Scraper conveyer straightness detection system based on combined positioning

Abstract

The invention discloses a scraper conveyor straightness detection system based on combined positioning, which relates to the technical field of straightness detection, and comprises a plurality of combined positioning devices integrated with a mounting main body, a posture sensing system, a laser sensing system and an electric control system, the two sensors are respectively installed on a scraper conveyor head and in each section of middle groove handrail circular tube and are used for carrying out posture and position monitoring on the whole line of the scraper conveyor. According to the invention, attitude sensing and laser measurement functions are integrated at the middle groove and the machine head of each section through the combined positioning device deployed in a distributed manner, so that the dynamic attitude and position data of each node of the whole line of the scraper conveyor can be acquired in real time, and a continuous and synchronous basic data source is provided for straightness calculation; the limitation of a traditional single-point or intermittent measurement method is overcome, full-coverage monitoring of the fuselage state is achieved, and a reliable basis is provided for working face straightness control.

Description

Technical Field

[0001] This invention relates to the field of straightness detection technology, specifically to a straightness detection system for scraper conveyors based on combined positioning. Background Technology

[0002] Scraper conveyors are crucial conveying equipment, consisting of components such as troughs, traction chains, scrapers, head drive chains, and tail tension sprockets, playing a vital role in coal production. Controlling the straightness of scraper conveyors in coal mining faces has always been a key technical challenge for achieving safe and intelligent mining. Monitoring the straightness of scraper conveyors is a fundamental condition for controlling the straightness of the working face. Since the coal mining machine relies on the scraper conveyor for operation, maintaining the conveyor's straightness ensures that the coal face remains straight after cutting by the machine. Therefore, the straightness of the scraper conveyor is a crucial link in achieving the "three straights and one level" control of the working face.

[0003] In the process of underground coal seam mining, scraper conveyors work in conjunction with coal mining machines and supports to complete operations such as coal dropping, loading, transporting, and pushing at the working face. Due to geological conditions and personnel operation, scraper conveyors are prone to horizontal bending or excessive pitch angles, leading to damage to the middle connecting dumbbells and end heads. Furthermore, the straightness of the working face cannot be guaranteed during pushing and pulling of the conveyor, which in turn causes faults such as scraper chain breakage, wear of the middle groove, and deformation of the machine body. In severe cases, it can even affect the normal operation of the entire coal mining process, seriously affecting production efficiency and bringing huge safety hazards. To address these issues, a scraper conveyor straightness detection system based on combined positioning is proposed. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a scraper conveyor straightness detection system based on combined positioning, comprising: The combined positioning device integrates an installation body, an attitude sensing system, a laser sensing system, and an electrical control system. Several of these combined positioning devices are installed in the head of the scraper conveyor and inside the circular tube of the handrail in each section of the middle trough. As the hardware carrier of the system, they integrate attitude sensing, laser measurement, and electrical control functions. Installed in each section of the middle trough and at the head of the conveyor, they enable distributed data acquisition and are used for continuous and real-time attitude and position monitoring of the entire scraper conveyor line, providing basic data for straightness calculation. The intelligent data processing terminal is communicatively connected to the combined positioning device. It is used to receive and fuse attitude and laser data, use Kalman filtering algorithm for error correction and position calibration, fit the attitude curve of the middle trough of the scraper conveyor and display it visually, so as to achieve high-precision detection of the straightness of the middle trough. The attitude perception system is used to collect the dynamic attitude information of the central trough in real time through the embedded attitude sensor, and transmit the data to the laser perception system and the intelligent data processing terminal to provide basic attitude data of the central trough of the scraper conveyor, supporting subsequent position calibration and straightness fitting. The laser sensing system consists of a ring-scanning laser emitter and a laser receiving target. It is used to calculate the relative offset between the middle troughs of adjacent scraper conveyors by the landing point characteristics of the laser beam on the laser receiving target, so as to realize the accurate position measurement between the middle troughs of adjacent scraper conveyors, provide high-precision position detection, correct the cumulative error of the attitude sensing system, and improve the measurement accuracy of the system. The electrical control system consists of a data acquisition and processing module and a power supply module. It is responsible for power supply, data acquisition, transmission and coordinated control between modules, ensuring stable operation of the system in harsh underground environments and enabling real-time data linkage and processing.

[0005] Preferably, the attitude sensing system performs the following steps: The dynamic attitude information of the central trough of the scraper conveyor in three-dimensional space is collected in real time by the attitude sensor embedded in the main body of the installation, including pitch angle, roll angle and yaw angle, so as to realize continuous and real-time monitoring of the three-dimensional attitude of the central trough and provide a basis for subsequent data processing. The collected dynamic attitude information is transmitted in real time to the laser receiving target in the laser sensing system through the data acquisition and processing module of the electronic control system. This is used for the adaptive adjustment of the laser receiving target's attitude. At the same time, the dynamic attitude information is uploaded to the intelligent data processing terminal as the basic attitude data source for the middle trough of the scraper conveyor, providing the initial state input for subsequent Kalman filter correction.

[0006] Preferably, the laser sensing system performs the following steps: A ring-scanning laser emitter is used to emit a laser beam to a laser receiving target in the middle trough of an adjacent scraper conveyor, forming a scanning plane to achieve non-contact, high-precision scanning coverage and avoid physical wear. The laser receiving target receives the laser beam and measures the distance between the laser's point of impact and the target's center. Simultaneously, coordinate transformation is performed by combining dynamic attitude information from the attitude perception system, and multi-source data is integrated to improve measurement robustness and environmental adaptability. The transformation matrix between the ring-scan laser coordinate system and the central trough coordinate system is established based on the DH parameter method, and the offset detection amount along the X-axis between the central troughs of adjacent scraper conveyors is calculated. As a precise position detection output, it achieves millimeter-level high-precision position detection and effectively suppresses accumulated errors.

[0007] Preferably, the calculation of the offset detection amount includes the following steps: Establish a circular laser coordinate system A coordinate system for the central trench is established with the laser beam emission point as the origin, the direction pointing towards the tail of the machine as the Y-axis, and the direction facing the coal wall as the X-axis. The origin of the coordinate system is the intersection of the central axis of the scraper conveyor trough and the circular pipe of the trough handrail. The direction pointing to the tail of the machine is the Y-axis, and the direction facing the coal wall is the X-axis. The DH parameter method is used to determine the coordinate transformation matrix between the ring-scan laser emission coordinate system and the central trough of the scraper conveyor. As shown in the following formula: ; In the formula: Indicates the coordinate system from the middle groove To the circular scanning laser coordinate system The coordinate transformation matrix; Indicates the yaw angle about the Z-axis; To represent the pitch angle about the Y-axis; To represent the roll angle about the X-axis; The coordinates of the center O of the laser receiving target in the central slot coordinate system are plotted. Let the coordinates of the origin of the central slot coordinate system in the excitation and emission coordinate system be... The distance from the laser impact point to the center of the target, as measured by the target, is... Combined with the transformation matrix The intersection point between the target and the circular scanning laser surface (x=m) can be obtained as follows: ; In the formula: This indicates that the center point O of the laser receiving target is in the central slot coordinate system. The three-dimensional coordinates below; This indicates that the origin of the central slot coordinate system is in the laser emission coordinate system. The three-dimensional coordinates below; This represents the distance from the point where the laser spot falls, as measured by the target, to the center O of the target. This represents the three-dimensional coordinates of the laser spot's landing point in the laser emission coordinate system; Following the previous equation, it is easy to see ,have ; From the above formula, the displacement measurement of the middle trough of the scraper conveyor along the X-axis is obtained. for: ; In the formula: It is a column vector, representing the unit direction vector from the target center O to the laser impact point in the target's own coordinate system (assuming its X-axis points to a certain measurement direction on the target plane); Indicates the laser spot landing point X-axis coordinate components in the laser emission coordinate system; for Coordinate vector in the laser coordinate system; The offset detection value of the central groove along the X-axis.

[0008] Preferably, the electronic control system performs the following coordinated control steps: The power module provides a stable power supply to the attitude sensing system, laser sensing system and data acquisition and processing module, ensuring the continuous and reliable operation of each subsystem in the harsh underground environment and avoiding monitoring interruption due to power supply fluctuations. The data acquisition and processing module simultaneously acquires data from the attitude sensor and measurement data from the laser receiving target, and timestamps the data to achieve real-time data linkage between the attitude sensing system and the laser sensing system. This ensures the temporal synchronization and spatial consistency of the measurement data, achieves high-precision spatiotemporal alignment of multi-source data, provides reliable input for subsequent fusion processing, and improves the overall measurement accuracy of the system.

[0009] Preferably, the intelligent data processing terminal performs the following data fusion steps: Receive dynamic attitude information and offset detection data from various combined positioning devices, establish a time series dataset, realize unified data management and time alignment, and provide structured input for subsequent fusion processing; By using the offset detection quantity measured by the laser sensing system as the observation quantity and the dynamic attitude information output by the attitude sensing system as the state quantity, a Kalman filter state space model is constructed to correct the attitude estimation error in real time, eliminate cumulative error, effectively suppress sensor drift and error accumulation, and significantly improve the overall accuracy and stability of straightness detection.

[0010] Preferably, the Kalman filter correction includes the following steps: Establish a state vector containing position, velocity, and attitude angle, as well as an observation vector containing offset detection, to construct a complete state observation system and lay the mathematical model foundation for high-precision fusion positioning; The state at the next moment is predicted based on the state-space model of the Kalman filter, and the prediction covariance matrix is ​​calculated. Then, the state estimate is updated using the offset detection measurement, the Kalman gain is calculated and the corrected attitude information is output, so as to realize the real-time correction of dynamic error and effectively suppress sensor drift and accumulated error. The corrected attitude information of each central slot is converted to a unified spatial absolute coordinate system, providing a consistent spatial reference benchmark for subsequent straightness fitting, ensuring the uniformity of the spatial benchmark of the entire machine's data, and supporting accurate straightness fitting and visualization analysis of the entire line.

[0011] Preferably, the transformation process of the absolute spatial coordinate system is as follows: A reference spatial coordinate system is established with the center of the circular tube of the handrail at the head of the scraper conveyor as the origin to ensure that the measurement reference is stable and reliable and to avoid the accumulation of coordinate system errors due to origin drift. Define the reference spatial coordinate directions: the positive Y-axis is along the direction of the conveyor's operation, the positive X-axis is perpendicular to the conveyor pointing towards the coal wall, and the positive Z-axis is perpendicular to the ground and pointing upwards. Establish a coordinate system that conforms to the actual layout of the underground working face, which is convenient for intuitive understanding and engineering application. The local attitude information of the central trough of all scraper conveyors is transformed into a reference spatial coordinate system to form a unified absolute spatial coordinate system. This enables the fusion analysis of multi-node data under a unified reference, providing a consistent spatial reference for the straightness calculation of the entire line.

[0012] Preferably, the intelligent data processing terminal also performs the following calibration steps: Based on the corrected attitude information output by the Kalman filter, a position calibration command is generated to realize online self-calibration of the measurement system and improve long-term operational stability. The calibration command is sent to the corresponding attitude sensing system through the electronic control system. The attitude sensing system updates its internal attitude estimation parameters according to the calibration command, realizes dynamic calibration of the detection position, suppresses sensor drift and accumulated error, and maintains consistent detection accuracy.

[0013] Preferably, in the intelligent data processing terminal, the process of fitting the attitude curve of the middle trough of the scraper conveyor is as follows: Based on the corrected local attitude information of the middle trough of each scraper conveyor in the absolute spatial coordinate system, its spatial position coordinates are extracted to provide a reliable and unified coordinate data basis for subsequent high-precision curve fitting. A polynomial curve fitting method is used to generate a continuous attitude curve of the central axis of the scraper conveyor in the horizontal plane, so as to realize the quantitative analysis and continuous description of the overall straightness state of the scraper conveyor. The fitted posture curves are displayed through a visual interface, presenting the straightness detection results of the entire scraper conveyor line. This allows operators to intuitively and in real-time monitor the conveyor's operating status and supports rapid decision-making and adjustments.

[0014] This invention provides a straightness detection system for scraper conveyors based on combined positioning. It has the following advantages: (I) The scraper conveyor straightness detection system based on combined positioning integrates attitude perception and laser measurement functions at the middle trough and head of each section through a distributed deployment of combined positioning devices. It can collect dynamic attitude and position data of each node of the entire scraper conveyor in real time, providing a continuous and synchronous basic data source for straightness calculation. It overcomes the limitations of traditional single-point or intermittent measurement methods, realizes full coverage monitoring of the machine body status, and provides a reliable basis for the straightness control of the working face.

[0015] (II) The straightness detection system of scraper conveyor based on combined positioning adopts a combination of attitude perception system and laser perception system. The attitude sensor provides basic attitude information, and the laser system accurately measures the offset between adjacent slots and uses the data to correct the cumulative error of the attitude sensor. The data is fused by Kalman filtering algorithm, which significantly improves the overall accuracy and anti-interference ability of the system in long-distance, multi-node detection and adapts to the complex vibration and dust environment in the well.

[0016] (III) The linearity detection system for scraper conveyors based on combined positioning has an intelligent data processing terminal that performs real-time Kalman filtering correction on attitude estimation based on laser observation data and can send calibration commands to the attitude perception system to realize dynamic updating of detection position and error compensation. This effectively suppresses the cumulative error caused by sensor drift, loose installation or environmental changes, and ensures that the system maintains high reliability and measurement consistency during long-term operation.

[0017] (iv) The scraper conveyor straightness detection system based on combined positioning fits the continuous attitude curve of the scraper conveyor's central axis in the horizontal plane and displays the straightness status of the entire line in real time in the visualization interface. Users can intuitively grasp the offset, bending trend and abnormal section of each slot, providing a quantitative basis for correction and adjustment during the working face advancement process, improving monitoring efficiency and response speed, and supporting automatic control and manual intervention in intelligent mining. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the working process of a scraper conveyor straightness detection system based on combined positioning according to the present invention. Figure 2 This is a schematic diagram of the overall structure of a scraper conveyor straightness detection system based on combined positioning according to the present invention; Figure 3 This is a schematic diagram of the overall structure of the combined positioning device. Figure 4 for Figure 3 A schematic diagram of the structure along direction A; Figure 5 This is a schematic diagram of the installation structure of the combined positioning device; Figure 6This is a schematic diagram illustrating the principle of offset calculation in a laser sensing system. Figure 7 This is a flowchart of the calculation process for the combined positioning device.

[0019] In the diagram: 1. Main installation unit; 2. Circular scanning laser emitter; 3. Laser receiving target; 4. Laser sensing system; 5. Attitude sensing system; 6. Electrical control system; 7. Power supply module; 8. Data acquisition and processing module; 9. Scraper conveyor trough; 10. Central trough handrail tube; 11. Scraper conveyor head; 12. Combined positioning device. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1, please refer to Figures 1 to 7 This invention provides a technical solution: a scraper conveyor straightness detection system based on combined positioning, comprising: The combined positioning device 12 integrates the mounting body 1, attitude sensing system 5, laser sensing system 4, and electrical control system 6. Several combined positioning devices 12 are installed in the head 11 of the scraper conveyor and in the circular tube 10 of the handrail of each section of the middle trough. As the hardware carrier of the system, it integrates attitude sensing, laser measurement and electrical control functions. Installed at the head of each section of the middle trough, it realizes distributed data acquisition and is used to continuously and in real time monitor the attitude and position of the entire scraper conveyor line, providing basic data for straightness calculation. The intelligent data processing terminal is connected to the combined positioning device 12 to receive and fuse attitude and laser data. It uses the Kalman filter algorithm for error correction and position calibration, fits the attitude curve of the middle trough 9 of the scraper conveyor and displays it visually, and realizes high-precision detection of the straightness of the middle trough. The attitude perception system 5 is used to collect the dynamic attitude information of the central trough in real time through the embedded attitude sensor and transmit the data to the laser perception system 4 and the intelligent data processing terminal. It provides the basic attitude data of the central trough 9 of the scraper conveyor and supports subsequent position calibration and straightness fitting. The attitude sensor embedded in the mounting body 1 collects the dynamic attitude information of the central trough 9 of the scraper conveyor in three-dimensional space in real time, including pitch angle, roll angle and yaw angle, so as to realize continuous and real-time monitoring of the three-dimensional attitude of the central trough and provide the basis for subsequent data processing. The collected dynamic attitude information is transmitted in real time to the laser receiving target 3 in the laser perception system 4 through the data acquisition and processing module 8 of the electronic control system 6 for the attitude adaptive adjustment of the laser receiving target 3. At the same time, the dynamic attitude information is uploaded to the intelligent data processing terminal as the basic attitude data source of the central trough 9 of the scraper conveyor, providing the initial state input for subsequent Kalman filter correction, ensuring the accuracy of the system measurement under dynamic working conditions, and suppressing the measurement error caused by attitude change. The laser sensing system 4, consisting of a ring-scanning laser emitter 2 and a laser receiving target 3, is used to calculate the relative offset between adjacent scraper conveyor middle troughs 9 by analyzing the characteristics of the laser beam's impact point on the laser receiving target 3. This enables precise position measurement between adjacent scraper conveyor middle troughs 9, providing high-precision position detection data to correct the cumulative error of the attitude sensing system 5 and improve the system's measurement accuracy. The ring-scanning laser emitter 2 emits a laser beam towards the laser receiving target 3 of the adjacent scraper conveyor middle troughs 9, forming a scanning plane to achieve non-contact, high-precision scanning coverage and avoid physical wear. The laser receiving target 3 receives the laser beam and measures the distance of the laser impact point relative to the target center. Simultaneously, coordinate transformation is performed by combining dynamic attitude information from attitude perception system 5, and multi-source data is integrated to improve measurement robustness and environmental adaptability. Based on the DH parameter method, the transformation matrix between the ring-scan laser coordinate system and the central trough coordinate system is established, and the offset detection amount along the X-axis between adjacent scraper conveyor central troughs 9 is calculated. As a precise position detection output, it achieves millimeter-level high-precision position detection and effectively suppresses accumulated errors; The specific work content is as follows: The attitude perception system 5 uses a high-precision MEMS attitude sensor embedded in the mounting body 1 to collect the dynamic attitude information of the middle trough 9 of the scraper conveyor in three-dimensional space in real time, including pitch angle, roll angle, and yaw angle. The sensor sampling frequency is set to 100Hz, and the measurement range covers pitch angle ±90°, roll angle ±180°, and yaw angle ±180°, with an angular resolution better than 0.1°, to meet the monitoring requirements for rapid changes in the attitude of the middle trough under complex downhole conditions. The collected attitude data is initially filtered and timestamped by the data acquisition and processing module 8 in the electronic control system 6, and then transmitted in real time via the CAN bus at a period of 10ms to the laser receiving target 3 in the laser perception system 4 for adaptive attitude compensation of the target, ensuring that the relative attitude of the laser measurement plane and the target receiving surface is consistent. At the same time, this dynamic attitude information is transmitted through... The industrial Ethernet protocol uploads data to the intelligent data processing terminal, serving as the basic attitude data source for the central slot. This provides initial state input for the subsequent Kalman filter algorithm, ensuring the system has a reliable attitude reference from the startup phase. After receiving real-time attitude data from the attitude sensing system 5, the laser sensing system 4 uses a circular scanning laser emitter 2 to emit a 905nm wavelength laser beam with a spot diameter of no more than 3mm at a frequency of 20Hz. The scanning angle range is ±30°, forming a stable scanning plane that covers the laser receiving target 3 adjacent to the central slot. The target uses a CCD array sensor with an effective photosensitive area of ​​50mm×50mm and a center positioning accuracy of 0.5mm. The target dynamically rotates and compensates its own coordinate system based on the received attitude information, ensuring accurate capture of the laser landing point position under different installation tilt angles. The distance between the laser landing point and the target center is measured. Based on the coordinate transformation matrix established by the DH parameter method, the offset detection amount along the X-axis between adjacent middle slots is calculated. This offset detection quantity, as a high-precision position observation, together with the attitude angle data output by the attitude sensor, forms the basis of multi-source fusion detection, effectively suppressing the error accumulation that may be generated by a single sensor in long-distance, multi-node detection; In addition, the calculation of the offset detection amount includes the following steps: Establish a circular laser coordinate system A coordinate system for the central trench is established with the laser beam emission point as the origin, the direction pointing towards the tail of the machine as the Y-axis, and the direction facing the coal wall as the X-axis. The origin of the coordinate system is the intersection of the central axis of the scraper conveyor trough 9 and the central trough handrail circular pipe 10. The direction pointing to the tail of the machine is the Y-axis, and the direction facing the coal wall is the X-axis. The DH parameter method is used to determine the coordinate transformation matrix between the ring-scan laser emission coordinate system and the central trough 9 of the scraper conveyor. As shown in the following formula: ; In the formula: Indicates the coordinate system from the middle groove To the circular scanning laser coordinate system The coordinate transformation matrix; Indicates the yaw angle about the Z-axis; To represent the pitch angle about the Y-axis; To represent the roll angle about the X-axis; The coordinates of the center O of the laser receiving target 3 in the central slot coordinate system are marked. Let the coordinates of the origin of the central slot coordinate system in the excitation and emission coordinate system be... The distance from the laser impact point to the center of the target, as measured by the target, is... Combined with the transformation matrix The intersection point between the target and the circular scanning laser surface (x=m) can be obtained as follows: ; In the formula: This indicates that the center point O of the laser receiving target is in the central slot coordinate system. The three-dimensional coordinates below; This indicates that the origin of the central slot coordinate system is in the laser emission coordinate system. The three-dimensional coordinates below; This represents the distance from the point where the laser spot falls, as measured by the target, to the center O of the target. This represents the three-dimensional coordinates of the laser spot's landing point in the laser emission coordinate system; Following the previous equation, it is easy to see ,have ; From the above formula, the displacement detection amount of the middle trough 9 of the scraper conveyor along the X-axis is obtained. for: ; In the formula: It is a column vector, representing the unit direction vector from the target center O to the laser impact point in the target's own coordinate system (assuming its X-axis points to a certain measurement direction on the target plane); Indicates the laser spot landing point X-axis coordinate components in the laser emission coordinate system; for Coordinate vector in the laser coordinate system; The offset detection amount of the central groove along the X-axis; The electrical control system 6, consisting of a data acquisition and processing module 8 and a power supply module 7, is responsible for system power supply, data acquisition, transmission, and collaborative control between modules. It ensures stable operation of the system in harsh underground environments, enables real-time data linkage and processing, and provides a stable power supply to the attitude sensing system 5, laser sensing system 4, and data acquisition and processing module 8. This ensures the continuous and reliable operation of each subsystem in harsh underground environments and avoids monitoring interruptions due to power supply fluctuations. The data acquisition and processing module 8 synchronously acquires attitude sensor data and measurement data from the laser receiving target 3 and timestamps them to achieve real-time data linkage between the attitude sensing system 5 and the laser sensing system 4. This ensures the temporal synchronization and spatial consistency of the measurement data, achieves high-precision spatiotemporal alignment of multi-source data, provides reliable input for subsequent fusion processing, and improves the overall measurement accuracy of the system. The specific work content is as follows: Power module 7 adopts an intrinsically safe design with a rated output voltage of 24VDC and a maximum output current of not less than 5A, which meets the explosion-proof standards for electrical equipment in coal mines. This module has built-in overvoltage, overcurrent, and short-circuit protection circuits, and can maintain stable output voltage within the input voltage fluctuation range of 18V to 36V, with a fluctuation rate not exceeding ±2%. Power module 7 is connected to attitude sensing system 5, laser sensing system 4, and data acquisition and processing module 8 through armored cables, providing a continuous and stable power supply to each subsystem. Under typical working conditions, the total power consumption of the entire combined positioning device 12 is controlled within 15W, ensuring that monitoring will not be interrupted due to power supply problems during continuous operation underground. Power module 7 has a low-power standby mode, which can automatically reduce the output power when the system is in a non-active detection state to extend the continuous working time of the equipment without external charging. Data acquisition and processing module 8 uses ARM Cortex-M7 as the core processor and has a built-in high-precision hardware clock source with a clock accuracy error of not more than ±10ppm. This module synchronously reads the attitude at a sampling frequency of 1kHz through the SPI interface. The sensor outputs raw triaxial angular velocity and acceleration data, and captures the laser landing point coordinate information uploaded by the laser receiving target 3 in real time through a parallel digital interface. Each batch of acquired data packets is appended with a UTC timestamp generated based on the GPS / BeiDou downhole synchronization timing system. The module's built-in frame synchronization algorithm is used to align data streams from different physical interfaces to ensure that the attitude data and laser measurement data correspond on the time axis. After the timestamp is completed, the data acquisition and processing module 8 sends the synchronized attitude data packets to the laser receiving target 3 via the CAN bus at a period of 10ms. The target performs dynamic rotation compensation on its local coordinate system based on the received real-time attitude angle information to eliminate the measurement reference plane deflection error caused by the attitude change of the central slot. At the same time, the raw attitude data with timestamps and the offset detection data are uploaded to the intelligent data processing terminal via the industrial Ethernet protocol. On the intelligent data processing terminal side, the data verification algorithm checks the integrity of multi-source data under the same timestamp and discards data frames with inconsistent times or abnormal formats to ensure that the data entering the fusion processing stage has good spatiotemporal consistency.

[0022] Example 2, as Figures 1 to 7As shown, based on Embodiment 1, the present invention provides a technical solution: the intelligent data processing terminal performs the following data fusion steps: receiving dynamic attitude information and offset detection data from each combined positioning device 12, establishing a time series dataset, realizing unified data management and time alignment, providing structured input for subsequent fusion processing, using the offset detection quantity measured by the laser sensing system 4 as the observation quantity, and the dynamic attitude information output by the attitude sensing system 5 as the state quantity, constructing a Kalman filter state space model, performing real-time correction of attitude estimation error, eliminating cumulative error, effectively suppressing sensor drift and error accumulation, and significantly improving the overall accuracy and stability of straightness detection; The specific work involves the intelligent data processing terminal periodically receiving dynamic attitude information and offset detection data uploaded from each combined positioning device 12 via the industrial Ethernet protocol. The data is transmitted in the form of data packets, each packet containing a UTC timestamp generated based on the GPS / BeiDou underground synchronization system. The terminal has a built-in data verification and alignment algorithm to verify the integrity of the received data packets, discarding data frames with missing timestamps or abnormal formats. Furthermore, the terminal aligns the attitude data and offset detection data from the same combined positioning device 12 according to the timestamps, forming a time-series dataset indexed by time. This dataset is organized with 10ms as the basic time unit to ensure the time synchronization between the attitude angle and the corresponding offset detection value at each moment. Based on the aligned time-series data, a discrete-time Kalman filter state-space model is constructed, and a nine-dimensional state vector is designed. Including position, velocity, and attitude angle, the offset detection quantity along the X-axis direction between the middle slots measured by the laser sensing system 4 is used as the observation vector. The state transition matrix is ​​designed based on the typical kinematic model of the middle slots in the downhole working face. The process noise covariance matrix Q and the observation noise covariance matrix R are obtained through calibration with a large amount of measured data. The observation noise variance of the attitude angle is set to (0.1°)², and the observation noise variance of the offset detection quantity is set to (0.5mm)². The filter uses the attitude angle provided by the attitude sensing system 5 as the initial state. In each 10ms filtering cycle, a prediction-update loop is executed. The state and covariance at the current moment are predicted according to the Kalman filter state space model. Then, the predicted state is corrected using the offset detection quantity. The Kalman gain is calculated and the optimal state estimate is updated to suppress the cumulative error of state estimation caused by the inherent drift of MEMS sensors and the downhole vibration environment. Kalman filter correction includes the following steps: establishing a state vector containing position, velocity, and attitude angle, and an observation vector containing offset detection quantities, constructing a complete state observation system to lay the mathematical model foundation for high-precision fusion positioning; predicting the state at the next moment based on the Kalman filter state space model and calculating the prediction covariance matrix; updating the state estimate using offset detection quantity observations; calculating the Kalman gain and outputting the corrected attitude information to achieve real-time correction of dynamic errors, effectively suppressing sensor drift and accumulated errors; and converting the corrected attitude information of each central slot to a unified spatial absolute coordinate system to provide a consistent spatial reference benchmark for subsequent straightness fitting, ensuring the uniformity of the spatial benchmark of the entire machine's data, and supporting accurate straightness fitting and visualization analysis of the entire line. The specific work involves two steps in each processing cycle: prediction and update using Kalman filtering. Based on the state estimation and state transition matrix from the previous time step, the attitude, position, and velocity at the current time step are predicted. Simultaneously, the prediction covariance matrix is ​​calculated. The measured offset detection data from the laser sensing system 4 is used as the input filter for the observation data. The predicted state is weighted and corrected by calculating the Kalman gain. The Kalman gain matrix is ​​adjusted in real time to balance the weights of the model prediction and the observation data. After iterative updates, a corrected nine-dimensional state vector is output, significantly suppressing the cumulative attitude angle error and controlling the accuracy of the horizontal position estimation. The accuracy meets the actual precision requirements for straightness control of coal mine working faces. The corrected attitude information of the middle trough 9 of each scraper conveyor is transformed into a unified spatial absolute coordinate system. This spatial absolute coordinate system takes the center of the handrail tube of the scraper conveyor head 11 as the origin, the X-axis is perpendicular to the conveyor and points to the coal wall, the Y-axis points to the tail along the conveying direction, and the Z-axis is vertically upward. During the transformation process, the local attitude data of the middle trough 9 of each scraper conveyor is transformed into the global coordinate system using the pre-calibrated installation parameters and coordinate transformation matrix to ensure that all node data have a consistent spatial reference benchmark. The transformed coordinate data is organized according to the time sequence. Furthermore, the transformation process of the absolute spatial coordinate system is as follows: taking the center of the handrail circular tube of the scraper conveyor head 11 as the origin, a reference spatial coordinate system is established to ensure the stability and reliability of the measurement reference and avoid the accumulation of coordinate system errors due to origin drift. The reference spatial coordinate directions are defined as follows: the positive Y-axis is along the conveyor running direction, the positive X-axis is perpendicular to the conveyor pointing towards the coal wall, and the positive Z-axis is perpendicular to the ground upward. A coordinate system that conforms to the actual layout of the underground working face is established, which is convenient for intuitive understanding and engineering application. The local attitude information of the middle trough 9 of all scraper conveyors is transformed into the reference spatial coordinate system to form a unified absolute spatial coordinate system, realize the fusion analysis of multi-node data under a unified reference, and provide a consistent spatial reference for the straightness calculation of the entire line. The specific work content is as follows: During implementation, the center of the circular tube of the handrail at the head of the scraper conveyor 11 is selected as the origin to construct a reference spatial coordinate system. This origin is located in a stable part of the head structure that is not easily affected by displacement, which facilitates the long-term stability of the coordinate reference. The coordinate axis directions are defined according to the actual working face layout: the positive Y-axis is set along the running direction of the scraper conveyor, i.e., from the head to the tail; the positive X-axis is perpendicular to the conveyor body and pointing towards the coal wall; and the positive Z-axis is perpendicular to the ground and upward. This reference spatial coordinate system conforms to the right-hand rule to ensure the consistency of the three-dimensional spatial description and the uniformity of engineering practices. The establishment of the coordinate system relies on the on-site calibration using a total station or laser tracker. The origin positioning error is controlled within ±5mm. The directional deviation does not exceed 0.1° to meet the actual needs of high-precision measurement and control in downhole. After the establishment of the reference spatial coordinate system, the local attitude information of the middle trough 9 of each scraper conveyor is transformed to the unified reference spatial coordinate system. The attitude data output in real time by each combined positioning device 12 includes pitch angle, roll angle and yaw angle, as well as the offset detection amount between adjacent troughs calculated based on the laser sensing system 4. During the transformation process, the pre-calibrated installation parameters - including the installation offset and installation attitude angle of each device in the handrail tube - are used in combination with the coordinate transformation matrix to transform the measured values ​​under the local coordinate system node by node to the global reference spatial coordinate system to obtain a unified absolute spatial coordinate system. The transformation calculation is performed in real time in the intelligent data processing terminal. The intelligent data processing terminal also performs the following calibration steps: Based on the corrected attitude information output by the Kalman filter, it generates a position calibration command to realize online self-calibration of the measurement system, improve long-term operational stability, and sends the calibration command to the corresponding attitude sensing system 5 through the electronic control system 6. The attitude sensing system 5 updates its internal attitude estimation parameters according to the calibration command to realize dynamic calibration of the detection position, suppress sensor drift and accumulated error, and maintain the consistency of detection accuracy. The specific work content is as follows: After the Kalman filter correction is completed in the intelligent data processing terminal, a corresponding position calibration command is generated based on the current optimal attitude state estimation. The position calibration command includes the compensation amount of the attitude angle of each node to adapt to the attitude fine-tuning requirements under the dynamic working conditions downhole. The position calibration command data is sent to the corresponding combined positioning device in a structured manner through the industrial Ethernet protocol. The transmission cycle is consistent with the filtering cycle to ensure the real-time nature of the correction feedback. The position calibration command includes the node number, timestamp, and three-dimensional attitude correction parameters to ensure that the data is accurately matched with the specific physical node and to avoid misalignment calibration. After receiving the position calibration command, the electronic control system 6 parses the command content through the built-in ARM Cortex-M7 processor and writes the correction parameters into the configuration register of the attitude perception system 5. The attitude perception system 5 dynamically adjusts the original attitude angle of its output based on the written compensation parameters and updates the deviation compensation term of the internal attitude fusion algorithm in real time to achieve adaptive calibration of the detection position, suppress the cumulative error introduced by sensor drift, loose installation, or environmental vibration, and maintain the high accuracy and reliability of the scraper conveyor straightness detection system during long-term operation. In the intelligent data processing terminal, the process of fitting the attitude curve of the middle trough 9 of the scraper conveyor is as follows: Based on the corrected local attitude information of the middle trough 9 of each scraper conveyor in the absolute spatial coordinate system, its spatial position coordinates are extracted to provide a reliable and unified coordinate data basis for subsequent high-precision curve fitting. The polynomial curve fitting method is used to generate a continuous attitude curve of the central axis of the scraper conveyor in the horizontal plane, realizing the quantitative analysis and continuous description of the overall straightness state of the scraper conveyor. The fitted attitude curve is displayed through a visual interface, presenting the straightness detection results of the entire scraper conveyor line, which makes it easy for operators to intuitively and in real time grasp the operating status of the conveyor and support rapid decision-making and adjustment. The specific work involves: Based on the corrected local attitude information of the central trough 9 of all scraper conveyors in the absolute spatial coordinate system, extracting the three-dimensional spatial coordinates corresponding to the central trough 9 of each scraper conveyor. The coordinate system has the center of the head handle circular pipe as the origin, the Y-axis pointing towards the tail of the conveyor along the conveying direction, the X-axis perpendicular to the conveyor and pointing towards the coal wall, and the Z-axis vertically upward. During coordinate extraction, pre-calibrated installation parameters are used to transform the local attitude of each trough to ensure that all nodes are expressed under a unified spatial reference, eliminating coordinate system inconsistencies caused by installation deviations. A cubic polynomial curve fitting method is used, with the Y-axis coordinate as the independent variable and the X-axis coordinate as the dependent variable, to model a continuous curve of the central axis of the scraper conveyor in the horizontal plane. During the fitting process, the least squares method is used to optimize the fitting coefficients to ensure that the curve is smooth and closely matches the actual trough distribution. Simultaneously, residual analysis is used to evaluate the goodness of fit and control... With a fitting error within ±5mm, the fitted curve can intuitively reflect the horizontal bending state of the scraper conveyor throughout the entire line and provide a quantitative basis for the straightness control of the working face, supporting subsequent automatic correction or manual adjustment decisions. Through the visualization interface integrated into the intelligent data processing terminal, the fitted scraper conveyor centerline curve is superimposed with the actual position points of the central trough 9 of each scraper conveyor. The visualization interface is presented in the form of a two-dimensional planar diagram, with the horizontal direction representing the conveying direction, i.e., the Y-axis, and the vertical direction representing the lateral offset, i.e., the X-axis. At the same time, different colors or marks are used to distinguish between the theoretical straight line and the actual curve. Users can monitor the straightness status of the entire line in real time through the interface, view the offset of each trough, the curvature of the curve, and the alarm information of key sections, so as to achieve intuitive understanding and rapid response of the working status of the scraper conveyor and improve the safety and operating efficiency during the working face advancement process.

[0023] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0024] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A straightness detection system for scraper conveyors based on combined positioning, characterized in that, include: The combined positioning device (12) integrates the installation body (1), attitude sensing system (5), laser sensing system (4) and electrical control system (6). Several combined positioning devices (12) are installed in the head (11) of the scraper conveyor and in the circular tube (10) of the middle trough handrail of each section, for monitoring the attitude and position of the entire scraper conveyor line. The intelligent data processing terminal is connected to the combined positioning device (12) for receiving and fusing attitude and laser data, using Kalman filtering algorithm for error correction and position calibration, fitting the attitude curve of the middle trough (9) of the scraper conveyor and displaying it visually. The attitude perception system (5) is used to collect the dynamic attitude information of the central trough in real time through the embedded attitude sensor, and transmit the data to the laser perception system (4) and the intelligent data processing terminal to provide the basic attitude data of the central trough (9) of the scraper conveyor. The laser sensing system (4) consists of a ring-scanning laser emitter (2) and a laser receiving target (3). It is used to calculate the relative offset between adjacent scraper conveyor middle troughs (9) by using the landing point characteristics of the laser beam on the laser receiving target (3) to correct the cumulative error of the attitude sensing system (5). The electronic control system (6) consists of a data acquisition and processing module (8) and a power supply module (7), and is responsible for system power supply, data acquisition, transmission and coordinated control between modules.

2. The straightness detection system for a scraper conveyor based on combined positioning according to claim 1, characterized in that: The attitude sensing system (5) performs the following steps: The attitude sensor embedded in the mounting body (1) collects the dynamic attitude information of the middle trough (9) of the scraper conveyor in three-dimensional space in real time, including pitch angle, roll angle and yaw angle; The collected dynamic attitude information is transmitted in real time to the laser receiving target (3) in the laser sensing system (4) through the data acquisition and processing module (8) of the electronic control system (6) for the adaptive adjustment of the attitude of the laser receiving target (3). At the same time, the dynamic attitude information is uploaded to the intelligent data processing terminal as the basic attitude data source of the scraper conveyor middle trough (9).

3. The straightness detection system for a scraper conveyor based on combined positioning according to claim 2, characterized in that: The laser sensing system (4) performs the following steps: A laser beam is emitted from a ring-scanning laser emitter (2) to a laser receiving target (3) in the middle trough (9) of an adjacent scraper conveyor to form a scanning plane; Laser receiving target (3) receives the laser beam and measures the distance of the laser landing point relative to the center of the target. At the same time, coordinate transformation is performed by combining dynamic attitude information from the attitude perception system (5); The transformation matrix between the ring-scan laser coordinate system and the central trough coordinate system is established based on the DH parameter method. The offset detection amount along the X-axis between the central troughs (9) of adjacent scraper conveyors is calculated. .

4. The straightness detection system for a scraper conveyor based on combined positioning according to claim 3, characterized in that: The calculation of the offset detection amount includes the following steps: Establish a circular laser coordinate system A coordinate system for the central trench is established with the laser beam emission point as the origin, the direction pointing towards the tail of the machine as the Y-axis, and the direction facing the coal wall as the X-axis. The origin of the coordinate system is the intersection of the central axis of the scraper conveyor trough (9) and the circular pipe (10) of the trough handrail. The Y-axis is the direction pointing to the tail of the machine, and the X-axis is the direction facing the coal wall. The DH parameter method was used to determine the coordinate transformation matrix between the ring-scan laser emission coordinate system and the central trough (9) of the scraper conveyor. As shown in the following formula: ； In the formula: Indicates the coordinate system from the middle groove To the circular scanning laser coordinate system The coordinate transformation matrix; Indicates the yaw angle about the Z-axis; To represent the pitch angle about the Y-axis; To represent the roll angle about the X-axis; The coordinates of the center O of the laser receiving target (3) in the central slot coordinate system are marked. Let the coordinates of the origin of the central slot coordinate system in the excitation and emission coordinate system be... The distance from the laser impact point to the center of the target, as measured by the target, is... Combined with the transformation matrix The intersection point between the target and the circular scanning laser surface can be obtained as follows: ； In the formula: This indicates that the center point O of the laser receiving target is in the central slot coordinate system. The three-dimensional coordinates below; This indicates that the origin of the central slot coordinate system is in the laser emission coordinate system. The three-dimensional coordinates below; This represents the distance from the point where the laser spot falls, as measured by the target, to the center O of the target. This represents the three-dimensional coordinates of the laser spot's landing point in the laser emission coordinate system; Following the previous equation, it is easy to see ,have ; From the above formula, the displacement detection amount of the middle trough (9) of the scraper conveyor along the X-axis is obtained. for: ； In the formula: is a column vector, representing the unit direction vector from the target center O to the laser impact point in the target's own coordinate system; Indicates the laser spot landing point X-axis coordinate components in the laser emission coordinate system; for Coordinate vector in the laser coordinate system; The offset detection value of the central groove along the X-axis.

5. The straightness detection system for a scraper conveyor based on combined positioning according to claim 1, characterized in that: The electronic control system (6) performs the following coordinated control steps: The power supply module (7) provides a stable power supply for the attitude sensing system (5), the laser sensing system (4) and the data acquisition and processing module (8); The data acquisition and processing module (8) synchronously acquires the attitude sensor data and the measurement data of the laser receiving target (3) and timestamps them to realize real-time data linkage between the attitude sensing system (5) and the laser sensing system (4).

6. The straightness detection system for a scraper conveyor based on combined positioning according to claim 1, characterized in that: The intelligent data processing terminal performs the following data fusion steps: Receive dynamic attitude information and offset detection data from each combined positioning device (12) and establish a time series dataset; The offset detection quantity measured by the laser sensing system (4) is used as the observation quantity, and the dynamic attitude information output by the attitude sensing system (5) is used as the state quantity. A Kalman filter state space model is constructed to correct the attitude estimation error in real time and eliminate the cumulative error.

7. The straightness detection system for a scraper conveyor based on combined positioning according to claim 6, characterized in that: The Kalman filter correction includes the following steps: Establish a state vector containing position, velocity, and attitude angle, as well as an observation vector containing offset detection data, to construct a complete state observation system; The state at the next moment is predicted based on the state-space model of the Kalman filter, and the prediction covariance matrix is ​​calculated. Then, the state estimate is updated using the offset detection observations, the Kalman gain is calculated, and the corrected attitude information is output. The corrected attitude information of each central slot is converted to a unified spatial absolute coordinate system, providing a consistent spatial reference benchmark for subsequent straightness fitting.

8. The straightness detection system for a scraper conveyor based on combined positioning according to claim 7, characterized in that: The transformation process of the absolute spatial coordinate system is as follows: A reference spatial coordinate system is established with the center of the handrail tube of the scraper conveyor head (11) as the origin; Define the reference spatial coordinate directions as follows: the positive Y-axis is along the direction of the conveyor's operation, the positive X-axis is perpendicular to the conveyor pointing towards the coal wall, and the positive Z-axis is perpendicular to the ground and pointing upwards. The local attitude information of the middle trough (9) of all scraper conveyors is converted into the reference space coordinates to form a unified absolute space coordinate system.

9. The straightness detection system for a scraper conveyor based on combined positioning according to claim 1, characterized in that: The intelligent data processing terminal also performs the following calibration steps: Based on the corrected attitude information output by the Kalman filter, a position calibration command is generated. The calibration command is sent to the corresponding attitude sensing system (5) through the electronic control system (6). The attitude sensing system (5) updates the internal attitude estimation parameters according to the calibration command to realize the dynamic calibration of the detection position.

10. A scraper conveyor straightness detection system based on combined positioning according to claim 1, characterized in that: In the intelligent data processing terminal, the process of fitting the attitude curve of the middle trough (9) of the scraper conveyor is as follows: Based on the corrected local attitude information of the middle trough (9) of each scraper conveyor in the absolute spatial coordinate system, its spatial position coordinates are extracted. A polynomial curve fitting method was used to generate a continuous attitude curve of the central axis of the scraper conveyor in the horizontal plane. The fitted posture curves are displayed through a visual interface, presenting the straightness test results of the entire scraper conveyor line.

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