Positioning and tracking system and method for pipe cleaner

Abstract

The invention relates to the technical field of tracking and monitoring of pipe cleaners of oil and gas pipelines, and discloses a positioning and tracking system and method for a pipe cleaner, and the system comprises a pipeline, the pipe cleaner and a control center; when the pipe cleaner runs, the inertial navigation module is used for calculating offset information of the pipe cleaner; the control module is used for obtaining corrected offset information; when the pipe cleaner passes through the sensing node signal range of the sensing node, the sensing node is used for transmitting absolute position information of the pipe cleaner to the pipe cleaner under the condition that a signal of a passive radio frequency identification tag arranged on the surface of the pipe cleaner is detected; the communication module is used for packaging the corrected offset information and absolute position information into a position information packet; and the control center is used for receiving and decoding the position information packet, obtaining a continuous pipe cleaner track and regularly correcting the pipe cleaner track through the absolute position information so as to obtain a real-time positioning result of the pipe cleaner. The problem that in the prior art, the positioning efficiency of a pipe cleaner is low can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of tracking and monitoring of pipe cleaners in oil and gas pipelines, and in particular to a positioning and tracking system and method for pipe cleaners. Background Art

[0002] When a pipeline cleaner is cleaning impurities from a pipeline, it is propelled by gas or liquid to move. When the pipeline cleaner is cleaning impurities, it will be worn and consumed. If the volume of the pipeline cleaner becomes smaller, the gas or liquid cannot push it forward and the pipeline cleaner will be retained in the pipeline. It is impossible to accurately locate the specific position of the pipeline cleaner and thus it cannot be removed.

[0003] The existing method of locating the position of the pig is usually to install a signal transmitter in the pig, and the staff carries a signal receiving device to detect each section. When the maximum signal reception value is detected, the position of the pig can be determined. However, this method not only consumes manpower and has low positioning efficiency, but also affects the normal transportation of oil and gas in the pipeline when the pig is blocked or lost in the pipeline, causing greater safety hazards. Summary of the invention

[0004] In view of this, the present application proposes a positioning and tracking system and method for a pipe cleaner, aiming to solve the problem of low positioning efficiency of pipe cleaners in current technology.

[0005] In the first aspect, the present application proposes a positioning and tracking system for a pipe cleaner, comprising: a pipeline, a pipe cleaner and a control center; sensor nodes are arranged at equal intervals in the pipeline and at key nodes of the pipeline, and wireless relay nodes are arranged between the sensor nodes at intervals of a preset number of intervals;

[0006] The pipe cleaner includes a control module, an inertial navigation module and a communication module; when the pipe cleaner is in operation, the inertial navigation module is used to continuously obtain the three-axis acceleration and angular velocity of the pipe cleaner and calculate the offset information of the pipe cleaner; the offset information includes relative displacement and angle change; the control module is used to correct the offset information of the pipe cleaner by using the Kalman filter method to obtain the corrected offset information; when the pipe cleaner passes through the sensor node signal range of the sensor node, the sensor node is used to transmit the absolute position information of the pipe cleaner to the pipe cleaner when the signal of the passive radio frequency identification tag set on the surface of the pipe cleaner is detected; the communication module is used to pack the corrected offset information and the absolute position information into a position information packet, and transmit the position information packet to the control center through the target sensor node closest to the pipe cleaner or the target wireless relay node closest to the pipe cleaner; the control center is used to receive and decode the position information packet, process the corrected offset information and the absolute position information by using the Kalman filter method, obtain a continuous pipe cleaner trajectory, and regularly correct the pipe cleaner trajectory by the absolute position information to obtain the real-time positioning result of the pipe cleaner.

[0007] Optionally, the control center is also used to analyze the speed and movement status of the pipe cleaner in real time, and output an alarm message and record the last detected position information of the pipe cleaner when the pipe cleaner fails to arrive at the next sensing node within a predetermined time or the control center fails to receive the pipe cleaner signal for several times.

[0008] Optionally, the communication module is specifically used for:

[0009] If the signal range of the communication module does not exceed the signal range of the target sensor node, the location information packet is transmitted to the target sensor node, so that the target sensor node transmits the location information packet to the control center;

[0010] If the signal range of the communication module exceeds the signal range of the target sensor node, the location information packet is transmitted to the target wireless relay node, so that the target wireless relay node transmits the location information packet to the sensor node and the control center.

[0011] Optionally, the control module is also used to perform initial calibration on the inertial navigation module and establish an effective connection between the communication module and the sensor node and the wireless relay node based on the coordinate information of the initial point and the excitation information of the initial sensor node in the pipeline; the coordinate information of the initial point is the coordinate information recorded when the pipe cleaner is placed at the initial position of the pipeline.

[0012] Optionally, the initial sensor node is used to generate a signal to trigger the passive radio frequency identification tag on the surface of the pig, and to determine that the pig has reached the initial position by reading the signal strength and characteristic information of the passive radio frequency identification tag, and transmit the initial absolute position information to the control module; the control module is used to transmit the initial absolute position information to the inertial navigation module, and set the initial absolute position information as the initial point r of the pig in the pipeline. INS，0 , the inertial navigation information initializes the accelerometer and gyroscope, and sets the initial velocity and initial attitude angle to zero;

[0013] Initial point r INS,0 Expressed as:

[0014] r INS,0 =(x 0 ,y 0 , z 0 );

[0015] Among them, x 0 is the initial x-axis coordinate value, y 0 is the initial y-axis coordinate value, z 0 is the initial z-axis coordinate value;

[0016] The initial velocity is expressed as:

[0017] v INS,0 =(0,0,0);

[0018] Among them, v INS,0 represents the initial velocity;

[0019] The initial attitude angle is expressed as:

[0020] θ INS,0 =(0,0,0);

[0021] Among them, θ INS,0 Expressed as the initial attitude angle.

[0022] Optionally, the inertial navigation module is specifically used for:

[0023] Get the three-axis acceleration of the pig, expressed as:

[0024] a(t)=[a x (t), a y (t), a z (t)];

[0025] Among them, a(t) is the acceleration of the three axes at time t, a x (t) is the acceleration component along the X-axis at time t, a y (t) is the acceleration component along the Y axis at time t, a z (t) is the acceleration component along the Z axis at time t;

[0026] Get the angular velocity of the pig, expressed as:

[0027] ω(t)=[ω x (t),ω y (t),ω z (t)];

[0028] Among them, ω(t) is the angular velocity at time t, ω x (t) is the angular velocity around the X axis at time t, ω y (t) is the angular velocity around the Y axis at time t, ω z (t) is the angular velocity around the Z axis at time t;

[0029] The pig attitude angle is calculated and expressed as:

[0030] θ(t)=θ(t-Δt)+ω(t)·Δt;

[0031] Among them, θ(t) is the attitude angle at time t, and Δt is the time interval for the pig to obtain data;

[0032] The three-axis acceleration of the pig is converted from the sensor coordinate system to the world coordinate system and expressed as:

[0033] a world (t) = R(θ)·a(t);

[0034] Among them, a world (t) is the three-axis acceleration of the world coordinate system at time t, and R(θ) is the rotation matrix composed of the angle change;

[0035] Update the pig speed, expressed as:

[0036] v(t)=v(t-Δt)+a world (t)·Δt;

[0037] Where v(t) is the speed of the pig at time t;

[0038] The position vector is calculated and expressed as:

[0039] r(t)=r(t-Δt)+v(t)·Δt;

[0040] Where r(t) is the position vector of the pig at time t;

[0041] The relative displacement and angle change of the pig are calculated and expressed as:

[0042] x pred =F·(t-Δt)+G·u(t);

[0043] Among them, xpred is the relative displacement and angle change of the pig, x is the state variable vector, including position vector, velocity and attitude angle, F is the state transfer matrix, G is the control input matrix, u(t) is the control input, including three-axis acceleration and angular velocity;

[0044] The state transfer matrix F is expressed as:

[0045]

[0046] Optionally, the control module is specifically used for:

[0047] x(t)=x pred +K·(z(t)-H·x pred );

[0048] Among them, x(t) is the corrected relative displacement and angle change of the pig, K is the Kalman gain coefficient, z(t) is the absolute position information, and H is the observation matrix.

[0049] Optional, control center, specifically used for:

[0050] x'(t)=∝·z(t)+(1-∝)·x(t);

[0051] Where x'(t) is the corrected trajectory position and ∝ is the correction coefficient.

[0052] Optionally, the key pipeline nodes include pipeline bends, pipeline branch nodes, and pipeline inspection ports; the key pipeline nodes also include blockage location points of pipe cleaners determined based on historical information; the preset number is three.

[0053] Optionally, the inertial navigation module is a group of micro-electromechanical system inertial measurement units integrated inside the pipe cleaner, including a three-axis accelerometer and a three-axis gyroscope.

[0054] Optionally, the sensor node and the wireless relay node both include a passive radio frequency identification tag receiver and a wireless communication module, and the wireless relay node adopts an adaptive path algorithm.

[0055] In a second aspect, a positioning and tracking method for a pipe cleaner is provided, which is applied to the positioning and tracking system for a pipe cleaner of any one of the first aspects, including: when the pipe cleaner is running, the three-axis acceleration and angular velocity of the pipe cleaner are continuously obtained, and the offset information of the pipe cleaner is calculated; the offset information includes relative displacement and angle change; the offset information of the pipe cleaner is corrected by using a Kalman filter method to obtain corrected offset information; when the pipe cleaner passes through the sensor node signal range of a sensor node, the absolute position information of the pipe cleaner is obtained when a signal of a passive radio frequency identification tag set on the surface of the pipe cleaner is detected; the Kalman filter method is used to process the corrected offset information and the absolute position information to obtain a continuous pipe cleaner trajectory, and the pipe cleaner trajectory is regularly corrected by the absolute position information to obtain a real-time positioning result of the pipe cleaner.

[0056] In a third aspect, a positioning and tracking device for a pipe cleaner is provided, comprising a memory and a processor; the memory is used to store computer execution instructions, and the processor is connected to the memory via a bus; when the positioning and tracking device for a pipe cleaner is running, the processor executes the computer execution instructions stored in the memory, so that the positioning and tracking device for a pipe cleaner executes the positioning and tracking method for a pipe cleaner described in the second aspect.

[0057] The positioning and tracking device for pipe cleaners may be an electronic device, or a part of an electronic device, such as a chip system in an electronic device. The chip system is used to support the electronic device to implement the functions involved in the first aspect and any possible implementation thereof, for example, to obtain, determine, and send the data and / or information involved in the positioning and tracking method for pipe cleaners. The chip system includes a chip, and may also include other discrete devices or circuit structures.

[0058] In a fourth aspect, a computer-readable storage medium is provided, the computer-readable storage medium comprising computer execution instructions, and when the computer execution instructions are executed on a computer, the computer executes the positioning and tracking method for a pipe cleaner described in the second aspect.

[0059] In a fifth aspect, a computer program product is also provided, which includes computer instructions. When the computer instructions are executed on a positioning and tracking device for a pipe cleaner, the positioning and tracking device for a pipe cleaner executes the positioning and tracking method for a pipe cleaner as described in the second aspect above.

[0060] It should be noted that the above-mentioned computer instructions may be stored in whole or in part on a computer-readable storage medium. The computer-readable storage medium may be packaged together with a processor of a positioning and tracking device for a pipe cleaner, or may be packaged separately from a processor of a positioning and tracking device for a pipe cleaner, and this embodiment of the application does not limit this.

[0061] The description of the second, third, fourth and fifth aspects of the present application can refer to the detailed description of the first aspect.

[0062] In the embodiments of the present application, the name of the above-mentioned positioning and tracking device for pipe cleaning does not limit the device or functional module itself. In actual implementation, these devices or functional modules may appear with other names. For example, the receiving unit may also be called a receiving module, a receiver, etc. As long as the functions of each device or functional module are similar to those of the present application, they belong to the scope of the claims of the present application and their equivalent technologies.

[0063] The present application provides a positioning and tracking system for a pipe cleaner with high positioning accuracy: by deploying equally spaced sensor nodes and wireless relay nodes in the pipeline, the present application can effectively cover key positions in the entire pipeline, especially deploying sensor nodes at pipeline bends, branch nodes, and historical locations with higher blockage risks, which significantly improves the positioning accuracy of the pipe cleaner. The pipe cleaner collects three-axis acceleration and angular velocity through an inertial navigation module, and can accurately calculate the relative displacement and attitude angle change of the pipe cleaner during operation. By combining the absolute position information of the sensor nodes, the Kalman filter method is used to correct the relative displacement error to achieve high-precision positioning; real-time positioning and trajectory tracking are possible: the present application obtains the position information of the pipe cleaner in real time through the inertial navigation module and sensor node of the pipe cleaner, and the control center can continuously receive and decode the position packet, track and regularly correct the trajectory of the pipe cleaner. The trajectory correction adopts the Kalman filter method. By regularly receiving the absolute position information of the sensor nodes, the trajectory data generated by the inertial navigation is adjusted to reduce the cumulative drift error and ensure the real-time positioning and accurate trajectory tracking of the pipe cleaner; the status of the pipe cleaner can be dynamically monitored: the control center can analyze the speed and movement status of the pipe cleaner in real time. If the pipe cleaner does not arrive at the next sensor node within the scheduled time or does not receive a signal continuously, the system will automatically alarm and record the last detection position, so as to timely discover the possible stagnation or blockage risk of the pipe cleaner; automatic calibration of the initial position and inertial navigation: when the pipe cleaner enters the pipeline, the present application automatically determines the initial position coordinates of the pipe cleaner through the excitation signal of the initial sensor node. Based on the coordinate information, the pipe cleaner control system performs initial calibration on the inertial navigation module, sets the initial position information, speed and attitude angle to zero, so that the inertial navigation module can perform accurate displacement and attitude calculations in the initial state; Distributed node communication improves data transmission reliability: The configuration of distributed wireless relay nodes and sensor nodes is adopted to realize multi-hop communication between the pipe cleaner and the control center, effectively expanding the coverage of data transmission. When the pipe cleaner exceeds the signal range of the sensor node, the data will be uploaded to the sensor node step by step through the wireless relay node, and finally transmitted to the control center to ensure the reliability of data transmission; Able to adapt to complex pipeline structures: The sensor node layout scheme of this application fully considers the key locations in the pipeline, such as turns, branches and historical blockages, and can cope with various terrain conditions in complex pipeline networks.Combining the inertial navigation module and the Kalman filtering method, the positioning accuracy of the pipe cleaner in complex structures is guaranteed; it has a flexible and adaptable adaptive path algorithm: by applying the adaptive path algorithm in the relay node, the present application can automatically select the best path for data transmission according to the current signal strength and communication link status, so that good transmission quality can be maintained in an unstable communication environment; it can conveniently troubleshoot: the present application monitors the status and position information of the pipe cleaner in real time. Once an abnormality occurs, it can immediately alarm and mark the last position of the pipe cleaner, which is convenient for operators to locate and deal with possible blockages or faults, thereby improving the safety and efficiency of pipe cleaning operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0065] Figure 1 This is a structural diagram of a positioning and tracking system for a pipe cleaning device according to an embodiment of the present application;

[0066] Figure 2 This is a flow chart of a method for positioning and tracking a pipe cleaner according to an embodiment of the present application;

[0067] Figure 3 This is a structural diagram of a positioning and tracking device for a pipe cleaning device according to an embodiment of the present application. DETAILED DESCRIPTION

[0068] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0069] See also Figure 1 As shown, an embodiment of the present application provides a positioning and tracking system for a pipe cleaning device, comprising:

[0070] Pipeline 101 , pig 102 and control center 105 .

[0071] Among them, sensor nodes 103 are arranged at equal intervals in the pipeline 101 and at key nodes of the pipeline, and wireless relay nodes 104 are arranged between the sensor nodes 103 at intervals of a preset number.

[0072] Optionally, sensor nodes are arranged at equal intervals in the pipeline and at key nodes of the pipeline, and wireless relay nodes are arranged between the sensor nodes at intervals of three intervals, that is, the preset number can be three.

[0073] In some embodiments, the pig includes a control module, an inertial navigation module, and a communication module.

[0074] In some embodiments, the control module is used to perform initial calibration on the inertial navigation module and establish an effective connection between the communication module and the sensor node and the wireless relay node based on the coordinate information of the initial point and the excitation information of the initial sensor node in the pipeline. The coordinate information of the initial point is the coordinate information recorded when the pig is placed at the initial position of the pipeline.

[0075] Specifically, the pipe cleaner can be placed at the initial position of the pipeline, and the coordinate information of the initial point can be recorded. The control system in the pipe cleaner can perform initial calibration on the inertial navigation module in the pipe cleaner according to the coordinate information of the initial point and the excitation information of the initial sensor node, and can establish an effective connection between the communication module in the pipe cleaner and the sensor node and the wireless relay node.

[0076] When the pig is running, the inertial navigation module is used to continuously obtain the three-axis acceleration and angular velocity of the pig and calculate the offset information of the pig. The offset information includes relative displacement and angle change.

[0077] Specifically, when the pipe cleaner is running, the inertial navigation module can continuously obtain the three-axis acceleration and angular velocity of the pipe cleaner, and calculate the relative displacement and angle change of the pipe cleaner.

[0078] The control module is used to correct the offset information of the pipe cleaner by using the Kalman filter method to obtain the corrected offset information.

[0079] When the pipe cleaner passes through the sensing node signal range of the sensing node, the sensing node is used to transmit the absolute position information of the pipe cleaner to the pipe cleaner when a signal of a passive radio frequency identification tag arranged on the surface of the pipe cleaner is detected.

[0080] The communication module is used to package the corrected offset information and absolute position information into a position information packet, and transmit the position information packet through the target sensor node closest to the pig or the target wireless relay node control center closest to the pig.

[0081] That is to say, when the pipe cleaner passes through the signal range of the sensor node, the sensor node detects the signal of the passive radio frequency identification tag set on the surface of the pipe cleaner, transmits the absolute position information to the pipe cleaner, and uses the Kalman filter method to correct the relative displacement to obtain the corrected relative displacement. The communication module packages the corrected relative displacement and absolute position information into a position information package and transmits it to the nearest sensor node. The sensor node transmits the position information package to the control center.

[0082] Specifically, when the pipe cleaner passes through the signal range of the sensor node, the sensor node detects the passive radio frequency identification (RFID) tag signal pre-set on the surface of the pipe cleaner. This process does not require additional power support, and the passive detection of the position of the pipe cleaner is achieved through the response mechanism of the RFID tag. After detecting the RFID tag, the sensor node immediately records the absolute position of the pipe cleaner and transmits this position information to the inside of the pipe cleaner through signal feedback. After receiving the absolute position information provided by the sensor node, the pipe cleaner combines it with the relative displacement data obtained by the inertial navigation module, uses the Kalman filter method to correct the relative displacement, and dynamically adjusts the possible errors in the inertial navigation module to obtain more accurate corrected displacement data. The communication module in the pipe cleaner integrates the corrected relative displacement and absolute position information into a position information package. The information package contains the actual coordinates, speed and other status information of the pipe cleaner at the current position. The pipe cleaner transmits the position information package to the nearest sensor node through point-to-point wireless communication. After receiving the information package, the sensor node relays it step by step and uploads it to the control center.

[0083] It should be noted that the relative displacement data calibrated by the absolute position provided by the sensor nodes can effectively reduce the cumulative error of the inertial navigation system and ensure the positioning accuracy of the pipe cleaner in long-distance pipelines. With the help of the layout of sensor nodes and the point-to-point transmission mode of the pipe cleaner, the information delay in the transmission process of the pipe cleaner position is reduced, so that the control center can grasp the dynamic position of the pipe cleaner in real time. The application of the Kalman filter method enables the pipe cleaner to correct its own relative displacement data according to the absolute position, thereby ensuring that the pipe cleaning operation is always carried out along the predetermined trajectory to avoid deviation or stagnation. Through real-time data feedback, the control center can intervene in time when the pipe cleaner is about to encounter a risk node or a possible jam, ensuring the smooth progress of the pipe cleaning process.

[0084] The control center is used to receive and decode the position information package, and use the Kalman filter method to process the corrected offset information and absolute position information to obtain a continuous pig trajectory, and regularly correct the pig trajectory through the absolute position information to obtain the real-time positioning result of the pig.

[0085] That is to say, the control center receives and decodes the position information packet, processes the corrected relative displacement and absolute position information using the Kalman filter method, obtains a continuous pipeline cleaning track, and regularly corrects the pipeline cleaning track using the absolute position information to achieve real-time positioning of the pipeline cleaning device.

[0086] Specifically, the control center continuously receives the position information package of the pipe cleaner uploaded by the sensor node, including the absolute position information, corrected relative displacement, speed and direction at each moment. The decoding module of the control center parses the information package into a data stream to facilitate subsequent calculation and processing. The decoded data is processed by Kalman filtering. The Kalman filter fuses the absolute position information and the corrected relative displacement to reduce noise interference and obtain a smoother and more accurate continuous pipe cleaner trajectory. The Kalman filter method recursively updates the position of the pipe cleaner in real time. Using the prediction and correction steps, each new position is dynamically adjusted based on the previous position information to improve the accuracy of the position prediction. The control center continuously records the processed data to form the trajectory information of the pipe cleaner moving in the pipeline. The trajectory information not only includes position changes, but also includes the moving speed and direction changes of the pipe cleaner, which helps to understand the operating status of the pipe cleaner. The control center uses the absolute position information as a benchmark and regularly corrects the relative trajectory of the pipe cleaner to ensure that the displacement error accumulated over time can be corrected in time to ensure the accuracy of the trajectory. The correction cycle is dynamically adjusted according to factors such as the length of the pipeline and the moving speed of the pipe cleaner to balance accuracy and real-time performance. The corrected pipe cleaner position data is displayed in real time on the monitoring interface of the control center. Operators can check the precise position and movement trend of the pipe cleaner at any time and take timely measures when it deviates from the predetermined trajectory.

[0087] It should be noted that through Kalman filter processing and absolute position correction, the control center can accurately track the position of the pipe cleaner and correct the displacement error in real time through the sensor node to ensure positioning accuracy. The Kalman filter method is used to integrate relative displacement and absolute position, so that the control center can obtain noise-free and continuous pipe cleaner position data, reduce the cumulative error caused by the inertial navigation system, and improve the reliability of positioning data. The trajectory information flow generated by the Kalman filter is smooth and stable, avoiding jumps or breaks in position information, so that the control center can more intuitively understand the operating status and motion trajectory of the pipe cleaner. Through regular correction of the absolute position, the cumulative error caused by deviation can be quickly adjusted to avoid the pipe cleaner deviating from the predetermined track in the pipeline and improve the accuracy of the operation.

[0088] In some embodiments, the control center is also used to analyze the speed and movement status of the pipe cleaner in real time, and output an alarm message and record the last detected position information of the pipe cleaner when the pipe cleaner fails to reach the next sensor node within the scheduled time or the control center fails to receive the pipe cleaner signal for several times.

[0089] That is to say, the control center analyzes the speed and movement status of the pipe cleaner in real time. If the pipe cleaner does not arrive at the next sensor node within the scheduled time or the control center does not receive the pipe cleaner signal for several times, an alarm will be issued and the position information of the pipe cleaner detected last time will be recorded.

[0090] Specifically, the control center conducts real-time analysis of the speed, position and motion state of the pipe cleaner, and calculates the speed change, acceleration and current position of the pipe cleaner through regular feedback information from the sensor nodes. If the speed is abnormal (such as sudden reduction, sharp acceleration or deceleration), the control center will identify it as a potential risk, record the relevant parameters and mark the abnormal state for subsequent inspection and processing. When the control center does not receive the signal of the pipe cleaner passing the next sensor node at the scheduled time, the abnormal detection mechanism will be activated. First, verify whether the sensor node signal is lost, and then analyze it based on the last known position, speed and movement direction of the pipe cleaner. If the pipe cleaner signal is not received for several consecutive times, or the pipe cleaner is analyzed to deviate from the scheduled route, the control center will immediately trigger an alarm. The alarm system will send a prompt message to the operator, indicating that the pipe cleaner may encounter obstacles or damage. The control center will record the last detected position, speed status and expected path of the pipe cleaner, and generate a detailed fault log through the console. The log information includes the last position of the pipe cleaner, the location of the sensor node that lost the signal, the detection time, etc. The fault log automatically generates a report to facilitate the operator to perform emergency maintenance on the pipe cleaner, eliminate the fault as soon as possible, and ensure the smooth progress of subsequent pipe cleaning tasks.

[0091] It should be noted that the real-time speed analysis, abnormal alarm and position recording functions improve the reliability of the pipe cleaner's operation, ensure that it reaches the next sensor node within the scheduled time, and effectively prevent stagnation in the pipeline. If the pipe cleaner encounters an obstacle in the pipeline, the system will automatically alarm and locate the last known position, shortening the troubleshooting time, allowing maintenance personnel to quickly locate and handle the fault, reducing the downtime of the pipe cleaning operation, and through multiple monitoring mechanisms, ensuring that the pipe cleaner will not deviate from the track or stop working due to undetected signal loss, ensuring that the pipe cleaning operation is smooth throughout the process and reducing unexpected risks. The system's real-time motion data and abnormal alarm records provide data support for subsequent analysis of the pipe cleaner's working performance, pipeline cleaning effects and optimization of pipe cleaning operations, facilitating the improvement of long-term management capabilities of pipeline maintenance.

[0092] Furthermore, key pipeline nodes include pipeline bends, pipeline branch nodes, and pipeline inspection ports.

[0093] Pipeline key nodes also include pig blockage location points summarized based on historical information.

[0094] Specifically, sensor nodes are installed at equal distances according to preset spacing inside the pipeline. These sensor nodes are continuously arranged to ensure that the pipe cleaner at any position in the pipeline can maintain effective communication and data transmission with the sensor nodes. Each sensor node can detect the position signal passing through the pipe cleaner to obtain absolute position data. At the same time, it serves as a data receiving and transmission terminal of the relay node. Sensor nodes are installed at important locations such as pipe cleaner bends, branch nodes, and inspection ports. These points are prone to problems such as unstable positioning of pipe cleaners, path changes, and potential blockages. Additional sensor nodes are deployed at locations prone to blockage marked by historical data, which can monitor the state changes of pipe cleaners at high-risk points and effectively avoid blockage risks. Wireless relay nodes are added between every three sensor nodes to ensure that the signal is not lost in long-distance transmission or complex terrain. The wireless relay node serves as a bridge between sensor nodes, receives signals and uploads them to the sensor nodes step by step, expands the communication coverage, and improves the stability of data transmission.

[0095] The distribution of wireless relay nodes makes the communication system in the pipeline more fault-tolerant. In areas with poor signal coverage, multi-hop transmission can be used to maintain smooth communication. The wireless relay nodes ensure that data is stable and not lost during the upload process from the pipe cleaner to the control center, ensuring the integrity and stability of data transmission. The deployment of sensor nodes and wireless relay nodes makes the positioning system more adaptable and versatile in various pipeline structures, and can be applied to pipelines of different lengths and complex structures. The flexible node configuration facilitates subsequent expansion, such as adding sensor nodes or relay nodes to adapt to longer distances or more complex terrain structures.

[0096] Furthermore, the inertial navigation module is a group of micro-electromechanical system inertial measurement units integrated inside the pipe cleaner, including a three-axis accelerometer and a three-axis gyroscope.

[0097] Furthermore, both the sensor node and the relay node include a passive radio frequency identification tag receiver and a wireless communication module, and the relay node adopts an adaptive path algorithm.

[0098] Specifically, the relay node uses an adaptive path selection algorithm to automatically select the optimal path to forward the data of the pipe cleaner according to the current signal strength and node connection status, ensuring signal stability and transmission efficiency. If a relay node has a signal abnormality or damage, the system automatically adjusts to the backup transmission path and uses other relay nodes to relay the transmission to avoid data loss. The step-by-step transmission method significantly improves the real-time and reliability of positioning data through the collaboration between the pipe cleaner and the sensor nodes and relay nodes, effectively covering complex pipeline areas or signal blind spots, and realizing accurate tracking of the pipe cleaner in long-distance pipelines.

[0099] In some embodiments, the initial sensor node is used to generate a signal to trigger a passive RFID tag on the surface of the pig, and to determine that the pig has reached an initial position by reading the signal strength and characteristic information of the passive RFID tag, and transmit the initial absolute position information to the control module.

[0100] The control module is used to transmit the initial absolute position information to the inertial navigation module and set the initial absolute position information as the initial point r of the pig in the pipeline. INS,0 , the inertial navigation information initializes the accelerometer and gyroscope, setting the initial velocity and initial attitude angle to zero.

[0101] That is to say, the control system in the pig performs initial calibration on the inertial navigation module in the pig according to the coordinate information of the initial point and the excitation information of the initial sensor node. The specific contents are as follows: the initial sensor node generates a signal to trigger the passive radio frequency identification tag on the surface of the pig. The initial sensor node determines that the pig has reached the initial position by reading the signal strength and characteristic information of the passive radio frequency identification tag, and transmits the initial absolute position information to the control system in the pig. The pig control system transmits the initial absolute position information to the inertial navigation module and sets the initial absolute position information as the initial point r of the pig in the pipeline. INS,0 , the inertial navigation information initializes the accelerometer and gyroscope, and sets the initial velocity and initial attitude angle to zero;

[0102] Initial point r INS,0 Expressed as:

[0103] r INS,0 =(x 0 ,y 0 , z 0 );

[0104] Among them, x 0 is the initial x-axis coordinate value, y 0 is the initial y-axis coordinate value, z 0 is the initial z-axis coordinate value;

[0105] The initial velocity is expressed as:

[0106] v INS,0 =(0,0,0);

[0107] Among them, v INS,0 represents the initial velocity;

[0108] The initial attitude angle is expressed as:

[0109] θ INS，0 =(0,0,0);

[0110] Among them, θ INS，0 Expressed as the initial attitude angle.

[0111] Specifically, before the pipe cleaner enters the pipeline, its initial position coordinates (such as the longitude and latitude at the entrance of the pipeline or the origin coordinates in the pipeline coordinate system) are determined, and the information is transmitted to the INS (inertial navigation) module inside the pipe cleaner. This initial position is used as the reference point for inertial navigation. After receiving the initial position coordinates, the INS module of the pipe cleaner stores them in the memory and synchronizes the current status information of the pipe cleaner (acceleration, velocity, angular velocity, etc.) to the control center to ensure the accuracy of positioning in the pipeline. During the operation of the pipe cleaner, the sensor nodes arranged along the pipeline will communicate with the pipe cleaner through excitation signals (such as radio signals, ultrasonic waves, etc.). When the pipe cleaner passes by the sensor node, the node will send its own position information and stimulate the INS module to recalibrate and initialize the position.

[0112] Furthermore, the inertial navigation module continuously obtains the three-axis acceleration and angular velocity of the pig, and calculates the relative displacement and angle change of the pig. The specific content is (that is, the inertial navigation module is specifically used for):

[0113] Get the three-axis acceleration of the pig, expressed as:

[0114] a(t)=[a x (t), a y (t), a z (t)];

[0115] Among them, a(t) is the acceleration of the three axes at time t, a x (t) is the acceleration component along the X-axis at time t, a v (t) is the acceleration component along the Y axis at time t, a z (t) is the acceleration component along the Z axis at time t;

[0116] Get the angular velocity of the pig, expressed as:

[0117] ω(t)=[ω x (t),ω y (t),ω z (t)];

[0118] Among them, ω(t) is the angular velocity at time t, ω x (t) is the angular velocity around the X axis at time t, ω y (t) is the angular velocity around the Y axis at time t, ω z (t) is the angular velocity around the Z axis at time t;

[0119] The pig attitude angle is calculated and expressed as:

[0120] θ(t)=θ(t-Δt)+ω(t)·Δt;

[0121] Among them, θ(t) is the attitude angle at time t, and Δt is the time interval for the pig to obtain data;

[0122] The three-axis acceleration of the pig is converted from the sensor coordinate system to the world coordinate system and expressed as:

[0123] a world (t) = R(θ)·a(t);

[0124] Among them, a world (t) is the three-axis acceleration of the world coordinate system at time t, and R(θ) is the rotation matrix composed of the angle change;

[0125] Update the pig speed, expressed as:

[0126] v(t)=v(t-Δt)+a world (t)·Δt;

[0127] Where v(t) is the speed of the pig at time t;

[0128] The position vector is calculated and expressed as:

[0129] r(t)=r(t-Δt)+v(t)·Δt;

[0130] Where r(t) is the position vector of the pig at time t;

[0131] The relative displacement and angle change of the pig are calculated and expressed as:

[0132] x pred =F·(t-Δt)+G·u(t);

[0133] Among them, x pred is the relative displacement and angle change of the pig, x is the state variable vector, including position vector, velocity and attitude angle, F is the state transfer matrix, G is the control input matrix, and u(t) is the control input, including three-axis acceleration and angular velocity.

[0134] Furthermore, the state transfer matrix F is expressed as:

[0135]

[0136] Furthermore, the relative displacement is corrected using the Kalman filter method to obtain a corrected relative displacement, the specific content of which is (that is, the control module is specifically used for):

[0137] x(t)=x pred +K·(z(t)-H·x pred );

[0138] Among them, x(t) is the corrected relative displacement and angle change of the pig, K is the Kalman gain coefficient, z(t) is the absolute position information, and H is the observation matrix.

[0139] Furthermore, the prediction step in the Kalman filter extrapolates the estimate of the previous moment through the state transfer matrix, and updates the error covariance according to the process noise covariance. If the initial state or covariance estimate of the prediction step is inaccurate, the error will gradually accumulate over time, thereby affecting the prediction of the error covariance.

[0140] P pred (t+Δt)=F·P(t)·F T +Q;

[0141] Among them, P pred is the predicted error covariance matrix, Q is the process noise covariance matrix, P(t) is the error covariance matrix at time t, and F T is the transposed matrix of F;

[0142] Update the error covariance matrix:

[0143] P′(t)=(IK·H)·P pred (t)

[0144] Where I is the identity matrix, P′(t) is the updated error covariance matrix;

[0145] The calculation of the Kalman gain coefficient is expressed as:

[0146] K=P pred (t)·H T ·(H·P pred ( t)·H T +R) -1

[0147] Among them, H T is the transposed matrix of the observation matrix.

[0148] It should be noted that the Kalman filter has a strong ability when facing noisy data. It reduces the impact of noise by taking a weighted average of the difference between the estimate of the system state and the actual observation value. It can not only handle process noise (uncertainty of the system model itself) and measurement noise (error in sensor readings), but also provide the best estimate of these noises. The Kalman filter is a recursive algorithm. Every time it receives new observation data, it updates the current state estimate and continuously optimizes it over time. It can estimate the system state in real time without saving a lot of data. This is very important for dynamic systems, especially in tracking moving objects (such as pipe cleaners, aircraft, robots, etc.). The Kalman filter has the property of optimal estimation. Under the condition of meeting the Gaussian noise assumption, the Kalman filter provides the minimum mean squared error (MMSE) estimate, which means that it can provide the most accurate estimate under noise and error conditions. This is crucial for applications that require high-precision positioning and tracking (such as GPS positioning, autonomous driving, flight control, etc.). Kalman filtering can not only obtain information from a single sensor, but also fuse data from multiple sensors (such as inertial navigation systems, GPS, radar, cameras, etc.). By fusing data from different sensors, the estimation accuracy can be improved and the impact of single sensor errors can be reduced. Kalman filtering can predict the future state of the system. In the absence of direct observation data (such as temporary loss of sensor signals), the Kalman filter can continue to predict the behavior of the system through a model of the current state. In Kalman filtering, the estimation process consists of two parts: prediction and update. The prediction part predicts the current system state based on the previous state, while the update part uses the current measurement data to adjust the prediction. In this way, the Kalman filter can continuously optimize the estimate of the system state and eliminate errors in historical data.

[0149] In some embodiments, the communication module is specifically used to:

[0150] If the signal range of the communication module does not exceed the signal range of the target sensor node, the location information packet is transmitted to the target sensor node, so that the target sensor node transmits the location information packet to the control center;

[0151] If the signal range of the communication module exceeds the signal range of the target sensor node, the location information packet is transmitted to the target wireless relay node, so that the target wireless relay node transmits the location information packet to the sensor node and the control center.

[0152] That is to say, the specific content of the sensor node transmitting the location information packet to the control center is: if the current communication module signal range exceeds the sensor node signal range, the communication module transmits the location information packet to the relay node, and the relay node uploads the location information packet to the sensor node level by level, and the sensor node transmits the location information packet to the control center.

[0153] Specifically, when the communication module signal of the pipe cleaner exceeds the signal range of the surrounding sensor nodes, the system automatically selects the nearest wireless relay node, and the communication module transmits the location information packet to the relay node; after receiving the location information packet, the relay node transmits the information upward step by step until it reaches the sensor node that can be directly connected to the control center, ensuring the integrity and accuracy of the location information packet; finally, the sensor node transmits the location information packet forwarded by the relay node to the control center, ensuring that the pipe cleaner's location data can be stably and accurately transmitted to the control center over long distances or under signal obstacles.

[0154] It should be noted that the setting of relay nodes effectively solves the transmission problems in complex environments such as long distances, partitions or discontinuous signals in pipelines, ensuring that the location information of the pipe cleaner can be transmitted back to the control center in real time. If a sensor node loses its signal or fails, the multi-level transmission mechanism of the relay node ensures that the system can still transmit data through other sensor or relay nodes, enhancing the system's fault tolerance. Relay nodes can share the signal reception and data forwarding work of sensor nodes, reduce the load on sensor nodes, and help reduce equipment wear and energy consumption, thereby extending the service life of sensor equipment.

[0155] Furthermore, the pig trajectory is regularly corrected through the absolute position information to achieve real-time positioning of the pig, which is expressed as (i.e., the control center, specifically used for):

[0156] x'(t)=∝·z(t)+(1-∝)·x(t);

[0157] Where x'(t) is the corrected trajectory position and ∝ is the correction coefficient.

[0158] In summary, the tracking method of the present application has high accuracy: by deploying equally spaced sensor nodes and wireless relay nodes in the pipeline, the present application can effectively cover the key positions in the entire pipeline, especially the deployment of sensor nodes at pipeline bends, branch nodes and historical locations with higher blockage risks, which significantly improves the positioning accuracy of the pipe cleaner. The pipe cleaner collects three-axis acceleration and angular velocity through the inertial navigation module, and can accurately calculate the relative displacement and attitude angle change of the pipe cleaner during operation. By combining the absolute position information of the sensor nodes, the Kalman filter method is used to correct the relative displacement error to achieve high-precision positioning; real-time positioning and trajectory tracking are possible: the present application obtains the position information of the pipe cleaner in real time through the inertial navigation module and sensor node of the pipe cleaner, and the control center can continuously receive and decode the position packet, track and regularly correct the trajectory of the pipe cleaner. The trajectory correction adopts the Kalman filter method. By regularly receiving the absolute position information of the sensor nodes, the trajectory data generated by the inertial navigation is adjusted to reduce the cumulative drift error and ensure the real-time positioning and accurate trajectory tracking of the pipe cleaner; the status of the pipe cleaner can be dynamically monitored: the control center can analyze the speed and movement status of the pipe cleaner in real time. If the pipe cleaner does not arrive at the next sensor node within the scheduled time or does not receive a signal continuously, the system will automatically alarm and record the last detection position, so as to timely discover the possible stagnation or blockage risk of the pipe cleaner; automatic calibration of the initial position and inertial navigation: when the pipe cleaner enters the pipeline, the present application automatically determines the initial position coordinates of the pipe cleaner through the excitation signal of the initial sensor node. Based on the coordinate information, the pipe cleaner control system performs initial calibration on the inertial navigation module, sets the initial position information, speed and attitude angle to zero, so that the inertial navigation module can perform accurate displacement and attitude calculations in the initial state; Distributed node communication improves data transmission reliability: The configuration of distributed wireless relay nodes and sensor nodes is adopted to realize multi-hop communication between the pipe cleaner and the control center, effectively expanding the coverage of data transmission. When the pipe cleaner exceeds the signal range of the sensor node, the data will be uploaded to the sensor node step by step through the wireless relay node, and finally transmitted to the control center to ensure the reliability of data transmission; Able to adapt to complex pipeline structures: The sensor node layout scheme of this application fully considers the key locations in the pipeline, such as turns, branches and historical blockages, and can cope with various terrain conditions in complex pipeline networks.Combining the inertial navigation module and the Kalman filtering method, the positioning accuracy of the pipe cleaner in complex structures is guaranteed; it has a flexible and adaptable adaptive path algorithm: by applying the adaptive path algorithm in the relay node, the present application can automatically select the best path for data transmission according to the current signal strength and communication link status, so that good transmission quality can be maintained in an unstable communication environment; it can conveniently troubleshoot: the present application monitors the status and position information of the pipe cleaner in real time. Once an abnormality occurs, it can immediately alarm and mark the last position of the pipe cleaner, which is convenient for operators to locate and deal with possible blockages or faults, thereby improving the safety and efficiency of pipe cleaning operations.

[0159] In some embodiments, Figure 2 As shown, the present application embodiment also provides a positioning and tracking method for a pipe cleaning device, which is applied to the above Figure 1 The pig positioning and tracking system includes:

[0160] S201. When the pipe cleaning device is running, the three-axis acceleration and angular velocity of the pipe cleaning device are continuously obtained, and the deviation information of the pipe cleaning device is calculated.

[0161] The offset information includes relative displacement and angle change.

[0162] S202: Use Kalman filtering method to correct the offset information of the pipe cleaner to obtain corrected offset information.

[0163] S203: When the pipe cleaner passes through the sensor node signal range of the sensor node, in the case where a signal of a passive radio frequency identification tag arranged on the surface of the pipe cleaner is detected, the absolute position information of the pipe cleaner is acquired.

[0164] S204, using Kalman filtering to process the corrected offset information and absolute position information to obtain a continuous pig trajectory, and regularly correcting the pig trajectory using the absolute position information to obtain a real-time positioning result of the pig.

[0165] It should be noted that the above-mentioned positioning and tracking methods for pipe cleaning devices are only some examples provided in this application. Figure 1 The methods and steps performed by the modules, nodes and control center in the positioning and tracking system for pipe cleaning shown are all within the protection scope of the present application.

[0166] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of the method. In order to realize the above functions, it includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0167] The embodiment of the present application can divide the functional modules of the positioning and tracking device for pipe cleaners according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware or in the form of software functional modules. Optionally, the division of modules in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation.

[0168] like Figure 3 , which is a schematic diagram of the structure of a positioning and tracking device for a pipe cleaner provided in an embodiment of the present application. Figure 3 The positioning and tracking device for a pipe cleaner shown includes: a communication unit 301 and a processing unit 302;

[0169] The communication unit 301 is used to continuously obtain the three-axis acceleration and angular velocity of the pipe cleaning device when the pipe cleaning device is running, and calculate the deviation information of the pipe cleaning device.

[0170] The offset information includes relative displacement and angle change.

[0171] The processing unit 302 is used to correct the offset information of the pipe cleaner by using a Kalman filter method to obtain corrected offset information.

[0172] The communication unit 301 is also used to obtain the absolute position information of the pipe cleaner when the pipe cleaner passes through the sensor node signal range of the sensor node and a signal of a passive radio frequency identification tag arranged on the surface of the pipe cleaner is detected.

[0173] The processing unit 302 is further used to process the corrected offset information and absolute position information using a Kalman filter method to obtain a continuous pig trajectory, and to periodically correct the pig trajectory using the absolute position information to obtain a real-time positioning result of the pig.

[0174] The embodiment of the present application further provides a computer-readable storage medium, which includes computer-executable instructions. When the computer-executable instructions are executed on a computer, the computer executes the positioning and tracking method for a pipe cleaner provided in the above embodiment.

[0175] The embodiment of the present application also provides a computer program product, which can be directly loaded into a memory and contains software code. After being loaded and executed by a computer, the computer program product can implement the positioning and tracking method for pipe cleaners provided in the above embodiment. Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention is described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that they can still modify or replace the technical solution of the present invention, and these modifications or equivalent replacements cannot make the modified technical solution deviate from the spirit and scope of the technical solution of the present invention.

[0176] The system provided in the above embodiment is only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present invention can be decomposed or combined. For example, the modules in the above embodiment can be combined into one module, or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing the modules or steps, and are not regarded as improper limitations of the present invention.

[0177] Those skilled in the art should be able to appreciate that the modules and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software or a combination of the two, and the programs corresponding to the software modules and method steps can be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs or any other form of storage medium known in the technical field. In order to clearly illustrate the interchangeability of electronic hardware and software, the composition and steps of each example have been generally described in the above description according to the function. Whether these functions are performed in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0178] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application rather than to limit it. Although the present application has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present application can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present application should be included in the scope of protection of the claims of the present application.

Claims

1. A positioning and tracking system for a pipe cleaning device, characterized in that: include: pipelines, pigs and control centres; Sensor nodes are arranged at equal intervals in the pipeline and at key nodes of the pipeline, and wireless relay nodes are arranged between the sensor nodes at intervals of a preset number of intervals; The pipe cleaner comprises a control module, an inertial navigation module and a communication module; When the pipe cleaner is running, the inertial navigation module is used to continuously obtain the three-axis acceleration and angular velocity of the pipe cleaner and calculate the offset information of the pipe cleaner; the offset information includes relative displacement and angle change; The control module is used to correct the offset information of the pipe cleaner using a Kalman filter method to obtain corrected offset information; When the pipe cleaner passes through the sensing node signal range of the sensing node, the sensing node is used to transmit the absolute position information of the pipe cleaner to the pipe cleaner when a signal of a passive radio frequency identification tag arranged on the surface of the pipe cleaner is detected; The communication module is used to package the corrected offset information and the absolute position information into a position information packet, and transmit the position information packet to the control center through the target sensor node closest to the pig or the target wireless relay node closest to the pig; The control center is used to receive and decode the position information packet, use the Kalman filter method to process the corrected offset information and the absolute position information to obtain a continuous pipeline cleaning track, and regularly correct the pipeline cleaning track through the absolute position information to obtain a real-time positioning result of the pipeline cleaning.

2. A positioning and tracking system for a pipe cleaner according to claim 1, characterized in that: The control center is also used to analyze the speed and movement status of the pipe cleaner in real time, and output an alarm message and record the position information of the pipe cleaner detected last time when the pipe cleaner fails to reach the next sensor node within a predetermined time or the control center fails to receive the pipe cleaner signal for several times.

3. A positioning and tracking system for a pipe cleaning device according to claim 1, characterized in that: The communication module is specifically used for: If the signal range of the communication module does not exceed the signal range of the target sensor node, transmitting the location information packet to the target sensor node, so that the target sensor node transmits the location information packet to the control center; If the signal range of the communication module exceeds the signal range of the target sensor node, the location information packet is transmitted to the target wireless relay node, so that the target wireless relay node transmits the location information packet to the sensor node and the control center.

4. A positioning and tracking system for a pipe cleaning device according to claim 1, characterized in that: The control module is also used to perform initial calibration on the inertial navigation module and establish an effective connection between the communication module, the sensor node and the wireless relay node according to the coordinate information of the initial point and the excitation information of the initial sensor node in the pipeline; the coordinate information of the initial point is the coordinate information recorded when the pipe cleaner is placed at the initial position of the pipeline.

5. A positioning and tracking system for a pipe cleaning device according to claim 4, characterized in that: The initial sensor node is used to generate a signal to trigger the passive radio frequency identification tag on the surface of the pig, and to determine that the pig has reached the initial position by reading the signal strength and characteristic information of the passive radio frequency identification tag, and transmit the initial absolute position information to the control module; The control module is used to transmit the initial absolute position information to the inertial navigation module, and set the initial absolute position information as the initial point r of the pig in the pipeline. INS,0 , the inertial navigation information initializes the accelerometer and gyroscope, and sets the initial velocity and initial attitude angle to zero; Initial point r INS,0 Expressed as: r INS,0 =(x0,y0,z0); Where x0 is the initial x-axis coordinate value, y0 is the initial y-axis coordinate value, and z0 is the initial z-axis coordinate value; The initial velocity is expressed as: v INS,0 ＝(0,0,0)； Among them, v INS,0 represents the initial velocity; The initial attitude angle is expressed as: i INS,0 =(0,0,0); Among them, θ INS,0 Expressed as the initial attitude angle.

6. A positioning and tracking system for a pipe cleaning device according to claim 1, characterized in that: The inertial navigation module is specifically used for: Get the three-axis acceleration of the pig, expressed as: a(t)=[a x (t),a y (t),a z (t)]; Among them, a(t) is the acceleration of the three axes at time t, a x (t) is the acceleration component along the X-axis at time t, a y (t) is the acceleration component along the Y axis at time t, a z (t) is the acceleration component along the Z axis at time t; Get the angular velocity of the pig, expressed as: ω(t)=[ω x (t),ω y (t),ω z (t)]; Among them, ω(t) is the angular velocity at time t, ω x (t) is the angular velocity around the X axis at time t, ω y (t) is the angular velocity around the Y axis at time t, ω z (t) is the angular velocity around the Z axis at time t; The pig attitude angle is calculated and expressed as: θ(t)=θ(t-Δt)+ω(t)·Δt; Among them, θ(t) is the attitude angle at time t, and Δt is the time interval for the pig to obtain data; The three-axis acceleration of the pig is converted from the sensor coordinate system to the world coordinate system and expressed as: a world (t)=R(θ)·a(t); Among them, a world (t) is the three-axis acceleration of the world coordinate system at time t, and R(θ) is the rotation matrix composed of the angle change; Update the pig speed, expressed as: v(t)=v(t-Δt)+a world (t)·Δt; Where v(t) is the speed of the pig at time t; The position vector is calculated and expressed as: r(t)=r(t-Δt)+v(t)·Δt; Where r(t) is the position vector of the pig at time t; The relative displacement and angle change of the pig are calculated and expressed as: x pred =F·(t-Δt)+G·u(t); Among them, x pred is the relative displacement and angle change of the pig, x is the state variable vector, including position vector, velocity and attitude angle, F is the state transfer matrix, G is the control input matrix, u(t) is the control input, including three-axis acceleration and angular velocity; The state transfer matrix F is expressed as:

7. A positioning and tracking system for a pipe cleaner according to claim 1, characterized in that: The control module is specifically used for: x(t)=x pred +K·(z(t)-H·x pred ); Among them, x(t) is the corrected relative displacement and angle change of the pig, K is the Kalman gain coefficient, z(t) is the absolute position information, and H is the observation matrix.

8. A positioning and tracking system for a pipe cleaning device according to claim 1, characterized in that: The control center is specifically used for: x'(t)=∝·z(t)+(1-∝)·x(t); Where x'(t) is the corrected trajectory position and ∝ is the correction coefficient.

9. A positioning and tracking system for a pipe cleaning device according to claim 1, characterized in that: The key nodes of the pipeline include pipeline bends, pipeline branch nodes, and pipeline inspection ports; The pipeline key nodes also include the blocking position points of the pipeline cleaning device determined according to historical information; the preset number is three.

10. A positioning and tracking system for a pipe cleaning device according to claim 1, characterized in that: The inertial navigation module is a group of micro-electromechanical system inertial measurement units integrated inside the pipe cleaning device, including a three-axis accelerometer and a three-axis gyroscope.

11. A positioning and tracking system for a pipe cleaning device according to claim 1, characterized in that: The sensor node and the wireless relay node both include a passive radio frequency identification tag receiver and a wireless communication module, and the wireless relay node adopts an adaptive path algorithm.

12. A method for positioning and tracking a pipe cleaner, characterized in that: The positioning and tracking system according to any one of claims 1 to 11 comprises: When the pipe cleaner is running, the three-axis acceleration and angular velocity of the pipe cleaner are continuously obtained, and the displacement information of the pipe cleaner is calculated; the displacement information includes relative displacement and angle change; Using a Kalman filter method to correct the offset information of the pipe cleaner to obtain corrected offset information; When the pipe cleaner passes through the sensor node signal range of the sensor node, in the case of detecting a signal of a passive radio frequency identification tag arranged on the surface of the pipe cleaner, obtaining the absolute position information of the pipe cleaner; The corrected offset information and the absolute position information are processed by Kalman filtering to obtain a continuous pig trajectory, and the pig trajectory is regularly corrected by the absolute position information to obtain a real-time positioning result of the pig.

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