Rail vehicle anti-skid control method

Abstract

The present application relates to a kind of rail vehicle anti-skid control method, the method comprises: obtaining the deceleration a 车 And wheel deceleration a 轴 When the deceleration a 车 Of the acquisition value of vehicle is within reasonable range, the deceleration a 车 Of vehicle is filtered;The axle speed of each axle is measured, and the vehicle speed is determined according to the comparison result of wheel deceleration and the deceleration of vehicle;According to the calculation formula of slip rate, the axle speed is calculated, and according to the corresponding relationship between slip rate and adhesion coefficient, the first ideal axle speed and the second ideal axle speed are determined;The measured axle speed is compared with the first ideal axle speed and the second ideal axle speed, to determine the air supply or exhaust or pressure maintenance of anti-skid valve.The present application solves the problem of inaccurate data source in the anti-skid control of rail vehicle in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of rail transit technology, and in particular relates to a method for anti-skid control of rail vehicles. Background Technology

[0002] Anti-skid systems for railway vehicles are technologies used to prevent wheel lock-up and scraping. Their main purpose is to maintain adhesion between the wheel and the rail to prevent wheel slippage. Currently, the main methods for detecting slippage include speed difference criteria and deceleration criteria.

[0003] Anti-skid systems for railway vehicles are designed to prevent wheel lock-up and tread abrasion. Currently, these systems typically use speed difference and deceleration criteria to detect skidding. The speed difference criterion is based on the difference between the vehicle's reference speed and the wheel axle speed, while the deceleration criterion relies on the reduction in wheel axle speed. When one of these criteria is met, the system triggers anti-skid control, adjusting brake cylinder pressure to eliminate skidding and thus prevent wheel tread abrasion.

[0004] However, there is a problem with the current method. The vehicle's reference speed is usually estimated, which can lead to inaccuracies in speed difference detection. Summary of the Invention

[0005] To address the shortcomings of related technologies, this invention provides a method for anti-skid control of rail vehicles, solving the technical problem of inaccurate anti-skid control data sources.

[0006] According to another aspect of this application, a method for anti-skid control of a rail vehicle is provided, the method comprising the following steps: obtaining the vehicle's deceleration a 车 Wheel reduction a 轴 And if the vehicle's deceleration is greater than the theoretical maximum deceleration, or if the vehicle's deceleration is 0 but the wheel deceleration is not 0, the vehicle's deceleration is discarded, and the deceleration of the spare vehicle is used; when the vehicle's deceleration a 车 When the collected values ​​are within a reasonable range, the deceleration a of the vehicle... 车 Filtering is performed, and an adaptive filtering algorithm is used to calculate compensation values ​​to eliminate errors caused by data acquisition fluctuations; the axle speed of each axle is measured, and the vehicle speed is calculated, including comparing the wheel deceleration 'a' of each axle. 轴 With the vehicle's deceleration a 车 If at least one axle has a wheel deceleration a 轴 Not greater than the measured deceleration a of the vehicle 车 If the maximum value among all axle speeds is taken as the vehicle speed; if the wheel deceleration of all axles is greater than the vehicle deceleration a... 车 The vehicle speed is calculated using the following formula: where is the previously calculated or updated vehicle axle speed, a 车The deceleration of the vehicle is calculated using the latest filtering method, where t is the sampling time interval; when the wheel deceleration of all axles is greater than the vehicle's deceleration a. 车 If all axles are in a sliding state, the ideal axle speed is calculated using the following formula for slip ratio: λ = (V_vehicle - V_axle) / V_vehicle * 100%. Based on the correspondence between slip ratio λ and the adhesion coefficient μ, the slip ratio at point β is determined as the first ideal axle speed, and the slip ratio at point α is determined as the second ideal axle speed. The slip ratio at point α is 1.5%, and the slip ratio at point β is 5%–25%. When the measured axle speed is less than the first ideal axle speed, the anti-slip valve is controlled to exhaust air. When the measured axle speed is greater than the second ideal axle speed, the anti-slip valve is controlled to pressurize air. When the measured axle speed is less than or equal to the second ideal axle speed but greater than or equal to the first ideal axle speed, the anti-slip valve is controlled to maintain pressure.

[0007] In one possible implementation, the adaptive filtering algorithm includes multiple consecutive samplings to calculate the vehicle's deceleration value over a period of time, with a sampling interval t of 100 ms and a sampling number of 5 times.

[0008] In one possible implementation, the vehicle's deceleration a 车 Filtering is performed using an adaptive filtering algorithm, calculated according to the following formula:

[0009]

[0010] e(k) = d(k) - y(k);

[0011] ω i (k+1)=ω i (k)+2μe(k)x(ki);

[0012] Where: x(k) is the input for sampling the vehicle's deceleration value, y(k) is the collected value of the output vehicle deceleration value, d(k) is the reference compensation value, which is the median of the most recent 5 calculated theoretical values, e(k) is the error value, and ω i (k) represents the weighting coefficient, and μ represents the step size;

[0013] Let X(k) be the autocorrelation matrix of x(k), λ max If μ is the largest eigenvalue of X(k), then the range of μ is (0 < μ < λ). max ), where μ=0.9999λ max .

[0014] In one possible implementation, the method further includes: calculating the theoretical brake cylinder pressure and adjusting the brake cylinder pressure in a priori anti-slip manner.

[0015] In one possible implementation, the relationship between the braking pressure P and the deceleration applied to the wheel axle is calculated based on the mechanical characteristics of the system, where P = κ * a 轴 , where κ is the mechanical coefficient.

[0016] In one possible implementation, the method for calculating the brake cylinder pressure includes obtaining the mechanical coefficient κ by first statistically analyzing and then looking up a table, and determining the correspondence between the brake cylinder pressure and the wheel axle deceleration based on real-time recorded and updated data.

[0017] In one possible implementation, the lookup table method uses previously statistically derived relationships between vehicle deceleration and theoretical brake cylinder pressure.

[0018] In one possible implementation, the method further includes controlling the anti-slip valve to operate based on the difference between the real-time collected brake cylinder pressure and the calculated theoretical brake cylinder pressure, so as to adjust the actual brake cylinder pressure to the theoretical value.

[0019] In one possible implementation, the vehicle deceleration 'a' when the axle speed reaches the first ideal speed after the braking command is applied is recorded and updated in real time. 车ideal This deceleration should be the maximum value or close to the maximum value of wheel-rail adhesion on this section of the road; substitute the vehicle's deceleration into P = κ * a to calculate the brake cylinder pressure P.

[0020] Based on the above technical solution, the anti-skid control method for rail vehicles according to the present invention automatically completes the feeding, angle adjustment, handling and testing of air springs, realizes the automation of air spring testing, improves the working efficiency of the production line and reduces the labor intensity of workers. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0022] Figure 1 A flowchart illustrating one implementation of a rail vehicle anti-skid control method;

[0023] Figure 2 A flowchart illustrating another implementation of a rail vehicle anti-skid control method;

[0024] Figure 3 The curve showing the relationship between the adhesion coefficient and slip ratio of a rail vehicle;

[0025] Figure 4 This is a block diagram illustrating the basic principle of anti-slip control. Detailed Implementation

[0026] The technical solutions in 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 a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0027] In the description of this invention, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] To address the problem of inaccurate data in existing technologies, this application provides a method for anti-skid control of rail vehicles.

[0031] See Figure 1 and Figure 2 In one possible implementation, the method includes the following steps: obtaining the vehicle's deceleration a 车 Wheel reduction a 轴 If the vehicle's deceleration is greater than the theoretical maximum deceleration, or if the vehicle's deceleration is 0 and the wheel deceleration is not 0, the vehicle's deceleration is discarded and the deceleration of the spare vehicle is used.

[0032] In the above scheme, vehicle deceleration is acquired through sensors. When the vehicle's deceleration exceeds the theoretical maximum value or an abnormal situation occurs (such as the vehicle deceleration being 0 while the wheel deceleration is not 0), the system automatically determines that the deceleration data is inaccurate and activates backup deceleration data. This design can improve data reliability and prevent safety risks caused by data errors.

[0033] When the vehicle decelerates a 车 When the collected values ​​are within a reasonable range, the deceleration a of the vehicle... 车 Filtering is performed, and an adaptive filtering algorithm is used to calculate compensation values ​​to eliminate errors caused by data acquisition fluctuations.

[0034] In the above implementation, the purpose of filtering is to reduce measurement errors caused by sensor fluctuations and external interference. By applying an adaptive filtering algorithm, the system can dynamically adjust the filtering parameters, thereby effectively improving the accuracy and stability of the data. This method is particularly important for dynamically changing driving environments.

[0035] Measure the axle speed of each axle and calculate the vehicle speed, including: comparing the wheel deceleration of axle a with the vehicle's deceleration a. 车 .

[0036] In the above scheme, the actual vehicle speed can be accurately calculated by comparing axle speeds and vehicle deceleration. The vehicle speed is determined to be the maximum value among all axle speeds when the wheel deceleration of at least one axle is no greater than the vehicle's deceleration. This method helps improve the accuracy of speed calculations, especially under complex driving conditions.

[0037] If the wheel deceleration of all axles is greater than the vehicle deceleration a 车 Then the vehicle speed is calculated according to a specific formula. This applies when the wheel deceleration of all axles is greater than the vehicle's deceleration *a*. 车 If this is the case, then all axes are in the process of sliding. Based on the formula for calculating the slip ratio, the ideal axis speed can be calculated.

[0038] In the above scheme, slippage is detected by comparing axle speed and vehicle deceleration. The formula for calculating the ideal axle speed takes into account the slip ratio, which helps to more accurately determine the actual motion state of the wheel axle and make reasonable speed adjustments accordingly, ensuring smooth vehicle operation and safe braking.

[0039] See Figure 3 Based on the correspondence between slip ratio λ and adhesion coefficient μ, the slip ratio at point β is determined to be the first ideal shaft speed, and the slip ratio at point α is determined to be the second ideal shaft speed.

[0040] In the above scheme, by setting two key slip ratio points (α point and β point), the degree of wheel and axle slippage can be effectively controlled. This control method helps optimize the adhesion performance between the wheel and axle and the track, improving the vehicle's driving stability and safety.

[0041] When the measured shaft speed is less than the first ideal shaft speed, the anti-slip valve is controlled to exhaust air; when the measured shaft speed is greater than the second ideal shaft speed, the anti-slip valve is controlled to fill air; when the measured shaft speed is less than or equal to the second ideal shaft speed and greater than or equal to the first ideal shaft speed, the anti-slip valve is controlled to maintain pressure.

[0042] In the above scheme, by monitoring the relationship between the axle speed and the ideal axle speed, the system can automatically adjust the state of the anti-slip valve to ensure optimal adhesion between the wheel axle and the track. This dynamic control method can effectively prevent pulley phenomena and improve braking efficiency and safety.

[0043] In one possible implementation, the adaptive filtering algorithm includes multiple consecutive samplings to calculate the vehicle's deceleration value over a period of time, with a sampling interval t of 100 ms and a sampling number of 5 times.

[0044] In the above scheme, the implementation of the adaptive filtering algorithm includes periodic sampling and data processing. By setting appropriate sampling intervals and frequencies, sufficient data points can be obtained to accurately calculate the vehicle's deceleration. This method helps to monitor the vehicle's status in real time, providing a reliable foundation for further data analysis.

[0045] In one possible implementation, the vehicle's deceleration 'a' is filtered using an adaptive filtering algorithm, calculated according to the following formula:

[0046]

[0047] e(k) = d(k) - y(k);

[0048] ω i (k+1)=ω i (k)+2μe(k)x(ki);

[0049] Where: x(k) is the input for sampling the vehicle's deceleration value, y(k) is the collected value of the output vehicle deceleration value, d(k) is the reference compensation value, which is the median of the most recent 5 calculated theoretical values, e(k) is the error value, and ω i (k) represents the weighting coefficient, and μ represents the step size;

[0050] Let X(k) be the autocorrelation matrix of x(k), λ max If μ is the largest eigenvalue of X(k), then the range of μ is (0 < μ < λ). max ), where μ=0.9999λmax .

[0051] In the above scheme, the adaptive filtering algorithm is implemented by using historical data to adjust the weight coefficients, thereby dynamically optimizing the filtering process. This method not only improves the accuracy of deceleration calculation but also adapts to various driving conditions and environmental changes.

[0052] In one possible implementation, the method further includes: calculating the theoretical brake cylinder pressure and adjusting the brake cylinder pressure in a priori anti-slip manner.

[0053] In the above scheme, by calculating the theoretical brake cylinder pressure and adjusting the actual pressure accordingly, slippage can be effectively prevented. This a priori anti-slip method helps to identify and address potential slippage situations in advance, thereby ensuring safe and stable braking of the vehicle.

[0054] In one possible implementation, the relationship between the braking pressure P and the deceleration applied to the wheel axle is calculated based on the mechanical characteristics of the system, where P = κ * a 轴 , where κ is the mechanical coefficient.

[0055] In the above approach, by analyzing the mechanical structural characteristics of the system, the relationship between braking pressure and wheel axle deceleration can be accurately determined. This method helps optimize the performance of the braking system and ensures effective braking of the vehicle under different conditions.

[0056] In one possible implementation, the method for calculating the brake cylinder pressure includes obtaining the mechanical coefficient κ by first statistically analyzing and then looking up a table, and determining the correspondence between the brake cylinder pressure and the wheel axle deceleration based on real-time recorded and updated data.

[0057] In one possible implementation, the lookup table method uses previously statistically derived relationships between vehicle deceleration and theoretical brake cylinder pressure.

[0058] In one possible implementation, the method further includes controlling the anti-slip valve to operate based on the difference between the real-time collected brake cylinder pressure and the calculated theoretical brake cylinder pressure, so as to adjust the actual brake cylinder pressure to the theoretical value.

[0059] In one possible implementation, the vehicle deceleration 'a' when the axle speed reaches the first ideal speed after the braking command is applied is recorded and updated in real time. 车ideal This deceleration should be the maximum value or close to the maximum value of wheel-rail adhesion on this section of the road; substitute the vehicle's deceleration into P = κ * a to calculate the brake cylinder pressure P.

[0060] In one possible implementation, if the collected brake cylinder pressure is greater than P, air can be vented according to different pressure difference levels until the brake cylinder pressure equals the calculated value. During this process, speed acquisition continues, and if the control algorithm should enter a higher level of venting based on the speed difference and deceleration criteria, then the higher level of control is entered. When the speed difference is controlled to be less than the judgment value, the anti-skid valve will charge or maintain pressure. When the speed difference is detected to change from less than the second theoretical value to greater than the second theoretical value again, the same method can be used to calculate the theoretical brake cylinder pressure value using the vehicle deceleration and control the anti-skid valve to operate.

[0061] In the above scheme, the theoretical brake cylinder pressure is calculated. Based on the system's mechanical structure characteristics, the relationship between the braking pressure P and the deceleration applied to the wheel axle is calculated: P = κ * a, where κ is a mechanical coefficient, which varies from system to system. Since vehicle components are not ideal rigid bodies, the relationship between braking pressure P and wheel axle deceleration may not be strictly linear. To avoid errors, κ can be obtained by first statistical analysis and then looking up a table. The vehicle deceleration a is recorded and updated in real-time when the axle speed reaches the first ideal speed after the braking command is applied. 车ideal This deceleration should be the maximum or near-maximum value of wheel-rail adhesion on this section of road. Substitute this vehicle deceleration into P = κ*a to calculate the brake cylinder pressure P. It should be noted that the brake cylinder pressure when the vehicle reaches the first ideal speed cannot be used as the ideal pressure value, because the brake cylinder pressure at this point comes from the braking command and has no direct relationship with vehicle deceleration, adhesion coefficient, etc.

[0062] In the above scheme, the anti-skid valve is activated in advance. If the collected brake cylinder pressure is greater than P, air is vented according to different pressure difference levels until the brake cylinder pressure equals the calculated value. During this process, speed data collection continues. If the control algorithm should enter a higher level of venting based on the speed difference and deceleration criteria, then the higher level of control is entered. When the speed difference is controlled to be less than the judgment value, the anti-skid valve will charge or maintain pressure. When the speed difference is detected to change from less than the second theoretical value to greater than the second theoretical value again, the same method can be used to calculate the theoretical brake cylinder pressure value using the vehicle deceleration and control the anti-skid valve to activate.

[0063] The anti-skid system of railway vehicles is used to prevent wheels from locking up and scraping. Currently, the main criteria for skidding detection are speed difference and deceleration.

[0064] Speed ​​difference criterion: When the speed of a certain axle is lower than the reference speed (base speed), the judgment value is reached. The reference speed is the maximum value calculated from the axle speeds of the four wheel pairs of the vehicle.

[0065] Deceleration criterion: When the deceleration of a certain axis reaches the judgment value;

[0066] When any of the above conditions occur, it is determined that the axle has engaged in braking slippage. The anti-slip control system regulates the brake cylinder pressure by controlling the anti-slip valve to eliminate slippage and prevent damage to the wheel tread.

[0067] Anti-slip control refers to reducing braking force when it is about to exceed the adhesion force (at which point it is judged as "slipping"), allowing the wheel to return to a rolling or mixed rolling-slipping state, thus preventing wheel slippage. The key to anti-slip control is timely and accurate judgment of when slippage is triggered and when it is resumed. Judging slippage too early will result in excessive loss of braking force, failing to fully utilize the adhesion between the wheel and rail, leading to a longer braking distance; judging it too late may cause tread abrasion or accelerate wheel flange wear, failing to provide anti-slip protection. Judging the resumption of slippage too early will affect the recovery of wheel-rail adhesion, easily leading to a new round of slippage; judging it too late, i.e., the total time for venting and pressure holding is too long, will increase the system's air consumption and lose some braking force, affecting braking distance and anti-slip efficiency.

[0068] Currently, most anti-skid devices use speed difference and deceleration as the basis for detecting skid movement. However, the calculation methods for the key parameter of speed difference, namely the vehicle's reference speed, still have some shortcomings in various systems. In addition, a large amount of data also shows that relying on deceleration as the criterion often causes the anti-skid device to react frequently to even slight skid movements.

[0069] Currently, the common practice is to use the highest speed of the vehicle's four axles as the reference speed when synchronized coasting has not occurred. However, when synchronized coasting begins, the highest axle speed no longer reflects the vehicle's actual speed, and in this case, the vehicle's reference speed must be estimated. The estimation method is as follows: using the vehicle's maximum deceleration 'a'... max As the slope of the velocity decrease, a virtual calculated value is obtained by stepping through time as a reference velocity.

[0070] V ref =V 前 -a max The speed of axle is only updated to the reference speed when the highest speed of one of the four axles exceeds the calculated reference speed. In reality, this calculated reference speed often decreases faster than the actual vehicle speed. The actual deceleration of the vehicle is not always constant; it depends on factors such as the current level, the slope, and whether skidding has occurred. Therefore, the reference speed obtained from this benchmark will cause the speed difference calculated by the anti-skid system to be smaller than the actual speed difference. Furthermore, this error increases over time, eventually causing the speed difference detection to fail and making it impossible to detect wheel and axle skidding in real time.

[0071] The above criteria and control algorithms rely solely on axle speed and its calculation results (axle deceleration, maximum axle speed, etc.), making it difficult to obtain and not utilize information such as wheel-rail adhesion, vehicle speed, and vehicle acceleration. This is not conducive to achieving the goal of anti-skid and fully utilizing adhesion to obtain a smaller braking distance.

[0072] The purpose of anti-skid control is to fully utilize the adhesion between the wheel and rail, which first requires the vehicle to meet the condition of achieving a large or maximum adhesion coefficient. According to research both domestically and internationally, there is a significant relationship between the adhesion coefficient and the slip ratio.

[0073] Define slip ratio

[0074]

[0075] Where λ is the slip ratio;

[0076] V 车 —Vehicle speed;

[0077] V 轴 —Axle speed;

[0078] If the slip ratio can be controlled within Figure 3 The adhesion between α and β can be utilized more fully.

[0079] Under normal circumstances, after the EBCU issues the exhaust command during braking, the speed difference between the vehicle and the maximum speed of each axle continues to increase. This is because by the time the EBCU detects that the speed difference exceeds the criterion, a short period of time has already passed since the difference occurred. When the EBCU controls the anti-skid valve to activate, the processes of exhaust valve activation, air pressure transmission, and reduction of braking force all require a certain amount of time. During these two periods, the speed difference may further increase, which undoubtedly increases the possibility of tread abrasion. For systems without pressure sensors, prior anti-skid measures can only be implemented with a relatively conservative strategy, such as starting exhaust when the speed difference is small, but this can easily lead to excessive loss of braking force. For anti-skid systems equipped with sensors that collect brake cylinder pressure, brake cylinder pressure is the source of slippage, and preventative anti-skid measures can be implemented.

[0080] This invention proposes an anti-skid control method using vehicle acceleration. By using the read vehicle acceleration to participate in skid judgment and anti-skid control, errors caused by estimation are avoided, the number of anti-skid valve actions is reduced, and adhesion can be utilized more fully. In addition, under the premise of introducing brake cylinder pressure, a priori anti-skid can be performed to minimize speed difference and avoid wheel tread abrasion.

[0081] To address these issues, this invention provides a novel anti-skid control method that uses vehicle acceleration as accurate input data, avoiding speed estimation errors, and incorporates brake cylinder pressure sensor information for prior anti-skid analysis. This method improves the performance of traditional railway vehicle anti-skid systems, enhancing system accuracy and efficiency, and contributing to improved safety and reliability of railway transportation.

[0082] This invention proposes a novel anti-skid control method that introduces a deceleration sensor, which can accurately determine the vehicle speed in a full-skid state. With accurate vehicle speed information, the control strategies at different speed levels will be more scientific and effective.

[0083] This control method, based on the relationship between slip ratio and adhesion coefficient statistically derived from the rail industry, controls the speed difference within a certain range rather than a fixed value. This appropriately reduces the number of times the anti-slip valve actuates and increases its service life. Controlling the slip ratio allows the vehicle to adaptively adjust the control strategy according to the actual adhesion coefficient, which is equivalent to making fuller use of adhesion to shorten the braking distance.

[0084] This invention introduces a pressure sensor, enabling preventative anti-skid measures. It reacts earlier than traditional anti-skid control technologies, reducing the possibility of excessive speed differences or even wheel lock-up. This technology can effectively reduce the maximum speed difference between the vehicle and the axle, allowing the speed difference between the vehicle and the axle to approach the ideal slip ratio more quickly than traditional control methods. It also increases the proportion of time the vehicle utilizes the maximum adhesion coefficient in the entire braking process, effectively reducing braking distance.

[0085] This invention solves the problem that vehicle speed is not easy to obtain accurately under full skidding conditions, so that subsequent anti-skid control strategies can be based on accurate data rather than estimated data. This ensures that the anti-skid control strategies achieve more significant effects, reduce the possibility of skidding or even lock-up, reduce wheel surface abrasion, increase wheel life, and reduce the distance of each braking.

[0086] Without compromising the anti-slip effect, this invention reduces the number of times the anti-slip valve operates, increases its service life, and saves costs.

[0087] This invention creatively proposes a priori anti-skid technology. Based on the system's mechanical characteristics and theoretical calculations, preventative anti-skid does not waste excessive braking force; it simply reduces the braking force that could lead to a further increase in speed difference. By detecting data at the source rather than solely relying on speed difference to derive control criteria, it reacts faster and acts earlier, effectively avoiding the possibility of skidding or even locking up due to large speed differences. Furthermore, it increases the proportion of time the ideal slip ratio takes into account during braking, which can effectively shorten braking distance, reduce tread abrasion or wheel flange wear, and increase wheel flange lifespan.

[0088] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0089] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A method for anti-skid control of rail vehicles, characterized in that, The method includes the following steps: a) Obtain the vehicle's deceleration a 车 Wheel reduction a 轴 If the deceleration of a vehicle is greater than the theoretical maximum deceleration, or if the deceleration of a vehicle is 0 and the wheel deceleration is not 0, the deceleration of that vehicle is discarded and the deceleration of a spare vehicle is used. b) When the vehicle decelerates a 车 When the collected values ​​are within a reasonable range, the deceleration a of the vehicle... 车 Filtering is performed, and an adaptive filtering algorithm is used to calculate compensation values ​​to eliminate errors caused by acquisition fluctuations. c) Measure the axle speed of each axle and calculate the vehicle speed, including: comparing the wheel reduction of each axle. 轴 With the vehicle's deceleration a 车 If at least one axle has a wheel deceleration a 轴 Not greater than the measured deceleration a of the vehicle 车 If the maximum value among all axle speeds is taken as the vehicle speed, then the vehicle speed is calculated according to the following formula: If the wheel deceleration of all axles is greater than the vehicle deceleration 'a', then the vehicle speed is calculated according to the following formula: , For the vehicle axle speed calculated or updated previously, a 车 The deceleration of the vehicle is calculated using the latest filtering method, and t is the sampling time interval. d) When the wheel deceleration of all axles is greater than the vehicle deceleration a 车 If all axes are in a sliding state, the ideal axis velocity can be calculated using the following formula for calculating the slip ratio. : According to slip ratio and The relationship between the adhesion coefficients is used to determine the first ideal axial velocity at point β and the second ideal axial velocity at point α; where, The point slip rate is 1.5%. Point slip rate is 5%-25%; e) When the measured shaft speed When the shaft speed is less than the first ideal shaft speed, control the anti-slip valve to exhaust air; when the measured shaft speed... When the shaft speed is greater than the second ideal shaft speed, control the anti-slip valve to charge air; when the measured shaft speed... When the shaft speed is less than or equal to the second ideal shaft speed and greater than or equal to the first ideal shaft speed, the anti-slip valve is controlled to maintain pressure.

2. The method according to claim 1, characterized in that, The adaptive filtering algorithm includes multiple consecutive samplings to calculate the vehicle's deceleration value over a period of time, with a sampling interval t of 100ms and a sampling number of 5 times.

3. The method according to claim 2, characterized in that, deceleration a of the vehicle 车 Filtering is performed using an adaptive filtering algorithm, calculated according to the following formula: ； ； ； in: The input for sampling the vehicle's deceleration value. To output the collected values ​​of the vehicle's deceleration, For reference compensation values, the median of the most recent 5 calculated theoretical values ​​is used here. This is the error value. These are the weighting coefficients. Step size; make for The autocorrelation matrix, for The largest eigenvalue, then The range of values ​​is ,in, .

4. The method according to claim 3, characterized in that, Also includes: Calculate the theoretical brake cylinder pressure and adjust the brake cylinder pressure using a priori anti-slip methods.

5. The method according to claim 4, characterized in that, Braking pressure is calculated based on the system's mechanical structure characteristics. The correspondence between the deceleration applied to the wheel axle and the deceleration applied to the wheel axle. ,in This is the mechanical coefficient.

6. The method according to claim 5, characterized in that, The method for calculating the brake cylinder pressure includes obtaining the mechanical coefficient using a method of first statistical analysis and then looking up a table. The relationship between brake cylinder pressure and wheel axle deceleration is determined based on real-time recorded and updated data.

7. The method according to claim 6, characterized in that, The method of first performing statistics and then looking up a table uses the previously statistical relationship between vehicle deceleration and theoretical brake cylinder pressure.

8. The method according to claim 7, characterized in that, Further, it includes controlling the anti-skid valve to operate based on the difference between the real-time collected brake cylinder pressure and the calculated theoretical brake cylinder pressure, so as to adjust the actual brake cylinder pressure to the theoretical value.

9. The method according to claim 8, characterized in that, Real-time recording and updating of vehicle deceleration when the axle speed reaches the first ideal speed after the braking command is applied. This deceleration should be the maximum or close to the maximum value of wheel-rail adhesion on this section of the road; substitute the vehicle's deceleration into... Calculate the brake cylinder pressure .

10. The method according to claim 9, characterized in that, If the collected brake cylinder pressure is greater than The system can then exhaust air according to different pressure difference levels until the brake cylinder pressure equals the calculated value. During this process, speed acquisition continues. If the control algorithm should enter a higher level of exhaust based on the speed difference and deceleration criteria, then it will enter a higher level of control. When the speed difference is controlled to be less than the judgment value, the anti-skid valve will charge air or maintain pressure. When the speed difference is detected to change from less than the second theoretical value to greater than the second theoretical value again, the same method can be used to calculate the theoretical brake cylinder pressure value using the vehicle deceleration and control the anti-skid valve to operate.

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