of the pipe pile inclination detection device 100 includes a main control unit 102, a command input unit 104, a sensor unit 106, a signal conditioning unit 108, an A/D conversion unit 110, a storage unit 112, and a display unit. 114. The communication interface 116 is started in sequence, and the device is ready to work.

B. Read the electronic compass 204 . The output value of the electronic compass 122 is the horizontal azimuth A, which is accurate to 1°. The main control unit 102 directly reads the output value of the electronic compass 122 .

C. Sampling X-axis acceleration 206 and sampling Z-axis acceleration 208 . The analog voltage signal output by the accelerometer 120 needs to be subjected to amplitude conversion and low-pass filtering by the signal conditioning unit 108 , and then converted to digital by the A/D conversion unit 110 before being processed by the main control unit 102 .

D. Calculate the pitch angle from the X-axis acceleration and the Z-axis acceleration, and perform Kalman filtering 212 . According to the formula (4), the longitudinal angle between the accelerometer plane and the horizontal plane is obtained, that is, the pitch angle (Pitch).

E. Sampling Y-axis acceleration 214 and sampling Z-axis acceleration 216 . Same as step C.

F. Calculate the roll angle from the Y-axis acceleration and the Z-axis acceleration, and perform a Kalman filter 220 . According to the formula (5), the lateral angle between the accelerometer plane and the horizontal plane is obtained, that is, the roll angle (Roll).

G. Synthesize the vertical tilt angle 226 from the pitch angle (Pitch) and the roll angle (Roll).

H. Acquiring temperatures at multiple measuring points 222 and performing multi-point temperature sensor compensation 224 . Since the output value of the accelerometer 120 will have zero drift as the temperature changes, the offset value must be corrected during calculation. This step can reduce the error caused by temperature. The correction value can refer to the temperature characteristic curve of the accelerometer 120 .

1. Display and store the result 230. The horizontal azimuth A and vertical inclination B collected and calculated by the pipe pile inclination detection device 100 are displayed on the display unit 114 on the one hand, and can be stored in the storage unit 112 on the other hand. According to one embodiment of the present invention, the detection result is displayed in real time, but the storage requires the operator to send a storage instruction. In this embodiment, the detection result of the pipe pile inclination detection device 100 is stored in a TXT file, and the data of each pipe pile is stored as a TXT file. In order to facilitate deletion by pile, the name of the TXT file is the pile number. In each TXT file, the pipe pile inclination detection result data is stored according to the measurement time. When the pipe pile is not selected, a new TXT file is automatically created and automatically numbered. The storage format of each measurement data is shown in Table 2 above.

The pipe pile inclination detection device and method of the present invention uses an accelerometer combined with an electronic compass to detect the vertical inclination angle B and the horizontal azimuth angle A of the pipe pile, uses a microcontroller to control acquisition and calculation of the inclination angle, and provides multi-point temperature compensation at the same time, which can accurately The utility model provides a special detection device and method for pipe piles to detect the inclination degree of pipe piles economically, conveniently and quickly.

While the foregoing description and drawings describe a preferred embodiment of the invention, it should be understood that various additions, modifications and substitutions are possible without departing from the spirit and scope of the principles of the invention as defined. Those skilled in the art should understand that the present invention may vary in form, structure, layout, proportion, material, elements, components and other aspects in actual application according to specific environment and work requirements without departing from the principle of the invention. Therefore, the embodiments disclosed here are only for illustration rather than limitation, and the protection scope of the present invention is defined by the technical solutions in the claims and their legal equivalents, rather than limited by the previous description.

Claims (6)

1. A device for detecting the inclination degree of pipe piles, the pipe pile inclination detection device (100) includes a main control unit (102), a command input unit (104), a sensor unit (106), and a signal conditioning unit (108) , A/D conversion unit (110), storage unit (112), display unit (114), communication interface (116), characterized in that: the command input unit (104) is connected to the main control unit (102), the sensor unit ( 106) After successively passing through the signal conditioning unit (108) and the A/D conversion unit (110), it is connected to the main control unit (102), the storage unit (112) is directly connected to the main control unit (102), and the display unit (114) is connected to the main control unit (102). The main control unit (102) is connected, the communication interface (116) is connected with the main control unit (102), and the storage unit (112) includes an SD card (128) and a Flash memory (130). 2. A device for detecting the inclination of pipe piles according to claim 1, characterized in that: the sensor unit (106) includes an electronic compass (122), and the electronic compass (122) is directly connected to the connected to the main control unit (102). 3. A device for detecting the inclination of pipe piles according to claim 1, characterized in that: the sensor unit (106) includes an accelerometer (120), and the signal conditioning unit (108) includes sequential Connected amplitude conversion unit (124) and low-pass filter unit (126), the accelerometer (120) sequentially passes through the amplitude conversion unit (124) and low-pass filter in the signal conditioning unit (108) The unit (126) and the A/D conversion unit (110) are then connected to the main control unit (102). 4. A device for detecting the inclination of pipe piles according to claim 1, characterized in that: the sensor unit (106) includes a temperature sensor (132), and the temperature sensor (132) is directly connected to The main control unit (102) is connected. 5 . The device for detecting the inclination of pipe piles according to claim 1 , characterized in that: the storage unit ( 112 ) includes an SD card ( 128 ) and a Flash memory ( 130 ). 6. A method for detecting the degree of inclination of pipe piles, the steps are: A. Device self-inspection (202): In the step of device self-inspection (202), each component of the pipe pile inclination detection device (100) includes a main control unit (102), a command input unit (104), and a sensor unit (106) , the signal conditioning unit (108), the A/D conversion unit (110), the storage unit (112), the display unit (114), and the communication interface (116) start; B. Reading the electronic compass (204): the main control unit (102) directly reads the output value of the electronic compass (122) to obtain the horizontal azimuth A; C. Sampling the X-axis acceleration (206), sampling the Z-axis acceleration (208), the accelerometer (120) outputs an analog voltage signal, and the signal conditioning unit (108) performs amplitude conversion and low-pass filtering, and then A/D conversion The unit (110) is converted into a digital quantity and processed by the main control unit (102); D. Calculate the longitudinal angle between the accelerometer plane and the horizontal plane, that is, the pitch angle, from the X-axis acceleration and the Z-axis acceleration, and perform Kalman filtering (212), and calculate according to formula (4) to obtain the pitch angle; E. Sampling Y-axis acceleration (214), sampling Z-axis acceleration (216), same as step C; F. Calculate the lateral angle between the accelerometer plane and the horizontal plane from the Y-axis acceleration and the Z-axis acceleration, that is, the roll angle, and perform Kalman filtering (220), and calculate according to formula (5) to obtain the roll angle; G. Synthesize vertical tilt angle B from pitch angle and roll angle (226); H. Obtain the temperature of 3-6 measuring points evenly distributed on the circuit board (222), and perform multi-point temperature compensation (224) according to the temperature characteristic curve of the accelerometer (120); I. Display and store the results (230), the horizontal azimuth A and the vertical inclination B acquired and calculated by the pipe pile inclination detection device (100) are displayed on the display unit (114) and stored in the storage unit (112) .

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