Pantograph height dynamic adjusting method fusing multi-sensor detection

Abstract

The invention discloses a pantograph height dynamic adjusting method fusing multi-sensor detection, and belongs to the technical field of rail transit vehicle control. The method comprises the following steps: synchronously acquiring pantograph distance, train body inertia measurement, train real-time speed and position and pre-stored route map data; the method comprises the steps of performing motion compensation on an original distance by using inertial data to obtain a net bow net height; predicting the height of a front contact line and the movement trend of a vehicle body according to the vehicle speed and a map, and generating a feedforward control instruction; meanwhile, generating a feedback instruction based on the deviation between the net height and the target value; and finally, dynamically evaluating line information certainty and data credibility, fusing feedforward and feedback instructions according to the weight, and outputting a comprehensive control signal to drive an execution mechanism. According to the method, the conversion from lag feedback to prediction feedforward is realized, the initiative and stability of adjustment are improved, and the pantograph-catenary current collection quality can be optimized.

Description

Technical Field

[0001] This invention relates to the field of rail transit vehicle control technology, specifically to an active control method for pantographs used in electric locomotives or EMUs, and more particularly to a dynamic pantograph height adjustment method based on multi-sensor information fusion and state prediction. Background Technology

[0002] In electrified railways, the pantograph is responsible for obtaining electrical energy from the overhead contact line. Maintaining stable and good contact between the pantograph and the contact wire is crucial for ensuring the safe and reliable operation of trains. The working height of the pantograph needs to be dynamically adjusted according to track conditions (such as contact wire slope and anchor joint) and train operating conditions (such as train speed and car body vibration) to maintain constant contact pressure.

[0003] Currently, the mainstream pantograph control method is mainly based on the feedback control principle. This involves using height or pressure sensors mounted on the pantograph to detect the pantograph-catenary system status in real time, comparing it with set values, and then driving the actuator to make adjustments. However, this pure feedback control method has inherent drawbacks: First, the adjustment behavior lags behind the occurrence of disturbances; the system only begins to respond after a height deviation occurs, resulting in poor dynamic tracking performance, especially prone to overshoot and oscillation when passing through areas with sudden changes in track gradient. Second, the sensor measurements mix the vehicle's own motion (such as nodding and bobbing) with the actual relative motion between the pantograph and the catenary; if this is not distinguished, it can introduce incorrect adjustments.

[0004] Existing technologies also incorporate inertial sensors (such as accelerometers and gyroscopes) to measure vehicle attitude, compensating for the impact of vehicle motion on the measured values. For example, algorithms can be used to subtract the vehicle motion component from the total height signal to obtain a more accurate net height. These methods improve static or steady-state accuracy to some extent, but they do not fundamentally solve the problem of adjustment lag. Their control logic is essentially still "reactive," unable to make preemptive, smooth adjustments to known, regular changes in contact wire height along the track ahead (such as the design gradient of long bridge and tunnel sections). Therefore, when dealing with complex and changing track conditions, existing methods still have significant shortcomings in terms of the timeliness, smoothness, and predictability of adjustments. Summary of the Invention

[0005] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide a pantograph height dynamic adjustment method that integrates multi-sensor detection to solve the problems mentioned in the background art. Specifically, the existing pantograph height adjustment methods suffer from untimely adjustment due to reliance on hysteresis feedback, are greatly affected by the combined interference of line and vehicle movement, and have insufficient pantograph-catenary tracking stability.

[0006] To address the aforementioned technical problems, this invention provides a method for dynamically adjusting pantograph height using multi-sensor detection. The method's technical concept lies in: by fusing direct ranging, vehicle inertial measurement, train status, and pre-stored track map information, first compensating for vehicle motion to determine the true pantograph-catenary distance, then predicting future track and vehicle status to generate feedforward commands, and simultaneously generating feedback commands based on real-time deviations. Finally, the feedforward and feedback commands are dynamically fused based on information reliability to achieve precise, smooth, and adaptive adjustment.

[0007] Based on this concept, the technical solution of the present invention is summarized as follows: A method for dynamic adjustment of pantograph height based on multi-sensor detection includes: Acquire multi-source data, including the first distance measurement value at the pantograph sliding plate, motion parameters collected by the vehicle body inertial measurement unit, real-time train speed and position information, and contact wire geometric parameters retrieved from a pre-stored digital track map based on the position information; Based on the motion parameters, motion compensation is performed on the first distance measurement value to obtain the net pantograph relative height value; Based on the running speed, position information and contact line geometric parameters, a prediction calculation is performed to generate prediction information including the contact line height change and vehicle motion state in the future time period. Generate feedforward control commands based on the predicted information; Feedback control commands are generated based on the deviation between the relative height of the pantograph net and the height of a dynamic target. Based on the real-time evaluation of the predicted information and the relative height of the net pantograph net, weighting coefficients are determined to weight and fuse the feedforward control command and the feedback control command to generate a comprehensive control command. The pantograph height adjustment actuator is driven according to the integrated control command.

[0008] Based on the basic scheme described above, the present invention may further include the following limiting or optimizing features: Furthermore, the motion compensation is achieved by calculating the vehicle body attitude angle and estimating the vertical displacement of the vehicle body's center of gravity, and then calculating the vertical motion compensation amount in conjunction with the pantograph's fixed installation position.

[0009] Furthermore, the prediction calculation is completed by determining the predicted mileage range, obtaining the contact line design height and slope data within the range, and simulating the predicted motion state of the vehicle body based on the vehicle dynamics model.

[0010] Furthermore, the dynamic target height value is obtained by querying the correspondence table between speed and target height and combining it with interpolation calculation.

[0011] Furthermore, the weighting coefficients are determined by separately evaluating the certainty of the predicted route and the reliability of the net height value, and then combining the results of the two evaluations.

[0012] Furthermore, the method also includes sensor data validity monitoring and system reconstruction steps. When the distance data is determined to be abnormal, a degradation control mode is activated, and when generating feedback instructions, the system switches to a backup data source and increases the weight of the feedforward instructions.

[0013] The technical solution provided by this invention, through the combination and synergistic effect of the above-mentioned specific technical features, produces the following effects: 1. Improved initiative and smoothness of height adjustment. By incorporating predictive calculations based on high-precision digital route maps and vehicle models, the system can anticipate changes in the gradient of the route ahead and predict its movement trend by combining this with the vehicle's dynamic response. The resulting feedforward control commands drive the pantograph to move ahead of time within the actuator's dynamic capability range, overcoming the inherent lag of traditional pure feedback control. This allows the pantograph slider to smoothly track changes in contact line height, reducing overshoot and repeated adjustments, and improving the smoothness of pantograph-catenary contact.

[0014] 2. Improved accuracy of pantograph-catenary distance measurement and control. By fusing angular velocity and linear acceleration data collected in real time from the vehicle's inertial measurement unit, the vehicle's attitude (pitch and roll) and vertical displacement of the center of gravity can be accurately calculated. Using this information to perform real-time motion compensation on the original distance measurement value at the pantograph, coupling interference caused by the rigid body motion of the vehicle can be eliminated, obtaining a net height value that purely reflects the relative position of the pantograph and the contact wire. This step provides a true and accurate controlled variable for subsequent feedback control, fundamentally improving the accuracy of closed-loop control.

[0015] 3. Enhanced system adaptability and robustness in handling complex operating conditions and partial faults. The system does not use a fixed feedforward / feedback ratio. Instead, it employs a dynamic evaluation module to analyze in real-time the completeness of the line data upon which the prediction is based, the number of key points, and cross-validate the consistency of multi-source information such as net height, inertial estimation height, and predicted height. Based on this evaluation result, the fusion weight coefficients are dynamically adjusted, allowing the system to prioritize feedforward for optimal performance when the line data is clear and the prediction is reliable. When encountering curves, switches, or when data reliability decreases, the feedback mechanism automatically enhances to ensure robustness. This adaptive mechanism ensures stable and reliable system operation in variable environments.

[0016] 4. Overall, it improves the quality of pantograph-catenary current collection and helps extend equipment life. The combined effects of improved stability, accuracy, and robustness are directly reflected in the pantograph-catenary interaction. Smooth tracking means a significant reduction in contact force fluctuations, which lowers the probability and intensity of derailment (arc). Stable electrical contact not only improves power transmission efficiency but also prevents electrical erosion of the pantograph slide and contact wire by arcing; simultaneously, smooth mechanical movement reduces impact and wear. Therefore, this invention optimizes current collection performance while positively contributing to extending the service life of the pantograph and contact wire. Attached Figure Description

[0017] Figure 1 This is a flowchart of the pantograph height dynamic adjustment system of the present invention.

[0018] Figure 2 This is a detailed flowchart of motion compensation and net height calculation according to the present invention.

[0019] Figure 3 A branch flowchart is generated for the feedforward control instructions of this invention. Detailed Implementation

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

[0021] Example 1 As attached Figures 1 to 3 This paper presents a method for dynamically adjusting the pantograph height by integrating multi-sensor detection. This method synchronously processes real-time data from a distance sensor at the pantograph slide, the vehicle's inertial measurement unit, and the train operation control system, and combines this data with pre-stored digital track map information to dynamically adjust the pantograph height. The adjustment process includes feedforward control based on a predictive model, feedback control based on real-time deviation, and an adaptive fusion of both.

[0022] A basic implementation process includes the following steps performed in sequence: Step 100: Synchronous acquisition of multi-source data.

[0023] The control unit performs the following operations synchronously within one processing cycle: 1. Acquire the output signal of the first distance sensor mounted on the pantograph sliding plate bracket to obtain the first distance measurement value characterizing the vertical distance from the sensor detection surface to the bottom surface of the contact wire. The first distance sensor may be, but is not limited to, a laser rangefinder, a microwave radar, or an ultrasonic sensor.

[0024] 2. Collect the signal output from the inertial measurement unit installed on the vehicle frame. This signal contains the raw data of the three-axis angular velocity and three-axis acceleration in the vehicle coordinate system.

[0025] 3. Receive and parse data packets from the train control system via the train communication network to obtain the train's real-time operating speed. With real-time location information based on route mileage .

[0026] 4. Using the aforementioned real-time location information Using an index, the system queries a pre-stored digital route map database to obtain the route geometry information for the current location and the predetermined area ahead. The digital route map stores at least contact wire design height data that strictly corresponds to the route mileage. and longitudinal slope data of the line The database can be a structured data table with route mileage as the key index.

[0027] Step 200: Calculate the relative height of the net pantograph netting.

[0028] This step is used to isolate the influence of vehicle motion from the original distance measurements, and the process is as follows: 1. Integrate the angular velocity signal output by the inertial measurement unit over time and fuse it with the accelerometer signal to correct for drift, thus calculating the current pitch angle of the vehicle body. with roll angle .

[0029] 2. Process the vertical acceleration signal to remove the gravitational acceleration component (whose magnitude is related to the attitude angle). , (related), and integrate the obtained acceleration, combined with the vehicle speed With map slope Information is used to estimate the vertical displacement change of the car body's center of gravity relative to the rail surface. .

[0030] 3. Based on the fixed installation position coordinates of the pantograph in the vehicle coordinate system and the solution obtained , and Calculate the displacement compensation amount of the pantograph mounting base in the absolute vertical direction caused by the vehicle body movement. One calculation formula is as follows: .

[0031] 4. Calculate the net height value : .in, The initial value of the vertical position of the mounting base when the system is calibrated to zero. It represents the instantaneous vertical distance between the slide and the contact line in the track reference frame.

[0032] Step 300: Forward state prediction.

[0033] This step extrapolates the future based on the current status and route information: 1. Based on real-time running speed and the preset look-ahead time Determine the predicted future time window and the corresponding driving mileage range The aforementioned look-ahead time The value of needs to balance prediction effectiveness and system processing latency; for example, it can be set to . .

[0034] 2. Extract the contact wire design height sequence within the aforementioned mileage range from the digital route map. With slope sequence Construct the spatial geometric profile of the contact line.

[0035] 3. Using the contact line geometry as system input, a simplified vehicle dynamics model is used for simulation. This model can reflect the vertical and pitch motions of the vehicle body, such as a two-degree-of-freedom model.

[0036] Using the current vehicle motion state and contact line geometry as input, the model's dynamic equations are solved using numerical integration methods (such as the Euler method or the Runge-Kutta method), and the predicted vertical displacement sequence of the vehicle's center of mass within future time windows is output. With predicted pitch angle sequence These sequences, as prediction results, are used to generate subsequent feedforward instructions.

[0037] Step 400: Generate feedforward control instructions.

[0038] This step calculates the feedforward action command based on the prediction results: 1. Combining predicted vehicle motion sequences and pantograph installation location Calculate the predicted absolute motion trajectory of the pantograph mounting base. : .

[0039] 2. Design the contact wire height variation trajectory. Predicted trajectory with mounting base Synthesizing, the target relative height trajectory of the pantograph is obtained. : .in This refers to the initial height of the pantograph slider relative to the mounting base when it is in its lowest mechanical zero position.

[0040] 3. Continuous trajectory Discretized into a sequence of position commands synchronized with the control system cycle. , as a feedforward control command.

[0041] Step 500: Generate feedback control instructions.

[0042] This step processes real-time measurement deviations for closed-loop correction: 1. Based on real-time running speed Query the preset speed-target height mapping table The target altitude setpoint at the current moment is calculated using linear interpolation. .

[0043] Specifically, at the current speed Located in the table, two adjacent velocity values and ( When the target height is between ) Press Calculation, where , They are respectively , The corresponding target height.

[0044] 2. Calculate the net height value Compared with the target set value Real-time deviation : .

[0045] 3. The deviation Input: Digital proportional-integral-derivative controller. Controller output: Calculated by the following formula: .in, , , For the pre-tuned controller gain, This represents the time from the initial time to the current time. The historical deviations are accumulated (integrated). The control period is the minimum fixed time interval for the system to perform data acquisition and calculation.

[0046] Step 600: Dynamically fuse and generate the final instruction.

[0047] This step adaptively synthesizes control commands: 1. Dynamically determine feedforward weight coefficients This coefficient is based on a real-time assessment of the certainty of the prediction information and the reliability of the sensor data.

[0048] 2. Perform weighted fusion to generate the final control command. : .

[0049] 3. Output final control command .

[0050] Step 700: Drive the actuator.

[0051] The control unit will issue the final control command. The signal is sent to the servo drive of the pantograph height adjustment actuator. The drive uses... Set the location point and collect feedback on the actual position of the actuator. By using internal closed-loop control of position, speed, or current, the deviation between the actual position and the command is reduced, thereby driving the motor or hydraulic cylinder to move and adjust the actual position. Trace instructions This allows for precise control of the pantograph's lifting mast position.

[0052] One implementation method for determining dynamic fusion weights In step 600 of the above dynamic adjustment process, the feedforward weight coefficient is dynamically determined. One specific implementation method is as follows, wherein .

[0053] Feedforward weighting coefficient Line determinism scoring and high credibility score A joint decision.

[0054] Line Determinism Score : To assess the completeness and predictability of route information within the prediction interval.

[0055] First, the proportion of mileage points with valid digital route map data (i.e., complete elevation and slope data) within the statistical prediction interval is determined. Secondly, identify the number of key points within this interval. Key points include abrupt changes in gradient, anchor joints, and electrical phase separation. Line determinism scoring. It can be calculated based on the completeness of the data and the number of key points within the prediction interval.

[0056] One calculation method is as follows: .in, The attenuation factor is a positive number less than 1, used to characterize the influence weight of key points on prediction determinism. Its specific value can be set according to the actual influence of key points on system stability.

[0057] High credibility rating Assess net height value Reliability. In a length of Within the sliding time window, calculate Sequence and height reference value derived from the prediction model Correlation coefficient of sequences For example, methods well-known in the field, such as the Pearson correlation coefficient, can be used for calculation. The high reliability score can be set as follows: This normalizes the value to the [0,1] interval.

[0058] Weight calculation: The route determinism score is compared with the high reliability score, and the smaller value is taken as the feedforward weight coefficient. The base value, that is It can be adjusted according to the real-time running speed. Fine-tune this base value, for example when Exceeding a certain threshold At that time, Set as ,in It is a small positive increment.

[0059] Implementation methods for sensor fault diagnosis and fault-tolerant control Based on the above methods, the following fault diagnosis and fault-tolerant control logic can be further included: Fault diagnosis: Continuously monitor the reasonableness of the data from the first distance sensor. Judgment criteria include: 1. Calculate the net height value Compared with the predicted reference value absolute value of the difference ,like Continuously exceeding the preset threshold The number of cycles is greater than Among them, the threshold The distance can be determined by combining the nominal accuracy of the first distance sensor with the maximum permissible error of the prediction model; This is a set positive integer used to avoid misjudgments caused by transient interference. Its value is related to the system control frequency and the required diagnostic reliability.

[0060] 2. Calculation instantaneous rate of change If it exceeds the threshold set based on the maximum physical speed of the pantograph .

[0061] If any condition is met, the signal of the first distance sensor is determined to be abnormal.

[0062] Fault-tolerant control reconfiguration: When an abnormal signal is detected, the system switches to degraded control mode. In this mode: 1. When generating feedback control commands, pause the use of [the system / mechanism]. Instead, the input to the feedback controller is switched to the height change calculated independently from the inertial measurement unit data, or the feedback controller is placed in a hold state.

[0063] 2. In the dynamic fusion step, the feedforward weight coefficients are... Forced to be set to a preset high value ,For example .

[0064] System recovery: Continuously monitors fault conditions. When continuously below the recovery threshold (in The number of periods is greater than When the fault flag is cleared, the system will return to normal operation. Implement feedback control and restore the dynamically calculated feedforward weight coefficients. .

[0065] The above description illustrates one or more implementation methods. Based on the described content, those skilled in the art can implement the methods.

[0066] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change. Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other. In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for dynamic adjustment of pantograph height based on multi-sensor detection, characterized in that, Includes the following steps: S1. Acquire multi-source data, including: the first distance measurement value at the pantograph sliding plate, motion parameters collected by the vehicle body inertial measurement unit, real-time train speed and position information, and contact wire geometric parameters retrieved from a pre-stored digital track map based on the position information. S2. Based on the motion parameters collected by the vehicle body inertial measurement unit, motion compensation is performed on the first distance measurement value to obtain the net pantograph net relative height value; S3. Based on the real-time running speed and location information of the train and the geometric parameters of the contact wire, perform prediction calculations to generate prediction information including the change in the height of the contact wire and the motion state of the vehicle body within a future set time period. S4. Based on the predicted information, generate feedforward control commands; S5. Generate feedback control commands based on the deviation between the relative height of the net pantograph net and the height of a dynamic target; S6. Based on the real-time evaluation of the predicted information and the relative height value of the net pantograph net, determine the feedforward weight coefficient and the feedback weight coefficient, and use the feedforward weight coefficient and the feedback weight coefficient to weight and fuse the feedforward control command and the feedback control command to generate a comprehensive control command. S7. Drive the pantograph height adjustment actuator according to the comprehensive control command.

2. The method for dynamic adjustment of pantograph height based on multi-sensor detection according to claim 1, characterized in that, Step S2 specifically includes: S21. Calculate the vehicle body attitude angle based on the angular velocity information in the motion parameters; S22. Based on the linear acceleration information in the motion parameters and the slope information in the contact line geometry parameters, estimate the vertical displacement of the vehicle body's center of gravity; S23. Calculate the vertical motion compensation of the pantograph mounting base based on the vehicle body attitude angle, the vertical displacement of the vehicle body center of gravity, and the installation position of the pantograph on the vehicle body. S24. Subtract the vertical motion compensation from the first distance measurement value to obtain the net pantograph net relative height value.

3. The method for dynamic adjustment of pantograph height based on multi-sensor detection according to claim 1, characterized in that, Step S3 specifically includes: S31. Determine the predicted mileage range based on the real-time running speed of the train and a preset time length; S32. Obtain the contact wire design height data and slope data within the predicted mileage range from the digital route map; S33. Based on the vehicle dynamics model, using the contact line design height data as input, calculate the predicted vertical displacement and predicted attitude angle of the vehicle body within the future set time period.

4. The pantograph height dynamic adjustment method integrating multi-sensor detection according to claim 3, characterized in that, Step S4 specifically includes: S41. Calculate the predicted motion trajectory of the pantograph mounting base based on the predicted vertical displacement, predicted attitude angle, and pantograph mounting position. S42. Based on the contact wire design height data and the predicted motion trajectory of the mounting base, calculate the target height trajectory of the pantograph; S43. Generate the feedforward control command based on the target height trajectory.

5. The method for dynamic adjustment of pantograph height based on multi-sensor detection according to claim 1, characterized in that, In step S5, the dynamic target height value is obtained by querying the correspondence table between speed and target height and combining it with interpolation calculation.

6. The method for dynamic adjustment of pantograph height based on multi-sensor detection according to claim 1, characterized in that, The determination of the feedforward weight coefficient and the feedback weight coefficient in step S6 includes: S61. Evaluate the route certainty, the evaluation is based on the completeness of the data of the digital route map within the prediction interval and the number of key points within the prediction interval. S62. Assess the reliability of height, the assessment is based on the consistency among the relative height of the net pantograph net, the height value calculated based on the motion parameters, and the height value derived from the prediction information. S63. Based on the assessment results of the line determinism and the assessment results of the high reliability, determine the feedforward weight coefficient, wherein the feedback weight coefficient is the difference between 1 and the feedforward weight coefficient.

7. The method for dynamic adjustment of pantograph height based on multi-sensor detection according to claim 1, characterized in that, It also includes step S8: sensor data validity monitoring and system reconstruction; Step S8 includes: when an abnormality is detected in the first distance measurement value, a degradation control mode is activated; In the degraded control mode, a backup data source is used when generating the feedback control command, and the feedforward weight coefficient is set to a fixed value.

8. The method for dynamic adjustment of pantograph height based on multi-sensor detection according to claim 7, characterized in that, The conditions for monitoring anomalies in the first distance measurement value are: the absolute value of the difference between the relative height of the net pantograph net and the reference height value derived from the prediction information continuously exceeds a first threshold; or, the rate of change of the relative height of the net pantograph net exceeds a second threshold.

9. The method for dynamic adjustment of pantograph height based on multi-sensor detection according to claim 1, characterized in that, The pre-stored digital route map is a database containing route mileage, as well as the design height of the contact wire and the longitudinal slope at each mileage point.

10. The method for dynamic adjustment of pantograph height based on multi-sensor detection according to claim 1, characterized in that, Step S7 specifically includes: sending the integrated control command as a position command to the servo driver, and the servo driver controlling the actuator to move so that the actual position of the pantograph tracks the position command.

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