Rail transit train longitudinal dynamic modeling traction and dynamic braking force calculation method

Abstract

The invention discloses a rail transit train longitudinal dynamic modeling traction and dynamic braking force calculation method, which comprises the following steps of: 1, acquiring the acceleration of a train, and calculating the sum of external forces borne by the train; 2, calculating the running resistance borne by the train; 3, air braking force borne by the train is calculated; 4, calculating the total traction force and the dynamic braking force of the train; and 5, distributing the total traction force and the dynamic braking force of the train to a specific vehicle. The method has the advantages that the method does not depend on acquisition of a locomotive performance curve any more, complexity and difficulty of locomotive control characteristic modeling in an existing method are simplified, accurate calculation and distribution of train traction and dynamic braking force can be achieved, and construction of a rail transit train longitudinal dynamic model is effectively supported.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of railway locomotive technology, in particular to a calculation method of longitudinal dynamics modeling of rail transit train and traction and dynamic braking force. BACKGROUND

[0002] At present, the longitudinal dynamics modeling of rail transit train has been widely applied in the fields of train stress and speed prediction, brake system and coupler design, train marshalling design, and driving strategy optimization for train autonomous operation, and plays an important role in ensuring train operation safety, improving railway operation efficiency and train operation comfort.

[0003] The calculation of traction and dynamic braking force has always been a key link and necessary input of the longitudinal dynamics modeling of train. The existing method usually relies on the locomotive performance curve provided by the manufacturer to model the traction characteristics at different traction notch and speed, but this method has the following problems.

[0004] Firstly, the data of locomotive performance curve is not easy to obtain. Secondly, even if the relevant data is supported, additional modeling work is needed to reflect the control characteristics of the locomotive and the changes of efficiency or thermal effect at different train speeds, which makes the implementation of the existing method very complex and difficult. Finally, the thermal degradation of the locomotive in actual operation and the transition of traction power when the traction notch changes are usually ignored or simplified in modeling, which affects the accuracy of the calculation of traction and dynamic braking force by the existing method.

[0005] In summary, there are at least the following technical problems:

[0006] The data of locomotive performance curve is not easy to obtain by relying on the locomotive performance curve provided by the manufacturer to model the traction characteristics at different traction notch and speed.

[0007] Secondly, even if the relevant data is supported, additional modeling work is needed to reflect the control characteristics of the locomotive and the changes of efficiency or thermal effect at different train speeds, which makes the implementation of the existing method very complex and difficult.

[0008] Finally, the thermal degradation of the locomotive in actual operation and the transition of traction power when the traction notch changes are usually ignored or simplified in modeling, which affects the accuracy of the calculation of traction and dynamic braking force by the existing method. SUMMARY

[0009] The main purpose of the present application is to provide a rail transit train longitudinal dynamics modeling traction and dynamic braking force calculation method and its use method, to solve the technical problems in the prior art that the locomotive performance curve provided by the manufacturer is relied on, the traction characteristics at different traction positions and speeds are modeled, and the data of the locomotive performance curve is not easy to obtain. Secondly, even if the relevant data support is obtained, additional modeling work is needed to reflect the control characteristics of the locomotive and the change of efficiency or thermal effect at different train speeds, which makes the implementation of the existing method very complex and difficult. Finally, the thermal degradation of the locomotive in the actual operation process, and the transition of the traction power when the traction position changes are usually ignored or simplified in modeling, which affects the precision of the existing method in calculating the traction and dynamic braking force.

[0010] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a rail transit train longitudinal dynamics modeling traction and dynamic braking force calculation method is provided, comprising:

[0011] Step 1: obtaining the train acceleration, calculating the sum of external forces acting on the train according to the total mass of the train and the train acceleration;

[0012] Step 2: calculating the running resistance of the train according to the basic running resistance of the train, the additional slope resistance of the train and the additional curve resistance of the train;

[0013] Step 3: calculating the air braking force of the train according to the friction coefficient at the contact between the wheel and the brake shoe, the pressure at the contact between the wheel and the brake shoe of a certain wheelset and the number of wheelsets of the train;

[0014] Step 4: calculating the total traction and dynamic braking force of the train according to the sum of external forces acting on the train, the running resistance of the train and the air braking force of the train;

[0015] Step 5: distributing the total traction and dynamic braking force of the train to specific vehicles.

[0016] Preferably, the calculation formula of step 1 is:

[0017] F train =Ma train

[0018] Wherein, F train is the sum of external forces acting on the train; a train is the train acceleration; M is the total mass of the train;

[0019] The train acceleration a train The calculation formula is as follows:

[0020]

[0021] Wherein, a trainis the acceleration of the train; v train is the speed of the train, which can be obtained by train operation monitoring device, vehicle-mounted radar, vehicle-mounted GPS.

[0022] Preferably, the external force acting on the train in step 1 includes traction, braking force and resistance, the direction of the force is the same as the direction of the acceleration, the forward direction of the train is positive, and the backward direction of the train is negative.

[0023] Preferably, the step 2 comprises:

[0024] Step 21: assuming that the train is composed of m vehicles, numbered from front to back as j = 1, 2, …, m according to the forward direction of the train, the basic running resistance F of the train is calculated. br The formula is as follows:

[0025]

[0026] Wherein, F br is the basic running resistance of the train; k1, k2 and k3 are basic running resistance coefficients; v j is the speed of the jth vehicle; M j is the mass of the jth vehicle; g is the acceleration of gravity; m is the train composed of m vehicles;

[0027] Step 22: the additional slope resistance of the train is calculated, and the formula is as follows:

[0028]

[0029] Wherein: F sr is the additional slope resistance of the train; w j is the slope of the jth vehicle in slope; M j is the mass of the jth vehicle; g is the acceleration of gravity; m is the train composed of m vehicles;

[0030] Step 23: the additional curve resistance of the train is calculated, and the formula is as follows:

[0031]

[0032] Wherein, F cr is the additional curve resistance of the train; R j is the radius of curvature of the jth vehicle in curve; M j is the mass of the jth vehicle; g is the acceleration of gravity; m is the train composed of m vehicles;

[0033] Step 24: the sum of the running resistance of the train is calculated, and the formula is as follows:

[0034] F r = F br +Fsr +F cr

[0035] wherein F r is the sum of the running resistance of the train; F br is the basic running resistance of the train; F sr is the additional grade resistance of the train; F cr is the additional curve resistance of the train.

[0036] Preferably, the vehicles constituting the train in step 21 can be divided into two categories of locomotives and freight cars, and the basic running resistance coefficients of the vehicles of the same type are the same, and the k1, k2 and k3 of the locomotive are 1.2, 0.0065 and 0.000279 respectively, and the k1, k2 and k3 of the freight car are 0.92, 0.0048 and 0.000125 respectively.

[0037] Preferably, the step 3 comprises:

[0038] Step 31: calculating the pressure at the contact between the wheel of the jth vehicle and the brake shoe is as follows:

[0039]

[0040] wherein K j is the pressure at the contact between the wheel of the jth vehicle and the brake shoe, S is the area of the piston of the brake cylinder, p is the pressure of the brake cylinder, η is the transmission efficiency of the basic brake device, γ is the brake ratio, k c is the number of brake cylinders, and k s is the number of brake shoes.

[0041] Step 32: calculating the sum of the air braking forces of the train is as follows:

[0042]

[0043] wherein F ab is the sum of the air braking forces of the train, f is the friction coefficient at the contact between the wheel and the brake shoe, and K j is the pressure at the contact between the wheel of the jth vehicle and the brake shoe, and m is the number of vehicles constituting the train.

[0044] Preferably, the step 31 comprises:

[0045] The pressure of the brake cylinder changes with time, and the pressure of the brake cylinder rises during air braking and drops during brake release, and the pressure of the brake cylinder can be obtained by the following method:

[0046] According to the characteristics of the brake control valve, the characteristics of the brake cylinder inflation and the characteristics of the brake wave propagation speed, an equivalent mathematical model of the gas flow in the brake device is constructed to calculate the instantaneous pressure of the brake cylinder of each vehicle.

[0047] constructing a gas dynamics model of the brake device of the locomotive vehicle, and calculating the instantaneous pressure of the brake cylinder of each section of the locomotive vehicle according to the calculation result of the gas dynamics model;

[0048] training a deep learning algorithm based on real vehicle operation data, and calculating the instantaneous pressure of the brake cylinder of each section of the locomotive vehicle by inputting the real-time data of the applied acceleration, the pressure reduction amount, the traction force, the electric braking force, the large brake pressure reduction amount, and the small brake pressure reduction amount.

[0049] Preferably, the calculation formula of step 4 is:

[0050] F t / db = F train -F r -F ab

[0051] wherein F t / db is the total traction force and dynamic braking force of the train; F train is the sum of external forces acting on the train; F r is the running resistance acting on the train; and F ab is the air braking force acting on the train.

[0052] Preferably, step 5 comprises:

[0053] Step 51: initializing the initial running time of the train as t = 0, and the end running time of the train as t max , assuming that the traction and dynamic braking force of the train is provided by n sections of vehicles in the train, and the vehicles are numbered from front to back as i = 1, 2,..., n according to the advancing direction of the train, assuming that the transmission time delay of the driver control data from the first master control vehicle to the i-th vehicle is t i , and calculating the initial traction and dynamic braking force provided by the i-th vehicle at t = 0 according to the following formula:

[0054]

[0055] wherein F is the traction and dynamic braking force provided by the i-th vehicle at the current time t; and i is the i-th vehicle.

[0056] Step 52: increasing the running time t of the train by 1, and sequentially judging whether t ≥ t i from i = 2 to i = n.

[0057] Preferably, step 5 further comprises:

[0058] Step 53: when t ≥ t i , calculating the traction and dynamic braking force provided by the i-th vehicle at the current time t according to the following formula: when t < t i ,

[0059]

[0060] wherein, is the traction and dynamic braking force provided by the i-th vehicle at the current time t; t i is the transmission time delay of the driver's operation data transmitted from the 1st vehicle to the i-th vehicle; t is the current time;

[0061] Step 54: calculate the traction and dynamic braking force provided by the 1st vehicle at the current time t according to the following formula:

[0062]

[0063] wherein, is the traction and dynamic braking force provided by the 1st vehicle at the current time t;

[0064] is the traction and dynamic braking force provided by the i-th vehicle at the current time t; F t / db (t) is the total traction and dynamic braking force of the train at the current time t.

[0065] Step 55: repeat steps 52, 53 and 54 until t = t max

[0066] The technical scheme of the present application has the following technical effects:

[0067] By obtaining the train acceleration, the sum of external forces acting on the train is calculated; the running resistance acting on the train is calculated; the air braking force acting on the train is calculated; the total traction and dynamic braking force of the train is calculated; and the total traction and dynamic braking force of the train is distributed to specific vehicles. This method no longer relies on the acquisition of locomotive performance curves, simplifying the complexity and difficulty of locomotive control characteristic modeling in existing methods, and can realize accurate calculation and distribution of train traction and dynamic braking force, effectively supporting the construction of longitudinal dynamics model of rail transit train, providing model and method support for train stress and speed prediction, brake system and coupler design, and driving strategy optimization for train autonomous operation. BRIEF DESCRIPTION OF DRAWINGS

[0068] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the present application, and together with the description of the exemplary embodiments of the present application and their description serve to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0069] Figure 1 shows the calculation flowchart of the traction and dynamic braking force calculation method for longitudinal dynamics modeling of rail transit train according to the present application. DETAILED DESCRIPTION

[0070] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0071] like Figure 1 As shown, an embodiment of the present invention provides a method for calculating traction and power braking force in longitudinal dynamic modeling of a rail transit train, including: step 1: obtaining the acceleration of the train, and calculating the sum of the external forces acting on the train according to the total mass of the train and the acceleration of the train; step 2: calculating the running resistance of the train according to the basic running resistance of the train, the additional slope resistance of the train and the additional curve resistance of the train; step 3: calculating the air braking force acting on the train according to the friction coefficient at the contact between the wheel and the brake shoe, the pressure at the contact between the wheel and the brake shoe of a certain section of the wheel and the number of sections of the train; step 4: calculating the total traction force and power braking force of the train according to the sum of the external forces acting on the train, the running resistance acting on the train and the air braking force acting on the train; step 5: allocating the total traction force and power braking force of the train to specific vehicles.

[0072] In this embodiment, step 1: obtain the train acceleration, and calculate the sum of the external forces acting on the train based on the total mass of the train and the train acceleration; the calculation formula for step 1 is:

[0073] F train =Ma train

[0074] Among them, F train is the sum of the external forces acting on the train; a train is the train acceleration; M is the total mass of the train;

[0075] Train acceleration a train The calculation formula is as follows:

[0076]

[0077] Among them, a train is the train acceleration; v train The train speed can be obtained through the train operation monitoring device, on-board radar, and on-board GPS.

[0078] In this embodiment, the external forces acting on the train in step 1 include traction, braking and resistance. The direction of the force is the same as the direction of acceleration, with the forward direction of the train being positive and the backward direction being negative.

[0079] In this embodiment, step 2: calculating the running resistance of the train based on the basic running resistance of the train, the additional slope resistance of the train, and the additional curve resistance of the train; step 2 includes:

[0080] Step 21: Suppose the train is composed of m vehicles, numbered from front to back as j = 1, 2,..., m in the direction of train movement, calculate the basic running resistance F of the train br The formula is as follows:

[0081]

[0082] Where F br is the basic running resistance of the train; k1, k2 and k3 are basic running resistance coefficients; v j is the speed of the jth vehicle; M j is the mass of the jth vehicle; g is the acceleration of gravity; m is the train composed of m vehicles;

[0083] Step 22: Calculate the additional slope resistance of the train The formula is as follows:

[0084]

[0085] Where F sr is the additional slope resistance of the train; w j is the slope of the jth vehicle in slope in thousandth; M j is the mass of the jth vehicle; g is the acceleration of gravity; m is the train composed of m vehicles;

[0086] Step 23: Calculate the additional curve resistance of the train The formula is as follows:

[0087]

[0088] Where F cr is the additional curve resistance of the train; R j is the radius of curvature of the jth vehicle in curve; M j is the mass of the jth vehicle; g is the acceleration of gravity; m is the train composed of m vehicles;

[0089] Step 24: Calculate the sum of the running resistance received by the train The formula is as follows:

[0090] F r = F br + F sr + F cr

[0091] Where F r is the sum of the running resistance received by the train; F br is the basic running resistance of the train; F sr is the additional slope resistance of the train; F cr is the additional curve resistance of the train.

[0092] In this embodiment, the vehicles constituting the train in step 21 can be divided into two categories: locomotives and freight cars. The basic running resistance coefficients of the same type of vehicles are the same. The k1, k2 and k3 of the locomotive are 1.2, 0.0065 and 0.000279 respectively, and the k1, k2 and k3 of the freight car are 0.92, 0.0048 and 0.000125 respectively.

[0093] In this embodiment, step 3: according to the friction coefficient of the wheel and the brake shoe at the contact, the pressure of the wheel and the brake shoe at the contact of a certain section of the wheel, and the number of the train, the air braking force of the train is calculated; step 3 includes:

[0094] Step 31: the pressure of the wheel and the brake shoe at the contact of the jth section of the vehicle is calculated as follows:

[0095]

[0096] wherein K j is the pressure of the wheel and the brake shoe at the contact of the jth section of the vehicle, S is the area of the brake cylinder piston, p is the brake cylinder pressure, η is the transmission efficiency of the basic brake device, γ is the brake ratio, k c is the number of brake cylinders, and k s is the number of brake shoes.

[0097] Step 32: the sum of the air braking forces of the train is calculated as follows:

[0098]

[0099] wherein F ab is the sum of the air braking forces of the train, f is the friction coefficient of the wheel and the brake shoe at the contact, K j is the pressure of the wheel and the brake shoe at the contact of the jth section of the vehicle, and m is the number of sections of the train.

[0100] In this embodiment, the f of different types of vehicles in the train is different. The friction coefficient of the locomotive can be calculated according to the formula , and the friction coefficient of the freight car can be calculated according to the formula .

[0101] In this embodiment, the step 31 includes:

[0102] The brake cylinder pressure changes with time. When air braking, the brake cylinder pressure rises, and when the brake is released, the brake cylinder pressure rises. The brake cylinder pressure can be obtained by the following method:

[0103] According to the brake control valve characteristics, the brake cylinder inflation characteristics and the brake wave propagation speed characteristics, an equivalent mathematical model of the gas flow in the brake device is constructed to calculate the instantaneous pressure of the brake cylinder of each section of the locomotive vehicle.

[0104] A gas dynamics model of the brake device of the locomotive vehicle is constructed, and the instantaneous pressure of the brake cylinder of each section of the locomotive vehicle is calculated according to the calculation result of the gas dynamics model;

[0105] A deep learning algorithm is trained based on real vehicle operation data, and the instantaneous pressure of the brake cylinder of each section of the locomotive vehicle is calculated by inputting real-time data of applied acceleration, pressure reduction amount, traction force, electric braking force, large brake pressure reduction amount, and small brake pressure reduction amount.

[0106] In this embodiment, step 4: calculating the total traction force and dynamic braking force of the train according to the sum of external forces acting on the train, the running resistance acting on the train, and the air braking force acting on the train; the calculation formula of step 4 is:

[0107] F t / db = F train -F r -F ab

[0108] Wherein, F t / db is the total traction force and dynamic braking force of the train; F train is the sum of external forces acting on the train; F r is the running resistance acting on the train; and F ab is the air braking force acting on the train.

[0109] In this embodiment, step 5: distributing the total traction force and dynamic braking force of the train to specific vehicles. Step 5 includes:

[0110] Step 51: initializing the initial running time of the train as t = 0, and the end running time of the train as t max , assuming that the traction and dynamic braking force of the train is provided by n sections of vehicles in the train, and the vehicles are numbered from front to back as i = 1, 2,..., n according to the forward direction of the train, assuming that the transmission delay of the driver's operation data from the first section of the master control vehicle to the i-th section of the vehicle is t i , and the initial traction and dynamic braking force provided by the i-th section of the vehicle at t = 0 is calculated according to the following formula;

[0111]

[0112] Wherein, is the traction and dynamic braking force provided by the i-th section of the vehicle at the current time t; and i is the i-th section of the vehicle.

[0113] Step 52: increasing the running time t of the train by 1, and sequentially judging whether t ≥ t i from i = 2 to i = n.

[0114] In this embodiment, step 5 further includes:

[0115] Step 53: when t ≥ t iWhen t < t i When t < t

[0116]

[0117] Wherein, is the traction and dynamic braking force provided by the ith section vehicle at the current time t; t i is the transmission time delay of the driver's operation data transmitted from the first section master vehicle to the ith section vehicle; t is the current time;

[0118] Step 54: calculate the traction and dynamic braking force provided by the first section vehicle at the current time t according to the following formula:

[0119]

[0120] Wherein, is the traction and dynamic braking force provided by the first section vehicle at the current time t;

[0121] is the traction and dynamic braking force provided by the ith section vehicle at the current time t; F t / db (t) is the total traction and dynamic braking force of the train at the current time t.

[0122] Step 55: repeat steps 52, 53 and 54 until t = t max

[0123] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0124] By obtaining the train acceleration, the sum of the external forces acting on the train is calculated; the running resistance acting on the train is calculated; the air braking force acting on the train is calculated; the total traction and dynamic braking force of the train is calculated; and the total traction and dynamic braking force of the train is distributed to specific vehicles. This method no longer relies on the acquisition of locomotive performance curves, simplifying the complexity and difficulty of locomotive control feature modeling in existing methods, and can realize accurate calculation and distribution of train traction and dynamic braking force, effectively supporting the construction of a longitudinal dynamics model of a rail transit train, and providing model and method support for train force and speed prediction, brake system and coupler design, and driving strategy optimization for train autonomous operation.

[0125] The above only describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for calculating traction and braking force in longitudinal dynamics modeling of rail transit trains, characterized in that: include: Step 1: Obtain the train acceleration and calculate the sum of the external forces acting on the train based on the total mass of the train and the train acceleration; Step 2: Calculate the running resistance of the train based on the basic running resistance of the train, the additional slope resistance of the train, and the additional curve resistance of the train; Step 3: Calculate the air braking force on the train based on the friction coefficient at the contact point between the wheel and the brake shoe, the pressure at the contact point between the wheel and the brake shoe of a certain section of the wheel, and the number of sections of the train; Step 4: Calculate the total traction force and dynamic braking force of the train based on the sum of the external forces acting on the train, the running resistance of the train, and the air braking force acting on the train; Step 5: Allocate the total traction force and power braking force of the train to specific vehicles.

2. The method for calculating traction and braking force of a rail transit train longitudinal dynamics model according to claim 1, characterized in that: The calculation formula of step 1 is: F train =Ma train Among them, F train is the sum of the external forces acting on the train; a train is the train acceleration; M is the total mass of the train; Train acceleration a train The calculation formula is as follows: Among them, a train is the train acceleration; v train The train speed can be obtained through the train operation monitoring device, on-board radar, and on-board GPS.

3. The method for calculating traction and braking force of a rail transit train longitudinal dynamics model according to claim 1, wherein: In step 1, the external forces acting on the train include traction, braking and resistance. The direction of the force is the same as the direction of acceleration, with the forward direction of the train being positive and the backward direction being negative.

4. The method for calculating traction and braking force for longitudinal dynamics modeling of a rail transit train according to claim 1, characterized in that: The step 2 includes: Step 21: Assume that the train consists of m vehicles, numbered j = 1, 2, ..., m from the front to the back according to the train's direction of travel. Calculate the basic running resistance F of the train. br The formula is as follows: Among them, F br is the basic running resistance of the train; k1, k2 and k3 are the basic running resistance coefficients; v j is the speed of the jth vehicle; M j is the mass of the jth vehicle; g is the acceleration due to gravity; m is the number of vehicles in the train; Step 22: The formula for calculating the additional slope resistance of the train is as follows: Among them: F sr is the additional slope resistance of the train; w j M is the slope of the ramp where the vehicle in section j is located in thousandths; j is the mass of the jth vehicle; g is the acceleration due to gravity; m is the number of vehicles in the train; Step 23: The formula for calculating the additional curve resistance of the train is as follows: Among them, F cr is the additional curve resistance of the train; R j M is the curvature radius of the curve where the vehicle in section j is located; j is the mass of the jth vehicle; g is the acceleration due to gravity; m is the number of vehicles in the train; Step 24: The formula for calculating the sum of the running resistances on the train is as follows: F r =F br +F sr +F cr Among them, F r is the sum of the running resistances of the train; F br is the basic running resistance of the train; F sr is the additional slope resistance of the train; F cr is the additional curve resistance of the train.

5. The method for calculating traction and braking force of a rail transit train longitudinal dynamics model according to claim 1, wherein: The vehicles constituting the train in step 21 can be divided into two categories: locomotives and freight cars. The basic running resistance coefficients of the same type of vehicles are the same: k1, k2, and k3 of the locomotive are 1.2, 0.0065, and 0.000279, respectively; and k1, k2, and k3 of the freight car are 0.92, 0.0048, and 0.000125, respectively.

6. The method for calculating traction and braking force for longitudinal dynamics modeling of a rail transit train according to claim 1, characterized in that: The step 3 comprises: Step 31: The formula for calculating the pressure at the contact point between the wheel and the brake shoe of the vehicle in section j is as follows: Among them, K j is the pressure at the contact point between the wheel and brake shoe of the jth vehicle, S is the area of ​​the brake cylinder piston, p is the brake cylinder pressure, η is the transmission efficiency of the basic brake device, γ is the braking ratio, k c is the number of brake cylinders, k s is the number of brake shoes; Step 32: The formula for calculating the sum of the air braking forces acting on the train is as follows: Among them, F ab is the sum of the air braking forces acting on the train, f is the friction coefficient at the contact point between the wheel and the brake shoe; K j is the pressure at the contact point between the wheel and brake shoe of the jth vehicle; m is the number of vehicles in the train.

7. The method for calculating traction and braking force for longitudinal dynamics modeling of a rail transit train according to claim 1, characterized in that: The step 31 includes: The brake cylinder pressure changes with time. When air braking is applied, the brake cylinder pressure rises. When the brake is released, the brake cylinder pressure rises. The brake cylinder pressure can be obtained by the following method: Based on the characteristics of the brake control valve, the brake cylinder charging characteristics, and the brake wave propagation velocity characteristics, an equivalent mathematical model of the gas flow in the brake device is constructed to calculate the instantaneous pressure of the brake cylinder of each locomotive vehicle; Constructing a gas dynamics model of the rolling stock braking device model, and calculating the instantaneous pressure of the brake cylinder of each rolling stock according to the calculation results of the gas dynamics model; The deep learning algorithm is trained based on actual vehicle operation data. By inputting real-time data on applied speed, decompression, traction, electric braking force, large gate decompression, and small gate decompression, the instantaneous pressure of the brake cylinder of each locomotive vehicle is calculated.

8. The method for calculating traction and braking force for longitudinal dynamics modeling of a rail transit train according to claim 1, characterized in that: The calculation formula of step 4 is: F t / db =F train -F r -F ab Among them, F t / db is the total traction force and power braking force of the train; F train The sum of the external forces acting on the train; F r F is the running resistance of the train; ab The air braking force on the train.

9. The method for calculating traction and braking force of a rail transit train longitudinal dynamics model according to claim 1, wherein: The step 5 comprises: Step 51: Initialize and set the train's initial running time to t=0 and the train's end running time to t max , assuming that the traction and braking force of the train are jointly provided by n vehicles in the train, numbered from front to back as i = 1, 2, ..., n according to the train's forward direction, and assuming that the transmission delay of the driver's control data from the first master control vehicle to the i-th vehicle is t i , the formula for calculating the initial traction and power braking force provided by the vehicle in section i at t = 0 is as follows; in, The traction and braking forces provided by the i-th vehicle at the current time t; i is the i-th vehicle; Step 52: Increase the train running time t by 1, and determine whether t ≥ t from i = 2 to i = n. i .

10. The method for calculating traction and braking force of a rail transit train longitudinal dynamics model according to claim 9, characterized in that: Step 5 also includes: Step 53: When t ≥ t i The formula for calculating the traction and braking force provided by the vehicle in section i at the current time t is as follows: i hour, in, The traction and braking force provided by the i-th vehicle at the current time t; t i is the transmission delay of the driver's control data from the first master vehicle to the i-th vehicle; t is the current time; Step 54: The formula for calculating the traction and power braking force provided by the first vehicle at the current time t is as follows: in: The traction and power braking forces provided by vehicle 1 at the current time t; The traction and braking force provided by the i-th vehicle at the current time t; F t / db (t) is the total traction force and power braking force of the train at the current time t. Step 55: Repeat steps 52, 53, and 54 until t=t max .

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