A method and system for absolute position fault-tolerant identification of hydraulic cylinders using magnetic micro-area coding

Abstract

This application proposes a fault-tolerant method and system for absolute position recognition of hydraulic cylinders using magnetic micro-area coding. The method includes: synchronously acquiring magnetic response information of magnetic micro-areas on the inner wall of the hydraulic cylinder using multiple magnetic sensors spaced at intervals along the axial direction of the hydraulic cylinder; extracting features from the magnetic response information to form a candidate magnetic area number set based on the extracted features; verifying the candidate magnetic area number set based on the motion state of the hydraulic cylinder piston and historical recognition results, and eliminating abnormal recognition results that do not conform to the motion law; when the current magnetic area recognition result is abnormal, correcting the magnetic area number using the coding relationship between magnetic areas or the joint features acquired by multiple sensors, and outputting the absolute position of the hydraulic cylinder piston based on the corrected magnetic area number. The technical solution of this application solves the unreliability problem of hydraulic cylinder magnetic micro-area coding position recognition caused by abnormal magnetic response or signal fluctuations in complex working conditions in coal mines, and achieves stable and fault-tolerant absolute position output.

Description

Technical Field

[0001] This application relates to the field of intelligent sensing and information processing technology for hydraulic equipment in underground coal mines, and in particular to a method and system for fault-tolerant identification of absolute position using magnetic micro-area coding of hydraulic cylinders. Background Technology

[0002] During the operation of hydraulic actuators such as hydraulic supports and pushing devices in underground coal mines, hydraulic cylinders are subjected to long-term environments of strong vibration, strong impact, high humidity, high dust, and complex electromagnetic interference. Even with magnetic coding to sense the stroke position of the hydraulic cylinder, the following problems may still occur during actual operation:

[0003] 1) The magnetic response characteristics of local magnetic micro-regions are weakened or abnormal due to manufacturing deviations, long-term service, or external magnetic interference; 2) The magnetic sensor outputs an abnormal signal instantaneously under vibration and impact conditions; 3) The underground power supply conditions are complex, with frequent power outages and restarts, resulting in the loss of historical states during the decoding process; 4) During rapid operations or complex switching of operating conditions, the results of a single magnetic zone identification may be misjudged.

[0004] Existing magnetic displacement detection methods mostly rely on single-point or instantaneous signal judgment. Once the magnetic response is abnormal, it can easily lead to incorrect position information, and there is a lack of a systematic fault-tolerant identification mechanism for complex underground working conditions. Therefore, it is urgent to propose a fault-tolerant identification method for underground coal mine applications, based on magnetic micro-area coding and absolute position decoding, in order to improve the reliability and engineering applicability of hydraulic cylinder stroke sensing. Summary of the Invention

[0005] This application provides a method and system for absolute position fault-tolerant identification of hydraulic cylinders using magnetic micro-area coding, which at least solves the technical problems of existing magnetic displacement detection methods in harsh working conditions such as strong vibration, strong interference, and unstable power supply in coal mines, where single-point failure or instantaneous signal abnormalities lead to poor position identification reliability and a lack of systematic fault tolerance mechanisms.

[0006] The first aspect of this application proposes a method for fault-tolerant identification of absolute position using magnetic micro-area coding in a hydraulic cylinder, the method comprising: Multiple magnetic sensors are arranged at intervals along the axial direction of the hydraulic cylinder to synchronously collect magnetic response information of the magnetic micro-regions on the inner wall of the hydraulic cylinder. Feature extraction is performed on the magnetic response information, and a candidate magnetic region number set is formed based on the extracted feature information; Based on the motion state of the hydraulic cylinder piston and the historical identification results, the candidate magnetic region number set is verified, and abnormal identification results that do not conform to the motion law are eliminated. When the current magnetic zone identification result is abnormal, the magnetic zone number is corrected by using the coding relationship between magnetic zones or the joint features collected by multiple sensors, and the absolute position of the hydraulic cylinder piston is output according to the corrected magnetic zone number.

[0007] Preferably, the step of synchronously acquiring magnetic response information of the magnetic micro-regions on the inner wall of the hydraulic cylinder using multiple magnetic sensors spaced apart along the axial direction of the hydraulic cylinder includes: The original magnetic response signal of the magnetic micro-region at the corresponding position is acquired synchronously by at least two magnetic sensing units arranged at intervals along the axial direction of the hydraulic cylinder. The original magnetic response signal is preprocessed by filtering and amplitude normalization to obtain magnetic response information that can be used for feature extraction.

[0008] Preferably, the step of extracting features from the magnetic response information and forming a candidate magnetic region number set based on the extracted feature information includes: Feature extraction is performed on the magnetic response information to obtain the magnetization direction features, magnetic response amplitude range features, and magnetic region spatial features; Based on the magnetization direction characteristics, magnetic response amplitude range characteristics, and magnetic region spatial characteristics of the magnetic region, a set of candidate magnetic region numbers is formed by matching them with a preset magnetic region coding feature library.

[0009] Preferably, the step of verifying the candidate magnetic region number set based on the motion state and historical identification results of the hydraulic cylinder piston, and eliminating abnormal identification results that do not conform to the motion pattern, includes: Based on the real-time movement direction and speed of the hydraulic cylinder piston, calculate the allowable range of magnetic zone number changes within the current sampling period; Based on the previous valid magnetic zone number determined by historical identification results, and combined with the allowed range of magnetic zone number variations, the candidate magnetic zone number set is filtered to eliminate abnormal identification results that exceed the range of variations.

[0010] Preferably, when the current magnetic zone identification result is abnormal, correcting the magnetic zone number using the coding relationship between magnetic zones or the joint features collected by multiple sensors includes: When the current magnetic zone identification result is determined to be inconsistent with the historical state or the magnetic response characteristics are abnormal, the current magnetic zone number is corrected based on the preset coding relationship between adjacent magnetic zones in the magnetic micro-area coding band, the spatial coding characteristics of non-equidistant magnetic zones, or the joint magnetic response characteristics collected by multiple magnetic sensing units.

[0011] Preferably, the method further includes: Periodically appearing identifying magnetic areas are set in the magnetic micro-area coding band on the inner wall of the hydraulic cylinder; When the magnetic sensing module identifies the marked magnetic area, it verifies and quickly locates the currently identified magnetic area number sequence based on the unique number of the marked magnetic area.

[0012] Furthermore, the calculation of the allowable range of magnetic zone number changes within the current sampling period based on the real-time movement direction and speed of the hydraulic cylinder piston includes: Based on the preset maximum movement speed of the hydraulic cylinder piston and the current sampling period, calculate the maximum number of magnetic regions that can be crossed per unit time. Using the maximum number of magnetic zones as a constraint, and in conjunction with the direction of movement, determine the allowable range of magnetic zone number changes starting from the previous valid magnetic zone number.

[0013] Preferably, the method further includes: After the system is powered off and restarted, the magnetic response information of the first sampling period after the restart is collected by the magnetic sensing module and the magnetic region combination features are extracted. The magnetic region combination features are matched with the stored historical valid magnetic region combination features to quickly restore the absolute position of the hydraulic cylinder piston.

[0014] The second aspect of this application proposes a magnetic micro-area coding absolute position fault-tolerant identification system for hydraulic cylinders, comprising: The acquisition module is used to synchronously acquire magnetic response information of the magnetic micro-regions on the inner wall of the hydraulic cylinder through multiple magnetic sensors arranged at intervals along the axial direction of the hydraulic cylinder. The extraction module is used to extract features from the magnetic response information and form a set of candidate magnetic region numbers based on the extracted feature information; The identification module is used to verify the candidate magnetic region number set based on the motion state of the hydraulic cylinder piston and historical identification results, and to remove abnormal identification results that do not conform to the motion law. The correction module is used to correct the magnetic zone number by using the coding relationship between magnetic zones or the joint features collected by multiple sensors when the current magnetic zone identification result is abnormal, and outputs the absolute position of the hydraulic cylinder piston according to the corrected magnetic zone number.

[0015] A third aspect of this application provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the method described in the first aspect.

[0016] The technical solutions provided by the embodiments of this application bring at least the following beneficial effects: This application proposes a fault-tolerant method and system for absolute position recognition of hydraulic cylinders using magnetic micro-area coding. The method includes: synchronously acquiring magnetic response information of magnetic micro-areas on the inner wall of the hydraulic cylinder using multiple magnetic sensors spaced apart along the axial direction of the hydraulic cylinder; extracting features from the magnetic response information to form a candidate magnetic area number set based on the extracted features; verifying the candidate magnetic area number set based on the motion state of the hydraulic cylinder piston and historical recognition results, and eliminating abnormal recognition results that do not conform to the motion law; when the current magnetic area recognition result is abnormal, correcting the magnetic area number using the coding relationship between magnetic areas or the joint features acquired by multiple sensors, and outputting the absolute position of the hydraulic cylinder piston based on the corrected magnetic area number. The technical solution of this application solves the unreliability problem of hydraulic cylinder magnetic micro-area coding position recognition caused by abnormal magnetic response or signal fluctuations in complex working conditions in coal mines, and achieves stable and fault-tolerant absolute position output.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart of an absolute position fault-tolerant identification method for a hydraulic cylinder using magnetic micro-area coding, according to an embodiment of this application. Figure 2 This is a structural diagram of a hydraulic cylinder magnetic micro-area coding absolute position fault-tolerant identification system according to an embodiment of this application. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0020] This application proposes a fault-tolerant method and system for absolute position recognition of hydraulic cylinders using magnetic micro-area coding. The method includes: synchronously acquiring magnetic response information of magnetic micro-areas on the inner wall of the hydraulic cylinder using multiple magnetic sensors spaced at intervals along the axial direction of the hydraulic cylinder; extracting features from the magnetic response information to form a candidate magnetic area number set based on the extracted features; verifying the candidate magnetic area number set based on the motion state of the hydraulic cylinder piston and historical recognition results, and eliminating abnormal recognition results that do not conform to the motion law; when the current magnetic area recognition result is abnormal, correcting the magnetic area number using the coding relationship between magnetic areas or the joint features acquired by multiple sensors, and outputting the absolute position of the hydraulic cylinder piston based on the corrected magnetic area number. The technical solution of this application solves the unreliability problem of hydraulic cylinder magnetic micro-area coding position recognition caused by abnormal magnetic response or signal fluctuations in complex working conditions in coal mines, and achieves stable and fault-tolerant absolute position output.

[0021] The following describes a hydraulic cylinder magnetic micro-area coding absolute position fault-tolerant identification method and system according to an embodiment of this application, with reference to the accompanying drawings.

[0022] Example 1 Figure 1 The flowchart below shows a method for fault-tolerant identification of absolute position using magnetic micro-area coding in a hydraulic cylinder according to an embodiment of this application. Figure 1 As shown, the method includes: Step 1: Simultaneously collect magnetic response information of the magnetic micro-regions on the inner wall of the hydraulic cylinder by using multiple magnetic sensors spaced apart along the axial direction of the hydraulic cylinder; In this embodiment of the disclosure, step 1 specifically includes: The original magnetic response signal of the magnetic micro-region at the corresponding position is acquired synchronously by at least two magnetic sensing units arranged at intervals along the axial direction of the hydraulic cylinder. The original magnetic response signal is preprocessed by filtering and amplitude normalization to obtain magnetic response information that can be used for feature extraction.

[0023] It should be noted that the raw information of the magnetic micro-region is acquired through a magnetic sensing module deployed on the piston assembly of the hydraulic cylinder. This magnetic sensing module comprises multiple magnetic sensing units arranged at certain intervals along the axial direction of the hydraulic cylinder, thus forming a distributed coverage of the magnetic coding band in space. During operation, all magnetic sensing units are configured to synchronously acquire the magnetic response information of the magnetic micro-region at their respective corresponding axial positions, thereby obtaining multi-source magnetic signal data with temporal consistency from different spatial points. This technique aims to synchronously acquire the physical characteristics of the magnetic micro-region from multiple independent observation points, providing a redundant and complementary raw data foundation for subsequent identification and fault-tolerant processing, effectively addressing the unreliability of single-point data caused by sensor momentary failures, weakening of local magnetic region characteristics, or external interference. For example, as a specific implementation, at least two magnetic sensing units arranged at axial intervals can be used to synchronously acquire magnetic response information at corresponding positions.

[0024] By employing the aforementioned multi-source synchronous acquisition technique, spatial redundancy can be introduced at the source of data acquisition, significantly improving the comprehensiveness and reliability of the original magnetic response information. This lays a solid data foundation for subsequent steps such as joint feature analysis, cross-validation, and fault-tolerant decision-making, making the entire identification system more robust to local signal anomalies.

[0025] Specifically, the first step involves synchronously acquiring the raw magnetic response signals. The input to this step comes from multiple magnetic micro-regions pre-set along the axial direction on the inner wall of the hydraulic cylinder. The processing involves synchronously acquiring the magnetic field signals of the corresponding magnetic micro-regions at a fixed sampling frequency using at least two magnetic sensing units spaced apart along the axial direction of the hydraulic cylinder, such as two linear Hall sensors with identical sensitivity. These two magnetic sensing units are rigidly mounted on the piston assembly of the hydraulic cylinder, and their axial spacing is designed to ensure that during piston movement, the two sensing units can simultaneously cover different magnetic micro-regions or different parts of the same magnetic region. The synchronization mechanism is achieved through a shared clock signal or a synchronous sampling circuit, ensuring that magnetic response data from different spatial locations are acquired at the same time. The output of this step is two or more sets of time-synchronized raw magnetic response signal sequences.

[0026] Subsequently, the original magnetic response signal is preprocessed by filtering and amplitude normalization. The input source for this step is the original magnetic response signal sequence output from the previous sub-step. The processing actions specifically include: first, filtering is performed using a digital low-pass filter (e.g., a Butterworth low-pass filter) to suppress high-frequency noise components introduced by downhole electromagnetic interference and circuit noise; simultaneously, a moving average filter can be used to further smooth random fluctuations in the signal. Next, amplitude normalization is performed. For each magnetic sensing channel, based on the maximum and minimum amplitude values ​​statistically obtained within a historical time window, the amplitude of the currently filtered signal is linearly transformed, mapping it to a unified preset amplitude range (e.g., [0, 1] or [-1, 1]). This normalization process aims to eliminate the influence of sensitivity drift caused by individual sensor differences, minor installation deviations, or long-term operation on the absolute value of the signal, ensuring the comparability of the amplitude information relied upon for subsequent feature extraction. The final output of this step is preprocessed and regularized magnetic response information, which includes denoised and amplitude-normalized magnetic field features, and can be directly used in subsequent preliminary identification steps of magnetic region features.

[0027] Through the above specific implementation methods, the original magnetic signal was effectively noise suppressed and standardized, which significantly improved the quality and consistency of the magnetic response information, laying a solid foundation for subsequent reliable feature extraction and fault-tolerant identification based on multi-sensor signals.

[0028] Step 2: Extract features from the magnetic response information and form a set of candidate magnetic region numbers based on the extracted feature information; In this embodiment of the disclosure, step 2 specifically includes: Feature extraction is performed on the magnetic response information to obtain the magnetization direction features, magnetic response amplitude range features, and magnetic region spatial features; Based on the magnetization direction characteristics, magnetic response amplitude range characteristics, and magnetic region spatial characteristics of the magnetic region, a set of candidate magnetic region numbers is formed by matching them with a preset magnetic region coding feature library.

[0029] It should be noted that feature extraction is performed on the acquired magnetic response information, and a candidate magnetic region number set is formed based on the extracted feature information. This step aims to extract key features that can characterize the magnetic micro-regions from the original magnetic response signal, and thereby preliminarily determine the range of the magnetic region where the hydraulic cylinder piston may be located. Specifically, by processing and analyzing the magnetic response information, one or more feature dimensions corresponding to the preset magnetic coding rules are extracted. These feature dimensions may include, but are not limited to, magnetization direction features reflecting magnetization polarity or direction, amplitude range features characterizing magnetic signal intensity, and spatial distribution features reflecting the axial arrangement of magnetic regions. Based on the extracted feature information, it is matched and compared with a pre-stored magnetic micro-region coding database or coding rules. This matching process aims to identify one or more possible magnetic micro-region numbers corresponding to the current magnetic response information, thereby forming a candidate magnetic region number set. This set reflects the preliminary identification results obtained based on the analysis of the current instantaneous signal, providing basic data for subsequent verification and correction steps. For example, as a specific implementation, feature extraction may include obtaining magnetic region magnetization direction features, magnetic response amplitude range features, and / or magnetic region spatial features, and forming the candidate magnetic region number set based on the matching results of these features and coding rules.

[0030] This step extracts key coding features from multi-dimensional magnetic response information and forms a candidate set, laying a reliable data foundation for subsequent accurate identification and fault-tolerant processing. It effectively improves the accuracy and robustness of the process from raw signals to preliminary position determination, and avoids the risk of position decoding failure due to misjudgment of a single feature.

[0031] Specifically, the first step is feature extraction. Its input comes from the raw magnetic response information synchronously acquired by multiple magnetic sensors in step S1, specifically the voltage or digital signal sequence output by each sensor. The processing includes parallel extraction of three types of features: magnetization direction features, magnetic response amplitude range features, and magnetic region spatial features. Specifically, for magnetization direction features, the magnetization direction of the magnetic micro-region aligned with the current magnetic sensing unit is determined by analyzing the zero-crossing point and polarity change of the magnetic response signal. For magnetic response amplitude range features, the signal peak value corresponding to each magnetic micro-region is calculated, and this peak value is compared and classified with multiple preset amplitude threshold ranges, for example, divided into three levels: "strong," "medium," and "weak." For magnetic region spatial features, based on the responses of multiple consecutive magnetic regions detected by the same magnetic sensing unit, the axial distance or time interval between the response peaks of adjacent magnetic regions is calculated. This feature reflects the spatial relationship of the non-equidistant arrangement in the magnetic micro-region coding band. The output of this sub-step is a set of feature data generated for each effective magnetic sensing unit. This set of data comprehensively includes the magnetization direction, amplitude range, and spatial feature information.

[0032] Subsequently, the matching and candidate set formation sub-step is executed. Its input sources are multiple sets of magnetic region feature data output from the previous sub-step, and a pre-established and stored magnetic region coding feature library. This feature library stores the standard magnetization direction, standard amplitude range, and standard spatial distance relative to neighboring magnetic regions corresponding to each magnetic micro-region number on the inner wall of the hydraulic cylinder. The processing action is as follows: the currently extracted feature combination (e.g., a feature vector containing a direction of N, an amplitude level of "medium," and a distance of `D1` from the previous magnetic region) is matched one-to-one with all feature templates in the feature library. In one possible implementation, the matching degree is evaluated by calculating the Euclidean distance between feature vectors or by setting a threshold for single-feature comparison. All magnetic region numbers with matching degrees exceeding the preset threshold are filtered out to form a candidate magnetic region number set. The output of this sub-step is a candidate set consisting of one or more potentially corresponding magnetic region numbers, providing input for subsequent verification and correction steps.

[0033] Through the above specific implementation methods, multi-dimensional matching is carried out by comprehensively utilizing magnetization direction, amplitude range and spatial characteristics, which significantly improves the accuracy and robustness of the initial identification of magnetic regions when a single feature is disturbed, and lays a reliable data foundation for subsequent fault-tolerant judgment.

[0034] Step 3: Based on the motion state of the hydraulic cylinder piston and the historical identification results, the candidate magnetic region number set is verified, and abnormal identification results that do not conform to the motion law are eliminated; In this embodiment of the disclosure, step 3 specifically includes: Based on the real-time movement direction and speed of the hydraulic cylinder piston, calculate the allowable range of magnetic zone number changes within the current sampling period; Based on the previous valid magnetic zone number determined by historical identification results, and combined with the allowed range of magnetic zone number variations, the candidate magnetic zone number set is filtered to eliminate abnormal identification results that exceed the range of variations.

[0035] The calculation of the allowable range of magnetic zone number changes within the current sampling period based on the real-time movement direction and speed of the hydraulic cylinder piston includes: Based on the preset maximum movement speed of the hydraulic cylinder piston and the current sampling period, calculate the maximum number of magnetic regions that can be crossed per unit time. Using the maximum number of magnetic zones as a constraint, and in conjunction with the direction of movement, determine the allowable range of magnetic zone number changes starting from the previous valid magnetic zone number.

[0036] It should be noted that after the initial identification of magnetic region features, the resulting set of candidate magnetic region numbers may contain erroneous results due to transient signal anomalies, magnetic response fluctuations, or sensor misjudgments. To improve the reliability of position identification, this step introduces constraints based on physical motion laws to verify the set of candidate magnetic region numbers. The basic principle is that the actual movement of the hydraulic cylinder piston is continuous in time, and its position change is limited by physical parameters such as the direction of movement and speed. Therefore, the currently identified candidate magnetic region numbers can be compared with the expected positions or number ranges calculated based on historical identification results and the current motion state. The verification process is achieved by comparing the candidate magnetic region numbers with the expected numbers or number change ranges calculated based on historical states and motion parameters, thereby identifying and eliminating abnormal identification results that significantly deviate from the continuous motion trajectory and are physically impossible. This constraint determination can be established based on kinematic models, preset physical limits, or empirical thresholds. For example, as a specific implementation method, the range of magnetic zone numbers that the piston may reach in the current sampling period can be calculated based on the direction and speed of the hydraulic cylinder piston and the magnetic zone number confirmed in the previous moment, and candidate numbers that exceed this range can be judged as abnormal and eliminated; as another example, by limiting the number of magnetic zones that can be identified per unit time, discontinuous abnormal results caused by signal jumps can be effectively suppressed.

[0037] By implementing this step, erroneous identification results caused by transient interference or local failures can be effectively filtered out, improving the robustness and reliability of the position identification process. This technique ensures that the output position information conforms to actual physical motion laws, providing a more reliable and practically sound data foundation for subsequent fault-tolerant correction and absolute position output.

[0038] Specifically, the verification process first calculates the allowable range of magnetic zone number changes within the current sampling period based on the real-time movement direction and speed of the hydraulic cylinder piston. The input sources are the real-time movement direction and speed of the piston obtained through hydraulic system sensors (such as differential calculation using displacement sensors or pressure change trend judgment), and the system-preset maximum movement speed of the hydraulic cylinder piston. The sampling period duration of the current data acquisition The processing action is as follows: based on the maximum speed of motion... With sampling period Calculate the maximum number of magnetic regions that the piston is theoretically allowed to traverse within a unit sampling period. The calculation formula is: ,in This represents the minimum axial spacing between adjacent magnetic regions within the magnetic micro-region coding band. Subsequently, the calculated... As a rigid constraint, combined with the real-time motion direction (extending or retracting), the numbering from the previous effective magnetic zone is determined. The starting range of permissible magnetic zone number variations. For example, if the direction of movement is extension, the permissible range of magnetic zone numbers is... If it is a retraction, then it is The output of this process is the range of permissible magnetic zone number variations that meet the motion continuity constraints within the current sampling period.

[0039] Subsequently, the previous valid magnetic zone number was determined based on the historical identification results. Based on the allowable range of magnetic zone numbering calculated above, the candidate magnetic zone numbering set formed in step 2 is... The filtering process is performed. The input sources are the allowed variation range and the previous valid magnetic zone number. and candidate set The processing steps are as follows: Each magnetic region number in the candidate set is compared with the allowed range of variation. All numbers exceeding the range are eliminated, and only those falling within the range are retained as valid candidates. If all candidate numbers are eliminated, the subsequent fault-tolerant correction step 4 is triggered. The output of this sub-step is a set of candidate magnetic region numbers selected after motion law verification. The results in this set are reasonable in terms of physical motion continuity, providing a more reliable basis for subsequent accurate judgment and fault-tolerant correction.

[0040] Through the above specific implementation methods, the kinematic laws of the hydraulic cylinder piston can be effectively utilized to verify the physical rationality of the preliminary identification results, directly suppressing abnormal changes in magnetic zone numbering caused by signal jumps and instantaneous interference, and significantly improving the robustness and reliability of the position identification process under complex working conditions such as downhole vibration and impact.

[0041] Step 4: When the current magnetic zone identification result is abnormal, the magnetic zone number is corrected by using the coding relationship between magnetic zones or the joint features collected by multiple sensors, and the absolute position of the hydraulic cylinder piston is output according to the corrected magnetic zone number.

[0042] In this embodiment of the disclosure, when the current magnetic zone identification result is abnormal, correcting the magnetic zone number using the coding relationship between magnetic zones or the joint features collected by multiple sensors includes: When the current magnetic zone identification result is determined to be inconsistent with the historical state or the magnetic response characteristics are abnormal, the current magnetic zone number is corrected based on the preset coding relationship between adjacent magnetic zones in the magnetic micro-area coding band, the spatial coding characteristics of non-equidistant magnetic zones, or the joint magnetic response characteristics collected by multiple magnetic sensing units.

[0043] It should be noted that during the magnetic zone identification process, when an anomaly is detected in the current identification result, a fault-tolerant correction step is executed to correct or finally confirm the magnetic zone number based on more reliable evidence, and output the absolute position of the hydraulic cylinder piston accordingly. The core of this step is that it does not rely on a single instantaneous identification result that may contain errors, but rather utilizes the inherent, more robust correlation information within the magnetic micro-area coding system for decision-making. Specifically, the correction process can logically verify and correct abnormal or contradictory identification results based on the coding relationships between magnetic zones, such as the relative positions of adjacent magnetic zones, spatial distribution patterns, or preset coding sequence logic. Alternatively or in combination, the correction process can also utilize joint features collected by multiple magnetic sensors. Through the complementarity, verification, or fusion of multi-source information, interference caused by abnormal signals from a single sensor or weakened local magnetic zone features can be overcome, thereby obtaining a more reliable magnetic zone number determination result. After completing the correction and confirming the magnetic zone number, the precise stroke position of the current hydraulic cylinder piston can be calculated and output based on the pre-established mapping relationship between each magnetic zone number and the axial absolute position of the hydraulic cylinder. For example, as one implementation method, the unique spatial characteristics of non-equidistant magnetic zone coding can be utilized to infer and compensate for missing magnetic zone numbers by analyzing the interval patterns of surrounding magnetic zones when local magnetic zone features are missing or weakened; or, periodic marker magnetic zones can be set in the magnetic coding sequence, and when such distinctive magnetic zones are identified, they can be used to quickly verify or anchor the segment where the current position is located, thereby correcting accumulated errors; as another example, after the system is powered off and restarted, the absolute position reference can be quickly restored by identifying and matching specific magnetic zone combination features recorded during the most recent valid operation, without performing a zero-return operation.

[0044] By implementing the above fault-tolerant correction steps, the accuracy of magnetic zone number identification can still be guaranteed even when the magnetic response signal is interfered with or locally abnormal. This significantly improves the reliability and robustness of the final output hydraulic cylinder absolute position information, ensuring the continuity and stability of the hydraulic actuator's position perception in complex downhole conditions.

[0045] Specifically, firstly, the system is triggered when it determines that the current magnetic zone identification result is abnormal. The input sources are the set of candidate magnetic zone numbers output after verification in step S3 and the stored sequence of historically valid magnetic zone numbers. The processing involves comparing the currently identified magnetic zone number with the next possible number predicted based on the historical sequence and piston movement speed. If they do not match, it is determined to be an abnormal state inconsistency. Simultaneously, the characteristics of the magnetic response information are analyzed. If the magnetic response amplitude collected by any magnetic sensing unit is consistently lower than a preset threshold or if the magnetization direction characteristics are contradictory, it is determined to be an abnormal magnetic response characteristic. The output is a clear anomaly determination flag and the current magnetic zone number to be corrected.

[0046] Based on the above anomaly detection, the system executes three logical reasoning and correction paths in parallel. The first path corrects based on the preset coding relationship between adjacent magnetic regions, with the input being the abnormal magnetic region number and its adjacent historical magnetic region numbers. Specifically, the magnetic micro-area coding band predefines rules for increasing or decreasing relationships between adjacent magnetic region numbers. During processing, the system, based on the piston's most recent movement direction (e.g., extension or retraction), starts from historical valid numbers and derives one or more of the most likely numbers based on this coding rule, thereby replacing or constraining the abnormal number. The second path corrects using the spatial coding characteristics of non-equidistant magnetic regions, with the input being the moment of occurrence of the magnetic region reflected by the magnetic response signals collected by multiple magnetic sensing units. The processing action is as follows: the system calculates the actual time interval between each magnetic sensing unit detecting the edge of the magnetic region within the current identification period and calculates the matching degree between this time interval and the preset, non-uniform theoretical physical distance (corresponding to a fixed time interval) between different numbered magnetic regions in the coding band. By finding the magnetic region number interval corresponding to the theoretical distance with the highest matching degree, the correction and confirmation of the abnormal number are achieved. The third path corrects the magnetic response based on the joint features collected by multiple magnetic sensing units. Its input is a subset of candidate magnetic region numbers generated after each magnetic sensing unit independently extracts its features. During processing, the system uses a voting mechanism or a weighted fusion algorithm based on the sensor signal-to-noise ratio to select the magnetic region number with the highest consensus from each subset. If a sensor is determined to have an abnormal output (such as an abnormally low signal amplitude), its weight is reduced or its data is excluded, and the correction is based primarily on the identification results of other normal sensors.

[0047] Finally, the system makes a comprehensive decision based on the outputs of the three correction paths. The input consists of the corrected candidate numbers or number ranges provided by the three paths. The processing steps are as follows: Numbers agreed upon by at least two paths are prioritized; if the results of the three paths differ, the correction result based on spatial coding features is given priority, as it relies on the inherent physical layout of the magnetic field and has stronger resistance to transient interference. The output is the finally confirmed, fault-tolerant corrected magnetic field number, which is then sent to the subsequent process in step 4 for absolute position mapping and output.

[0048] Through the above specific implementation methods, when the magnetic response is abnormal or the identification status is inconsistent, the system can comprehensively utilize the logical rules of the coding band, physical space characteristics and multi-sensor redundant information to perform cross-verification and reasoning from multiple dimensions, which significantly improves the accuracy and reliability of magnetic zone number correction and enhances the fault tolerance capability of the overall position identification system under complex downhole working conditions.

[0049] In this embodiment of the disclosure, the method further includes: Periodically appearing identifying magnetic areas are set in the magnetic micro-area coding band on the inner wall of the hydraulic cylinder; When the magnetic sensing module identifies the marked magnetic area, it verifies and quickly locates the currently identified magnetic area number sequence based on the unique number of the marked magnetic area.

[0050] In this embodiment of the disclosure, the method further includes: After the system is powered off and restarted, the magnetic response information of the first sampling period after the restart is collected by the magnetic sensing module and the magnetic region combination features are extracted. The magnetic region combination features are matched with the stored historical valid magnetic region combination features to quickly restore the absolute position of the hydraulic cylinder piston.

[0051] The following section provides a detailed description of the complete implementation of the absolute position fault-tolerant identification method for magnetic micro-area coding in hydraulic cylinders.

[0052] In this embodiment, the method is applied to a hydraulic support pushing jack in an underground coal mine. The inner wall of the hydraulic cylinder is pre-machined with a magnetic micro-area coding strip along the axial direction. The coding strip consists of a series of magnetic micro-areas magnetized according to specific rules. Each magnetic micro-area has a unique number and is mapped to the absolute stroke position of the hydraulic cylinder piston. A magnetic sensing module is fixedly mounted on the hydraulic cylinder piston assembly and moves with the piston. Specifically, the magnetic sensing module includes two magnetic sensing units, such as Hall sensors, arranged at intervals along the axial direction of the hydraulic cylinder. The center-to-center distance between the two units is designed to be slightly less than the axial length of a single magnetic micro-area to ensure that, in most cases, at least one magnetic sensing unit can effectively cover a magnetic micro-area.

[0053] In the multi-source acquisition step of magnetic response, two magnetic sensing units synchronously acquire the raw magnetic response signal of the magnetic micro-region corresponding to their location at a fixed sampling frequency (e.g., 1 kHz). The raw signal is an analog voltage quantity, reflecting the change in magnetic induction intensity. The raw signal is then preprocessed: first, a low-pass filter (e.g., a Butterworth filter with a cutoff frequency of 100 Hz) is used to filter out high-frequency noise; then, the filtered signal is normalized to map the signal amplitude to the interval [0, 1] to eliminate the influence of individual sensor differences and power supply fluctuations, finally obtaining the magnetic response information that can be used for subsequent processing.

[0054] In the preliminary identification step of magnetic region features, feature extraction is performed on the preprocessed magnetic response information. Specifically, the extracted features include: 1) Magnetization direction features of the magnetic region, which are determined by judging the zero-crossing point and slope sign of the magnetic response signal to determine the N / S pole orientation of the magnetic micro-region; 2) Magnetic response amplitude range features, which divide the normalized signal amplitude into several discrete ranges (e.g., "high", "medium", "low"), with each magnetic micro-region corresponding to a specific amplitude range feature; 3) Spatial features of the magnetic region, in this embodiment, the magnetic micro-regions are arranged with non-equidistant intervals, and the axial distance between adjacent magnetic regions constitutes a unique spatial coding sequence. The system pre-stores a feature database of all magnetic micro-regions, which records the above feature combinations corresponding to each magnetic region number. The feature extraction module matches the feature combinations extracted by the current two magnetic sensing units with the feature database, generating one or more possible magnetic region numbers for each magnetic sensing unit, forming an initial set of candidate magnetic region numbers.

[0055] In the state continuity constraint determination step, the system introduces the physical motion law of the hydraulic cylinder piston as a strong constraint. First, the system estimates the real-time motion direction (extending or retracting) and speed of the piston by calculating the change of magnetic zone number within a continuous sampling period or by using an additional speed sensor. Based on the preset maximum piston speed and current sampling period duration Calculate the maximum number of magnetic regions that the piston is allowed to traverse within one sampling period. The calculation formula is: ,in This represents the minimum center distance between adjacent magnetic regions. The system maintains a historical valid magnetic region number. For each number in the current candidate magnetic field number set... Calculate its relationship with The difference If the piston moves in the extending direction, then only... If it is a retraction, then only... At the same time, it must meet the following requirements. Eliminate all candidate numbers that do not satisfy the above continuity constraints to obtain a candidate set that has been verified by physical laws.

[0056] In the fault-tolerance correction step, the system handles uncertainties or anomalies that may still exist after continuity constraints. The fault-tolerance mechanism is multi-layered. First, it employs multi-sensor joint decision-making: if the identification results of two magnetic sensing units are consistent after continuity constraints, they are directly adopted; if they are inconsistent, the identification result of the sensing unit with better signal quality (e.g., higher signal-to-noise ratio) is prioritized. Second, it utilizes non-equidistant spatial coding features: when a magnetic region is weakened due to contamination and cannot be reliably identified by a single sensor, the system can combine the adjacent valid magnetic region numbers identified by two sensors with a pre-stored non-equidistant interval sequence to logically interpolate the number of the currently weakened magnetic region. Third, it utilizes periodically identified magnetic regions: in the magnetic micro-area coding band, a marker magnetic region with a special amplitude or direction combination is set every fixed number of magnetic regions (e.g., every 20 magnetic regions). When the system identifies a marker magnetic region, it can immediately perform absolute verification and correction on the currently identified magnetic region number sequence to achieve rapid positioning. Fourth, in the event of a system power outage and restart, the system stores the combined features of the magnetic regions covered by the two magnetic sensing units each time it outputs a valid absolute position. After restarting, the magnetic sensing module collects the magnetic response information of the first sampling cycle and extracts the combined features, matching them with the stored historical combined features, thereby quickly restoring the absolute position without the need for a zero-return operation.

[0057] In the absolute position output step, after confirming the currently valid magnetic zone number through the above steps, the system queries the preset magnetic zone number-absolute position mapping table. This mapping table records the absolute stroke (unit: mm) of the hydraulic cylinder piston corresponding to the center point of each magnetic zone number. Finally, the system outputs this absolute stroke position value for use in the electro-hydraulic control system of the hydraulic support.

[0058] The hydraulic cylinder magnetic micro-area coding absolute position fault-tolerant identification method proposed in this embodiment has the following advantages: 1. Significantly improves the reliability of hydraulic cylinder absolute position recognition for complex working conditions in underground coal mines; 2. Possesses fault tolerance and correction capabilities in cases of abnormal magnetic response and local failure; 3. It does not rely on zero-return operations, making it suitable for environments with frequent power outages and restarts downhole; 4. It has strong compatibility with magnetic micro-area encoding and decoding methods and is easy to integrate into systems.

[0059] In summary, the absolute position fault-tolerant identification method for hydraulic cylinder magnetic micro-area coding proposed in this embodiment solves the unreliability problem caused by abnormal magnetic response or signal fluctuation in the position identification of hydraulic cylinder magnetic micro-area coding under complex working conditions in coal mines, and realizes stable and fault-tolerant absolute position output.

[0060] Example 2 Figure 2This is a structural diagram of a hydraulic cylinder magnetic micro-area coding absolute position fault-tolerant identification system according to an embodiment of this application, as shown below. Figure 2 As shown, the system includes: The acquisition module 100 is used to synchronously acquire magnetic response information of the magnetic micro-regions on the inner wall of the hydraulic cylinder through multiple magnetic sensors arranged at intervals along the axial direction of the hydraulic cylinder. Extraction module 200 is used to extract features from the magnetic response information and form a set of candidate magnetic region numbers based on the extracted feature information; The identification module 300 is used to verify the candidate magnetic area number set based on the motion state of the hydraulic cylinder piston and historical identification results, and to remove abnormal identification results that do not conform to the motion law. The correction module 400 is used to correct the magnetic zone number by using the coding relationship of the magnetic zone or the joint features collected by multiple sensors when the current magnetic zone identification result is abnormal, and output the absolute position of the hydraulic cylinder piston according to the corrected magnetic zone number.

[0061] In this embodiment of the disclosure, the acquisition module 100 is further configured to: The original magnetic response signal of the magnetic micro-region at the corresponding position is acquired synchronously by at least two magnetic sensing units arranged at intervals along the axial direction of the hydraulic cylinder. The original magnetic response signal is preprocessed by filtering and amplitude normalization to obtain magnetic response information that can be used for feature extraction.

[0062] In this embodiment of the disclosure, the extraction module 200 is further configured to: Feature extraction is performed on the magnetic response information to obtain the magnetization direction features, magnetic response amplitude range features, and magnetic region spatial features; Based on the magnetization direction characteristics, magnetic response amplitude range characteristics, and magnetic region spatial characteristics of the magnetic region, a set of candidate magnetic region numbers is formed by matching them with a preset magnetic region coding feature library.

[0063] In this embodiment of the disclosure, the identification module 300 is further configured to: Based on the real-time movement direction and speed of the hydraulic cylinder piston, calculate the allowable range of magnetic zone number changes within the current sampling period; Based on the previous valid magnetic zone number determined by historical identification results, and combined with the allowed range of magnetic zone number variations, the candidate magnetic zone number set is filtered to eliminate abnormal identification results that exceed the range of variations.

[0064] Furthermore, the identification module 300 is also used for: Based on the preset maximum movement speed of the hydraulic cylinder piston and the current sampling period, calculate the maximum number of magnetic regions that can be crossed per unit time. Using the maximum number of magnetic zones as a constraint, and in conjunction with the direction of movement, determine the allowable range of magnetic zone number changes starting from the previous valid magnetic zone number.

[0065] In this embodiment of the disclosure, the correction module 400 is further configured to: When the current magnetic zone identification result is determined to be inconsistent with the historical state or the magnetic response characteristics are abnormal, the current magnetic zone number is corrected based on the preset coding relationship between adjacent magnetic zones in the magnetic micro-area coding band, the spatial coding characteristics of non-equidistant magnetic zones, or the joint magnetic response characteristics collected by multiple magnetic sensing units.

[0066] In this embodiment of the disclosure, the correction module 400 is further configured to: Periodically appearing identifying magnetic areas are set in the magnetic micro-area coding band on the inner wall of the hydraulic cylinder; When the magnetic sensing module identifies the marked magnetic area, it verifies and quickly locates the currently identified magnetic area number sequence based on the unique number of the marked magnetic area.

[0067] In this embodiment of the disclosure, the correction module 400 is further configured to: After the system is powered off and restarted, the magnetic response information of the first sampling period after the restart is collected by the magnetic sensing module and the magnetic region combination features are extracted. The magnetic region combination features are matched with the stored historical valid magnetic region combination features to quickly restore the absolute position of the hydraulic cylinder piston.

[0068] In summary, the hydraulic cylinder magnetic micro-area coding absolute position fault-tolerant identification system proposed in this embodiment solves the unreliability problem caused by abnormal magnetic response or signal fluctuation in the position identification of hydraulic cylinder magnetic micro-area coding under complex working conditions in coal mines, and realizes stable and fault-tolerant absolute position output.

[0069] Example 3 To implement the above embodiments, this disclosure also proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in Embodiment 1.

[0070] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0071] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0072] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for absolute position fault-tolerant identification of a hydraulic cylinder using magnetic micro-area coding, characterized in that, The method includes: Multiple magnetic sensors are arranged at intervals along the axial direction of the hydraulic cylinder to synchronously collect magnetic response information of the magnetic micro-regions on the inner wall of the hydraulic cylinder. Feature extraction is performed on the magnetic response information, and a candidate magnetic region number set is formed based on the extracted feature information; Based on the motion state of the hydraulic cylinder piston and the historical identification results, the candidate magnetic region number set is verified, and abnormal identification results that do not conform to the motion law are eliminated. When the current magnetic zone identification result is abnormal, the magnetic zone number is corrected by using the coding relationship between magnetic zones or the joint features collected by multiple sensors, and the absolute position of the hydraulic cylinder piston is output according to the corrected magnetic zone number.

2. The method as described in claim 1, characterized in that, The method of synchronously acquiring magnetic response information of the magnetic micro-regions on the inner wall of the hydraulic cylinder by using multiple magnetic sensors spaced apart along the axial direction of the hydraulic cylinder includes: The original magnetic response signal of the magnetic micro-region at the corresponding position is acquired synchronously by at least two magnetic sensing units arranged at intervals along the axial direction of the hydraulic cylinder. The original magnetic response signal is preprocessed by filtering and amplitude normalization to obtain magnetic response information that can be used for feature extraction.

3. The method as described in claim 1, characterized in that, The step of extracting features from the magnetic response information and forming a candidate magnetic region number set based on the extracted feature information includes: Feature extraction is performed on the magnetic response information to obtain the magnetization direction features, magnetic response amplitude range features, and magnetic region spatial features; Based on the magnetization direction characteristics, magnetic response amplitude range characteristics, and magnetic region spatial characteristics of the magnetic region, a set of candidate magnetic region numbers is formed by matching them with a preset magnetic region coding feature library.

4. The method as described in claim 1, characterized in that, The process of verifying the candidate magnetic region number set based on the motion state and historical identification results of the hydraulic cylinder piston, and eliminating abnormal identification results that do not conform to the motion pattern, includes: Based on the real-time movement direction and speed of the hydraulic cylinder piston, calculate the allowable range of magnetic zone number changes within the current sampling period; Based on the previous valid magnetic zone number determined by historical identification results, and combined with the allowed range of magnetic zone number variations, the candidate magnetic zone number set is filtered to eliminate abnormal identification results that exceed the range of variations.

5. The method as described in claim 1, characterized in that, When the current magnetic zone identification result is abnormal, the method of correcting the magnetic zone number using the coding relationship between magnetic zones or the joint features collected by multiple sensors includes: When the current magnetic zone identification result is determined to be inconsistent with the historical state or the magnetic response characteristics are abnormal, the current magnetic zone number is corrected based on the preset coding relationship between adjacent magnetic zones in the magnetic micro-area coding band, the spatial coding characteristics of non-equidistant magnetic zones, or the joint magnetic response characteristics collected by multiple magnetic sensing units.

6. The method as described in claim 1, characterized in that, The method further includes: Periodically appearing identifying magnetic areas are set in the magnetic micro-area coding band on the inner wall of the hydraulic cylinder; When the magnetic sensing module identifies the marked magnetic area, it verifies and quickly locates the currently identified magnetic area number sequence based on the unique number of the marked magnetic area.

7. The method as described in claim 4, characterized in that, The calculation of the allowable range of magnetic zone number changes within the current sampling period based on the real-time movement direction and speed of the hydraulic cylinder piston includes: Based on the preset maximum movement speed of the hydraulic cylinder piston and the current sampling period, calculate the maximum number of magnetic regions that can be crossed per unit time. Using the maximum number of magnetic zones as a constraint, and in conjunction with the direction of movement, determine the allowable range of magnetic zone number changes starting from the previous valid magnetic zone number.

8. The method as described in claim 1, characterized in that, The method further includes: After the system is powered off and restarted, the magnetic response information of the first sampling period after the restart is collected by the magnetic sensing module and the magnetic region combination features are extracted. The magnetic region combination features are matched with the stored historical valid magnetic region combination features to quickly restore the absolute position of the hydraulic cylinder piston.

9. A hydraulic cylinder magnetic micro-area coding absolute position fault-tolerant identification system based on the hydraulic cylinder magnetic micro-area coding absolute position fault-tolerant identification method according to any one of claims 1-8, characterized in that, The system includes: The acquisition module is used to synchronously acquire magnetic response information of the magnetic micro-regions on the inner wall of the hydraulic cylinder through multiple magnetic sensors arranged at intervals along the axial direction of the hydraulic cylinder. The extraction module is used to extract features from the magnetic response information and form a set of candidate magnetic region numbers based on the extracted feature information; The identification module is used to verify the candidate magnetic region number set based on the motion state of the hydraulic cylinder piston and historical identification results, and to remove abnormal identification results that do not conform to the motion law. The correction module is used to correct the magnetic zone number by using the coding relationship between magnetic zones or the joint features collected by multiple sensors when the current magnetic zone identification result is abnormal, and outputs the absolute position of the hydraulic cylinder piston according to the corrected magnetic zone number.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1-8.

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