阅读说明：本技术 一种管道内检测里程***及里程定位采集方法 (Mileage locator for in-pipeline detection and mileage positioning acquisition method ) 是由 汤晓英 赵番 侯少星 王洁璐 于 2019-11-28 设计创作，主要内容包括：本发明提供了一种管道内检测里程定位器及里程定位采集方法,里程定位器包括FPGA芯片模块,所述FPGA芯片模块分别连接三轴加速度传感器、ADC转换模块、电平转换模块、两块SPI Flash芯片模块、两块RS485接口芯片模块、晶振、温补晶振和电源管理模块。本发明通过将三个霍尔角度传感器分别安装在三个里程轮内,以相位差为90°电子角的增量脉冲信号采用差分方式传输给FPGA,利用三个里程轮的脉冲信号,采用里程轮脉冲均分算法,以计算检测器的速度,同时采集三轴加速度信号,对里程数据进行补偿,提高了里程定位系统的抗干扰能力和测量精度。通过RS485与内检测器进行通讯,快速实时的将数据传输给内检测器进行存储,实现缺陷或几何变形位置的精确定位。(The invention provides a mileage locator for in-pipeline detection and a mileage positioning acquisition method, wherein the mileage locator comprises an FPGA chip module, and the FPGA chip module is respectively connected with a triaxial acceleration sensor, an ADC conversion module, a level conversion module, two SPI Flash chip modules, two RS485 interface chip modules, a crystal oscillator, a temperature compensation crystal oscillator and a power management module. According to the invention, the three Hall angle sensors are respectively arranged in the three mileage wheels, incremental pulse signals with the phase difference of 90 degrees are transmitted to the FPGA in a differential mode, the pulse signals of the three mileage wheels are utilized, a mileage wheel pulse averaging algorithm is adopted to calculate the speed of the detector, three-axis acceleration signals are simultaneously collected to compensate mileage data, and the anti-interference capability and the measurement precision of the mileage positioning system are improved. The RS485 communication with the inner detector is adopted, data are rapidly transmitted to the inner detector in real time to be stored, and accurate positioning of the defect or geometric deformation position is achieved.)

1. The utility model provides a detect mileage locator in pipeline, mileage locator places in the pipeline in the detector, through RS485 and the communication of pipeline in the detector, its characterized in that: the device comprises an FPGA chip module, wherein the FPGA chip module is respectively connected with a three-axis acceleration sensor and is used for collecting acceleration signals of a detector in a pipeline to compensate mileage data;

the Hall angle sensor is used for converting the magnetic field change generated by the rotation of the mileage wheel into an incremental pulse signal and sending the incremental pulse signal to the FPGA chip module for recording the mileage of the internal detector;

the SPI Flash chip module is used for storing measured mileage data and triaxial acceleration sensor data; the SPI Flash chip module II is used for storing programs of the FPGA chip module;

the RS485 interface chip module I is used for transmitting the driving mileage and the GPS time to an external internal detector so as to synchronize the pipeline defect or geometric deformation, the driving mileage and the GPS time; and the RS485 interface chip module II is used for receiving a time service signal of an external GPS time service device so as to synchronize a system clock.

The crystal oscillator is used for providing a clock signal for the FPGA chip module;

the temperature compensation crystal oscillator is used for providing a stable GPS clock with temperature compensation based on the GPS time service signal;

and the power supply management module is used for providing power supply required by the FPGA chip module.

2. The in-duct mileage detecting locator as claimed in claim 1, wherein: and the three-axis acceleration sensor is in communication connection with the FPGA chip module through the ADC conversion module.

3. The in-duct mileage detecting locator as claimed in claim 1, wherein: the Hall angle sensors are respectively installed in the three mileage wheels.

4. The in-duct mileage detecting locator as claimed in claim 1, wherein: the Hall angle sensor is connected with the FPGA chip module through the level conversion module.

5. A mileage positioning collection method based on the mileage locator of any one of claims 1 to 4, comprising the steps of:

(1) arranging a mark box on the ground, segmenting the pipeline to carry out geographic coordinate positioning, sending a signal to the ground mark box when the inner detector passes through the lower part of the ground mark box, and recording the GPS time and the position information which the inner detector passes through by the mark box;

(2) before the detection in the pipeline, an external GPS time service device is utilized to respectively grant a GPS clock to an internal detector and a mileage positioner for synchronizing a system clock, and the mileage positioner calculates the time of the mileage positioner in the pipeline according to an internal temperature compensation crystal oscillator;

(3) the mileage positioner adopts a mileage wheel pulse equipartition algorithm and selects the average value of three mileage wheel pulses to calculate the speed of the inner detector;

(4) the mileage locator collects three-axis acceleration signals to judge the acceleration of the inner detector;

(5) the mileage locator adopts the following method to calculate the driving mileage of the inner detector in a certain time:

when the pressure difference between two sides in the inner detector pipeline is kept unchanged, the running speed of the inner detector is kept unchanged, and the initial speed is v₀And the driving mileage of the inner detector at the time t is as follows:

s₀＝∫₀ ^tv₀dt＝v₀*t

because the speed of the medium in the pipeline is influenced by the factors of pipeline deformation, elbow, pressure difference change and the like, the speed of the internal detector in the pipeline is changed frequently, and the internal detector is set within 0 moment to detectInitial velocity of the machine is v₀If the acceleration of the detector is a (t) at time t, the velocity at time t is:

v(t)＝v₀+∫₀ ^ta(t)dt

the mileage of the inner detector is:

s＝∫₀ ^tv(t)dt

＝v₀*t+∫₀ ^t∫₀ ^ta(t)d²t

＝s₀+∫₀ ^t∫₀ ^ta(t)d²t

(6) the mileage positioner transmits the mileage and the corresponding time to the inner detector through the RS485 interface chip module;

(7) the inner detector utilizes the GPS time to synchronously detect the pipeline defect or geometric deformation value, the driving mileage and the GPS time;

(8) the internal detector reads and stores the data of the laser gyroscope in real time;

(9) after the detection in the pipeline is finished, importing the defect or geometric deformation information of the inner detector, the mileage and the time acquired by the mileage positioner and the data of the laser gyroscope into a PC (personal computer);

(10) the GPS time and the position information recorded by each ground marker box and passed by the inner detector are imported into a PC;

(11) the PC machine utilizes the defect or geometric deformation information of the inner detector, the mileage and the time acquired by the mileage locator, the ground marker box records the GPS time and the position information which are passed by the inner detector, the laser gyroscope data, and the accurate position of the defect or the geometric deformation of the pipeline in the pipeline is calculated off line.

6. The in-pipeline detected mileage positioning and collecting method according to claim 5, characterized in that: the triaxial acceleration sensor is used for converting the acquired acceleration signal through the ADC conversion module and then storing the converted acceleration signal into the SPIFlash chip module I through the FPGA chip module.

7. The in-pipeline detected mileage positioning and collecting method according to claim 5, characterized in that: the increment pulse signal of the Hall angle sensor is transmitted in a differential mode by using a series of square wave pulses with the phase difference of 90-degree electronic angle, and is stored into the SPI Flash chip module I through the FPGA chip module.

Technical Field

The invention relates to a mileage locator for in-pipeline detection and a mileage positioning acquisition method, and belongs to the field of in-pipeline detection.

Background

The long-distance pipeline is easy to crack, corrode and thin due to exposure to various complex and severe environmental conditions, and great potential safety hazards are brought to normal operation of the pipeline. Therefore, the long-distance pipeline needs to be subjected to internal detection and defect positioning, the probability of pipeline leakage accidents is reduced to the maximum extent, and technical guarantee is provided for safe operation of the long-distance pipeline.

In-pipeline detection, a magnetic leakage inner detector or a deformation inner detector is used for detecting metal corrosion defects and geometric deformation of the inner wall and the outer wall of the pipeline, and a mile wheel is used for positioning the positions of the defects or the geometric deformation in the pipeline. When the inner detector passes through the elbow, the mileage wheel can not well contact the pipe wall, so that slipping occurs, and the mileage positioning is inaccurate. Therefore, the mileage positioning system with strong anti-interference capability, real-time detection and high precision is designed, and important technical guarantee can be provided for corrosion detection, accurate positioning and safe operation of the long-distance pipeline.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a device for detecting mileage in a pipeline and a method for positioning and acquiring the mileage, so that the defects or geometric deformation positions can be accurately positioned in the pipeline.

In order to achieve the purpose, the technical scheme of the invention provides a mileage locator for in-pipeline detection, the mileage locator is placed in a detector in a pipeline and is communicated with the detector in the pipeline through RS485, and the mileage locator is characterized in that: the device comprises an FPGA chip module, wherein the FPGA chip module is respectively connected with a three-axis acceleration sensor and is used for collecting acceleration signals of a detector in a pipeline to compensate mileage data;

the Hall angle sensor is used for converting the magnetic field change generated by the rotation of the mileage wheel into an incremental pulse signal and sending the incremental pulse signal to the FPGA chip module for recording the mileage of the internal detector;

the SPI Flash chip module is used for storing measured mileage data and triaxial acceleration sensor data; the SPI Flash chip module II is used for storing programs of the FPGA chip module;

the RS485 interface chip module I is used for transmitting the driving mileage and the GPS time to an external internal detector so as to synchronize the pipeline defect or geometric deformation, the driving mileage and the GPS time; and the RS485 interface chip module II is used for receiving a time service signal of an external GPS time service device so as to synchronize a system clock.

The crystal oscillator is used for providing a clock signal for the FPGA chip module;

the temperature compensation crystal oscillator is used for providing a stable GPS clock with temperature compensation based on the GPS time service signal;

and the power supply management module is used for providing power supply required by the FPGA chip module.

Preferably, the three-axis acceleration sensor is in communication connection with the FPGA chip module through the ADC conversion module.

Preferably, the hall angle sensors are respectively installed in the three mileage wheels.

Preferably, the hall angle sensor is connected with the FPGA chip module through a level conversion module.

The invention also provides a positioning and collecting method for the detected mileage in the pipeline, which is characterized by comprising the following steps:

(1) arranging a mark box on the ground, segmenting the pipeline to carry out geographic coordinate positioning, sending a signal to the ground mark box when the inner detector passes through the lower part of the ground mark box, and recording the GPS time and the position information which the inner detector passes through by the mark box;

(2) before the detection in the pipeline, an external GPS time service device is utilized to respectively grant a GPS clock to an internal detector and a mileage positioner for synchronizing a system clock, and the mileage positioner calculates the time of the mileage positioner in the pipeline according to an internal temperature compensation crystal oscillator;

(3) the mileage positioner adopts a mileage wheel pulse equipartition algorithm and selects the average value of three mileage wheel pulses to calculate the speed of the inner detector;

(4) the mileage locator collects three-axis acceleration signals to judge the acceleration of the inner detector;

(5) the mileage locator adopts the following method to calculate the driving mileage of the inner detector in a certain time:

when insideUnder the condition that the pressure difference between two sides in the detector pipeline is kept unchanged, the running speed of the inner detector is kept unchanged, and the initial speed is v₀And the driving mileage of the inner detector at the time t is as follows:

because the velocity of the medium in the pipeline is influenced by the factors of pipeline deformation, elbow, pressure difference change and the like, the velocity of the inner detector in the pipeline is changed frequently, and the initial velocity of the inner detector at the moment of 0 is set as v₀If the acceleration of the detector is a (t) at time t, the velocity at time t is:

the mileage of the inner detector is:

(6) the mileage positioner transmits the mileage and the corresponding time to the inner detector through the RS485 interface chip module;

(7) the inner detector utilizes the GPS time to synchronously detect the pipeline defect or geometric deformation value, the driving mileage and the GPS time;

(8) the internal detector reads and stores the data of the laser gyroscope in real time;

(9) after the detection in the pipeline is finished, importing the defect or geometric deformation information of the inner detector, the mileage and the time acquired by the mileage positioner and the data of the laser gyroscope into a PC (personal computer);

(10) the GPS time and the position information recorded by each ground marker box and passed by the inner detector are imported into a PC;

(11) the PC machine utilizes the defect or geometric deformation information of the inner detector, the mileage and the time acquired by the mileage locator, the ground marker box records the GPS time and the position information which are passed by the inner detector, the laser gyroscope data, and the accurate position of the defect or the geometric deformation of the pipeline in the pipeline is calculated off line.

Preferably, the acceleration signal acquired by the triaxial acceleration sensor is converted by the ADC conversion module and then stored in the SPI Flash chip module i through the FPGA chip module.

Preferably, the incremental pulse signals of the hall angle sensor are transmitted in a differential mode by using a series of square wave pulses with a phase difference of 90 degrees electronic angle, and are stored into the SPI Flash chip module i through the FPGA chip module.

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, the three Hall angle sensors are respectively arranged in the three mileage wheels, incremental pulse signals with the phase difference of 90 degrees are transmitted to the FPGA in a differential mode, the pulse signals of the three mileage wheels are utilized, a mileage wheel pulse averaging algorithm is adopted to calculate the speed of the detector, three-axis acceleration signals are simultaneously collected to compensate mileage data, and the anti-interference capability and the measurement precision of the mileage positioning system are improved. The RS485 communication with the inner detector is adopted, data are rapidly transmitted to the inner detector in real time to be stored, and accurate positioning of the defect or geometric deformation position is achieved.

Drawings

FIG. 1 is a schematic diagram of an in-pipeline mileage detecting locator module according to the present invention;

FIG. 2 is a diagram of a Hall angle sensor incremental pulse output protocol, wherein the horizontal axis represents position and the vertical axis represents pulse signals;

FIG. 3 is a circuit diagram of a Hall angle sensor interface;

FIG. 4 is a circuit diagram of a triaxial acceleration sensor interface;

FIG. 5 is a circuit diagram of an ADC conversion module interface;

fig. 6 is a connection diagram of the mileage detecting locator and the inner detector in the pipeline.

Detailed Description

In order to make the invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings.

The in-pipeline detection mileage positioner is placed in a in-pipeline detector and is communicated with the in-pipeline detector through RS485 and comprises an FPGA chip module, a triaxial acceleration sensor, three Hall angle sensors, two SPI Flash chip modules, two RS485 interface chip modules, a crystal oscillator, a temperature compensation crystal oscillator, an ADC conversion module, a level conversion module and a power management module. Wherein the crystal oscillator frequency is 100MHz, and the temperature compensation crystal oscillator frequency is 10 MHz. The FPGA chip module is respectively connected with the triaxial acceleration sensor, the ADC conversion module, the level conversion module, the two SPIFlash chip modules, the two RS485 interface chip modules, the crystal oscillator module, the temperature compensation crystal oscillator module and the power management module. The three-axis acceleration sensor is connected with the FPGA chip module through the ADC conversion module, and the Hall angle sensor is connected with the FPGA chip module through the level conversion module, as shown in FIG. 1.

The FPGA chip module adopts Spartan-6XC6SLX45 FGPA for realizing mileage positioning data acquisition. And the SPIFlash chip module is used for storing the measured mileage data and the triaxial acceleration sensor data. The SPI Flash chip module is used for storing programs of the FPGA chip module. And the RS485 interface chip module I is used for transmitting the driving mileage and the GPS time to an external internal detector so as to synchronize the pipeline defect or geometric deformation, the driving mileage and the GPS time. And the RS485 interface chip module is used for receiving GPS time service signals so as to synchronize a clock. The crystal oscillator has the frequency of 100MHz and is used for providing clock signals for the FPGA chip. The temperature compensation crystal oscillator is used for providing a stable GPS clock with temperature compensation based on the GPS time service signal. The power management module is used for providing +1.8V, +1.2V, +3.3V and +5V power for the FPGA chip module.

The Hall angle sensor is a Vert-X31E angle sensor of CONTELEC company and is used for acquiring a mileage wheel pulse signal. The Hall angle sensors are three and are arranged inside three different mileage wheels. The Vert-X31E sensor has the advantages of no mechanical wear magnetic field induction measurement, incremental pulse output, 360-degree measuring range, IP67 protection level, 14-bit resolution and independent linearity<Plus or minus 0.5 percent. The sensor consists of a magnetic block and a sensor, wherein the magnetic block is arranged on a rotating shaft of a mileage wheel, and the rotation of the mileage wheel causes the direction of a magnetic field to changePosition information is obtained by calculating each incremental value (number of steps) from a certain origin to obtain a real-time digital quantity angle signal, and each rotation is carried out by 128 pulses. FIG. 2 is a Vert-X31E incremental pulse output protocol, where u is a reference pulse. Series square wave pulse signal U with increment signal with phase difference of 90-degree electronic angle_AAnd U_BAnd carrying out transmission. Incremental signal U_AAnd U_BThe distance between two adjacent edges of (a) is a measurement step distance. In order to ensure that the signals can be output in a differential mode and improve the anti-interference capability of the sensor, the sensor also outputs an inverted signal U of the incremental signal_A-And U_B-. Fig. 3 shows a VERT-X31E interface circuit, U9 shows a VERT-X31E sensor, the sensor output is 5V level, the FPGA I/O interface level is 3.3V, and U6 uses LSF0108 of TI company to realize the conversion from 3.3V to 5V level. LSF0108 is a bi-directional voltage transition and supports up to 100MHz level transition speed without the use of a DIR pin.

The triaxial acceleration sensor samples a high-precision analog triaxial acceleration sensor MMA7361 of the Feichalcar company. Because the inner detector can generate forward inclination, backward inclination, left inclination, right inclination and other postures when running in the pipeline, the mileage positioning is influenced. Therefore, the MMA7361 is employed to detect acceleration values in real time to calibrate the mileage information. The MMA7361 has two measuring ranges of 1.5g and 6g, and can change the voltage value of the output signal according to the movement direction of the inner detector, and the core algorithm is to establish a function mapping relation between the output voltage and the acceleration. Fig. 4 shows an MMA7361 interface circuit, in which U4 shows an MMA7361 sensor. According to the actual operation condition of the detector in the pipeline, the g-SELECT pin is set to be at a high level, namely a 6g mode is selected, and the corresponding sensitivity is 206 mv/g. In the normal operating state, the ACC _ SLEEP signal is high. And meanwhile, starting a SELF Test mode, and completing internal SELF-Test of the chip before working. When the signal of each axis is not moving (0g), the output is 1.65V. If moving in one direction, the output voltage will change according to the moving direction and the set sensitivity of the sensor.

Taking the X axis as an example, the corresponding relationship between the applied acceleration and the output voltage is as follows:

wherein ADC _ ACCX is the binary number sampled by ADC, 14 is the resolution of ADC, V_REFIs an ADC reference voltage, V_ZEROFor ADC samples (0g) in the detector inactive state, gRange is 6 g. The ADC conversion module reads the output signal, and the movement and the direction of the output signal can be detected.

The ADC conversion module adopts 14-bit SAR type ADCAD7949 of ADI company for sampling and is used for acquiring a three-axis acceleration signal. Its typical offset error is + -0.5 LSB, the integral nonlinearity is + -0.5 LSB, and the signal-to-noise ratio of the output signal is 85.5 dB. And the voltage reference VREF of the ADC is selected to be 2.5V, and the ADC is communicated with the FPGA by adopting an SPI bus. Fig. 5 shows an interface circuit of the AD7949, and U1 shows an AD7949 chip.

Fig. 6 is a connection diagram of the mileage detecting localizer and the internal detector in the pipeline provided by the invention. The inner detection mileage positioner is connected with the inner detector through the RS485 interface module, the other RS485 interface of the inner detector is connected with the laser gyroscope, the inner detector guides data after the inner detection is completed into the PC through the USB interface, and the ground marking box is connected with the PC through a serial port.

The invention also provides a positioning and collecting method for the detected mileage in the pipeline, which comprises the following steps:

(1) arranging a mark box on the ground, segmenting the pipeline to carry out geographic coordinate positioning, sending a signal to the ground mark box when the inner detector passes through the lower part of the ground mark box, and recording the GPS time and the position information which the inner detector passes through by the mark box;

(2) before detection in the pipeline, an external GPS time service device is utilized to respectively grant a GPS clock to an internal detector and a mileage positioner for synchronizing a system clock, and the mileage positioner calculates the time of the mileage positioner in the pipeline according to an internal 10MHz temperature compensation crystal oscillator;

(3) the mileage positioner adopts a mileage wheel pulse equipartition algorithm and selects the average value of 3 mileage wheel pulses to calculate the speed of the inner detector;

(4) the mileage locator collects three-axis acceleration signals to judge the acceleration of the inner detector;

(5) the mileage locator adopts the following method to calculate the driving mileage of the inner detector in a certain time:

when the pressure difference between two sides in the inner detector pipeline is kept unchanged, the running speed of the inner detector is kept unchanged, and the initial speed is v₀And the driving mileage of the inner detector at the time t is as follows:

the velocity of the medium in the pipeline is influenced by the factors of pipeline deformation, elbow, pressure difference change and the like, the velocity of the inner detector in the pipeline is changed frequently, and the initial velocity of the inner detector at the moment of 0 is set to be v₀If the acceleration of the detector is a (t) at time t, the velocity at time t is:

the mileage of the inner detector is:

(6) the mileage locator transmits the mileage and the corresponding time to the inner detector through the RS485 interface;

(7) the inner detector utilizes the GPS time to synchronously detect the pipeline defect or geometric deformation value, the driving mileage and the GPS time;

(8) the internal detector reads and stores the data of the laser gyroscope in real time;

(9) after the detection in the pipeline is finished, importing the defect or geometric deformation information of the inner detector, the mileage and the time acquired by the mileage positioner and the data of the laser gyroscope into a PC (personal computer);

(10) the GPS time and the position information recorded by each ground marker box and passed by the inner detector are imported into a PC;

(11) the PC machine utilizes the defect or geometric deformation information of the inner detector, the mileage and the time acquired by the mileage locator, the ground marker box records the GPS time and the position information which are passed by the inner detector, the laser gyroscope data, and the accurate position of the defect or the geometric deformation of the pipeline in the pipeline is calculated off line.