A speed control method and system for a pipe detector

Abstract

The application discloses a speed control method and system of a pipeline detector, and relates to the field of oil and gas pipeline detection. The method comprises the following steps: a mileage wheel module reads speed data of an inner detector; a main control module obtains speed change information of the inner detector according to the speed data; and the main control module controls a valve module to adjust the opening degree of a flow hole of the inner detector according to the speed change information, until the running speed of the inner detector is within a preset running speed range. The method guarantees the stability of the detector speed control algorithm under the disturbance of interference signals.

Description

Technical Field

[0001] This invention relates to the field of oil and gas pipeline inspection, and in particular to a speed control method and system for a pipeline detector. Background Technology

[0002] An in-pipeline detector is a device that performs online, non-destructive testing of pipelines, driven by the medium inside the pipeline, without interrupting the operation of oil and gas pipelines. The most widely used technologies for in-pipeline testing include piezoelectric ultrasonic testing (UT), electromagnetic ultrasonic testing (EMAT), and magnetic flux leakage testing (MFT).

[0003] Among them, piezoelectric ultrasound requires the addition of a coupling agent between the detection probe and the pipeline to be tested, making it unsuitable for use in natural gas pipelines; although electromagnetic ultrasound has high detection accuracy, its post-processing technology for detection signals is still imperfect.

[0004] Therefore, magnetic flux leakage detection remains the most widely used method for testing within long-distance natural gas pipelines. For example... Figure 15 The diagram illustrates magnetic flux leakage detection. Its principle is based on the high magnetic permeability of oil and gas pipeline materials. During detection, if the pipe wall is intact, the magnetized magnetic lines of force within the pipe wall will be evenly distributed. If the pipe wall has defects, the magnetic lines of force will be distorted and leak out. The magnetic sensing element mounted on the internal detector can then detect these leaking magnetic lines. By analyzing the detected magnetic signals, pipe wall defects can be quantitatively analyzed.

[0005] Although magnetic flux leakage (MFL) detection is widely used in natural gas pipeline inspection due to its advantages such as not requiring a coupling agent and being relatively easy to process detection signals, it imposes certain limitations on the operating speed of the internal detector. Firstly, the process of magnetizing the pipe wall using the internal detector's built-in permanent magnet and reaching magnetic saturation takes time. Before the pipe wall reaches a certain level of magnetic saturation, the magnetic signal detection equipment cannot perform detection. Secondly, as the permanent magnet moves with the internal detector, eddy currents are induced between the permanent magnet and the pipe wall. These eddy currents are opposite in direction to the original excitation magnetic field, thus weakening the magnetization level of the pipe wall and affecting the detection of the magnetic signal. Therefore, controlling the operating speed of the MFL internal detector is essential for MFL detection.

[0006] In view of the technology research on the in-pipeline detector of long-distance natural gas pipeline, it is analyzed that in the research on the speed control of the in-pipeline detector at home and abroad, the model is mostly established by simplifying the structure of the in-pipeline detector and the flow field environment, without considering the influence of the sealing bowl of the in-pipeline detector on the power model of the in-pipeline detector in the running process; and when the in-pipeline detector bowl is researched, only the bowl itself is researched, without considering the analysis in combination with the whole model of the in-pipeline detector; furthermore, the research on the speed control strategy and control system design of the in-pipeline detector is rarely reported, and a series of problems and deficiencies exist. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a speed control method and system of a pipeline detector in view of the deficiencies of the prior art.

[0008] The technical scheme for solving the above technical problem is as follows:

[0009] A speed control method of a pipeline detector, comprising:

[0010] The odometer wheel module reads the speed data of the in-pipeline detector;

[0011] The main control module obtains the speed change information of the in-pipeline detector according to the speed data;

[0012] The main control module controls the valve module to adjust the opening degree of the flow hole of the in-pipeline detector according to the speed change information, until the running speed of the in-pipeline detector is within the preset running speed range.

[0013] The present application has the beneficial effects that the speed control strategy of the in-pipeline detector proposed in the present application combines the historical detection data and the actual working condition of the in-pipeline detector of the long-distance natural gas pipeline, and on the basis of the speed control model of the in-pipeline detector, a speed control algorithm is designed, which ensures the stability of the detector speed control algorithm under the disturbance of interference signals.

[0014] Further, the main control module controls the valve module to adjust the opening degree of the flow hole of the in-pipeline detector according to the speed change information, until the running speed of the in-pipeline detector is within the preset running speed range, specifically comprising:

[0015] The main control module adjusts the opening degree of the flow hole of the in-pipeline detector by the PID control algorithm in combination with the speed change information, until the running speed of the in-pipeline detector is within the preset running speed range.

[0016] Further, the main control module obtains the speed change information of the in-pipeline detector according to the speed data, specifically comprising:

[0017] The main control module calculates the speed change information of the inner detector according to the pipeline mileage, historical monitoring data and real-time detected front and rear pressure values.

[0018] The beneficial effect of the further scheme is that the detector speed is controlled in advance based on the historical detection data, and the fuzzy PID speed control is used as compensation for auxiliary control, the overall system of the inner detector of the long-distance natural gas pipeline is designed in combination with the functional requirements of the control system.

[0019] Further, the historical monitoring data includes pipeline mileage data, elevation data and feature data.

[0020] Further, the force state of the inner detector during pipeline operation is analyzed to obtain the front and rear pressure values.

[0021] Another technical solution of the present application to solve the above technical problems is as follows:

[0022] A speed control system of a pipeline detector, comprising: a mileage wheel module, a main control module and a valve module;

[0023] The mileage wheel module is used to read the speed data of the inner detector.

[0024] The main control module is used to obtain the speed change information of the inner detector according to the speed data.

[0025] The main control module is used to control the valve module to adjust the opening degree of the flow hole of the inner detector according to the speed change information, until the running speed of the inner detector is within the preset running speed range.

[0026] The beneficial effect of the present application is that the pipeline inner detector speed control strategy combines the historical detection data and actual working conditions of the inner detector of the long-distance natural gas pipeline, and a speed control algorithm is designed based on the inner detector speed control model, which ensures the stability of the detector speed control algorithm under the disturbance of interference signals.

[0027] Further, the main control module is specifically used to adjust the opening degree of the flow hole of the inner detector by a PID control algorithm in combination with the speed change information, until the running speed of the inner detector is within the preset running speed range.

[0028] Further, the main control module is used to calculate the speed change information of the inner detector according to the pipeline mileage, historical monitoring data and real-time detected front and rear pressure values.

[0029] The beneficial effect of adopting the above further scheme is that the detector speed is controlled in advance based on historical detection data, and fuzzy PID speed control is used as compensation for auxiliary control, and the overall system of the detector in the long-distance natural gas pipeline is designed in combination with the functional requirements of the control system.

[0030] Further, the historical monitoring data includes pipeline mileage data, elevation data and feature data.

[0031] Further, the force state of the inner detector during pipeline operation is analyzed to obtain the front and rear pressure values.

[0032] The advantages of the additional aspects of the present application will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A flowchart of a speed control method of a pipeline detector provided for an embodiment of the present application;

[0034] Figure 2 A structural block diagram of a speed control system of a pipeline detector provided for an embodiment of the present application;

[0035] Figure 3 A fluid dynamics simulation model schematic diagram provided for other embodiments of the present application;

[0036] Figure 4 A leather cup friction simulation model schematic diagram provided for other embodiments of the present application;

[0037] Figure 5 An inner detector speed control model schematic diagram provided for other embodiments of the present application;

[0038] Figure 6 An inner detector speed control fuzzy PID algorithm simulation diagram provided for other embodiments of the present application;

[0039] Figure 7 An overall block diagram of an inner detector control system provided for other embodiments of the present application;

[0040] Figure 8 An overall architecture diagram of an electrical system provided for other embodiments of the present application;

[0041] Figure 9 A Hall sensor interface circuit schematic diagram provided for other embodiments of the present application;

[0042] Figure 10A valve motor drive circuit schematic diagram provided for other embodiments of the present application;

[0043] Figure 11 A force diagram of a detector in a pipeline provided for other embodiments of the present application;

[0044] Figure 12 A relief hole cross section simplified diagram provided for other embodiments of the present application;

[0045] Figure 13 A fuzzy PID algorithm structure block diagram provided for other embodiments of the present application;

[0046] Figure 14 A main control program flow chart provided for other embodiments of the present application;

[0047] Figure 15 A magnetic flux leakage detection schematic diagram provided for other embodiments of the present application. DETAILED DESCRIPTION

[0048] The principles and features of the present application are described below in conjunction with the accompanying drawings, and the embodiments are only used to explain the present application, and are not used to limit the scope of the present application.

[0049] As shown, a speed control method of a pipeline detector provided for an embodiment of the present application, comprising: Figure 1

[0050] S1, the odometer wheel module reads the speed data of the inner detector; wherein the speed data is the running speed of the inner detector in the pipeline, and the unit is m / s.

[0051] S2, the main control module obtains the speed change information of the inner detector according to the speed data; it should be noted that the main control module calculates the speed change information of the inner detector according to the pipeline mileage, historical monitoring data and real-time detected front and rear pressure values. Wherein, the pipeline mileage can be understood as the distance from the starting position (or a certain mark point) of the pipeline, and the unit is km. For example, the pipeline mileage is 10km, which means that the distance from the starting point is 10km.

[0052] It should be noted that the calculation process of the front and rear pressure values can include:

[0053] The force formula of the detector is as follows:

[0054] ma=P b A b -P f A f -F f -mgsinα,

[0055] In the formula, m represents the mass of the detector, a represents the running acceleration of the detector, P​b Pf represents the pressure at the front of the detector, A b Pf represents the pressure at the front of the detector, A f Pf represents the pressure at the front of the detector, A f Pf represents the pressure at the front of the detector, A

[0056]

[0057] n represents the number of orifices, β represents the orifice opening, r represents the orifice radius, F f Pf represents the pressure at the front of the detector, A f = fmgcos α f represents the friction coefficient, and α represents the angle between the central axis of the detector and the horizontal direction.

[0058] S3, the main control module controls the valve module to adjust the orifice opening of the inner detector according to the speed change information until the running speed of the inner detector is within the preset running speed range. It should be noted that the main control module adjusts the orifice opening of the inner detector by combining the speed change information through the PID control algorithm until the running speed of the inner detector is within the preset running speed range.

[0059] In an embodiment, the process in which the main control module controls the valve module to adjust the orifice opening of the inner detector according to the speed change information can include:

[0060] The historical monitoring data of the pipeline mileage, elevation, etc. and the real-time detected front and rear pressure values are brought into the above formula to calculate the pipeline speed change in advance, and the orifice opening is adjusted through the following formula.

[0061]

[0062] β represents the orifice opening, P f Pf represents the pressure at the front of the detector, n represents the number of orifices, A b Pf represents the pressure at the front of the detector, n represents the number of orifices, A b Pf represents the pressure at the front of the detector, n represents the number of orifices, A

[0063] It should be noted that in an embodiment, the main control module can include: the main control module has the functions of acquiring information of other modules and processing, performing control algorithm calculation, outputting signal control valve motor action, etc. It mainly includes circuits related to the working mode of the whole system, such as: real-time clock circuit, crystal oscillator circuit, reset circuit, ST-LINK download interface circuit, serial download interface circuit, and startup mode selection circuit, etc.

[0064] The odometer wheel module can include: the function of the odometer wheel module is to detect the running speed of the inner detector, the main control chip captures the signals detected by the three groups of hall sensors through the I / O port, and obtains the running speed data of the inner detector after calculation and processing, so the module mainly includes six-way hall sensor signal detection circuit.

[0065] The valve module can include: the function of the valve module is to receive the control signal sent by the main control module, control the action of the valve motor, thereby adjusting the valve opening degree, and realizing the control of the speed of the inner detector. The valve motor is selected from the brushless DC motor of Maxon Company, and the motor driver is the brushless DC motor driver of Elmo Company, so the valve module includes a motor drive interface module. Since the designed valve opening degree has a certain range limit, limit switches are designed at the left and right limit positions of the valve, so the valve module also includes a limit switch interface circuit.

[0066] In an embodiment, it also includes: a power module: the power module is used for power supply of the entire control system and the motor and the motor driver. Moreover, considering that the battery carried by the inner detector has limited power, in order to avoid the situation that the control system cannot work due to insufficient battery power during the running of the inner detector, and the inner detector is stuck in the pipe, a power voltage and current power detection module is designed for the power module to monitor the battery in real time and make emergency treatment when the power is insufficient.

[0067] It also includes: a data storage module: the data storage module includes a 4Gb flash memory circuit, which is used for storing the time, speed and detection data of the inner detector during the operation of the inner detector.

[0068] The pipeline inner detector speed control strategy provided by the application combines the historical detection data and actual working conditions of the natural gas long-distance pipeline inner detector, and designs a speed control algorithm based on the inner detector speed control model, so as to ensure the stability of the detector speed control algorithm under the disturbance of interference signals.

[0069] Optionally, in some embodiments, the main control module controls the valve module to adjust the opening degree of the flow hole of the inner detector according to the speed change information until the running speed of the inner detector is within the preset running speed range, specifically including:

[0070] The main control module adjusts the opening degree of the flow hole of the inner detector according to the speed change information through the PID control algorithm until the running speed of the inner detector is within the preset running speed range.

[0071] Optionally, in some embodiments, the main control module obtains the speed change information of the inner detector according to the speed data, specifically including:

[0072] The main control module calculates the speed change information of the inner detector according to the pipeline mileage, historical monitoring data and real-time detected front and rear pressure values.

[0073] The application performs advanced control on the detector speed based on historical detection data, and performs auxiliary control by using fuzzy PID speed control as compensation, and designs the overall system of the inner detector of the long-distance natural gas pipeline in combination with the functional requirements of the control system. The system has strong adaptability and stability for the working environment of the pipeline detector.

[0074] Optionally, in some embodiments, the historical monitoring data includes pipeline mileage data, elevation data and feature data.

[0075] Optionally, in some embodiments, the method further comprises: analyzing the stress state of the inner detector during pipeline operation to obtain the front and rear pressure values.

[0076] In an embodiment, based on the mechanical model of the inner detector of the long-distance natural gas pipeline, MATLAB / SIMULINK is used to simulate the dynamic system of the inner detector. As shown in Figure 3 、 4 According to the fluid dynamics model and the friction mechanics model of the skin bowl, the simulation models are established respectively. In combination with the working principle and speed regulation mechanism of the inner detector, the speed control model of the inner detector is established. Among them, Figures 3-6 is the mature simulation model in MATLAB.

[0077] In an embodiment, the inner detector of the long-distance natural gas pipeline is a nonlinear system, and the state of the nonlinear system is related to not only its own structure and parameters, but also the initial value of its state vector and input. Moreover, due to the strong nonlinearity of the inner detector system, there is strong coupling between parameters. Therefore, it is difficult to analyze the motion process and performance of the system and establish a control system to control the running speed by using conventional nonlinear control system design methods such as local linearization, phase plane method or description function method. For such a strong nonlinear system, computer simulation analysis is a powerful tool for designing and analyzing the control strategy. Among them, MATLAB / SIMULINK software has a leading position in the field of control system modeling and simulation due to its powerful computing power and rich toolbox resources. Therefore, the application first builds a simulation model of the inner detector of the long-distance natural gas pipeline in MATLAB / SIMULINK, as shown in Figure 5 .

[0078] In another embodiment, the simulation diagram of the fuzzy PID algorithm for the speed control of the inner detector is as shown in Figure 6 .

[0079] In another embodiment, the present application is based on the internal detector control system function requirements, combined with the actual working condition of the internal detector, to build the overall scheme of the internal detector control system. As shown in Figure 7 The overall block diagram of the internal detector control system mainly includes the main control module, the odometer module, the valve module, the power module and the data storage module. Figure 8 The overall architecture of the electrical system is shown in the figure.

[0080] The main control module: The main control module has the functions of obtaining information from other modules, processing, performing control algorithm calculation, outputting signal to control valve motor action, etc. It mainly includes circuits related to the working mode of the whole system, such as real-time clock circuit, crystal oscillator circuit, reset circuit, ST-LINK download interface circuit, serial port download interface circuit and start-up mode selection circuit, etc.

[0081] Odometer module: The function of the odometer module is to detect the running speed of the internal detector. The main control chip captures the signals detected by the three groups of Hall sensors through the I / O port, and obtains the running speed data of the internal detector after calculation and processing. Therefore, this module mainly contains six-way Hall sensor signal detection circuit, as shown in Figure 9 .

[0082] Valve module: The function of the valve module is to receive the control signal sent by the main control module, control the action of the valve motor, and adjust the valve opening to realize the control of the internal detector speed. The valve motor is selected from the brushless DC motor of Maxon Company, and the motor driver is the brushless DC motor driver of Elmo Company. Therefore, the valve module includes the motor drive interface module. Since the designed valve opening has a certain range limit, limit switches are designed at the left and right limit positions of the valve. Therefore, the valve module also includes the limit switch interface circuit.

[0083] Power module: The power module is used to power the entire control system and the motor and motor driver. Considering that the battery carried by the internal detector has limited power, in order to avoid the situation that the control system cannot work due to insufficient battery power during the running of the internal detector, and the internal detector is stuck in the pipe, the power module is designed with a power voltage and current power detection module to monitor the battery situation in real time and make emergency treatment when the power is insufficient.

[0084] Data storage module: The data storage module includes a 4Gb Flash memory circuit, which is used to store the time, speed and detection data of the internal detector during operation.

[0085] In another embodiment, the detector speed is controlled in advance based on historical detection data, and is assisted by fuzzy PID speed control as compensation, and the hardware system and software system of the inner detector speed control system are developed based on the foregoing inner detector control system overall scheme.

[0086] The hardware system can include:

[0087] The main control module hardware design: in order to realize the calculation of the control algorithm of the inner detector control system and the control of other modules in the control system, and considering the design cost and efficiency, and leaving an interface for subsequent function expansion, the STM32F103ZET6 microprocessor produced by the STMicroelectronics Company is selected as the core of the main control module. The kernel of the STM32F103ZET6 adopts Cortex-M3, the highest working frequency of which is 72MHz, and can reach 1.25DMips / MHz (Dhrystone 2.1) when accessing the memory at 0 waiting period, and can perform single-cycle multiplication and hardware division, and also has 512KB of Flash program memory and 64KB of SRAM, which can quickly and accurately perform the calculation work of the fuzzy PID control algorithm.

[0088] The odometer wheel module hardware design: the odometer wheel module is only composed of the interfaces of three groups of six-way Hall sensors, as shown in Figure 9 The interface circuit of the first group of Hall sensors is shown in the figure, and the other two groups of four-way circuits are completely the same as the first group, and the interface terminals of the main controller are Qencoder2A, Qencoder2B, Qencoder3A and Qencoder3B. Among them, the TLP293 optocoupler chip is set, which converts the 24V voltage output by the Hall sensor into a 3.3V voltage signal received by the main control chip, and at the same time realizes the isolation of input and output electrical signals, increases the circuit anti-interference ability, and increases the precision of the odometer wheel in measuring the running speed of the inner detector. The SN74AUP2G17 is a low-power double Schmidt trigger buffer produced by Texas Instruments, which is used to buffer the signals from the Hall sensor, so that the main controller working at high frequency and the Hall sensor unit working at low frequency can work coordinately.

[0089] The valve module hardware design: the valve module circuit includes a motor driving circuit and a valve limit signal receiving circuit, as shown in Figure 10The motor driving circuit is shown. The SN74LVC4245 is an eight-way bus bidirectional transceiver with a three-state output produced by Texas Instruments, and has a level conversion function of 3.3V to 5V. The DIR port is the chip direction selection terminal, when the DIR port is high, the A port is the input terminal, and the B port is the output terminal; when the DIR port is low, the B port is the input terminal, and the A port is the output terminal. In the circuit, the DIR port is grounded, that is, the DIR port is always low, and the chip always inputs signals from the B port connected with the main controller and outputs signals from the A port connected with the motor driver. The circuit realizes the control of the rotation angle of the valve motor in the form of pulses, and the pulse signals are sent to the transceiver from the main controller to the MOTOR_PULSE, and then are sent to the motor driver from the PULSE port asynchronously. The EN port is the motor enable port, the DIR is the motor steering selection port, and the MOTOR_EN and MOTOR_DIR are the input terminals of the main controller corresponding thereto.

[0090] The pipeline detector speed control system software can include:

[0091] The function of the natural gas long-distance pipeline detector speed control main program is to realize the reading, comparison and control of the opening degree of the inner detector valve of the inner detector speed information.

[0092] The present application considers the influence of the inner detector sealing bowl on the inner detector power model during its operation, and further completes the speed control simulation model of the natural gas long-distance pipeline detector. The present application fills the gap in the research on the speed control of the pipeline detector at home and abroad; the speed control strategy of the pipeline detector proposed by the present application combines the historical detection data and the actual working condition of the natural gas long-distance pipeline detector, and on the basis of the speed control model of the inner detector, a speed control algorithm is designed to ensure the stability of the detector speed control algorithm under the disturbance of the interference signal; the present application performs advance control on the detector speed based on the historical detection data, and performs auxiliary control by using the fuzzy PID speed control as compensation, and designs the overall system of the natural gas long-distance pipeline detector in combination with the functional requirements of the control system. The system has strong adaptability and stability for the working environment of the pipeline detector.

[0093] In an embodiment, as Figure 2 shown, a speed control system of a pipeline detector includes a mileage wheel module 1101, a main control module 1102, and a valve module 1103.

[0094] The mileage wheel module 1101 is configured to read speed data of the inner detector.

[0095] The main control module 1102 is configured to obtain speed change information of the inner detector according to the speed data.

[0096] The main control module 1103 is configured to control the valve module to adjust the opening degree of the bleed hole of the inner detector according to the speed change information until the running speed of the inner detector is within the preset running speed range.

[0097] The pipeline inner detector speed control strategy provided by the application combines historical detection data and actual working conditions of the natural gas long-distance pipeline inner detector, and designs a speed control algorithm based on an inner detector speed control model, thereby ensuring the stability of the detector speed control algorithm under the disturbance of interference signals.

[0098] Optionally, in some embodiments, the main control module 1102 is specifically configured to adjust the opening degree of the bleed hole of the inner detector by a PID control algorithm in combination with the speed change information until the running speed of the inner detector is within the preset running speed range.

[0099] Optionally, in some embodiments, the main control module 1102 is configured to calculate the speed change information of the inner detector according to the pipeline mileage, historical monitoring data and real-time detected front and rear pressure values.

[0100] The application performs advanced control on the detector speed based on historical detection data, and performs auxiliary control by compensating with fuzzy PID speed control, and designs a natural gas long-distance pipeline inner detector overall system in combination with the functional requirements of the control system. The system is strong in adaptability and stability in view of the working environment of the pipeline detector.

[0101] Optionally, in some embodiments, the historical monitoring data includes pipeline mileage data, elevation data and feature data.

[0102] Optionally, in some embodiments, the method further includes analyzing the stress state of the inner detector during pipeline operation to obtain the front and rear pressure values.

[0103] It can be understood that in some embodiments, some or all of the optional implementation manners in the above embodiments can be included.

[0104] It should be noted that the above embodiments are product embodiments corresponding to the prior method embodiments, and the description of the optional implementation manners of the product embodiments can refer to the corresponding description in the above method embodiments, which will not be repeated here.

[0105] In another embodiment, a speed control method of a natural gas pipeline inner detector, a detector control hardware system for implementing the method and a speed control system software composition.

[0106] The speed control method is to control the detector speed in advance based on historical detection data, and to assist the control by fuzzy PID speed control as compensation. The specific implementation is as follows:

[0107] (1) The control system loads the pipeline historical detection data, including pipeline mileage, elevation, and feature (weld, elbow, etc.) data. Among them, the elevation refers to the pipeline altitude, and the unit is m.

[0108] (2) The force state of the detector in the pipeline (such as Figure 11 ) is analyzed, and the cross section of the flow hole is shown in Figure 12 .

[0109] The force formula of the detector is as follows:

[0110] ma=P b A b -P f A f -F f -mgsinα,

[0111] In the formula, m represents the mass of the detector, a represents the running acceleration of the detector, P b represents the pressure behind the detector, A b represents the force area behind the detector, P f represents the pressure in front of the detector, A f represents the force area in front of the detector,

[0112]

[0113] n is the number of flow holes, β is the opening of the flow hole, r is the radius of the flow hole, F f represents the frictional resistance of the detector, F f =fmgcos α , f is the friction coefficient, and α represents the angle between the central axis of the detector and the horizontal direction.

[0114] (3) The pipeline mileage, elevation, and other historical monitoring data, as well as the real-time detected front and rear pressure values are brought into the above formula, and the pipeline speed change is calculated in advance. The opening of the flow hole is adjusted by the following formula.

[0115]

[0116] β is the opening of the flow hole, P f represents the pressure in front of the detector, n is the number of flow holes, A b represents the force area behind the detector, P b represents the pressure behind the detector, f is the friction coefficient, m represents the mass of the detector, and α represents the angle between the central axis of the detector and the horizontal direction.

[0117] (4) Real-time monitoring of the detector speed by sensors, and fine-tuning of the detection speed by a fuzzy PID control algorithm to ensure stable operation of the detector.

[0118] The PID control algorithm can achieve the function of controlling the speed of the inner detector. However, since the pK, iK and dK parameters of the PID control algorithm are fixed, the dynamic performance, anti-interference ability and robustness of the inner detector control system, which is a nonlinear system, are not ideal. This will cause the inner detector to take a long distance to stabilize the speed at the set value when it is disturbed by speed, which undoubtedly reduces the confidence of the inner detector detection information. The fuzzy PID control algorithm can adjust the pK, iK and dK parameters of the PID control algorithm in real time according to the system error and error change rate, and improve the performance of the control system. For example, as shown in the figure. The fuzzy PID control algorithm continuously obtains information such as the deviation ε(t) and the change rate dε / dt of the actual running speed of the inner detector system and the target speed, and adjusts the pK, iK and dK parameters of the PID control algorithm online according to the fuzzy rules to achieve the purpose of improving the dynamic performance of the system. Figure 13

[0119] In another embodiment, the speed control system software is specifically implemented as follows: the function of the natural gas long-distance pipeline inner detector speed control main program is to realize the reading, comparison and control of the inner detector speed information, and the opening of the inner detector bleed hole, for example, by controlling the valve action of the motor to adjust the opening of the bleed hole, to change the pressure difference ΔP and the force area ΔS, thereby changing the force F of the inner detector (F = ΔP * ΔS), and further changing the inner detector running speed. Figure 14 ​The flow chart of the speed control main program of the natural gas long-distance pipeline internal detector is shown. After the system is initialized, the historical detection data of the pipeline is stored in the flash memory, and then the running time, speed, mileage and magnetic flux leakage detection information of the internal detector are recorded and stored in the flash memory. It should be noted that the internal detector is mainly used for detecting pipeline abnormalities (including deformation, corrosion, cracks and the like) and positioning. The magnetic flux leakage detection information can reflect the abnormal signals of the pipeline, so as to determine whether the pipeline has defects such as deformation, corrosion, cracks and the like. The running time, speed, mileage and the like of the internal detector are used to determine the position of the abnormal signals, so that the maintenance personnel can accurately find the pipeline that needs to be maintained, and then repair the pipeline. According to the detection signals of the detector, the pipeline characteristics are automatically compared to realize data alignment, and then the running speed change of the detector is predicted according to the pipeline information, and the opening degree of the bleed hole is adjusted. The valve adjustment process is entered. First, it is judged whether the speed of the internal detector is greater than or less than the set speed. If the speed is greater than the set speed, the forward rotation flag bit of the valve is set. If the speed is less than the set speed, the reverse rotation flag bit of the valve is set. The real-time speed of the internal detector read by the mileage wheel module is compared with the set speed. The detection signals include the time, speed, mileage and magnetic flux leakage detection information mentioned above. The pipeline characteristics include welds (the length of a single pipeline is generally 12 m, and the pipelines are connected by welding), bends (the pipelines are not laid in a straight line in some special areas, and the bends are used for connection), tees (the pipelines are used for the download of medium such as petroleum, natural gas and the like), and the like. These characteristics are very obvious in the detection signals and are the main basis for comparing the detection data with the actual pipeline mileage at present. According to the detection signals of the detector, the pipeline characteristics are automatically compared to realize data alignment. Specifically, the internal detector can run up to hundreds of kilometers at a time. Due to the slippage of the mileage wheel and the running fluctuation of the detector, there is a deviation between the mileage information recorded by the detector and the actual mileage of the pipeline. If the deviation is too large, hundreds of meters of pipeline may need to be dug to find the defect position. The actual positions of the welds, bends, tees and the like of the pipeline are accurately mastered by the pipeline operation unit, and these characteristics are very detailed in the detection signals. The position of the defect can be accurately positioned by calculating the number of welds (or bends, tees and the like) before and after the defect in the detection signals, which facilitates the pipeline repair personnel to repair the pipeline. Through the alignment of the detection data and the actual pipeline data, the pipeline defect can be positioned within a few meters. At present, there is relatively mature data analysis software that can automatically align the data.

[0120] The degree value is compared with the ideal running speed of the internal detector set by the system. When the error exceeds the allowable range, the valve opening adjustment is started. The fuzzy control submodule is entered. First, the speed error and the change rate of the deviation of the internal detector are calculated, and then the fuzzy and fuzzy reasoning are carried out. The pk, ik and dk parameters of the PID controller are updated, so as to calculate the output valve position pulse signal and adjust the valve opening.

[0121] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. It is to be understood that the use of the singular herein includes the plural unless the context clearly dictates otherwise. The term "comprising" means "including, but not limited to". The term "comprising" or "comprises" or "comprised of" as used herein is synonymous with "including", "having", "containing" or "characterized by". The term "comprising" or "comprises" or "comprised of" as used herein does not exclude the presence of other elements or steps. The term "consisting essentially of" means including the elements or steps specified, but not excluding the presence of other elements or steps that do not materially affect the characteristics of the method or composition. The term "consisting of" means including, and limited to, whatever follows the term "consisting of". The term "consisting of" is used as a synonym of "consisting only of" or "only of". The term "consisting essentially of" is used as a synonym of "consisting of" or "consisting only of". The term "consisting of" is used as a synonym of "consisting only of" or "only of".

[0122] In several embodiments provided in the present application, it should be understood that the disclosed device and method can be implemented in other ways. For example, the above-described method embodiments are only illustrative, for example, the division of steps is only a logical function division, and actual implementation can have another division manner, for example, multiple steps can be combined or integrated into another step, or some features can be ignored or not executed.

[0123] The above method, if realized in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art, or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the embodiments of the method of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0124] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A speed control method for a pipe detector, characterized by, The application relates to a pipeline internal detector speed control method and device. The speed data of the internal detector is read by a mileage wheel module; The speed change information of the internal detector is obtained by a main control module according to the speed data; The opening degree of the flow hole of the internal detector is adjusted by a valve module according to the speed change information until the running speed of the internal detector is within a preset running speed range; The speed change information of the internal detector is obtained by the main control module according to the pipeline mileage, historical monitoring data and real-time detected front and back pressure values; The calculation process of the front and back pressure values comprises: The force formula of the internal detector is: The opening degree of the flow hole of the internal detector is adjusted by the valve module according to the speed change information until the running speed of the internal detector is within a preset running speed range; ， wherein m represents the mass of the inner detector, a represents the running acceleration of the inner detector, P b represents the back pressure of the inner detector, A b represents the back force area of the inner detector, P f represents the front pressure of the inner detector, A f represents the front force area of the inner detector, , n is the number of the leakage holes, β is the opening of the leakage holes, r is the radius of the leakage holes, F f represents the friction resistance suffered by the detector, , f is the friction coefficient, and α represents the included angle between the central axis of the inner detector and the horizontal direction; The adjustment process of the opening degree of the flow hole of the internal detector by the valve module according to the speed change information comprises: The historical monitoring data and the real-time detected front and back pressure values are brought into the force formula of the internal detector to calculate the pipeline speed change in advance, and the opening degree of the flow hole is adjusted through the following formula: The historical monitoring data comprises pipeline mileage data, elevation data and characteristic data. ， n is the number of orifices, A b represents the force on the back of the detector, f is the friction coefficient, and m represents the mass of the detector.

2. A speed control method for a pipe detector according to claim 1, wherein, The application further relates to a pipeline internal detector speed control device.

3. The method of claim 1, wherein, The force state of the internal detector during pipeline operation is analyzed to obtain the front and back pressure values. The application relates to a pipeline internal detector speed control method and device.

4. A speed control system for a pipe detector, characterized by The speed data of the internal detector is read by a mileage wheel module; The speed change information of the internal detector is obtained by a main control module according to the speed data; The opening degree of the flow hole of the internal detector is adjusted by a valve module according to the speed change information until the running speed of the internal detector is within a preset running speed range; The speed change information of the internal detector is obtained by the main control module according to the pipeline mileage, historical monitoring data and real-time detected front and back pressure values; The calculation process of the front and back pressure values comprises: The force formula of the internal detector is: The opening degree of the flow hole of the internal detector is adjusted by the valve module according to the speed change information until the running speed of the internal detector is within a preset running speed range; The adjustment process of the opening degree of the flow hole of the internal detector by the valve module according to the speed change information comprises: ， where m represents the mass of the inner detector, a represents the operating acceleration of the inner detector, P b represents the back pressure of the inner detector, A b represents the back force area of the inner detector, P f represents the front pressure of the inner detector, A f represents the front force area of the inner detector, , n is the number of the leakage holes, β is the opening of the leakage holes, r is the radius of the leakage holes, F f represents the friction resistance suffered by the detector, f is the friction coefficient, and α represents the included angle between the central axis of the inner detector and the horizontal direction; The historical monitoring data and the real-time detected front and back pressure values are brought into the force formula of the internal detector to calculate the pipeline speed change in advance, and the opening degree of the flow hole is adjusted through the following formula: The historical monitoring data comprises pipeline mileage data, elevation data and characteristic data. The application further relates to a pipeline internal detector speed control device. ， n is the number of orifices, A b represents the force on the back of the detector, f is the friction coefficient, and m represents the mass of the detector.

5. A speed control system for a pipe detector according to claim 4, wherein, The force state of the internal detector during pipeline operation is analyzed to obtain the front and back pressure values.

6. A speed control system for a pipe detector according to claim 4 or 5, wherein, ​ ​

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