Short-distance parking speed planning method for urban rail transit train, device, and medium

Abstract

The present invention relates to a short-distance parking speed planning method for an urban rail transit train, a device, and a medium. The method comprises the following steps: step S1, at a reference curve level, designing a plurality of short-distance speed planning scenarios on the basis of delay characteristics and acceleration response gradient characteristics of a train; step S2, constructing a quadratic equation-based speed planning module and a linear equation-based speed planning module on the basis of the similarity between the operation processes of the plurality of short-distance speed planning scenarios; and step S3, providing a speed condition and a distance condition under which a planning solution is present in each scenario, and a selection mechanism when two target speed planning solutions are present. Compared with the prior art, the present invention has the advantages of avoiding overshooting during short-distance parking and improving operation efficiency.

Description

Methods, equipment, and media for planning the speed of close-range stops for urban rail transit trains Technical Field

[0001] This invention relates to urban rail transit signaling systems, and more particularly to a method, equipment, and medium for planning the speed of urban rail transit trains stopping close to stations. Background Technology

[0002] Urban rail transit has advantages such as large capacity, punctuality, and energy efficiency, and carries most of the passenger flow of urban public transportation systems. With the advancement of urbanization, more and more newly opened lines have adopted interconnected fully automated operation systems to meet the increasingly high requirements of train density. The reliability and efficiency of train automatic driving systems have a significant impact on the operational capacity of the lines. During peak hours, the train operation density is getting higher and higher, and the tracking interval between two trains is getting smaller and smaller, almost reaching the design limit of the line's operational capacity.

[0003] During the train's entry into a station and stopping, interference such as temporary closure of the preceding signal or a brief locomotive signal failure may cause a phenomenon where the train first brakes heavily to decelerate and then resumes full-speed traction. If the stopping point is too close at this time, the train, with its large time delay characteristics, is prone to overshooting the reference speed. This is because the reference curve calculation in the conventional station stopping function is based on real-time motion planning. When the stopping point is far away, the ATO control module has sufficient adjustment time to allow the train to transition from the section cruise state and decelerate into the sliding motion state of the reference stop. However, when the stopping point is close, if the train's time delay response characteristics, distance constraints, and control command change rate constraints are not considered, the train's kinematic state will not have enough time to adjust to the sliding motion state and will not be able to follow the reference speed curve well, leading to the train overshooting the reference speed.

[0004] Although fully automatic operation systems are equipped with forward and reverse automatic skip functions, by applying small-level traction and coordinating with light braking, the train can be controlled to run slowly at low speeds, achieving accurate recalibration in the case of inaccurate stopping, the skip function is suitable for precise stopping tasks within 5m of the stopping point. In short-distance stopping tasks where the stopping distance exceeds 5m, the low-speed operation characteristics of the skip function will seriously affect the operating efficiency of busy lines. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art by providing a method, equipment and medium for planning the speed of close-range stops of urban rail transit trains.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] According to a first aspect of the present invention, a method for planning the speed of close-range stops for urban rail transit trains is provided, the method comprising the following steps:

[0008] Step S1: At the reference curve level, design multiple short-distance speed planning scenarios based on the train delay characteristics and acceleration response gradual change characteristics.

[0009] Step S2: Based on the similarity of various near-distance velocity planning scenarios during operation, construct a quadratic equation velocity planning module and a linear equation velocity planning module;

[0010] Step S3 provides the speed and distance conditions for the planning solution in each scenario, as well as the selection mechanism when there are two target speed planning solutions.

[0011] As a preferred technical solution, the train delay characteristics in step S1 include traction delay, braking delay, and full service brake release delay; the acceleration response gradual characteristics include traction acceleration response, traction deceleration response, braking deceleration response, braking acceleration response, and full service brake deceleration relief characteristics.

[0012] As a preferred technical solution, the gradual characteristic of the acceleration response in step S1 is approximately described by the acceleration change process of a constant Jerk value; the near-distance velocity planning scenario in step S1 involves differential relationship calculations between four variables: acceleration rate of change, acceleration, velocity, and distance.

[0013] As a preferred technical solution, the quadratic equation velocity planning module in step S2 includes nine time periods, namely traction delay, acceleration increase of constant Jerk value, uniform acceleration, acceleration decrease of constant Jerk value, uniform speed operation, deceleration increase of constant Jerk value, uniform deceleration, and deceleration decrease of constant Jerk value.

[0014] As a preferred technical solution, the planning solution of the quadratic equation speed planning module in step S2 is the speed during the uniform running stage, and the initial state of the train in the quadratic equation speed planning module includes the stationary state and the uniform running state with initial speed.

[0015] As a preferred technical solution, the parameter configuration of the quadratic equation speed planning module in step S2 includes two types. The first type is determined by the train characteristics, including traction delay and braking delay. The second type is the project setting value, including the uniform speed segment running time, the maximum allowable acceleration value and the rate of change of acceleration, as well as the minimum allowable deceleration value and the rate of change of deceleration.

[0016] As a preferred technical solution, the quadratic equation velocity planning module in step S2 includes a first velocity boundary condition and a second velocity boundary condition, wherein the source of the first velocity boundary condition is that the time of the uniform acceleration segment must be greater than or equal to zero, and the source of the second velocity boundary condition is that the time of the uniform deceleration segment must be greater than or equal to zero.

[0017] As a preferred technical solution, the distance boundary calculation of the quadratic equation speed planning module in step S2 depends on the speed boundary conditions, and the existence condition of the planning solution of the quadratic equation speed planning module is that the distance to the parking point is greater than or equal to the distance boundary of the quadratic equation speed planning module.

[0018] As a preferred technical solution, the linear equation speed planning module in step S2 includes 7 time periods, namely, the delay of the release of the full service brake, the decrease of the full service brake deceleration with constant Jerk value, the uniform speed operation, the increase of the deceleration with constant Jerk value, the uniform deceleration, and the decrease of the deceleration with constant Jerk value.

[0019] As a preferred technical solution, the planning solution of the linear equation speed planning module in step S2 is the speed during the uniform running stage, and the initial state of the train in the linear equation speed planning module is the moment when the train is in the full service braking deceleration and begins to release.

[0020] As a preferred technical solution, the parameter configuration of the linear equation speed planning module in step S2 includes two types. The first type is determined by the train characteristics, including full service braking delay and braking delay. The second type is the project setting value, including full service braking deceleration, full service braking deceleration mitigation rate, constant speed segment running time, allowable minimum deceleration value and deceleration rate, and allowable maximum acceleration rate.

[0021] As a preferred technical solution, the stopping and braking phase of the linear equation velocity planning module in step S2 includes four time periods: braking delay, increasing deceleration with constant Jerk value, uniform deceleration, and decreasing deceleration with constant Jerk value.

[0022] As a preferred technical solution, the distance boundary of the linear equation speed planning module in step S2 includes three parts of running distance: the running distance during the full service braking release delay period, the running distance during the full service braking deceleration relief change period, and the running distance during the stop braking period.

[0023] The existence condition for the solution of the linear velocity planning module is that the distance to the parking point is greater than or equal to the distance boundary of the linear velocity planning module.

[0024] As a preferred technical solution, each scenario in step S3 includes a stationary state planning scenario and a deceleration state planning scenario. The initial state of the train in the deceleration state planning scenario is when the train is in the moment when the full service braking deceleration begins to release. The deceleration state planning scenario includes a first type of sub-scenario, a second type of sub-scenario, and a third type of sub-scenario.

[0025] The first type of sub-scenario is when the train's speed drops to zero during the full braking release delay period, and then enters the quadratic equation speed planning module process in a stationary state;

[0026] The second type of sub-scenario is the process of the train reducing its speed to zero during the full-use braking deceleration period and then entering the quadratic equation speed planning module process in a stationary state;

[0027] The third sub-scenario is when the train's speed does not drop to zero after the full service braking is released. In this case, there are two possible solutions: a quadratic equation speed solution and a linear equation speed solution.

[0028] As a preferred technical solution, the initial speed value of the quadratic equation speed planning module in the first type of sub-scenario is 0, and the initial distance value is the parking point distance minus the actual running distance during the full common braking release delay period;

[0029] In the second type of sub-scenario, the initial speed value of the quadratic equation speed planning module is 0, and the initial distance value is the distance to the parking point minus the running distance of two time periods, which are the running distance of the full-use braking release delay period and the actual running distance of the full-use braking deceleration relief period.

[0030] In the third sub-scenario, the initial speed value of the quadratic equation speed planning module is the estimated speed at the moment when the full-use braking deceleration is reduced to 0, and the initial distance value is the distance to the parking point minus the running distance of two time periods, which are the running distance of the full-use braking release delay period and the running distance of the full-use braking deceleration relief period.

[0031] As a preferred technical solution, the initial speed value of the linear equation speed planning module in the third sub-scenario is the train speed at the moment when the full-use braking begins to release, and the initial distance value is the distance to the stopping point.

[0032] According to a second aspect of the present invention, an electronic device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the program to implement the method described thereon.

[0033] According to a third aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described thereon.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] 1) At the reference curve level, in addition to considering the train's delay characteristics, this invention also uses the acceleration change process of constant Jerk values ​​to approximate the first-order acceleration response process of the train. Therefore, the planned target speed curve is suitable for the train traction and braking response characteristics during the process of stopping at close range.

[0036] 2) Compared with conventional stop functions, this invention can avoid the phenomenon of mark rushing during close-range stop processes.

[0037] 3) Compared to the skip function, this invention can accurately stop at the platform while ensuring operational efficiency.

[0038] 4) This invention fills the gap between the conventional stop function and the jump function. These three functions complement each other and cover the stop needs of the entire distance range. Their reasonable use not only ensures accurate stopping but also improves operational efficiency. Attached Figure Description

[0039] Figure 1 is a schematic diagram of the variables in the short-distance speed planning process of urban rail transit trains according to the present invention;

[0040] Figure 2 is a schematic diagram of the classification of urban rail transit train close-range stopping speed planning scenarios according to the present invention;

[0041] Figure 3 is a flowchart of the urban rail transit train near-distance stop speed planning function of the present invention;

[0042] Figure 4 is a schematic diagram of the quadratic equation speed planning for close-range stops of urban rail transit trains according to the present invention.

[0043] Figure 5 is a schematic diagram of the linear equation speed planning for close-range stops of urban rail transit trains according to the present invention.

[0044] Figure 6 shows the urban rail transit train T of the present invention. ird A schematic diagram of a speed planning process where the speed decreases to zero within a given time.

[0045] Figure 7 shows the urban rail transit train T of the present invention. irj A schematic diagram of a speed planning process where the speed decreases to zero within a given time.

[0046] Figure 8 is a schematic diagram of the existence of two speed planning solutions for urban rail transit trains stopping at close range in this invention. Detailed Implementation

[0047] 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, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0048] This invention addresses the speed planning problem encountered in near-station stops for urban rail transit trains by presenting a speed planning method for this task. At the reference curve level, considering both train delay and acceleration response characteristics, various near-station stop speed planning scenarios are designed. Based on the similarities in the operation of these scenarios, two basic modules are reconstructed: a quadratic equation speed planning module and a linear equation speed planning module. The speed and distance conditions for the planning solutions in each scenario, as well as the selection mechanism when two planning solutions exist, are discussed.

[0049] This invention is achieved through the following technical solution, as detailed below:

[0050] Step 1: Describe the short-distance speed planning process based on the train's delay characteristics and the gradual change characteristics of its acceleration response;

[0051] Step 2: The basic module for quadratic equation velocity programming was established, and the existence conditions of the programming solution were given;

[0052] Step 3: The basic module for linear velocity programming was established, and the existence conditions of the programming solution were given;

[0053] Step 4: The initial conditions for the velocity planning solutions of the quadratic and linear equations in the complex scenario are given;

[0054] Step 5 presents the selection mechanism when there are two target velocity planning solutions in a complex scenario.

[0055] The train delay characteristics in step 1 include traction delay, braking delay, and full service brake release delay.

[0056] The gradual change characteristics of train acceleration response in step 1 include traction acceleration response, traction deceleration response, braking deceleration response, braking acceleration response, and full-use braking deceleration relief characteristics.

[0057] The gradual characteristic of the acceleration response in step 1 is approximated by the acceleration change process of a constant Jerk value.

[0058] The near-distance velocity planning process in step 1 involves differential relationship calculations between four variables: the rate of change of acceleration (i.e., Jerk), acceleration, velocity, and distance.

[0059] The quadratic equation velocity planning process in step 2 includes nine time periods: traction delay, acceleration increasing with constant Jerk value, uniform acceleration, acceleration decreasing with constant Jerk value, uniform speed operation (including braking delay), deceleration increasing with constant Jerk value, uniform deceleration, and deceleration decreasing with constant Jerk value.

[0060] In step 2, the solution to the quadratic equation velocity programming refers to the velocity during the uniform motion phase.

[0061] The initial state of the train in step 2, which involves quadratic equation velocity planning, includes a stationary state and a uniform running state with an initial velocity.

[0062] In step 2, the parameter configuration for the quadratic equation speed planning has two types. The first type is determined by the train characteristics, including traction delay and braking delay. The second type is the project setting value, including the uniform speed segment running time, the maximum allowable acceleration value and the rate of change of acceleration, as well as the minimum allowable deceleration value and the rate of change of deceleration.

[0063] The source of the first velocity boundary condition in step 2 of the quadratic equation velocity planning is that the time of the uniformly accelerated running segment must be greater than or equal to zero.

[0064] The source of the second velocity boundary condition in step 2 of the quadratic equation velocity planning is that the time of the uniformly decelerated running segment must be greater than or equal to zero.

[0065] In step 2, the distance boundary calculation for the quadratic equation velocity programming depends on the velocity boundary conditions.

[0066] The existence condition for the solution of the quadratic equation velocity programming in step 2 is that the distance to the parking point is greater than or equal to the distance boundary of the quadratic equation velocity programming.

[0067] The speed planning process in step 3 includes seven time periods: full service brake release delay, full service brake deceleration decrease with constant Jerk value, uniform speed operation (including braking delay), deceleration increase with constant Jerk value, uniform deceleration, and deceleration decrease with constant Jerk value.

[0068] In step 3, the solution to the linear equation velocity programming problem refers to the velocity during the uniform motion phase.

[0069] In step 3, the initial state of the train in the linear equation speed planning is the moment when the train begins to release the full service braking deceleration.

[0070] In step 3, the parameter configuration for the linear equation speed planning has two types. The first type is determined by the train characteristics, including full service braking delay and braking delay. The second type is the project setting value, including full service braking deceleration, full service braking deceleration mitigation rate, constant speed segment running time, minimum allowable deceleration value and deceleration rate, and maximum allowable acceleration rate.

[0071] The stopping and braking phase in the linear equation velocity planning process in step 3 consists of four time periods: braking delay, increasing deceleration with constant Jerk value, uniform deceleration, and decreasing deceleration with constant Jerk value.

[0072] In step 3, the distance boundary of the linear velocity planning consists of three parts: the running distance during the full service braking release delay period, the running distance during the full service braking deceleration relief change period, and the running distance during the stop braking period.

[0073] The existence condition for the solution of the linear velocity programming in step 3 is that the distance to the parking point is greater than or equal to the distance boundary of the linear velocity programming.

[0074] In step 4, the initial state of the train in the composite scenario is the moment when the train begins to release the full service braking deceleration.

[0075] In step 4, the first sub-scenario under the composite scenario is when the train's speed drops to zero during the full braking release delay period, and then enters the quadratic equation speed planning process in a stationary state.

[0076] In step 4, the initial speed value of the quadratic equation speed planning in the first sub-scenario of the composite scenario is 0, and the initial distance value is the distance to the parking point minus the actual running distance during the full-use brake release delay period.

[0077] The second sub-scenario in step 4 of the composite scenario is when the train's speed drops to zero during the full-use braking deceleration period and then enters the quadratic equation speed planning process in a stationary state.

[0078] In step 4, the initial speed value of the quadratic equation speed planning in the second sub-scenario of the composite scenario is the estimated speed at the moment when the full-use braking deceleration is reduced to 0. The initial distance value is the distance to the parking point minus the running distance of two time periods, which are the running distance during the full-use braking release delay period and the actual running distance during the full-use braking deceleration relief period.

[0079] In step 4, the third sub-scenario under the composite scenario is that the train's speed does not drop to zero after the full service braking is released. In this case, there are two possible solutions: a quadratic equation speed solution and a linear equation speed solution.

[0080] In step 4, the initial speed value of the quadratic equation speed planning in the third sub-scenario of the composite scenario is 0, and the initial distance value is the distance to the parking point minus the running distance of two time periods, which are the running distance of the full-use braking release delay period and the running distance of the full-use braking deceleration relief period.

[0081] In step 4, the initial speed value of the first-order equation speed planning in the third sub-scenario of the composite scenario is the train speed at the moment when the full-use brake begins to release, and the initial distance value is the distance to the stopping point.

[0082] The specific implementation process of this invention is as follows:

[0083] 1. Short-distance stop speed planning process

[0084] Since a train is a system with a large inertial time delay, its time delay characteristics and acceleration response characteristics must be considered during the planning of train speeds for near-station stops. The traction and braking model of urban rail transit trains is usually described using a first-order time-delay system, as shown in equation (1):

[0085] Where K is the steady-state gain coefficient, representing the mapping relationship between the signal system output level and the train response acceleration in steady state, and T and τ These are the system time constant and the pure delay, respectively, representing the system's transient characteristics.

[0086] In order to characterize the transient acceleration characteristics described in formula (1), in the process of planning the speed of train stopping close to the station, in addition to considering the train's delay characteristics, it is also necessary to consider the gradual characteristics of the acceleration response. Here, the acceleration change process with constant Jerk value is used to approximate the first-order acceleration response process.

[0087] The speed planning process involves differential relationship calculations between four variables: the rate of change of acceleration (i.e., Jerk), acceleration, velocity, and distance. These variables describe the train response process, as shown in formula (2):

[0088] Where t represents the time variable, t0 represents the initial planning time, a(t) represents the acceleration variable, v(t) represents the velocity variable, s(t) represents the distance variable, and J represents the rate of change of acceleration, which is a constant value in the time interval [t0,t].

[0089] Figure 1 illustrates the speed planning process for train departure from a stationary state, along with the graphical curves of relevant variables at each stage. The train's response characteristics after departure from a stationary state can be approximated by nine stages: traction delay, traction acceleration response, uniform acceleration, traction deceleration response, uniform speed (including braking delay), braking deceleration response, uniform deceleration, and braking acceleration response. The traction delay and braking delay stages consider the train's traction and braking delay characteristics. In the traction acceleration response, traction deceleration response, braking deceleration response, and braking acceleration response stages, the Jerk value is a configuration parameter combining the train's response characteristics. Additionally, the running time in the uniform speed stage and the acceleration values ​​in the uniform acceleration and uniform deceleration stages are also configuration parameters. Finally, the cumulative planned distance for each stage must equal the distance to the train's stopping point.

[0090] 2. Short-distance stop speed planning scenario

[0091] Considering near-station stop speed planning under two conditions: the first is target speed planning when the train is stationary, and the second is target speed planning when the train is decelerating and braking. The second type of target speed planning can be further subdivided into several sub-scenarios. Figure 2 shows three typical scenarios in near-station stop speed planning. Typical scenario 1 involves the train departing from a stationary state and experiencing three operating conditions: traction, constant speed, and braking. Typical scenario 2 involves the train experiencing three operating conditions after the deceleration and braking process. Typical scenario 3 involves the train experiencing two operating conditions after the deceleration and braking process. Based on the similarities in the operation of these various scenarios, two basic modules can be reconstructed: a quadratic equation speed planning module and a linear equation speed planning module.

[0092] The train's near-stop speed planning function flow is shown in Figure 3. First, it determines whether the train's distance to the stopping point is within a preset threshold range. If the condition is not met, speed planning is not performed. The reasons are as follows: one possibility is that the train is far enough from the stopping point, in which case, similar to a regular stopping process, the train has enough time to enter a sliding motion state during braking to ensure stopping accuracy. Another possibility is that the train is too close to the stopping point, requiring a low-speed jump function to achieve accurate stopping. If the stopping point distance condition is met, the target speed planning process for the two states is then determined. If the train is stationary, the quadratic equation speed planning module with an initial speed of zero is used for target speed planning. If the train is in a braking and deceleration state due to interference from the track ahead, the train speed at the end of the braking release process needs to be estimated when the interference disappears. If the estimated speed is zero, the quadratic equation speed planning module with an initial speed of zero can be used. If the estimated speed is not zero, there may be target speed planning processes under typical scenarios 2 and 3, requiring the calculation of the quadratic equation planning speed after braking release and the linear equation planning speed for constant speed operation after braking release, respectively. If two programming solutions exist simultaneously, the solution with the largest target speed should be selected to ensure operational efficiency.

[0093] 3. Solution to the quadratic equation velocity programming and its existence conditions

[0094] Figure 4 illustrates the target speed planning process for train departure from a stationary state. Corresponding to typical scenario 1 in Figure 2, a total of 9 time intervals are involved, and the planned speed for the constant speed segment can be obtained using a quadratic equation. md The time intervals represent train traction delays. Time interval T1 represents the change in traction acceleration at a constant Jerk value, time interval T2 represents the uniform acceleration process, time interval T3 represents the change in traction deceleration at a constant Jerk value, and time interval T4 represents the uniform speed operation process. bd The time periods represent train braking delays. Time period T5 represents the braking deceleration process with a constant Jerk value, time period T6 represents the uniform deceleration process, and time period T7 represents the braking acceleration process with a constant Jerk value. Here, T... md and T bd Related to the train delay characteristics, it is a definite constant value. T4 is the project setting value, which is also a definite constant value. The planned speed V in the uniform speed stage is the variable to be solved.

[0095] The acceleration change time for the four constant Jerk values ​​is shown in equation (3).

[0096] Where A max and A min J represents the maximum and minimum allowable acceleration values ​​during the target velocity planning process, respectively. max and Jmin These represent the maximum and minimum allowable rates of change of acceleration, respectively.

[0097] Although the initial speed of the train is zero in this scenario, without loss of generality, the initial speed is represented by the variable v0. The distance to the stopping point is represented by the symbol S. Applying the condition that the sum of the running distances in each time period equals the distance to the stopping point, the quadratic equation for calculating the planned speed V can be obtained, as shown in formula (4). 2 +BV+C=0 (4)

[0098] The expression for the quadratic coefficient A is as follows: A = 1 / (2A) max )-1 / (2A min ),

[0099] The expression for the coefficient B of the linear term is as follows: B = T⁴ + T bd +(T3+T5) / 2, the expression for the coefficient C of the constant term is as follows:

[0100] Based on the requirement that the time interval T2 of uniform acceleration is not less than zero, the first boundary condition for the planned velocity is obtained, as shown in formula (5), V lim_1 =v0+A max (T1+T3) / 2 (5)

[0101] Similarly, the time interval T6 for uniformly decelerated operation should not be less than zero, thus obtaining the second boundary condition for the planned speed, as shown in formula (6), V lim_2 =-A min (T5+T7) / 2 (6)

[0102] Therefore, combining formulas (5) and (6), the final planning velocity boundary condition is obtained, as shown in formula (7), V lim =max(V lim_1 V lim_2 (7)

[0103] According to the boundary condition V of the planned velocity lim The boundary condition expression for the distance, slim_two_order, can be obtained, as shown in formula (8). The distance S from the parking point must be greater than or equal to slim_two_order; otherwise, the quadratic equation programming for velocity has no solution. slim_two_order = s md +s1+s2+s3+s4+sbd +s5+s6+s7 (8)

[0104] The expressions for each item are as follows, s md =v0T md , s4=V lim T4, s bd =V lim T bd ,

[0105] 4. Solution to the velocity programming problem based on a linear equation and its existence conditions

[0106] Figure 5 illustrates the linear equation target speed planning process under train deceleration conditions, corresponding to typical scenario 3 in Figure 2, which involves a total of 7 time periods. ird The time period represents the delay in releasing the train's service brakes. At the beginning of this time period, the train receives information such as the opening of the route ahead and begins to release the previously applied service brakes. irj The time interval T4 represents the full-time braking deceleration process with constant Jerk values, while the time interval T4 represents the uniform speed operation process. bd The time periods represent the train braking delay. Time period T5 represents the braking deceleration process with constant Jerk value, time period T6 represents the uniform deceleration process, and time period T7 represents the braking acceleration process with constant Jerk value.

[0107] Use T ird and T bd The difference between the standard braking delay and the braking delay is used to distinguish between these two values, which are related to the train's delay characteristics and are constant values. (The last sentence appears to be incomplete and possibly refers to a time period, possibly T.) ird and T irj During these two time periods, the train speed decreases to the constant speed of segment T4, denoted by V, and this value can be determined. In the process of solving the speed problem using a linear equation, T4 is the variable to be solved.

[0108] The acceleration change time for the three constant Jerk values ​​is shown in equation (9).

[0109] Where A immo J represents the full-time braking deceleration. immo A represents the rate of change of deceleration during full-duration braking. min J represents the minimum permissible braking deceleration. min and J max This indicates the minimum and maximum permissible rate of change of braking deceleration.

[0110] After T ird and Tirj The expression for the train's constant speed V after a certain time, which is also the solution to the linear equation programming speed problem, is shown in formula (10): V = v0 + A immo T ird +A immo T irj / 2 (10)

[0111] Based on the condition that the sum of the running distances in each time period equals the distance to the parking point, the linear equation for calculating the running time T4 in the uniform speed segment can be obtained, as shown in formula (11): VT4 + slim_one_order = S (11)

[0112] Where T4 is the variable to be solved, V is the uniform speed obtained through formula (10), S is the distance to the parking point, and slim_one_order is the distance limit of the speed in the linear equation programming, as shown in formula (12), slim_one_order=s ird +s irj +s one_order (12)

[0113] The expressions for each item are as follows.

[0114] If the distance S from the parking point is greater than or equal to slim_one_order, then the uniform speed time T4 obtained by formula (11) is greater than or equal to zero, indicating that the speed solution of the linear equation is valid. Conversely, if the distance boundary condition is not met, then there is no speed solution of the linear equation.

[0115] 5. Velocity planning solutions and selection mechanisms in complex scenarios

[0116] This section presents the target velocity planning process for a vehicle with an initial velocity using either a linear or quadratic equation in a complex scenario. Scenario 2 in Figure 2 is merely an example within a complex scenario. According to T... ird and T irj The train speed reduction during these two time periods can be categorized into three sub-scenarios. The first sub-scenarios is T. ird The train speed has dropped to zero within the specified time period. The second sub-scenario is at T. irj The train speed drops to zero within a certain time period; the third sub-scenario is after passing T. ird and T irj After these two time periods, the train speed did not drop to zero.

[0117] The first type of sub-scenario is T. ird The train speed drops to zero within a certain time period, as shown in Figure 6, during the train brake release delay T.ird During the time period, the train's full service braking deceleration is A. immo The actual running distance during the process of the train speed dropping to zero can be obtained according to formula (13).

[0118] Among them, t ird =-v0 / A immo .

[0119] The subsequent target velocity planning process is the same as the quadratic equation velocity planning scenario in the stationary state, with an initial velocity of 0 and a distance value of SS. ird .

[0120] The second type of sub-scenario is T. irj The train speed drops to zero during the time period, as shown in Figure 7, that is, after the full service brake release delay T. ird After that, the train's speed did not drop to zero until T. irj The train's speed only dropped to zero during that time period. At T irj The time taken for the train speed to drop to zero within a given time period can be obtained using equation (14), J immo t 2 / 2+A immo t+v0+A immo T ird =0 (14)

[0121] Solution t that meets the conditions irj The expression is shown in formula (15).

[0122] The discriminant

[0123] In t irj The actual running distance within the time period is shown in formula (16).

[0124] The subsequent target velocity planning process is the same as the quadratic equation velocity planning scenario in the stationary state, with an initial velocity of 0 and a distance value of Ss. ird -S irj .

[0125] The third sub-scenario is when the train speed does not drop to zero after the full-use braking is released, i.e., after passing T... ird and T irjAfter these two time periods, the train speed did not drop to zero. If both distance and speed conditions are suitable at this point, the speed planning for near-stopping will result in solutions for both quadratic and linear equations. The initial speed value v0 and distance value S are used in the linear equation planning process. The initial speed value V is used in the quadratic equation planning process. immo The estimated speed at the moment when the full-time braking deceleration is reduced to 0 is shown in formula (17), V immo =v0+A immo T ird +A immo T irj / 2 (17)

[0126] Distance value is Ss ird -s irj .

[0127] As shown in Figure 8, the left graph represents the solution for velocity planning using a linear equation, with a planned speed of 3.6 kph. The train travels at an approximate planned speed for the final leg of the journey, taking 146.6 seconds. The right graph represents the solution for velocity planning using a quadratic equation, with a planned train speed of 7.5 kph. This solution includes traction acceleration, constant speed, and braking processes. Due to the higher planned speed, the entire journey takes only 140.6 seconds, saving 6 seconds compared to the left graph. From a practical operational perspective, choosing the maximum planned speed from the two solutions saves time and improves operational efficiency. Therefore, if both solutions exist, the maximum planned speed should be selected.

[0128] The above is an introduction to the method embodiments. The following embodiments using electronic devices and storage media will further illustrate the solution of the present invention.

[0129] This invention also provides an electronic device including a central processing unit (CPU), which can perform various appropriate actions and processes according to computer program instructions stored in a read-only memory (ROM) or loaded from a storage unit into a random access memory (RAM). The RAM may also store various programs and data required for device operation. The CPU, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0130] Multiple components in the device are connected to the I / O interface, including: input units such as keyboards and mice; output units such as various types of displays and speakers; storage units such as disks and optical discs; and communication units such as network interface cards (NICs), modems, and wireless transceivers. The communication unit allows the device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0131] The processing unit performs the various methods and processes described above, such as the methods of the present invention. For example, in some embodiments, the methods of the present invention may be implemented as computer software programs tangibly contained in a machine-readable medium, such as a storage unit. In some embodiments, part or all of the computer program may be loaded and / or installed on the device via ROM and / or a communication unit. When the computer program is loaded into RAM and executed by the CPU, one or more steps of the methods of the present invention described above may be performed. Alternatively, in other embodiments, the CPU may be configured to execute the methods of the present invention by any other suitable means (e.g., by means of firmware).

[0132] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: Field Programmable Gate Arrays (FPGAs), Application-Specific Integrated Circuits (ASICs), Application Standard Products (ASSPs), System-on-Chip (SoCs), Complex Programmable Logic Devices (CPLDs), and so on.

[0133] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0134] In the context of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0135] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

A speed planning method for urban rail transit train close-range stopping is characterized in that, The method includes the following steps: Step S1: At the reference curve level, design multiple short-distance speed planning scenarios based on the train delay characteristics and acceleration response gradual change characteristics. Step S2: Based on the similarity of various near-distance velocity planning scenarios during operation, construct a quadratic equation velocity planning module and a linear equation velocity planning module; Step S3 provides the speed and distance conditions for the planning solution in each scenario, as well as the selection mechanism when there are two target speed planning solutions. The urban rail transit train short-distance stopping speed planning method according to claim 1 is characterized in that, The train delay characteristics in step S1 include traction delay, braking delay, and full service brake release delay; the acceleration response gradual characteristics include traction acceleration response, traction deceleration response, braking deceleration response, braking acceleration response, and full service brake deceleration relief characteristics. The urban rail transit train short-distance stopping speed planning method according to claim 1 is characterized in that, The gradual characteristic of the acceleration response in step S1 is approximated by the acceleration change process of a constant Jerk value; the near-distance velocity planning scenario in step S1 involves differential relationship calculations between four variables: acceleration rate of change, acceleration, velocity, and distance. The urban rail transit train short-distance stopping speed planning method according to claim 1 is characterized in that, The quadratic equation velocity planning module in step S2 includes nine time periods: traction delay, acceleration increasing with constant Jerk value, uniform acceleration, acceleration decreasing with constant Jerk value, uniform speed operation, deceleration increasing with constant Jerk value, uniform deceleration, and deceleration decreasing with constant Jerk value. The urban rail transit train short-distance stopping speed planning method according to claim 1 is characterized in that, The solution of the quadratic equation speed planning module in step S2 is the speed during the uniform running stage. The initial state of the train in the quadratic equation speed planning module includes the stationary state and the uniform running state with initial speed. The urban rail transit train short-distance stopping speed planning method according to claim 1 is characterized in that, The parameter configuration of the quadratic equation speed planning module in step S2 includes two types. The first type is determined by the train characteristics, including traction delay and braking delay. The second type is the project setting value, including the uniform speed segment running time, the maximum allowable acceleration value and the rate of change of acceleration, as well as the minimum allowable deceleration value and the rate of change of deceleration. The urban rail transit train short-distance stopping speed planning method according to claim 1 is characterized in that, The quadratic equation velocity planning module in step S2 includes a first velocity boundary condition and a second velocity boundary condition. The first velocity boundary condition is derived from the fact that the time of the uniformly accelerated running segment must be greater than or equal to zero, and the second velocity boundary condition is derived from the fact that the time of the uniformly decelerated running segment must be greater than or equal to zero. The urban rail transit train short-distance stopping speed planning method according to claim 1 is characterized in that, The distance boundary calculation of the quadratic equation speed planning module in step S2 depends on the speed boundary conditions. The existence condition of the planning solution of the quadratic equation speed planning module is that the distance to the parking point is greater than or equal to the distance boundary of the quadratic equation speed planning module. The urban rail transit train short-distance stopping speed planning method according to claim 1 is characterized in that, The linear equation speed planning module in step S2 includes seven time periods: full service brake release delay, full service brake deceleration decrease with constant Jerk value, constant speed operation, deceleration increase with constant Jerk value, uniform deceleration, and deceleration decrease with constant Jerk value. The urban rail transit train short-distance stopping speed planning method according to claim 1 is characterized in that, The solution of the linear equation speed planning module in step S2 is the speed during the uniform running phase, and the initial state of the train in the linear equation speed planning module is the moment when the train begins to release the full service braking deceleration. The urban rail transit train short-distance stopping speed planning method according to claim 1 is characterized in that, The parameter configuration of the linear equation speed planning module in step S2 includes two types. The first type is determined by the train characteristics, including full service braking delay and braking delay. The second type is the project setting value, including full service braking deceleration, full service braking deceleration relief rate of change, constant speed segment running time, allowable minimum deceleration value and deceleration rate of change, and allowable maximum acceleration rate of change. The method according to claim 1, characterized in that, The stopping and braking phase of the linear equation velocity planning module in step S2 includes four time periods: braking delay, increasing deceleration with constant Jerk value, uniform deceleration, and decreasing deceleration with constant Jerk value. The urban rail transit train short-distance stopping speed planning method according to claim 1 is characterized in that, The distance boundary of the linear equation speed planning module in step S2 includes three parts of running distance: the running distance during the full service braking release delay period, the running distance during the full service braking deceleration relief change period, and the running distance during the stop braking period. The existence condition for the solution of the linear velocity planning module is that the distance to the parking point is greater than or equal to the distance boundary of the linear velocity planning module. The urban rail transit train short-distance stopping speed planning method according to claim 1 is characterized in that, Each scenario in step S3 includes a stationary state planning scenario and a deceleration state planning scenario. The initial state of the train in the deceleration state planning scenario is the moment when the train begins to release the full service braking deceleration. The deceleration state planning scenario includes a first type of sub-scenario, a second type of sub-scenario, and a third type of sub-scenario. The first type of sub-scenario is when the train's speed drops to zero during the full braking release delay period, and then enters the quadratic equation speed planning module process in a stationary state; The second type of sub-scenario is the process of the train reducing its speed to zero during the full-use braking deceleration period and then entering the quadratic equation speed planning module process in a stationary state; The third sub-scenario is when the train's speed does not drop to zero after the full service braking is released. In this case, there are two possible solutions: a quadratic equation speed solution and a linear equation speed solution. The urban rail transit train short-distance stopping speed planning method according to claim 14 is characterized in that, In the first type of sub-scenario, the initial speed value of the quadratic equation speed planning module is 0, and the initial distance value is the distance to the parking point minus the actual running distance during the full-use brake release delay period; In the second type of sub-scenario, the initial speed value of the quadratic equation speed planning module is 0, and the initial distance value is the distance to the parking point minus the running distance of two time periods, which are the running distance of the full-use braking release delay period and the actual running distance of the full-use braking deceleration relief period. In the third sub-scenario, the initial speed value of the quadratic equation speed planning module is the estimated speed at the moment when the full-use braking deceleration is reduced to 0, and the initial distance value is the distance to the parking point minus the running distance of two time periods, which are the running distance of the full-use braking release delay period and the running distance of the full-use braking deceleration relief period. The urban rail transit train short-distance stopping speed planning method according to claim 14 is characterized in that, In the third sub-scenario, the initial speed value of the linear equation speed planning module is the train speed at the moment when the full-use brakes begin to release, and the initial distance value is the distance to the stopping point. An electronic device comprising a memory and a processor, the memory having stored thereon a computer program, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1 to 16. A computer-readable storage medium having stored thereon a computer program, characterized in that When the program is executed by the processor, it implements the method as described in any one of claims 1 to 16.

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