An automatic pantograph lowering method and system based on pantograph contact force and hard point monitoring

Abstract

The application provides an automatic pantograph lowering method and system based on pantograph contact force and hard point monitoring, relates to the technical field of pantograph control of rail transit, and solves the technical problems that the existing automatic pantograph lowering system has low reliability, is prone to misresponse or refusal to act, and cannot prevent faults. The method comprises the following steps: obtaining contact force data and acceleration data, and arranging and generating a contact force data matrix F and an acceleration data matrix A; the matrix is compared with preset force reference thresholds and acceleration reference thresholds; if the trigger condition is met, an automatic pantograph lowering determination algorithm is executed; the algorithm comprises time domain analysis of the contact force data to determine whether the preset contact force abnormal determination condition is met, and time domain analysis of the acceleration data to determine whether the preset acceleration abnormal determination condition is met; if the abnormal determination conditions are met simultaneously, an automatic pantograph lowering action is triggered and a signal is sent. The application is used in the automatic pantograph lowering process.

Description

Technical Field

[0001] This application relates to the field of pantograph control technology in rail transit, and in particular to an automatic pantograph lowering method and system based on pantograph contact force and hard point monitoring. Background Technology

[0002] Currently, during actual operation of railway vehicles, the pantograph and the overhead contact line form a unique mechanical friction pair and an electrical coupling friction pair. Due to the special nature of their motion, high-temperature adhesion and impact-induced breakage between the pantograph and the contact line are severe. Once the pantograph head slide plate is damaged, it can exceed the dynamic envelope of the pantograph, leading to a pantograph-contact line severance accident. The automatic pantograph lowering system, as a protective device after a pantograph malfunction, is crucial for preventing pantograph-contact line accidents. Existing automatic pantograph lowering functions are mainly achieved by installing a flexible air duct at the pantograph head. When a pantograph-contact line malfunction causes the slide plate to break or wear to its limit, the air duct leaks, resulting in a drop in control air pressure and triggering the automatic pantograph lowering function. However, this mechanical protection scheme based on flexible air ducts has many drawbacks: First, in the event of foreign object blockage, bending of the air duct, or human error, the automatic pantograph lowering system may fail to respond or respond falsely, resulting in low reliability. Second, adding air ducts and various control valves increases the system's potential failure points and raises the operation and maintenance costs of the pantograph. Finally, this method only triggers protection after a fault occurs (such as a broken sliding plate causing air leakage), failing to prevent faults and making it difficult to avoid destructive impacts on the contact network and pantograph. Therefore, there is an urgent need for an automatic pantograph lowering technology that can improve response accuracy, reduce the failure rate, and provide fault early warning. Summary of the Invention

[0003] This application provides an automatic pantograph lowering method and system based on pantograph contact force and hard point monitoring, which solves the technical problems of low reliability, easy false response or failure to operate, and inability to prevent failure in existing automatic pantograph lowering systems.

[0004] To achieve the above objectives, this application adopts the following technical solution: Firstly, an automatic pantograph lowering method based on pantograph contact force and hard point monitoring is provided, including: Acquire and process contact force and acceleration data to generate contact force data matrix F and acceleration data matrix A; The contact force data matrix F and the acceleration data matrix A are compared with the preset component force reference thresholds. and acceleration reference threshold Compare; If max(F) > Or max(A) > If this occurs, the automatic bow lowering determination algorithm is triggered; the automatic bow lowering determination algorithm includes: Step S1: Perform time-domain analysis on the contact force data to determine whether the preset contact force anomaly judgment conditions are met; the contact force anomaly judgment conditions include a first resultant force condition, a first component force condition, and a second component force condition; Step S2: Perform time-domain analysis on the acceleration data to determine whether the preset acceleration anomaly judgment conditions are met; If the abnormal judgment conditions in steps S1 and S2 are met simultaneously, the automatic bow lowering action is triggered, and an automatic bow lowering signal is sent to the vehicle control center.

[0005] Based on the above technical solution, in the automatic pantograph lowering method based on pantograph contact force and hard point monitoring provided in this application, the traditional mechanical triggering method of the air duct hose is replaced by introducing a dual judgment logic of contact force and acceleration data, which effectively avoids failure to operate or false operation caused by pipe blockage or bending, and improves the reliability of the system.

[0006] In conjunction with the first aspect above, in one possible implementation, the expressions for the contact force data matrix F and the acceleration data matrix A are: , ; in, i It is a positive integer. For contact force sensor h The measured number i Contact force at each data point h =1,2,3,4; Triaxial accelerometer m of d The first axis measured i The acceleration of each data point m =1,2, d = x , y , z .

[0007] In conjunction with the first aspect above, in one possible implementation, the first resultant force condition is: ; And when the maximum resultant force is reached data points j ,satisfy: ; in, The preset resultant force reference threshold, This is a dynamic correction value for the resultant force calculated based on historical monthly contact force resultant force envelope data. The resultant force matrix of the contact forces. The expression is: .

[0008] In conjunction with the first aspect mentioned above, in one possible implementation, the condition for the first component force is: ; The second component force condition is: ; Where F(1,:) and F(2,:) represent the timing data of the two contact force sensors on the front slide, respectively, and F(3,:) and F(4,:) represent the timing data of the two contact force sensors on the rear slide, respectively. This is the dynamic correction value of the component force calculated based on historical monthly contact force component envelope data.

[0009] In conjunction with the first aspect above, in one possible implementation, the acceleration anomaly determination condition is: ; in, To provide a comprehensive representation of the data for each axis in the acceleration data matrix A, For data points j The column vector formed by the acceleration values, This is a dynamic correction value for acceleration calculated based on historical monthly acceleration envelope data.

[0010] In conjunction with the first aspect mentioned above, one possible implementation also includes: analyzing the contact force data, acceleration data, and corresponding track and velocity data collected during historical operation using machine learning or big data analytics methods, and dynamically updating the dynamic correction values. , and .

[0011] In conjunction with the first aspect above, in one possible implementation, the contact force data and acceleration data are synchronously acquired by contact force sensors and triaxial acceleration sensors installed on the front and rear pantograph slides, respectively, at a preset sampling frequency. There are four contact force sensors, two of which are used to monitor the contact force of the front slide and the other two are used to monitor the contact force of the rear slide; there are two triaxial acceleration sensors, which respectively monitor the acceleration of the front and rear slides.

[0012] In conjunction with the first aspect mentioned above, one possible implementation also includes: using a demodulator to perform fault self-diagnosis on the contact force sensor and the triaxial acceleration sensor. The demodulator integrates a contact force monitoring module and a hard point monitoring module, which process the contact force data and acceleration data in real time, respectively, and upload the processing results to the communication host. The communication host has an embedded automatic bow lowering judgment algorithm, which is combined with the track information and vehicle speed for comprehensive judgment.

[0013] In conjunction with the first aspect mentioned above, one possible implementation also includes: after sending an automatic pantograph lowering signal to the vehicle control center, the vehicle control center issues a speed reduction or stopping instruction to subsequent trains on the same line based on the automatic pantograph lowering signal.

[0014] Secondly, an automatic pantograph lowering system based on pantograph contact force and hard point monitoring is provided, including: a data acquisition and processing module, a data comparison module, a pantograph lowering determination module, and a pantograph lowering execution module; The data acquisition and processing module is used to acquire and process contact force data and acceleration data to generate contact force data matrix F and acceleration data matrix A. The data comparison module is used to compare the contact force data matrix F and the acceleration data matrix A with a preset component force reference threshold. and acceleration reference threshold Compare; The bow descent determination module is used to determine if max(F) > Or max(A) > If this occurs, the automatic bow lowering determination algorithm is triggered; the automatic bow lowering determination algorithm includes: Step S1: Perform time-domain analysis on the contact force data to determine whether the preset contact force anomaly judgment conditions are met; the contact force anomaly judgment conditions include a first resultant force condition, a first component force condition, and a second component force condition; Step S2: Perform time-domain analysis on the acceleration data to determine whether the preset acceleration anomaly judgment conditions are met; If the abnormal judgment conditions in steps S1 and S2 are met simultaneously, the bow lowering execution module will trigger an automatic bow lowering action and send an automatic bow lowering signal to the vehicle control center.

[0015] This application provides an automatic pantograph lowering method and system based on pantograph contact force and hard point monitoring. Compared with existing technologies, it has the following significant advantages: First, this application abandons the traditional mechanical triggering method using air duct hoses and innovatively adopts contact force sensors and acceleration sensors to acquire real-time operating data. Data fusion analysis is used to trigger pantograph lowering, completely eliminating the risk of system failure or malfunction caused by air duct hose blockage, bending, or human error, significantly reducing the system failure rate and improving the response reliability of automatic pantograph lowering. Second, this application achieves accurate identification and graded early warning of pantograph-catenary faults by setting multi-level judgment logic including resultant force conditions, component force conditions, and acceleration conditions, combined with dynamic correction values ​​based on historical big data. It can identify abnormal trends and take measures in advance before the pantograph breaks or suffers severe wear, effectively preventing destructive failures and expanding the protection range of automatic pantograph lowering. Finally, this application utilizes machine learning and big data analysis technology to self-correct the judgment threshold, enabling the system to adapt to the operating characteristics of different lines and speed conditions, achieving continuous optimization of the judgment model, and further improving the safety and reliability of train operation.

[0016] It should be understood that the descriptions of technical features, technical solutions, beneficial effects, or similar language in this application do not imply that all features and advantages can be achieved in any single embodiment. Rather, it is understood that the description of a feature or beneficial effect means that a specific technical feature, technical solution, or beneficial effect is included in at least one embodiment. Therefore, the descriptions of technical features, technical solutions, or beneficial effects in this specification do not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions, and beneficial effects described in this embodiment can be combined in any suitable manner. Those skilled in the art will understand that embodiments can be implemented without one or more specific technical features, technical solutions, or beneficial effects of a particular embodiment. In other embodiments, additional technical features and beneficial effects may be identified in specific embodiments that do not embody all embodiments. Attached Figure Description

[0017] Figure 1 A flowchart illustrating an automatic pantograph lowering method based on pantograph contact force and hard point monitoring, provided for an embodiment of this application; Figure 2 This is a schematic diagram of the overall process for automatic bow lowering determination provided in an embodiment of this application; Figure 3 This is a schematic diagram of the overall framework of an automatic bow lowering architecture provided in an embodiment of this application; Figure 4 This is a system architecture diagram of an automatic pantograph lowering system based on pantograph contact force and hard point monitoring, provided for an embodiment of this application. Detailed Implementation

[0018] In the description of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, "at least one" means one or more, and "multiple" means two or more. The terms "first," "second," etc., do not limit the quantity or order of execution, and "first," "second," etc., do not necessarily imply differences.

[0019] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0022] Example 1: like Figure 1 As shown, this embodiment provides an automatic pantograph lowering method based on pantograph contact force and hard point monitoring. This method integrates contact force monitoring data and hard point monitoring data to construct a dual-determination logical closed loop, effectively identifying pantograph-catenary faults and promptly executing protective actions.

[0023] Specifically, the method includes the following steps: Step S101: Obtain contact force data and acceleration data, organize them, and generate contact force data matrix F and acceleration data matrix A.

[0024] In this embodiment, the data acquisition process is performed synchronously at a preset high sampling frequency (e.g., 2500Hz) by sensor components installed on the pantograph slide plate. The contact force data matrix F is used to characterize the change of the interaction force between the pantograph slide plate and the contact wire over time, while the acceleration data matrix A is used to characterize the impact or vibration experienced by the pantograph during operation. By processing the raw acquired data, such as removing noise and normalizing it, a structured matrix form is generated, laying the foundation for subsequent rapid comparison and analysis.

[0025] Step S102: Compare the contact force data matrix F and the acceleration data matrix A with the preset component force reference threshold. and acceleration reference threshold Compare them.

[0026] The force reference threshold mentioned here and acceleration reference threshold These are boundary values ​​set based on the safety envelope under normal pantograph operating conditions. It should be understood that... and The specific values ​​are not fixed and can be adjusted adaptively according to different line grades, vehicle speeds, or pantograph models. For example, in high-speed operating scenarios, the normal fluctuation range of contact force may increase. The setting value can be increased accordingly to avoid accidental triggering.

[0027] Step S103, if max(F) > Or max(A) > If this occurs, the automatic bow lowering judgment algorithm will be triggered.

[0028] This step constitutes the "pre-triggering mechanism" of the method in this application. During the long-term operation of the pantograph, it is in a normal state most of the time. If a complex judgment algorithm is executed for every frame of data, it will consume a lot of computing resources and reduce the system response speed. Therefore, this application designs this precondition, which only activates the subsequent depth judgment algorithm when "suspected abnormal" features exceeding the benchmark threshold appear in the collected data. This design ensures the real-time monitoring while reducing the computational load of the system.

[0029] Step S104: Execute the automatic bow lowering determination algorithm, which specifically includes steps S1 and S2.

[0030] Step S1: Perform time-domain analysis on the contact force data to determine whether the preset contact force anomaly determination conditions are met; the contact force anomaly determination conditions include a first resultant force condition, a first component force condition, and a second component force condition.

[0031] Time-domain analysis refers to the extraction and evaluation of features such as amplitude, duration, and rate of change of contact force data over time. The criteria for determining abnormal contact force are not based on a single dimension, but rather incorporate multiple constraints involving resultant and component forces. The first resultant force condition focuses on whether the vertical force on the pantograph as a whole exceeds the limit, while the first and second component force conditions focus on the force balance of the front and rear contact plates, respectively. This multi-condition setup can accurately distinguish between instantaneous impacts caused by hard points in the contact wire and structural damage to the contact plates themselves (such as breakage or uneven wear), thus avoiding interference from false alarms from a single sensor.

[0032] Step S2: Perform time-domain analysis on the acceleration data to determine whether the preset acceleration anomaly judgment conditions are met.

[0033] Acceleration data is an important supplementary dimension reflecting the contact status of the pantograph and catenary. Significant acceleration abrupt changes occur when the pantograph encounters a hard point in the catenary, a pantograph-catenary fault, or an impact from a foreign object. Time-domain analysis of the acceleration data can capture high-frequency impact signals that might be missed by contact force monitoring. Setting abnormal acceleration judgment conditions provides a second layer of protection for fault identification.

[0034] In step S105, if the abnormal judgment conditions in steps S1 and S2 are met simultaneously, the automatic bow lowering action is triggered, and an automatic bow lowering signal is sent to the vehicle control center.

[0035] This step embodies the core design concept of "multi-dimensional data fusion" in this application. The system only recognizes a genuine pantograph-catenary fault when both abnormal contact force and abnormal acceleration occur simultaneously. This AND logic design significantly improves the accuracy and robustness of fault determination. For example, if only the contact force data is abnormal (such as sensor failure or instantaneous wind load), while the acceleration data is normal, the system will determine it as a non-fault state, thus avoiding false pantograph descent caused by pipe bends or foreign object blockages in traditional flexible hose protection systems; the reverse is also true. Through this dual confirmation mechanism, this application effectively eliminates the risk of false alarms caused by single sensor failure or accidental environmental interference, ensuring the accurate triggering of automatic pantograph descent. Ultimately, the automatic pantograph descent signal not only drives the emergency descent of the vehicle's pantograph, allowing the other pantograph to maintain current collection, but also simultaneously notifies the vehicle control center, providing a basis for subsequent operational scheduling decisions.

[0036] Example 2: This embodiment, based on Embodiment 1, provides a detailed explanation of the specific data structures and calculation processes for the automatic bow lowering judgment algorithm. A schematic diagram of the overall process for automatic bow lowering judgment is shown below. Figure 2As shown. Those skilled in the art should understand that the specific numerical formulas and threshold settings below are merely illustrative examples intended to help understand the core logic of this application, and not to unduly limit the scope of protection of this application.

[0037] First, regarding the structured processing of the data. The expressions for the contact force data matrix F and the acceleration data matrix A are: , .

[0038] Specifically, i It is a positive integer. For contact force sensor h The measured number i Contact force at each data point h =1,2,3,4; Triaxial accelerometer m of d The first axis measured i The acceleration of each data point m =1,2, d = x , y , z This matrix construction method is not a simple data stacking, but rather closely corresponds to the physical structure of the pantograph. Pantographs typically have two sliding plates, front and rear, to ensure current collection stability. The first two columns of data in matrix F, F(1,:) and F(2,:), correspond to the timing data of the two contact force sensors installed on the front sliding plate, respectively, while the last two columns, F(3,:) and F(4,:), correspond to the timing data of the two sensors on the rear sliding plate. Similarly, the acceleration data matrix A covers the data from both the front and rear sliding plates (…). m =1,2) vibration components in the three orthogonal directions of x, y, and z. This comprehensive data matrix design provides a complete data foundation for subsequent multidimensional analysis from "overall stress" to "local impact", ensuring the comprehensiveness of fault feature extraction.

[0039] Secondly, regarding the specific implementation of the contact force anomaly judgment condition, this condition comprises three sub-conditions, constrained from the perspectives of resultant force and component forces, respectively. The first resultant force condition is: ; And when the maximum resultant force is reached data points j ,satisfy: ; in, The preset resultant force reference threshold, This is a dynamic correction value for the resultant force calculated based on historical monthly contact force resultant force envelope data. The resultant force matrix of the contact forces. The expression is: .

[0040] This introduces the concept of a "static baseline threshold". "and "dynamic correction value" A combined judgment mechanism. This is typically set to a large safety boundary value (e.g., 300N), representing the maximum allowable resultant force limit of the pantograph under extreme conditions; while This is a dynamic correction value for the resultant force calculated based on historical monthly contact force resultant force envelope data. The ingenuity of this design lies in: As a "hard threshold" to prevent extreme overload, As a form of "soft compensation," it can adapt to normal contact force fluctuations under different line grades and operating speeds. For example, in high-speed operating sections or sections with many hard points in the overhead contact line, the range of normal contact force fluctuations will increase. The threshold will increase accordingly, thus raising the judgment threshold and preventing false triggering of pantograph lowering due to normal pantograph-catenary vibration; conversely, on smooth tracks, This reduces and improves system sensitivity. This "dynamic and static combined" threshold setting method effectively solves the problem of "either false alarms or missed alarms" in the face of complex and ever-changing line operating conditions, which is a problem of traditional single threshold method.

[0041] Based on satisfying the resultant force condition, it is also necessary to further determine the component force conditions to locate the specific fault location. The first component force condition is: ; The second component force condition is: ; Where F(1,:) and F(2,:) represent the timing data of the two contact force sensors on the front slide, respectively, and F(3,:) and F(4,:) represent the timing data of the two contact force sensors on the rear slide, respectively. This is a dynamic correction value for the component force calculated based on historical monthly contact force envelope data. It should be understood that the pantograph contactor may experience uneven wear or localized breakage during operation. In such cases, the overall resultant force may not change significantly, but the component force corresponding to the damaged contactor will show significant anomalies. By setting a first component force condition (front contactor contactor contactor contactor contactor contactor contactor) and a second component force condition (rear contactor ...

[0042] Secondly, regarding the implementation of the acceleration anomaly detection condition, its expression is: ; in, To provide a comprehensive representation of the data for each axis in the acceleration data matrix A, For data points j The column vector formed by the acceleration values, This is a dynamic correction value for acceleration calculated based on historical monthly acceleration envelope data. The second norm (||·||) was used 2 The magnitude of the acceleration vector is calculated to comprehensively characterize the impact intensity of triaxial acceleration. Compared to single-axis determination, vector magnitude determination avoids missed detections caused by sensor installation angle deviations or randomness in impact direction, and more accurately reflects the degree of hard point impact received by the pantograph. Similarly, a dynamic correction value is introduced. This makes the acceleration threshold environmentally adaptable, enabling it to distinguish between normal track joint impacts and abnormal pantograph-catenary impacts.

[0043] Finally, to achieve adaptive updating of the aforementioned dynamic correction values, the method in this embodiment further includes: analyzing the contact force data, acceleration data, and corresponding track and speed data collected during historical operation using machine learning or big data analysis methods, and dynamically updating the dynamic correction values. , and Specifically, the system accumulates massive amounts of operational logs during long-term operation. These logs not only contain sensor data but also correlate with specific route mileage information and real-time vehicle speed. Through big data analytics, the normal distribution patterns of contact force and acceleration can be identified for different route sections (such as viaducts, tunnels, and curves) and at different speed levels. For example, the system can learn that the normal fluctuation range of contact force increases when passing through a specific curve at high speed in rainy weather, and automatically adjust the operating speed for that condition accordingly. This machine learning-based adaptive mechanism enables the automatic bow reduction judgment algorithm of this application to have the ability to "self-evolve." As the operating mileage increases, the judgment model will become more and more in line with the current line characteristics, thereby building a "defense depth" that dynamically adjusts with changes in the environment, ensuring high reliability and high accuracy of the system throughout its entire life cycle.

[0044] Example 3: This embodiment focuses on describing the hardware architecture layout and data acquisition and processing chain for implementing the above-described automatic bow lowering method. This hardware architecture serves as the physical carrier of the method embodiment; through reasonable sensor placement and modular design, it ensures comprehensive data acquisition and real-time processing.

[0045] Specifically, contact force and acceleration data are synchronously acquired at a preset sampling frequency by contact force sensors and triaxial accelerometers installed on the front and rear pantograph slides, respectively. There are four contact force sensors: two for monitoring the contact force on the front slide and two for monitoring the contact force on the rear slide. There are two triaxial accelerometers, one for monitoring the acceleration of the front slide and the other for the acceleration of the rear slide. The specific installation method is as follows: Figure 3 As shown, the pantograph is equipped with contact force sensors 1, 2, 3, and 4, and triaxial accelerometers 1 and 2. Contact force sensors 1 and 2 monitor the contact force on the front slide plate, while contact force sensors 3 and 4 monitor the contact force on the rear slide plate. Triaxial accelerometer 1 monitors the acceleration on the front slide plate, and triaxial accelerometer 2 monitors the acceleration on the rear slide plate. This arrangement is not arbitrary but tightly coupled with the judgment algorithm in Embodiment 2. Two contact force sensors are configured on each of the front and rear slide plates, forming a full-bridge or half-bridge measurement structure. This not only accurately measures the total resultant contact force but also precisely identifies the "first component force condition" or "second component force condition" described in Embodiment 2 by comparing the force differences between the front and rear slide plates, thereby determining whether the slide plate experiences uneven wear or localized breakage. Such precise fault location cannot be achieved with only a single total force sensor. Similarly, the triaxial accelerometer enables the system to capture vibration components in the x, y, and z directions, providing a complete physical basis for constructing the acceleration data matrix A and calculating the vector modulus, thus avoiding missed detections that might occur with monitoring in only one direction. In practical applications, the preset sampling frequency can be set to 2500Hz, meaning 2500 data points are collected per second. This high-frequency sampling can capture transient impact signals in pantograph-catenary contact, providing rich time-series data for time-domain analysis.

[0046] After data acquisition, the method in this embodiment further includes: performing fault self-diagnosis on the contact force sensor and triaxial accelerometer using a demodulator. The demodulator integrates a contact force monitoring module and a hard point monitoring module, which process the contact force data and acceleration data in real time, respectively, and upload the processing results to the communication host. The communication host has an embedded automatic pantograph lowering judgment algorithm, which is combined with track information and vehicle speed for comprehensive judgment. Figure 3As shown, the sensor data is transmitted to the demodulator, which includes a contact force monitoring module and a hard point monitoring module. The contact force monitoring module analyzes and processes the data measured by the contact force sensor, while the hard point monitoring module analyzes and processes the data measured by the acceleration sensor. The demodulator then aggregates the analyzed and processed data and uploads it to the communication host. The communication host incorporates an automatic pantograph lowering method. By performing time-domain and frequency analysis and comparison of the collected contact force and acceleration data, and fusing the line and speed data, the system determines whether to automatically lower the pantograph.

[0047] Specifically, the demodulator, as the core unit of data preprocessing, has an internal "contact force monitoring module" that is specifically responsible for processing the grating signals or electrical signals from the four contact force sensors, converting them into digital contact force values; while the "hard point monitoring module" focuses on processing the vibration signals from the acceleration sensor. This modular division of labor design enables parallel data processing, greatly improving the system's response speed. Regarding the specific implementation of "fault self-diagnosis," the demodulator can employ a signal loop detection mechanism. For example, at the initial stage of system startup or during operational breaks, the demodulator sends detection pulses to the sensors. If the amplitude, frequency, or phase of the signal returned by the sensors is within a preset normal range, the sensors and connecting lines are considered normal; if the feedback signal is lost, attenuated excessively, or exhibits short-circuit characteristics, it is determined that the sensor is faulty or the line is abnormal. In this case, the demodulator can immediately report a fault code to the communication host, locking the automatic bow-drop judgment algorithm to prevent false triggering due to sensor failure. This pre-emptive self-checking mechanism constructs the system's first line of defense.

[0048] Furthermore, the communication host, acting as the decision-making center, receives pre-processed data uploaded by the demodulator and combines it with real-time train operation information (such as kilometer markers, gradients, and curve radii) and train speed information for comprehensive analysis. It should be understood that the high-frequency sampling capability of the hardware architecture (e.g., 2500Hz) and the real-time processing capability of the demodulator complement each other. The demodulator uploads massive amounts of real-time data to the communication host via a high-speed data bus (such as CAN bus or Ethernet), and the communication host utilizes its powerful computing capabilities to run complex automatic pantograph lowering judgment algorithms. This architecture of "edge computing (demodulator pre-processing) + cloud decision-making (communication host comprehensive judgment)" effectively balances the contradiction between data transmission bandwidth and real-time decision-making, ensuring a millisecond-level response from the occurrence of an anomaly to the issuance of the pantograph lowering command, fully embodying the design concept of "structural support function."

[0049] Example 4: This embodiment focuses on describing the safety linkage application scenario of this application in actual rail transit operation. Based on the above embodiments 1 to 3, this application not only realizes automatic protection of individual vehicles, but also constructs a full-line safety protection system through interaction with the vehicle control center.

[0050] Specifically, the method also includes: after sending an automatic pantograph lowering signal to the vehicle control center, the vehicle control center issues speed reduction or stopping instructions to subsequent trains on the same line based on the automatic pantograph lowering signal. This process embodies the safety extension of the technical solution of this application from "point" to "line". It should be understood that if the pantograph encounters a serious pantograph-catenary fault during operation (such as a broken catenary, severe hard point impact, or broken contact plate), it often means that the current catenary condition is no longer suitable for high-speed current collection. If only this train performs automatic pantograph lowering, and subsequent trains continue to approach the fault point at high speed, a secondary impact is very likely to occur, leading to a more serious pantograph-catenary accident. Therefore, the linkage mechanism designed in this application has extremely high practical application value.

[0051] The following is a detailed explanation using a specific closed-loop fault handling scenario as an example: Scenario: Train A is traveling at high speed in a certain section when the pantograph's sliding plate is struck by a foreign object on the overhead contact line.

[0052] Step S401, Anomaly Detection and Data Acquisition. The contact force sensor and triaxial accelerometer mounted on the pantograph's front slide plate monitor the severe impact signal in real time. The contact force data instantaneously exceeds the component force reference threshold. Meanwhile, the acceleration data exceeded the acceleration reference threshold. The contact force monitoring module and hard point monitoring module in the demodulator immediately detected the anomaly and uploaded the processed contact force data matrix F and acceleration data matrix A to the communication host.

[0053] Step S402, Algorithm Judgment and Decision. The automatic pantograph lowering judgment algorithm embedded in the communication host is triggered. The algorithm first performs time-domain analysis on the contact force data and determines that it meets the first component force condition (abnormal force on the front sliding plate); at the same time, it performs time-domain analysis on the acceleration data and determines that it meets the acceleration anomaly judgment condition. Since both conditions are met simultaneously, the system confirms that a real pantograph-catenary fault has occurred, rather than accidental interference.

[0054] Step S403: Local protection is activated. The communication host immediately outputs a control command to drive the pantograph pneumatic system to perform a rapid pantograph lowering action, preventing further damage to the pantograph or damage to the contact wire. Simultaneously, the train switches to the standby pantograph for current collection or enters coasting mode.

[0055] Step S404, Remote Signal Transmission. Simultaneously with the pantograph lowering action, the communication host sends an automatic pantograph lowering signal to the vehicle control center (OCC) via a vehicle-to-ground wireless communication system (such as GSM-R or 5G-R). This signal not only includes the pantograph lowering event itself, but preferably also includes diagnostic data such as the precise kilometer marker at the time of the fault, train speed, peak contact force, and peak acceleration, providing data support for the control center's scheduling decisions.

[0056] Step S405, line safety linkage. After receiving the signal, the vehicle control center analyzes the fault location information. Considering that foreign objects or damage to the overhead contact line may persist, the control center immediately issues dispatch instructions to subsequent trains B and C on the same line and in the same direction. The instructions may include speed limit instructions (such as a speed limit of 45 km / h when passing through the fault area) or emergency stop instructions, depending on the severity of the fault. Upon receiving the instructions, subsequent trains take braking or speed reduction measures in advance, thereby avoiding high-speed entry into the fault section under unknown risks.

[0057] As can be seen from the above scenarios, this application forms a complete closed loop for fault handling by combining "automatic pantograph lowering of a single train" with "centralized coordinated dispatching." This design not only protects the operational safety of the train itself, but more importantly, through information sharing, it prevents secondary accidents that may occur to subsequent trains, greatly improving the overall safety level of rail transit operations.

[0058] Based on the above technical solutions, this application provides an automatic pantograph lowering method based on pantograph contact force and hard point monitoring, which has the following significant advantages compared with existing technologies: First, this application abandons the traditional mechanical triggering method of the air duct hose and innovatively uses contact force sensors and acceleration sensors to obtain real-time operating data. Data fusion analysis is used to trigger pantograph lowering, completely eliminating the risk of system failure or malfunction caused by air duct hose blockage, bending, or human error, significantly reducing the system failure rate and improving the response reliability of automatic pantograph lowering. Second, this application achieves accurate identification and graded early warning of pantograph-catenary faults by setting multi-level judgment logic including resultant force conditions, component force conditions, and acceleration conditions, combined with dynamic correction values ​​based on historical big data. It can identify abnormal trends and take measures in advance before the pantograph breaks or suffers severe wear, thereby effectively preventing destructive failures and expanding the protection range of automatic pantograph lowering. Finally, this application utilizes machine learning and big data analysis technology to self-correct the judgment threshold, enabling the system to adapt to the operating characteristics of different lines and speed conditions, achieving continuous optimization of the judgment model, and further improving the safety and reliability of train operation.

[0059] Example 5: like Figure 4 As shown, this embodiment provides an automatic pantograph lowering system 100 based on pantograph contact force and hard point monitoring. This system presents a functional architecture of the automatic pantograph lowering methods described in Embodiments 1 to 4 above. Through modular division, the functional boundaries and collaborative relationships of each component are clearly defined, providing clear guidance for hardware implementation. Specifically, the system includes: a data acquisition and processing module 10, a data comparison module 20, a pantograph lowering determination module 30, and a pantograph lowering execution module 40.

[0060] The data acquisition and processing module 10 is used to acquire and process contact force and acceleration data to generate a contact force data matrix F and an acceleration data matrix A. At the hardware level, this module's function is mainly achieved by the contact force sensors and triaxial accelerometers installed on the front and rear pantograph slides, as well as the signal processing circuitry inside the demodulator. Specifically, the sensors are responsible for sensing analog signals from the physical world, the demodulator is responsible for converting the analog signals into digital signals, and performing preprocessing operations such as filtering and amplification, ultimately organizing them into the standard matrix format defined in the aforementioned embodiments. It should be understood that the data acquisition and processing module is not limited to a simple collection of physical sensors, but also includes logical functions for signal conditioning and data cleaning to ensure that the quality of the output data meets the requirements of subsequent algorithms.

[0061] The data comparison module 20 is used to compare the contact force data matrix F and the acceleration data matrix A with a preset component force reference threshold. and acceleration reference threshold The comparison is performed. This module's function is typically implemented by the demodulator's internal logic units (such as FPGA or DSP chips) or the preprocessing thread of the communication host. Its core function is to execute the "pre-triggered mechanism" described earlier. By comparing the current data extreme values ​​with the benchmark threshold in real time, this module can quickly filter out suspected abnormal data segments, thereby triggering the subsequent in-depth judgment process. This design separates the high-frequency data comparison task from the complex judgment algorithm, effectively reducing the computational load of the main control unit and improving the system's real-time response capability.

[0062] The bow descent determination module 30 is used to determine if max(F) > Or max(A) > If the automatic bow lowering judgment algorithm is triggered, the automatic bow lowering judgment algorithm includes: Step S1: Perform time-domain analysis on the contact force data to determine whether the preset contact force anomaly judgment conditions are met; the contact force anomaly judgment conditions include a first resultant force condition, a first component force condition, and a second component force condition; Step S2: Perform time-domain analysis on the acceleration data to determine whether the preset acceleration anomaly judgment conditions are met. This module is the "brain" of the entire system, and its hardware carrier is mainly a communication host (such as an embedded industrial computer or a dedicated controller). The communication host internally stores the judgment algorithm program that executes the judgment algorithm described in detail in the aforementioned embodiment 2. When the trigger signal sent by the data comparison module is received, the bow lowering judgment module retrieves the stored historical data and dynamic correction values ​​( , and This module performs complex time-domain analysis and logical operations. Its design fully embodies the core concept of "multi-dimensional data fusion" in this application, achieving accurate identification and hierarchical judgment of pantograph-catenary faults through hardware and software collaboration.

[0063] If the abnormal judgment conditions in steps S1 and S2 are simultaneously met, the pantograph lowering execution module 40 triggers an automatic pantograph lowering action and sends an automatic pantograph lowering signal to the vehicle control center. The function of this module is jointly implemented by the output interface circuit of the communication host, the pantograph pneumatic control valve, and the vehicle-to-ground communication equipment. Once the pantograph lowering judgment module outputs a fault confirmation command, the pantograph lowering execution module immediately drives the pneumatic solenoid valve to actuate, achieving rapid lowering of the pantograph; simultaneously, it packages and sends the fault information to the vehicle control center via the wireless communication unit. It should be understood that the pantograph lowering execution module not only performs mechanical actions but also undertakes the function of information interaction, and is a key execution mechanism for realizing single-vehicle protection and line linkage safety protection.

[0064] Through the collaborative work of the four modules described above, this embodiment constructs a complete automatic pantograph lowering system. This system decomposes complex monitoring and control logic into independent yet interconnected functional modules, facilitating not only hardware selection and integration but also subsequent system maintenance and functional upgrades. For example, if the judgment algorithm needs to be updated, only the software program of the pantograph lowering judgment module needs to be modified, without changing the data acquisition hardware, demonstrating excellent modular decoupling characteristics. This architectural design strongly supports the implementation of the aforementioned method embodiment, ensuring the reliability, real-time performance, and accuracy of the automatic pantograph lowering function.

[0065] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0066] In implementation, each step of the method provided in this embodiment can be completed by integrated logic circuits in the processor or by instructions in software form. The steps of the method disclosed in the embodiments of this application can be directly manifested as being executed by a hardware processor, or being executed by a combination of hardware and software modules in the processor.

[0067] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software programs, implementation can be, in whole or in part, in the form of a computer program product. This computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device containing one or more servers, data centers, etc., that can be integrated with the medium. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks (SSDs)).

[0068] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, disclosure, and appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0069] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. An automatic pantograph lowering method based on pantograph contact force and hard point monitoring, characterized in that, include: Acquire and process contact force and acceleration data to generate contact force data matrix F and acceleration data matrix A; The contact force data matrix F and the acceleration data matrix A are compared with the preset component force reference thresholds. and acceleration reference threshold Compare; If max(F) > Or max(A) > If so, the automatic bow lowering judgment algorithm will be triggered; The automatic bow lowering determination algorithm includes: Step S1: Perform time-domain analysis on the contact force data to determine whether the preset contact force anomaly judgment conditions are met; The abnormal contact force determination conditions include a first resultant force condition, a first component force condition, and a second component force condition; Step S2: Perform time-domain analysis on the acceleration data to determine whether the preset acceleration anomaly judgment conditions are met; If the abnormal judgment conditions in steps S1 and S2 are met simultaneously, the automatic bow lowering action is triggered, and an automatic bow lowering signal is sent to the vehicle control center.

2. The automatic pantograph lowering method based on pantograph contact force and hard point monitoring according to claim 1, characterized in that, The expressions for the contact force data matrix F and the acceleration data matrix A are: ， ； in, i It is a positive integer. For contact force sensor h The measured number i Contact force at each data point h =1,2,3,4; Triaxial accelerometer m of d The first axis measured i The acceleration of each data point m =1,2, d = x , y , z .

3. The automatic pantograph lowering method based on pantograph contact force and hard point monitoring according to claim 2, characterized in that, The first resultant force condition is: ； And when the maximum resultant force is reached data points j ,satisfy: ； in, The preset resultant force reference threshold, This is a dynamic correction value for the resultant force calculated based on historical monthly contact force resultant force envelope data. The resultant force matrix of the contact forces. The expression is: 。 4. The automatic pantograph lowering method based on pantograph contact force and hard point monitoring according to claim 3, characterized in that, The first component force condition is: ； The second component force condition is: ； Where F(1,:) and F(2,:) represent the timing data of the two contact force sensors on the front slide, respectively, and F(3,:) and F(4,:) represent the timing data of the two contact force sensors on the rear slide, respectively. This is the dynamic correction value of the component force calculated based on historical monthly contact force component envelope data.

5. The automatic pantograph lowering method based on pantograph contact force and hard point monitoring according to claim 4, characterized in that, The acceleration anomaly detection criteria are as follows: ； in, To provide a comprehensive representation of the data for each axis in the acceleration data matrix A, For data points j The column vector formed by the acceleration values, This is a dynamic correction value for acceleration calculated based on historical monthly acceleration envelope data.

6. The automatic pantograph lowering method based on pantograph contact force and hard point monitoring according to claim 5, characterized in that, Also includes: By using machine learning or big data analytics, contact force data, acceleration data, and corresponding track and speed data collected during historical operation are analyzed, and dynamic correction values ​​are dynamically updated. , and .

7. The automatic pantograph lowering method based on pantograph contact force and hard point monitoring according to claim 1, characterized in that, The contact force data and acceleration data are synchronously collected at a preset sampling frequency by contact force sensors and triaxial acceleration sensors installed on the front and rear pantographs, respectively. There are four contact force sensors, two of which are used to monitor the contact force of the front pantograph and the other two are used to monitor the contact force of the rear pantograph; there are two triaxial acceleration sensors, which are used to monitor the acceleration of the front and rear pantographs, respectively.

8. The automatic pantograph lowering method based on pantograph contact force and hard point monitoring according to claim 7, characterized in that, Also includes: The demodulator performs fault diagnosis on the contact force sensor and the triaxial acceleration sensor. The demodulator integrates a contact force monitoring module and a hard point monitoring module, which process the contact force data and acceleration data in real time and upload the processing results to the communication host. The communication host has an embedded automatic pantograph lowering judgment algorithm and makes a comprehensive judgment based on the track information and vehicle speed.

9. The automatic pantograph lowering method based on pantograph contact force and hard point monitoring according to claim 1, characterized in that, Also includes: After sending an automatic pantograph lowering signal to the vehicle control center, the vehicle control center issues speed reduction or stopping instructions to subsequent trains on the same line based on the automatic pantograph lowering signal.

10. An automatic pantograph lowering system based on pantograph contact force and hard point monitoring, applied to the automatic pantograph lowering method based on pantograph contact force and hard point monitoring as described in any one of claims 1-9, characterized in that, include: The module includes a data acquisition and processing module, a data comparison module, a bow lowering determination module, and a bow lowering execution module. The data acquisition and processing module is used to acquire and process contact force data and acceleration data to generate contact force data matrix F and acceleration data matrix A. The data comparison module is used to compare the contact force data matrix F and the acceleration data matrix A with a preset component force reference threshold. and acceleration reference threshold Compare; The bow descent determination module is used to determine if max(F) > Or max(A) > If so, the automatic bow lowering judgment algorithm will be triggered; The automatic bow lowering determination algorithm includes: Step S1: Perform time-domain analysis on the contact force data to determine whether the preset contact force anomaly judgment conditions are met; The abnormal contact force determination conditions include a first resultant force condition, a first component force condition, and a second component force condition; Step S2: Perform time-domain analysis on the acceleration data to determine whether the preset acceleration anomaly judgment conditions are met; If the abnormal judgment conditions in steps S1 and S2 are met simultaneously, the bow lowering execution module will trigger an automatic bow lowering action and send an automatic bow lowering signal to the vehicle control center.

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