A method and system for pre-defined performance control of train formations to eliminate initial error constraints

Abstract

This invention discloses a train formation preset performance control method and system for eliminating initial error constraints. Specifically, for each vehicle, a preset boundary interval formed by upper and lower boundary functions is constructed, further proposed as a monotonic tubular boundary function, determined jointly by convergence terms and piecewise compensation terms. A time-varying adjustment function is introduced to construct a correction error for the global formation position tracking error, ensuring that at the initial moment, regardless of the initial value of the global formation position tracking error, the correction error always lies within the initial preset boundary. After a delay adjustment time, the correction error is restored to the true global formation position tracking error. Finally, it is used to construct an error dynamic model, solve for the control input of the vehicle controller, and realize traction or braking control of each vehicle. This invention, through the above technical design, allows the initial formation tracking error to exceed the constraint boundary without requiring a precise initial state, and features adjustable transient performance, a simple control structure, and ease of engineering deployment.

Description

Technical Field

[0001] This invention belongs to the field of rail transit train operation control, specifically relating to a train formation preset performance control method and system for eliminating initial error constraints. This method is a preset performance control method for multi-mass point multi-train formations. Background Technology

[0002] Train platooning can improve line transport capacity, reduce operating intervals, and improve energy consumption. To enable multiple train formations or multiple vehicles in the same train to operate collaboratively at predetermined intervals and target speeds, existing research typically designs controllers based on control methods such as consistency theory, sliding mode control, and preset performance control.

[0003] However, traditional preset performance control usually implies an important premise: the actual initial error must be within the preset performance boundary. Only when this initial feasibility condition is met can the normalized error variable and error transformation function be effectively defined, and the subsequent controller can be constructed correctly. However, in actual train operation scenarios, the above-mentioned initial feasibility condition is difficult to always meet. For example, when a train starts from a standstill, the actual distance between adjacent vehicles or adjacent trains may have unknown deviations, i.e., the distance is unknown or too close / too far; a running train formation may receive new trains dynamically merging in, whose initial relative distance and speed are unknown; sensor measurements, communication delays, or positioning errors may cause the initial state obtained by the controller to be inconsistent with the actual state; vehicle actuator capabilities and comfort constraints also limit the instantaneous change capability of the control input. All of the above factors may cause the actual initial formation tracking error to exceed the traditional preset performance boundary. If no compensation measures are taken, it will lead to:

[0004] 1. The normalized error variable may become undefined, leading to irreversible error transformation and failure of the preset performance controller;

[0005] 2. Initial out-of-bounds errors can cause drastic changes in transient control inputs, which can easily lead to sudden changes in traction or braking commands or even actuator saturation.

[0006] When the actual initial error exceeds the preset performance boundary, traditional preset performance control faces fundamental technical obstacles: First, the normalized error variable may exceed the domain, the error transformation may be irreversible, or the control law may be impossible to calculate; Second, if the problem is addressed simply by relaxing the performance boundary or increasing the control gain, it may cause abrupt changes in traction / braking commands, affecting ride comfort and potentially causing actuator saturation; Third, before the actual error re-enters the boundary, traditional methods cannot simultaneously guarantee the maintenance of safe distance, speed tracking, and smooth control input.

[0007] While existing train or vehicle platooning control schemes can achieve coordinated control between vehicles to some extent, none of them disclose a mechanism that ensures the effectiveness of preset performance error transformation and restores the true error constraint after a finite delay adjustment time when the actual initial error is unknown or exceeds the limit. Therefore, a new preset performance control method for train platooning is needed to eliminate the dependence of traditional preset performance control on the requirement that the actual initial error must be within the performance boundary. Summary of the Invention

[0008] This invention primarily addresses the technical limitations inherent in traditional performance function structures, which lead to a dependency in traditional preset performance control where the actual initial error must be within the performance boundary. To resolve this, a method and system for preset performance control of train formations that eliminates the initial error constraint is proposed. The technical solution of this invention introduces a delay adjustment mechanism, a time-varying adjustment function, and a correction error construction method. This allows preset performance control to be implemented without requiring the actual initial error to be within the boundary beforehand, thus eliminating the dependence of traditional preset performance control on the feasibility of the initial actual error.

[0009] Furthermore, the present invention proposes a constraint interval formed by a monotonic tubular boundary function, which, compared to the traditional bilaterally symmetric performance function, imposes a more stringent constraint on error overshoot.

[0010] Specifically, the present invention provides a train formation preset performance control method for eliminating initial error constraints, comprising the following steps:

[0011] Step 1: Obtain information about each vehicle in the train formation. The vehicle information includes operating status information, inter-vehicle communication topology information, and target operating information.

[0012] Step 2: Based on the vehicle information, determine the formation tracking error for each vehicle, and construct a correction error for the global formation position tracking error within the formation tracking error. This correction error is achieved by using two time-varying adjustment functions to correct the global formation position tracking error, ensuring that the initial time... Regardless of the initial global formation position tracking error value, the correction error always remains within the initial preset boundary; during the delay adjustment time Then, the corrected error is restored to the true global formation position tracking error;

[0013] Step 3: Based on the corrected error, construct an error dynamic model to solve for the control input of the vehicle controller and apply it to the vehicle actuators to perform traction or braking control on each vehicle, thereby achieving stable train formation.

[0014] It should be understood that the core condition for the correction error design is that the correction error falls within the preset boundary range at the initial moment and recovers to the true global formation position tracking error after a delay adjustment time. Correction error models that satisfy this characteristic can be considered to meet the requirements of the technical solution of this invention and fall within the protection scope of this invention.

[0015] Optionally, the mathematical model for the correction error is:

[0016]

[0017] In the formula, For the first The correction error of the j-th car of the train, where t is time. The first time at time t The global formation position tracking error of the j-th car of a train, and two time-varying adjustment functions for each car. , as follows:

[0018]

[0019] Among them, coefficient , To delay the adjustment time, the initial value , The initial time respectively The upper and lower boundaries are boundary values ​​for global formation position tracking error.

[0020] Optionally, upper boundary functions are constructed for the global formation position tracking errors of each vehicle. and lower boundary function And simultaneously satisfy the following conditions:

[0021] Upper and lower boundary functions , In the interval [0, All of the above are monotonic functions. The specified convergence time, i.e., the time at which the characterization function converges;

[0022] t is greater than or equal to the specified convergence time When, upper and lower boundary functions , Both are fixed constants;

[0023] When t is greater than or equal to 0, the upper boundary Always greater than the lower boundary .

[0024] Optionally, the upper boundary function and the lower boundary function Both are determined by the attenuation and compensation terms that tend towards the steady-state boundary values, where the upper and lower boundary functions , Compensation items and All employ a piecewise convergence strategy, as detailed below:

[0025] when In the initial stage, compensation terms are introduced smoothly to avoid abrupt changes in control input;

[0026] when During the transition phase, the continuous convergence and smooth connection of the error are achieved by adjusting the parameters of the cosine function.

[0027] when At this time, the compensation items will no longer have an effect, and all compensation items will be set to 0.

[0028] Optionally, in step 3, a normalized auxiliary error variable is first constructed using the corrected error, and then an error dynamic model is constructed based on the normalized auxiliary error variable. The normalized auxiliary error variable is:

[0029]

[0030] In the formula, To normalize the auxiliary error variable, Let be the upper boundary function. Let it be the lower boundary function. To correct for errors.

[0031] Optionally, the error dynamic model is a full-drive error system model, specifically:

[0032]

[0033] In the formula, Auxiliary error variable The second and first differentials, To control the input, This represents the communication connection weight between the j-th car of the i-th train and the p-th car within the same train. To restrain the gain, Indicates the first i Train No. j The neighbor set of each vehicle; Indicates the first i The first train p One vehicle, Indicates the first y The first train p One vehicle; for The first-order differential, Global formation speed tracking error in formation tracking error Custom variables , satisfy:

[0034] , , , ;

[0035] In the formula, for The first differential; for The first differential; , Time-varying adjustment function The first and second derivatives; , The first Train number y and train number y The first derivative of the vehicle speed; For target speed The first differential; Time-varying adjustment function The second derivative; variable This is used to represent the weighted in-degree of the j-th vehicle in the i-th train in the communication topology.

[0036] Optionally, the control inputs of each vehicle Including nonlinear compensation terms and status feedback items ,Right now ; It is used to compensate for vehicle dynamics nonlinearity, inter-vehicle coupling terms, target operation information introduction terms, and boundary function variation terms; Used to enhance the convergence and robustness of closed-loop error systems.

[0037] The present invention also provides a system based on the above method, comprising:

[0038] The information acquisition module is used to acquire information about each vehicle in the train formation, including operating status information, inter-vehicle communication topology information, and target operating information.

[0039] The error determination module is used to determine the formation tracking error of each vehicle based on the vehicle information, and to construct a correction error for the global formation position tracking error in the formation tracking error. The correction error is achieved by using two time-varying adjustment functions to correct the global formation position tracking error, so that the initial time... Regardless of the initial global formation position tracking error value, the correction error always remains within the initial preset boundary; during the delay adjustment time Then, the corrected error is restored to the true global formation position tracking error;

[0040] The control module is used to construct an error dynamic model based on the corrected error, to solve for the control input of the vehicle controller and apply it to the vehicle actuators to perform traction or braking control on each vehicle, thereby achieving stable train formation.

[0041] The present invention also provides a train system, which includes a train formation and a control terminal. Each train consists of multiple vehicles, and each vehicle is equipped with a controller. The controller is equipped with a processor and a memory. The processor calls a computer program stored in the memory to implement the steps of the above-described control method.

[0042] The present invention also provides a computer-readable storage medium storing a computer program that is invoked by a processor to implement the steps of the above-described control method.

[0043] Compared with the prior art, the technical solution of this invention achieves the following progress and effects:

[0044] 1) This invention introduces a delay adjustment mechanism, a time-varying adjustment function, and a method for constructing error correction, so that the initial time... Regardless of the initial global formation position tracking error value, the correction error always remains within the initial preset boundary; during the delay adjustment time Subsequently, the corrected error is restored to the true global formation position tracking error. Therefore, the technical solution of the present invention does not require the true initial error to be within the boundary beforehand, allowing the preset performance control to still be implemented. This eliminates the dependence of traditional preset performance control on the feasibility of the initial true error, allowing the initial value of the train formation tracking error to exceed the constraint boundary, and reducing the dependence on the accurate measurement of the initial state.

[0045] 2) In practical applications, this invention can be adjusted... , and The three time constants represent a trade-off between transient performance and steady-state accuracy.

[0046] 3) Compared with the traditional bilateral preset performance boundary, the new upper and lower boundary functions proposed in this invention can apply stricter constraints in the transient stage, thereby suppressing overshoot.

[0047] 4) This invention uses only low-complexity algebraic operations to complete the error transformation, making it more suitable for vehicle-mounted real-time control deployment.

[0048] 5) Furthermore, this invention provides a fully driven error system model with preset performance constraints for multi-mass, multi-train systems. This model is more concise and compact, offering significant advantages for control input design. Since the control variables can be directly and explicitly solved in the error model, controller design is simplified. In addition, the fully driven nature of the error system allows for the convenient application of standard nonlinear control techniques such as feedback linearization and sliding mode control to ensure system convergence. Attached Figure Description

[0049] To more clearly illustrate the embodiments of the present invention or the solutions of the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a flowchart of a train formation preset performance control method and system for eliminating initial error constraints provided by the present invention.

[0051] Figure 2 This is a schematic diagram of the cooperative operation of the multi-mass point and multi-train system of the present invention.

[0052] Figure 3 This is a schematic diagram of the finite-time preset performance function of the present invention.

[0053] Figure 4 This is a schematic diagram showing the relationship between the correction error, the true error, and the upper and lower boundaries.

[0054] Figure 5 This is a schematic diagram of the error evolution trajectory.

[0055] Figure 6 This is a control flowchart of a train formation preset performance control method and system for eliminating initial error constraints provided by the present invention. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The technical features involved in the various embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.

[0057] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0059] The technical solution of this invention introduces a delay adjustment mechanism, a time-varying adjustment function, and a method for constructing error correction, enabling preset performance control to be implemented without requiring the actual initial error to be within the boundary beforehand. Therefore, the technical concept of this invention is as follows:

[0060] Step 1: Obtain information on each vehicle in the train formation. Vehicle information includes operating status information, inter-vehicle communication topology information, and target operating information.

[0061] Step 2: Determine the formation tracking error for each vehicle based on vehicle information, and construct a correction error for the global formation position tracking error within the formation tracking error. The correction error is achieved by using two time-varying adjustment functions to correct the global formation position tracking error, ensuring that the initial time... Regardless of the initial global formation position tracking error value, the correction error always remains within the initial preset boundary; during the delay adjustment time Afterwards, the error was corrected to restore the true global formation position tracking error;

[0062] Step 3: Construct an error dynamic model based on the corrected error to solve for the control input of the vehicle controller and apply it to the vehicle actuators to perform traction or braking control on each vehicle, thereby achieving stable train formation.

[0063] The following section will illustrate the implementation process of each step and the optional implementation techniques with examples.

[0064] like Figure 1 An embodiment of the present invention provides a train formation preset performance control method for eliminating initial error constraints, comprising:

[0065] Step S1: Obtain information about each vehicle in the train formation. The vehicle information includes operating status information, inter-vehicle communication topology information, and target operating information. The operating status information includes at least the position and speed of each vehicle, and the target operating information includes at least the target speed.

[0066] It should be understood that there are relevant definitions in the field for train formation operation status information, inter-vehicle communication topology information and target operation information. Under the premise of satisfying step S1, the present invention does not specifically limit the above definitions and acquisition methods.

[0067] Step S2: Based on the operating status information, communication topology information, and target operating information, define the formation tracking error for each car in the train formation. This formation tracking error includes at least the global formation position tracking error.

[0068] Among them, formation tracking error is an error term designed to ensure stable formation tracking. Referring to the expertise in this field, error terms characterizing this feature are considered to meet the technical requirements of this invention. Generally, this invention divides formation tracking error into two items: a relative error term characterizing the communication relationship between adjacent vehicles within the same train and other trains, and a vehicle target operation information tracking term.

[0069] Step S3: For the global formation position tracking error, construct upper monotonic tubular boundary functions and lower monotonic tubular boundary functions for each car in the train formation. Both the upper and lower monotonic tubular boundary functions contract monotonically with time and are determined by convergence terms and piecewise compensation terms to form a preset boundary interval that evolves over time, ensuring that the global formation position tracking error is within a certain time delay adjustment period. It then lies within a preset boundary interval. It should be understood that the upper monotonic tubular boundary function and the lower monotonic tubular boundary function proposed in this embodiment are the best alternatives of the present invention, but not the only feasible ones, as will be explained in detail below.

[0070] Step S4: Construct a time-varying adjustment function, and construct a correction error based on the time-varying adjustment function and the global formation position tracking error, so that the correction error falls within the preset boundary range at the initial time, and is restored to the true global formation position tracking error after a preset delay adjustment time;

[0071] Step S5: Based on the correction error and the upper monotonic tubular boundary function and the lower monotonic tubular boundary function, construct normalized auxiliary error variables, transform the original error constraint preservation problem into a bounded preservation problem of normalized auxiliary error variables, and construct a full-drive error system model based on the normalized auxiliary error variables.

[0072] Step S6: Based on the all-drive error system model, synthesize the overall control variables of each vehicle and apply them to the actuators of each vehicle to perform traction or braking control on each vehicle, thereby realizing train formation.

[0073] Similarly, steps S5 and S6 described above are only preferred feasible methods of the present invention, but not the only feasible methods.

[0074] In some embodiments, step S1 specifically includes:

[0075] like Figure 2 As shown, there are N train formations, each consisting of M cars. Adjacent cars exchange information, and the onboard controller periodically collects the real-time position of each car. ,speed Receive target speed and the target displacement obtained by integrating the target velocity It also acquires the communication topology between vehicles, the coupler connection relationship, and the target operation information sent by the ground system (ground control center). and The communication topology weights can be derived from... and express, Indicates the first The first train The vehicle and the first one on the same train The communication connection weight between vehicles is determined by a value greater than 0, indicating that the vehicle is considered a neighbor; if the value is equal to 0, the vehicle is not a neighbor. Indicates the first The first train The vehicle and the first The first train The communication connection weight between vehicles is determined by a value greater than 0, indicating that the vehicle is considered a neighbor; if the value is equal to 0, the vehicle is not a neighbor. Indicates the first The first train The vehicle is located on the same train. Within the neighbor set of each vehicle; Indicates the first The first train The vehicle is located in the first The first train Within the neighbor set of the vehicles; the first The first train Whether a vehicle has the ability to directly receive target operation information depends on the traction gain. Characterization, if This means that it can receive target runtime information; otherwise... .

[0076] In some embodiments, formation tracking errors are mainly divided into position tracking errors and velocity tracking errors. This application focuses on the study of position tracking errors. The global formation position tracking error defined below is an example of an embodiment of the present invention. In other feasible embodiments, error terms that ensure stable position tracking are also feasible. Similarly, the velocity tracking error described below is only an example.

[0077] For the first The first train One vehicle has a displacement error. With speed error displacement error This indicates the deviation of the vehicle's current position from its target reference position, which is determined by the target position. and the positional offset determined by the vehicle formation structure Together they constitute, speed error This indicates the deviation of the vehicle's current speed from the target speed;

[0078]

[0079] Where t represents time. It represents the distance between the front of the rear car and the rear of the front car in two adjacent train sets. Let l be the number of vehicles in the m-th train, and l be the length of the vehicle. Used to construct a global formation reference position, enabling the positional relationships between vehicles of different trains to be described in a unified coordinate system, thereby facilitating the construction of formation tracking errors that include multi-vehicle coupling relationships. Indicates the first The number of vehicles in a train.

[0080] Based on this, define the first Global formation position tracking error of the j-th car of a train Global formation speed tracking error This allows it to simultaneously include the relative error term between the vehicle and its neighboring vehicles, as well as the target's tracking information. It can be written as:

[0081]

[0082] In the formula, Let represent the set of neighbors of the j-th vehicle of the i-th train; This represents the p-th car of the i-th train. This represents the p-th car of the y-th train; and They represent the first The first train The vehicle and the The first train Displacement error of each vehicle; and They represent the first The first train The vehicle and the The first train Speed ​​error of individual vehicles.

[0083] In some embodiments, step S3 specifically includes:

[0084] Considering the difficulty in accurately obtaining the initial operating state during actual train operation, the initial global formation position tracking error... It may not be within the traditional preset performance boundaries. Therefore, the technical solution of this invention preferably does not directly address the global formation position tracking error. Instead of applying traditional symmetric boundaries, a pair of monotonically shrinking upper boundary functions are constructed for each vehicle. and lower boundary function The two form a tubular pre-defined boundary interval that evolves over time, serving as a boundary to reduce the global formation position tracking error. Delay adjustment time Then the following conditions are met:

[0085]

[0086] The error evolution trajectory diagram is shown below. Figure 5 As shown, This is the delay adjustment time, used to set the duration for the recovery from the corrected error to the true error. Reduce It can speed up recovery, but it will increase transient control input; increase While this is beneficial for smooth control, it delays the process of the actual error regaining control of the constraint-maintaining process. Therefore, The boundary function should be selected comprehensively based on the initial error amplitude, actuator capability, and comfort requirements. Both the upper and lower boundary functions are determined by the attenuation term and the compensation term that tend towards the steady-state boundary value.

[0087] The upper boundary function in this embodiment and lower boundary function The settings are as follows:

[0088]

[0089] In the formula, and They are and The derivative; upper boundary coefficient Lower boundary coefficient , and These are the steady-state values ​​at the upper and lower boundaries, respectively. The specified convergence time, i.e., the time at which the characterization function converges. It is used to achieve in convergence; and The upper boundary functions are respectively and lower boundary function The compensation item. In this embodiment, the compensation item... and A piecewise convergence strategy is adopted, as follows:

[0090]

[0091]

[0092] Where: pre-convergence time t represents time; a constant ,constant , and These are the upper boundary functions. and lower boundary function Initial values; custom variables for the upper bound function. User-defined variables for the lower bound function Custom variables , , and satisfy:

[0093]

[0094] Where: boundary function parameters Boundary function parameters Boundary function parameters Boundary function parameters Boundary function parameters Boundary function parameters Boundary function parameters Boundary function parameters .

[0095] The above parameters are obtained by solving... and The differential equation is derived from this. The schematic diagram illustrating the curve evolution of the upper and lower boundary functions in this invention is shown below. Figure 3 As shown. Specify the convergence time. and pre-convergence time To a certain extent, all choices can be freely made. Reduce and Although it can speed up the convergence speed, A large value within a given timeframe can lead to a surge in control force; conversely, an excessively large value can reduce dynamic response performance. Therefore, under actual operating conditions, the value should be adjusted appropriately based on those conditions. and The value is then determined. Furthermore, the segmented compensation term provided in this embodiment... and It consists of three stages, when In the initial stage, its main function is to smoothly introduce compensation terms and avoid abrupt changes in control input; when During the transition phase, the continuous convergence and smooth transition of the error are achieved by adjusting the parameters of the cosine function; when At this point, the system enters the steady-state phase of the performance function, at which point the compensation term no longer plays a role. This segmented design can effectively balance convergence speed and control smoothness, ensuring high-performance operation (steady-state and transient performance) of multi-mass, multi-train systems within a specified time.

[0096] It should be understood that the above-mentioned segmented compensation items and This is a preferred design in the embodiments of the present invention, but it is not the only feasible approach. For example, replacing the piecewise function with a smooth function or a polynomial compensation term is also feasible. It is only necessary to redesign the boundary function parameters to satisfy the compensation function.

[0097] It should also be understood that the upper and lower boundary functions given in the above embodiments are considered to be the best embodiments of the present invention. In other feasible embodiments, other functions that satisfy the following definition for the upper and lower boundary functions of monotonic classes also satisfy the requirements of the present invention:

[0098] 1. Upper and lower boundary functions , In the interval [0, All of the above are monotonic functions;

[0099] 2. t is greater than or equal to When, upper and lower boundary functions , Both are fixed constants;

[0100] 3. When t is greater than or equal to 0, the upper boundary Always greater than the lower boundary .

[0101] It should also be understood that, in addition to monotonic functions, embodiments of the present invention may also refer to existing technologies in the art to set other boundaries, as long as they satisfy: the global formation position tracking error within the delay adjustment time. It then lies within the constraint interval formed by the upper and lower boundaries.

[0102] It should be understood that, regarding the technical problem to be solved by this invention—the dependence that traditional preset performance control requires the actual initial error to be within the performance boundary—the following design is proposed for step S4 of this invention:

[0103] To eliminate global formation position tracking error Corresponding to true initial error The constraint that the function must be located inside the boundary requires designing two time-varying adjustment functions for each vehicle. and ,as follows:

[0104]

[0105] Among them, the initial value ;coefficient Used to ensure Strictly not equal to 0, based on time-varying adjustment function and The following design addresses the global formation position tracking error. Correction error:

[0106]

[0107] in, It is a positive function that monotonically increases to 1. hour, for , hour, The value is 1. It is a function that monotonically decreases to 0. hour, for , hour, The value is 0. The two functions are designed this way to ensure... It remains within the constraints.

[0108] By designing a time-varying adjustment function and The value, that is, no matter how large. Both can obtain a midpoint close to the initial preset constraint boundary. Furthermore, when hour, This means that the modified error accurately recovers the true error after the delay adjustment. Figure 4 The diagram illustrates the relationship between the correction error, the true error, and the upper and lower boundaries. It shows that the global formation position tracking error (true formation tracking error) is compensated at the initial moment. The deviation from the preset boundary range causes the correction error. Located within a preset boundary range; continuously decaying within a preset delay adjustment time, thus correcting the error. The tracking error gradually approaches the actual formation tracking error; when the time reaches or exceeds the preset delay adjustment time, the time-varying adjustment function decays to zero, correcting the error. Restore to true formation tracking error Therefore, it can be seen that the present invention does not simply amplify the boundary function to accommodate arbitrary initial errors, nor does it forcibly pull back the true error by increasing the control gain. Instead, it uses a mechanism of "initial feasible correction error - continuous delay adjustment - true error recovery" to ensure that the preset performance error transformation remains effective when the initial error is unknown or exceeds the limit.

[0109] against The value is generally determined when the following conditions are met. The value should be as small as possible under certain conditions, such as 1.0001. Its value can be adjusted appropriately through simulation, and it needs to meet certain requirements. It is within the constraints.

[0110] In some embodiments, step S5 specifically includes:

[0111] Based on the correction error and the upper and lower boundary functions, a normalized auxiliary error variable is constructed. This auxiliary error variable Used to characterize correction error The dynamic changes within a preset boundary range. By ensuring that the auxiliary error variable remains bounded, it is indirectly guaranteed that the correction error will not exceed the preset boundary range.

[0112] Preset delay adjustment time Previously, the auxiliary error variable constrained the correction error, thus ensuring the effectiveness of the controller's error transformation; within the preset delay adjustment time Subsequently, since the correction error has been restored to the true formation tracking error, the boundedness of the auxiliary error variable further ensures that the true formation tracking error remains within the preset boundary range.

[0113] Furthermore, a full-drive error system model with preset performance is constructed based on auxiliary error variables. This model refers to the unified transformation of factors such as the original train dynamics, formation coupling error, target operating input, and monotonic pipe boundary function derivatives into the auxiliary error dynamic equations. This allows the control variables to be solved explicitly within the error model, facilitating subsequent controller design.

[0114] This embodiment is based on error correction. and the normalized auxiliary error variables constructed from the upper and lower boundary functions. :

[0115]

[0116] Furthermore, based on the auxiliary error variables, the model of the total drive error system with preset performance constraints is as follows:

[0117]

[0118] In the formula, Auxiliary error variable The second and first derivatives, for First-order differential, custom variable , satisfy:

[0119] , , , .

[0120] In the formula, for The first differential; for The first differential; , Time-varying adjustment function The first and second derivatives; , The first Train number y and train number y The first derivative of the vehicle speed; For target speed The first differential; Time-varying adjustment function The second derivative; variable ; For global formation speed tracking error .

[0121] It should be understood that if a fully driven error system is not used, auxiliary error variables can be utilized. The error model can still be used to design other feasible technical solutions, such as referring to existing technologies in this field, or for example, using the backstepping method for stepwise recursive control. However, this method includes a virtual control law, and differentiating the auxiliary error variable inevitably requires multiple differentiations of the virtual control law. Multiple differential and algebraic operations are required to explicitly solve for the control variable. This can lead to the problem of differential explosion, making it less convenient for engineering implementation compared to a fully driven error system.

[0122] The embodiments of the present invention preferably utilize auxiliary error variables. A simpler fully driven error system model was established, and the terms... It provides a direct approach to control input design because This is directly and explicitly represented, thus simplifying controller design. Furthermore, conditions... This allows a series of standard nonlinear control techniques, such as feedback linearization and sliding mode control, to be easily applied to ensure system convergence.

[0123] The formula, based on an error dynamics model, is designed to apply control inputs to the actuators of each vehicle, enabling the actuators to output traction / braking. In other words, the overall control input of each vehicle corresponds to the traction / braking control commands received by the vehicle actuators, which can be further converted into traction force and braking force. The rules and technical feasibility of using the error dynamics model to obtain control inputs and then converting them into traction and braking force are known in the art, and this invention will not provide specific explanations therein.

[0124] The control input, considered as the controller for each train, acts on the braking and traction control units on the vehicles to change speed and maintain safe distances. In this field, an integral terminal sliding surface can be introduced to improve the finite-time convergence capability of platooning tracking errors. Alternatively, backstepping control, sliding mode control, adaptive control, robust control, model predictive control, or neural network compensation control can be used to replace the specific controller, as long as they can ensure that the normalized auxiliary error variable is bounded and that the vehicle actuator outputs satisfy the traction / braking constraints.

[0125] In some embodiments, the control input may include a nonlinear compensation component and a state feedback component. The nonlinear compensation component is used to compensate for vehicle dynamics nonlinearities, inter-vehicle coupling terms, target operating information introduction terms, and boundary function variation terms; the state feedback component is used to enhance the convergence and robustness of the closed-loop error system. (See below:)

[0126] Based on the all-drive error system model, a nonlinear compensation component is designed. as follows:

[0127]

[0128] In the formula, ; The integral terminal sliding surface shown below is used to ensure global formation position tracking error. Convergence.

[0129]

[0130] In the formula, the user-defined variable Custom coefficients are used to address coupling error. , , , , , , and It is a positive odd number. , Let be the integration variable, representing the time from 0 to t.

[0131] calculate The time derivative is as follows, which then determines the state feedback part. :

[0132]

[0133] In the formula, Auxiliary error variable The first differential;

[0134]

[0135] in, To control the gain.

[0136] Finally, the overall control variables of each vehicle are synthesized. This process is applied to the actuators of each vehicle to control traction or braking for each vehicle, thus achieving train formation control. The specific control flowchart is as follows: Figure 6 As shown;

[0137] Overall control variables This represents the control input applied to the j-th car of the i-th train. The compensation variable in the above example... It is mainly used to offset system coupling terms, target input terms, model nonlinearity, and state feedback variables. It is mainly used to enhance the convergence and robustness of closed loops.

[0138] In some embodiments, the present invention also provides a system based on the above method, including an information acquisition module, an error determination module, and a control module connected in sequence.

[0139] The information acquisition module is used to acquire information about each vehicle in the train formation, including operating status information, inter-vehicle communication topology information, and target operating information. The error determination module is used to determine the formation tracking error for each vehicle based on the vehicle information, and to construct a correction error for the global formation position tracking error within the formation tracking error. This correction error is achieved by using two time-varying adjustment functions to correct the global formation position tracking error, ensuring that the initial time... Regardless of the initial global formation position tracking error value, the correction error always remains within the initial preset boundary; during the delay adjustment time Afterwards, the corrected error is restored to the true global formation position tracking error; the control module is used to construct an error dynamic model based on the corrected error, so as to solve the control input of the vehicle controller and act on the vehicle actuator to perform traction or braking control on each vehicle to achieve stable train formation.

[0140] In some embodiments, the present invention also provides a train system comprising a train formation, each train consisting of multiple vehicles, each vehicle being equipped with a controller, the controller having a processor and a memory, the processor calling a computer program stored in the memory to implement the steps of the above control method.

[0141] In some embodiments, the present invention also provides a computer-readable storage medium storing a computer program that is invoked by a processor to implement the steps of the control method described above.

[0142] Please refer to the explanation of the method above for the specific implementation process of each step.

[0143] It should be understood that, in the embodiments of the present invention, the processor may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor. The memory may include read-only memory and random access memory, and provides instructions and data to the processor. A portion of the memory may also include non-volatile random access memory. For example, the memory may also store device type information.

[0144] The readable storage medium is a computer-readable storage medium. It can be an internal storage unit of the hardware or software device in any of the foregoing embodiments (e.g., the hard drive or memory of the controller), or it can be an external storage device of the controller, such as a plug-in hard drive, smart memory card (SMC), secure digital card (SD card), flash memory card, etc., equipped on the controller. Furthermore, the storage medium can also simultaneously include both the controller's internal storage unit and external storage device.

[0145] Based on the above understanding, the core part of the technical solution of this invention that contributes to the prior art, or all or part of the content of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and contains several instructions to cause a computer device (such as a personal computer, server, or network device) to execute all or part of the steps of the methods described in the various embodiments of this invention. Available storage media include, but are not limited to: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0146] Those skilled in the art will understand that embodiments of this application can be provided in the form of a method, system, or computer program product. Therefore, this application can be implemented entirely in hardware, entirely in software, or a combination of hardware and software. Furthermore, this application can also be implemented as a computer program product containing computer-usable program code on a computer-readable storage medium (such as a disk storage device, CD-ROM, optical storage, etc.). Embodiments of this application are described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products. It should be understood that the function of each step in the flowchart and / or each block in the block diagram can be implemented by computer program instructions. These computer program instructions can be executed by a processor of a general-purpose computer, special-purpose computer, or other programmable data processing device to generate means for implementing the functions specified in the flowchart and / or block diagrams. These instructions can also be stored in a computer-readable storage medium to cause a computer or other programmable device to operate in a particular manner, thereby producing an article of manufacture containing instruction means to implement the functions specified in the flowchart and / or block diagrams. Furthermore, the instructions can be loaded onto a computer or other programmable device to form a computer-implemented processing flow by performing a series of operational steps, so that the instructions executed on the computer or other programmable device can implement the functional steps specified in the flowchart and / or block diagrams.

[0147] It should be emphasized that the examples described in this invention are illustrative rather than limiting. Therefore, this invention is not limited to the examples described in the specific embodiments. Any other embodiments derived by those skilled in the art based on the technical solutions of this invention, without departing from the spirit and scope of this invention, whether modifications or substitutions, are also within the protection scope of this invention.

Claims

1. A method for pre-setting performance control of train formations to eliminate initial error constraints, characterized in that: Includes the following steps: Step 1: Obtain information about each vehicle in the train formation. The vehicle information includes operating status information, inter-vehicle communication topology information, and target operating information. Step 2: Based on the vehicle information, determine the formation tracking error for each vehicle, and construct a correction error for the global formation position tracking error within the formation tracking error. This correction error is achieved by using two time-varying adjustment functions to correct the global formation position tracking error, ensuring that the initial time... Regardless of the initial global formation position tracking error value, the correction error always remains within the initial preset boundary; during the delay adjustment time Then, the corrected error is restored to the true global formation position tracking error; Step 3: Based on the corrected error, construct an error dynamic model to solve for the control input of the vehicle controller and apply it to the vehicle actuators to perform traction or braking control on each vehicle, thereby achieving stable train formation.

2. The method according to claim 1, characterized in that: The mathematical model for the correction error is: ； In the formula, For the first The correction error of the j-th car of the train, where t is time. The first time at time t The global formation position tracking error of the j-th car of a train, and two time-varying adjustment functions for each car. , as follows: ； Among them, coefficient , To delay the adjustment time, the initial value , The initial time respectively The upper and lower boundaries are boundary values ​​for global formation position tracking error.

3. The method according to claim 1, characterized in that: Constructing upper boundary functions for the global formation position tracking errors of each vehicle and lower boundary function And simultaneously satisfy the following conditions: Upper and lower boundary functions , In the interval [0, All of the above are monotonic functions. The specified convergence time, i.e., the time at which the characterization function converges; t is greater than or equal to the specified convergence time When, upper and lower boundary functions , Both are fixed constants; When t is greater than or equal to 0, the upper boundary Always greater than the lower boundary .

4. The method according to claim 3, characterized in that: The upper boundary function and the lower boundary function Both are determined by the attenuation and compensation terms that tend towards the steady-state boundary values, where the upper and lower boundary functions , Compensation items and All employ a piecewise convergence strategy, as detailed below: when In the initial stage, compensation terms are introduced smoothly to avoid abrupt changes in control input; when During the transition phase, the continuous convergence and smooth connection of the error are achieved by adjusting the parameters of the cosine function. when At this time, the compensation items will no longer have an effect, and all compensation items will be set to 0.

5. The method according to claim 1, characterized in that: In step 3, a normalized auxiliary error variable is first constructed using the corrected error, and then an error dynamic model is constructed based on the normalized auxiliary error variable. The normalized auxiliary error variable is: ； In the formula, To normalize the auxiliary error variable, Let be the upper boundary function. Let it be the lower boundary function. To correct for errors.

6. The method according to claim 5, characterized in that: The error dynamic model is a full-drive error system model, specifically: ； In the formula, Auxiliary error variable The second and first derivatives, To control the input, This represents the communication connection weight between the j-th car of the i-th train and the p-th car within the same train. To restrain the gain, Indicates the first i Train No. j The neighbor set of each vehicle; Indicates the first i The first train p One vehicle, Indicates the first y The first train p One vehicle, for The first-order differential, Global formation speed tracking error in formation tracking error Custom variables , satisfy: ， ， ， ； In the formula, for The first derivative; for The first differential; , Time-varying adjustment function The first and second derivatives; , The first Train number y and train number y The first derivative of the vehicle speed; For target speed The first derivative; Time-varying adjustment function The second derivative; variable This is used to represent the weighted in-degree of the j-th vehicle in the i-th train in the communication topology.

7. The method according to claim 6, characterized in that: The control inputs of each vehicle Including nonlinear compensation terms and status feedback items ,Right now ; It is used to compensate for vehicle dynamics nonlinearity, inter-vehicle coupling terms, target operation information introduction terms, and boundary function variation terms; Used to enhance the convergence and robustness of closed-loop error systems.

8. A system based on the method of any one of claims 1-7, characterized in that: include: The information acquisition module is used to acquire information about each vehicle in the train formation, including operating status information, inter-vehicle communication topology information, and target operating information. The error determination module is used to determine the formation tracking error of each vehicle based on the vehicle information, and to construct a correction error for the global formation position tracking error in the formation tracking error. The correction error is achieved by using two time-varying adjustment functions to correct the global formation position tracking error, so that the initial time... Regardless of the initial global formation position tracking error value, the correction error always remains within the initial preset boundary; during the delay adjustment time Then, the corrected error is restored to the true global formation position tracking error; The control module is used to construct an error dynamic model based on the corrected error, to solve for the control input of the vehicle controller and apply it to the vehicle actuators to perform traction or braking control on each vehicle, thereby achieving stable train formation.

9. A train system, characterized in that: The system includes a train formation and control terminal. Each train consists of multiple vehicles, and each vehicle is equipped with a controller. The controller is equipped with a processor and a memory. The processor calls a computer program stored in the memory to implement the steps of the method according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that: A computer program is stored, which is invoked by a processor to implement the steps of the method according to any one of claims 1-7.

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