Suspension system control method, device, equipment and medium of high-speed maglev train

Abstract

This application discloses a control method, device, equipment, and medium for the levitation system of a high-speed maglev train, relating to the field of maglev control technology. The method includes: constructing a target dynamic model of a single-point levitation system; applying time-varying constraints to the dynamic trajectory of the levitation gap tracking error using a preset performance function; converting the constrained error into an unconstrained variable using a preset mapping function, and designing a sliding surface containing nonlinear power terms and piecewise continuous functions based on the unconstrained variable; generating an actual control voltage based on the compensation signal output by the anti-saturation auxiliary system and the sliding surface; the actual control voltage includes an equivalent control law for maintaining the unconstrained variable's sliding on the sliding surface and a reaching control law for driving the unconstrained variable to the sliding surface; and adjusting the voltage across the electromagnet coil according to the actual control voltage to control the levitation gap. Through the technical solution of this application, rapid convergence and improved robustness of the high-speed maglev train levitation system can be achieved.

Description

Technical Field

[0001] This invention relates to the field of magnetic levitation control technology, and in particular to the control method, device, equipment and medium for the levitation system of high-speed maglev trains. Background Technology

[0002] High-speed maglev trains achieve vehicle levitation through electromagnetic force, eliminating wheel-rail contact and offering advantages such as ultra-high speed operation, low noise, and high energy efficiency. As the core subsystem of high-speed maglev trains, the electromagnetic levitation system requires precise control of the 8-10mm air gap, with an allowable deviation of no more than ±4mm, placing extremely high demands on the controller's response speed and reliability. However, the levitation system is inherently open-loop unstable and highly nonlinear, easily affected by external disturbances such as track irregularities and aerodynamic disturbances, leading to levitation gap instability. Existing control schemes still face many unresolved technical challenges and are insufficient to meet the actual operational requirements of high-speed maglev levitation systems.

[0003] First, the input saturation problem is not adequately considered. The control force of the suspension controller is limited by the on-board power supply voltage and can only vary within a specific range. Ignoring this constraint can easily lead to performance degradation or even system instability. Second, the fixed-time convergence characteristic has insufficient adaptability. Existing fixed-time control methods are mostly designed for linear systems or disturbed pure integral systems, while electromagnetic levitation systems inherently possess open-loop instability and strong nonlinearity, and are significantly affected by load changes and air gap fluctuations. Directly applying existing methods has significant limitations. Third, the adaptability of preset performance control is lacking. Existing preset performance control schemes mostly assume ideal actuator operation and do not fully consider the nonlinearity and uncertainty of electromagnetic levitation systems. They cannot effectively constrain the transient and steady-state characteristics of tracking errors simultaneously through preset performance functions. In addition, the adjustable range of the air gap in electromagnetic levitation systems is limited, placing high demands on the controller's response speed and reliability. Existing solutions lack robustness under multiple disturbances (including track irregularities and aerodynamic forces), making it difficult to stably maintain air gap balance. The core reason is the lack of deep integration of input constraints, fixed-time convergence, and preset performance control, failing to collaboratively address the problems caused by nonlinearity, disturbances, and input saturation. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a control method, device, equipment, and medium for the levitation system of high-speed maglev trains, which can achieve a comprehensive improvement in levitation control accuracy, response speed, robustness, and engineering practicality, providing an efficient control solution for the stable and reliable operation of high-speed maglev trains. The specific solution is as follows:

[0005] In a first aspect, this application discloses a control method for the levitation system of a high-speed maglev train, including:

[0006] Construct a target dynamic model for a single-point suspension system;

[0007] The tracking error of the suspension gap is defined based on the target dynamic model, and a time-varying constraint is applied to the dynamic trajectory of the tracking error using a preset performance function to obtain the constraint error.

[0008] The constraint error is converted into an unconstrained variable by a preset mapping function, and a sliding surface containing nonlinear power terms and piecewise continuous functions is designed based on the unconstrained variable.

[0009] An anti-saturation auxiliary system is constructed, and an actual control voltage is generated based on the compensation signal output by the anti-saturation auxiliary system and the sliding surface; wherein, the anti-saturation auxiliary system is used to compensate for the input saturation effect of the electromagnet; the actual control voltage includes an equivalent control law and a reaching control law, the equivalent control law is used to maintain the unconstrained variable sliding on the sliding surface, and the reaching control law is used to drive the unconstrained variable to reach the sliding surface;

[0010] The voltage across the electromagnet coil is adjusted according to the actual control voltage to control the levitation gap.

[0011] Optionally, the construction of the target dynamic model for the single-point suspension system includes:

[0012] A dynamic model of a single-point suspension system considering track irregularities is constructed; the system equations of the dynamic model are: ;in, For the mass of the electromagnet, z The distance between the magnetic pole surface and the absolute reference plane. t For the current time, for The second derivative, g This is the value of gravitational acceleration. Electromagnetic force, External random disturbance. Permeability, N The number of turns of the electromagnet coil. S The area of ​​the electromagnet poles is denoted as . i The excitation current of the suspending electromagnet, For suspension gap, r The track is not smooth;

[0013] Define state variables and transform the dynamic model into state-space form to obtain the target dynamic model; wherein, let The system equations of the target dynamics model in state-space form are: ; , , To control the input, The total disturbance caused by external disturbances and track irregularities.

[0014] Optionally, based on the target dynamic model, the tracking error of the suspension gap is defined, and a time-varying constraint is applied to the dynamic trajectory of the tracking error using a preset performance function to obtain the constraint error, including:

[0015] The tracking error of the suspension gap is defined based on the target dynamics model; wherein, the tracking error is... , The suspension gap, This is the reference input value for the suspension gap;

[0016] Design a preset performance function, and use the preset performance function to apply time-varying constraints to the dynamic trajectory of the tracking error to obtain the constraint error; the preset performance function is: ;in, T The transition time from the initial state to the steady state of the preset performance function. t For the current time, Adjusting parameters for curve shape, The initial value of the preset performance function is... This is the final value of the preset performance function.

[0017] Optionally, the constraint error can be converted into an unconstrained variable using a preset mapping function, including:

[0018] A relative error is defined based on the preset performance function and the constraint error, and corresponding boundary conditions are set for the relative error; the relative error is: The boundary conditions are: ,in, , These are preset boundary parameters. This is the initial value of the tracking error;

[0019] Design a preset mapping function, and convert the relative error into an unconstrained variable using the preset mapping function; the preset mapping function is: ,in, For symbol switching items, This is the first parameter to be designed.

[0020] Optionally, the sliding surface can be designed as follows: ;in, For first-order unconstrained variables, For second-order unconstrained variables, , This is the second parameter to be designed. , For symbolic functions, For the piecewise continuous function, , This is the third parameter to be designed. This is the segmentation threshold.

[0021] Optionally, an anti-saturation auxiliary system is constructed, and an actual control voltage is generated based on the compensation signal output by the anti-saturation auxiliary system and the sliding surface, including:

[0022] Define the input saturation deviation and design an anti-saturation auxiliary system based on the input saturation deviation; the input saturation deviation is... , For saturation control input, u For ideal control input; the anti-saturation auxiliary system is: ;in, , This is the fourth parameter to be designed. The output of the anti-saturation auxiliary system, for The first derivative, s The sliding surface, T The transition time from the initial state to the steady state of the preset performance function. As the initial threshold, It is a 2-norm;

[0023] Design equivalent control law: ;

[0024] Design approach control law: ;in, q for , , , This is the fifth parameter to be designed;

[0025] The equivalent control law and the approaching control law are combined, and the actual control voltage is generated based on the compensation signal output by the anti-saturation auxiliary system and the sliding surface.

[0026] Optionally, adjusting the voltage across the electromagnet coil according to the actual control voltage to control the levitation gap includes:

[0027] The control algorithm for generating the actual control voltage is discretized using the forward Euler method, and the discretized control algorithm is embedded into the suspension controller.

[0028] Based on the aforementioned levitation controller, it communicates with the levitation operation platform in real time via the controller local area network bus to receive sensor data collected online by the levitation operation platform;

[0029] Based on the sensor data, the discretized control algorithm is executed by the suspension controller, and the actual control voltage is output to adjust the voltage across the electromagnet coil to control the suspension gap.

[0030] Secondly, this application discloses a levitation system control device for a high-speed maglev train, comprising:

[0031] The model building module is used to construct the target dynamics model of a single-point suspension system.

[0032] The constraint design module is used to define the tracking error of the suspension gap based on the target dynamic model, and to apply time-varying constraints to the dynamic trajectory of the tracking error using a preset performance function to obtain the constraint error.

[0033] The sliding surface design module is used to convert the constraint error into an unconstrained variable through a preset mapping function, and to design a sliding surface containing a nonlinear power term and a piecewise continuous function based on the unconstrained variable.

[0034] A control law design module is used to construct an anti-saturation auxiliary system and generate an actual control voltage based on the compensation signal output by the anti-saturation auxiliary system and the sliding surface. The anti-saturation auxiliary system is used to compensate for the input saturation effect of the electromagnet. The actual control voltage includes an equivalent control law and a reaching control law. The equivalent control law is used to maintain the unconstrained variable sliding on the sliding surface, and the reaching control law is used to drive the unconstrained variable to reach the sliding surface.

[0035] The control implementation module is used to adjust the voltage across the electromagnet coil according to the actual control voltage to control the suspension gap.

[0036] Thirdly, this application discloses an electronic device, which includes a processor and a memory; wherein the memory is used to store a computer program, which is loaded and executed by the processor to implement the suspension system control method of the high-speed maglev train as described above.

[0037] Fourthly, this application discloses a computer-readable storage medium for storing a computer program; wherein the computer program, when executed by a processor, implements the aforementioned method for controlling the levitation system of a high-speed maglev train.

[0038] The beneficial effects of this application are as follows: First, by using the single-point suspension system as the basic unit of the high-speed maglev train suspension system, a high-fidelity dynamic model is constructed, which can accurately characterize the coupling relationship between gap, electromagnetic force, and disturbance, laying a precise model foundation for subsequent control design. Second, by using a preset performance function to quantitatively constrain the transient and steady-state processes of the suspension gap tracking error, it ensures from the source that the error always meets the stringent control requirements of millimeter-level precision for high-speed maglev under high-speed operation conditions. Combined with a mapping function, the constrained error is transformed into an unconstrained free variable, completely solving the problems of complex controller design and high computational difficulty under constrained conditions, greatly simplifying the design of subsequent control laws, and simultaneously achieving decoupling between error constraints and control design, making the design of control strategies more flexible and efficient. The designed sliding surface ensures that the system state converges to the equilibrium point within a fixed time through nonlinear power terms, while the use of piecewise continuous functions avoids the singularity problem of traditional sliding surfaces near the equilibrium point, keeping the control signal smooth and effectively suppressing control chattering. To address the engineering bottleneck of input saturation, an anti-saturation auxiliary system is introduced to compensate for the saturation effect in real time. This ensures that the control law operates effectively within the actuator's limitations, preventing performance degradation or instability caused by input saturation. Furthermore, based on the compensation signal and sliding surface output by the anti-saturation auxiliary system, an actual control voltage containing both an equivalent control law and a reaching control law is generated. This voltage is used to maintain the sliding motion and drive state reaching the sliding surface, respectively. This ensures the core characteristic of unconstrained variables converging within a fixed time while compensating for input saturation effects and rapidly suppressing disturbances. Together, these two technologies output precise and ideal control commands to the levitation system. Finally, the actual control voltage is applied to the electromagnet, enabling the levitation system to achieve high-precision, fast-response levitation gap tracking even under multiple constraints such as track irregularities, external disturbances, and input saturation. This significantly improves the stability and robustness of high-speed maglev trains under complex operating conditions.

[0039] Furthermore, the suspension system control device, equipment, and storage medium for a high-speed maglev train provided in this application correspond to the aforementioned suspension system control method for a high-speed maglev train and have the same effect. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0041] Figure 1 This is a flowchart of a levitation system control method for a high-speed maglev train disclosed in this application;

[0042] Figure 2 This is a schematic diagram of a high-speed maglev train and levitation system disclosed in this application;

[0043] Figure 3 This is a schematic diagram of a single-point suspension control system disclosed in this application;

[0044] Figure 4 This is a schematic diagram of a preset performance function under different parameters disclosed in this application;

[0045] Figure 5 This application discloses a closed-loop control system diagram for a suspension system based on a preset performance framework.

[0046] Figure 6 This is a schematic diagram illustrating the control effect comparison disclosed in this application;

[0047] Figure 7 This is a schematic diagram of the suspension system control device for a high-speed maglev train disclosed in this application;

[0048] Figure 8 This is a structural diagram of an electronic device disclosed in this application. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] Currently, high-speed maglev suspension systems suffer from problems such as input saturation (voltage limitation), strong nonlinearity, and disturbances (track irregularities). Existing high-speed maglev train suspension system control schemes do not fully consider these constraints, and their fixed-time convergence characteristics are not adaptable enough. Furthermore, the preset performance control does not take into account input saturation.

[0051] To this end, this application provides a control scheme for the suspension system of a high-speed maglev train, which aims to solve problems such as input saturation, strong nonlinearity, insufficient robustness under multiple disturbances, and lack of adaptability to fixed-time convergence. It integrates advanced technologies such as fixed-time convergence and preset performance control to achieve precise and stable control of the suspension system with air gap.

[0052] This invention discloses a control method for the levitation system of a high-speed maglev train. See [link to relevant documentation]. Figure 1 As shown, the method includes:

[0053] Step S11: Construct the target dynamic model of the single-point suspension system.

[0054] As attached Figure 2 As shown, the high-speed maglev train consists of components such as the car body, suspension frame, and suspension electromagnets. Its suspension system adopts an overlapping structure, where adjacent electromagnets are connected end-to-end through the suspension frame to form a flexible suspension structure that provides joint support. This design aims to improve operational safety. Based on the symmetry of the overlapping structure, a single-point suspension can be considered as the basic unit of the high-speed maglev train's suspension system. When a suspension unit fails, adjacent units can continue to provide support through the overlapping structure, thereby preventing the car body from contacting the track.

[0055] In this step, a single-sided, single-point suspension system is selected for analysis, focusing on the vibration of the electromagnets and the changes in the suspension gap in the maglev train. Based on a thorough consideration of the nonlinearity of the electromagnetic levitation force, track geometric irregularities, and external random disturbances, a high-fidelity target dynamic model of the single-point suspension system, incorporating the vehicle-levitation-track coupling characteristics, is established. All subsequent control designs are based on this model. (See attached...) Figure 3 As shown, after applying voltage to both ends of the electromagnet coil, an excitation current is generated in the electromagnet coil. Under the action of the current, the suspended electromagnet generates an electromagnetic force. The direction of the electromagnetic force is upward, causing the suspended electromagnet to move vertically and maintain a constant gap with the track.

[0056] It should be noted that this model uses the suspension gap as the state variable and integrates external disturbances and track irregularities into a total disturbance term. Specifically, the target dynamic model of the single-point suspension system is constructed, including:

[0057] A dynamic model of a single-point suspension system considering track irregularities is constructed; the system equations of the dynamic model can be expressed as: (1);

[0058] In the formula, For the mass of the electromagnet, z The distance between the magnetic pole surface and the absolute reference plane. for The second derivative, g This is the value of gravitational acceleration. Electromagnetic force, External random disturbance. Permeability, N The number of turns of the electromagnet coil. S The area of ​​the electromagnet poles is denoted as . i The excitation current of the suspending electromagnet, The suspension gap is the distance between the orbital surface and the absolute reference plane. r The track is not smooth; wherein, t For the current time, with The parameter indicates that this parameter is a dynamic quantity that changes over time, not a fixed value. For example, The distance between the electromagnet poles and the absolute reference plane varies at different times, which is consistent with the actual situation of real-time changes in gaps and current during the operation of maglev trains.

[0059] To facilitate subsequent controller design, the above model is transformed into a state-space form. Define the state variables, let... and define control inputs Then the state-space form of the target dynamics model can be expressed as: (2);

[0060] in, , ; The total disturbance caused by external disturbances and track irregularities is integrated into a lumped disturbance term through this integration process, which makes it easier for the controller to suppress the disturbance through observation or compensation mechanisms.

[0061] It is evident that the state-space model of the target dynamics model fully describes the dynamic characteristics of a single-point suspension system under track irregularities and external disturbances. This model provides a unified mathematical foundation for the subsequent design of preset performance functions, the construction of sliding surfaces, and the derivation of anti-saturation control laws.

[0062] Step S12: Define the tracking error of the suspension gap based on the target dynamic model, and apply time-varying constraints to the dynamic trajectory of the tracking error using a preset performance function to obtain the constraint error.

[0063] To achieve high-precision control of the suspension gap, the suspension gap tracking error is first defined based on the target dynamics model: (3);

[0064] in, For suspension gap, The reference input value is the suspension gap; the control objective is to minimize the tracking error. e 1 It converges to zero while satisfying transient and steady-state performance indicators.

[0065] To ensure the high-speed maglev suspension system smoothly and accurately follows the target gap trajectory, a preset performance function is designed using tracking error as a performance indicator. As long as the error follows this function, the millimeter-level accuracy requirements of engineering can be met. This function, by reasonably setting initial values, termination values, transition time, and shape parameters, limits the dynamic range of tracking error, thus obtaining the constraint error and meeting the safety limits of the suspension gap. Preset performance function Designed as a piecewise function:

[0066] (4);

[0067] in,T The transition time from the initial state to the steady state of the preset performance function. t For the current time, Adjusting parameters for curve shape, The initial value of the preset performance function is... This is the final value of the preset performance function.

[0068] It should be noted that the selection of parameters for the preset performance function directly affects the convergence speed, overshoot, steady-state accuracy, and smoothness of the control input of the system tracking error. For example... Figure 4 The figure shows the curve shape of the preset performance function under different parameter values. As can be seen from the figure, by adjusting the parameters... T and It allows for flexible design of error convergence speed and transition process shape, thereby meeting dynamic performance requirements under different working conditions.

[0069] In one specific implementation, T Indicates expected error entering For highly dynamic suspension systems, this parameter should be selected within a certain time range; a smaller value can be chosen. ; Used to adjust the shape of a function curve, with a typical range of values. The boundary of the system's initial tracking error. Typically, a value slightly larger than the actual initial error is chosen, such as... System termination tracking error boundary The settings need to be configured according to task requirements. Generally, the steady-state time interval fluctuation of the suspension system is small, so it can be selected. .

[0070] Step S13: Convert the constraint error into an unconstrained variable using a preset mapping function, and design a sliding surface containing nonlinear power terms and piecewise continuous functions based on the unconstrained variable.

[0071] Understandably, designing a controller directly based on constrained errors would involve various constraints and be computationally extremely complex. Therefore, in this step, a relative error is further constructed based on the tracking error and a preset performance function. This constrained relative error is then transformed into an unconstrained variable through a switching unconstrained mapping. This maps the originally restricted domain one-to-one to the unconstrained space. Controlling the unconstrained variable is equivalent to ensuring the actual tracking error conforms to all preset rules, eliminating the need to consider any error constraints and significantly simplifying the design. The relative error is: To ensure that the suspension gap fluctuates within a safe range, the following boundary conditions are set for the relative error:

[0072] (5);

[0073] in, , These are preset boundary parameters used to adjust the allowable asymmetric boundary for error; This is the initial value for the tracking error; this constraint ensures that the tracking error is always limited to a preset performance function. Within the defined envelope, quantitative control of overshoot, convergence speed, and steady-state error can be achieved.

[0074] Furthermore, the following unconstrained preset mapping function is constructed to transform constrained error variables into unconstrained variables, facilitating subsequent sliding mode control law design:

[0075] (6);

[0076] For symbol switching items, for , ;for , ; This is the first parameter to be designed. The relative error is transformed into an equivalent unconstrained variable through the above mapping.

[0077] Thus, through the controller designed with the aforementioned preset performance function and unconstrained mapping, the original suspension gap tracking error e1 is transformed into an unconstrained variable. This transformation process ensures that the system's suspension gap tracking error always meets the set dynamic trajectory constraints during convergence, thus laying the foundation for achieving high-precision, quantifiable suspension control.

[0078] Furthermore, a fixed-time nonsingular terminal sliding surface with preset properties is designed. This sliding surface balances fixed-time convergence and nonsingularity, with its corresponding properties corresponding to nonlinear power terms and piecewise continuous functions, respectively. For ease of description... ,use The sliding surface design, based on unconstrained variable design and satisfying preset performance, is as follows:

[0079] (7);

[0080] in, For first-order unconstrained variables, For second-order unconstrained variables, The gain coefficient of the sliding surface. The exponent of the power term and the second parameter to be designed are both indicated by the superscript in square brackets, which signifies a power function with reserved sign. , It is a symbolic function.

[0081] The sliding surface consists of three parts: linear terms. Provides basic proportional adjustment; nonlinear power term It plays a dominant role when the system state is far from the equilibrium point, utilizing its high gain characteristic to accelerate the convergence process; piecewise continuous function term. It is used to solve the singularity problem of traditional terminal sliding mode near the equilibrium point, and to ensure the continuity and doubling of the sliding surface in the whole state range.

[0082] in, For a piecewise continuous function, it is expressed as: (8);

[0083] For polynomial coefficients, The exponent is the power term, and the other two are the third parameters to be designed. The pre-set segmentation threshold is used to define the region far from the equilibrium point and the neighborhood of the equilibrium point.

[0084] pass Continuous and smooth design to avoid... Singularities may occur in the vicinity, while ensuring the continuity and differentiability of the sliding surface globally. This is understandable, as the sliding surface is directly based on unconstrained variables. Design, and The system inherently contains time-varying constraint information on tracking error for the preset performance function. Therefore, when the system state moves on the sliding surface, its convergence process naturally meets the preset dynamic performance requirements (such as overshoot limit, steady-state accuracy, etc.). By designing a suitable preset performance function, it can be ensured that the system meets the expected performance indicators on the sliding surface, thus realizing the organic integration of preset performance control and sliding mode control.

[0085] In one specific implementation, the parameters of the sliding surface need to be tuned according to the dynamic characteristics and performance requirements of the system: (1) Select according to the non-singular and fixed time requirements. (2) Preliminary selection , , First adjust Improve dynamics, readjust and (3) To ensure convergence within a fixed time and rapid convergence when far from the origin, the following values ​​are often used: (4) In order to make exist When it is close to 0, it is mainly due to Dominant, selectable , , .

[0086] Step S14: Construct an anti-saturation auxiliary system and generate an actual control voltage based on the compensation signal output by the anti-saturation auxiliary system and the sliding surface; wherein, the anti-saturation auxiliary system is used to compensate for the input saturation effect of the electromagnet; the actual control voltage includes an equivalent control law and a reaching control law, the equivalent control law is used to maintain the unconstrained variable sliding on the sliding surface, and the reaching control law is used to drive the unconstrained variable to reach the sliding surface.

[0087] In practical engineering applications, the electromagnet drive voltage of the high-speed maglev train's levitation system is limited by the onboard power supply capacity, exhibiting a clear saturation limit. When the maglev train is levitation or facing significant disturbances, substantial tracking errors may occur. In such cases, the current command generated by the control law may momentarily exceed the electromagnet drive current saturation limit, failing to provide the required electromagnetic force, thus leading to decreased control performance or even system instability. To address this issue, this step introduces an anti-saturation compensation mechanism within a fixed-time preset performance control framework, constructing an anti-saturation auxiliary system, as specifically designed below:

[0088] First, define the input saturation deviation. ,in, For saturation control input, u To achieve ideal control input; secondly, to compensate for the adverse effects of saturation on system dynamics, an anti-saturation auxiliary system is designed based on input saturation deviation:

[0089] (9);

[0090] in, , This is the fourth parameter to be designed. The output of the anti-saturation auxiliary system, for The first derivative, s The sliding surface, T The transition time from the initial state to the steady state of the preset performance function. As the initial threshold, It is a 2-norm.

[0091] In one specific implementation, the initial threshold Set according to the saturation limit of the drive current; nonlinear term While ensuring convergence, overcompensation should be avoided, and the parameters... k 1 and k 3 The design is based on the degree of actuator saturation. This mechanism enables the system to accurately track the desired floating position even under current constraints, and the control current gradually decreases back to the actuator's allowable range.

[0092] Furthermore, based on the sliding surface designed in the aforementioned steps, the actual control voltage is constructed using a combination of equivalent control law and approaching control law. The control law structure is as follows: u=u e +u r .in, u e The equivalent control law is a continuous control part used to maintain the sliding of the unconstrained variable on the sliding surface, which ensures the fixed-time convergence characteristic of the unconstrained variable on the sliding surface. u r To approximate the control law, it is used to drive unconstrained variables to the sliding surface, compensate for controller saturation, and provide robustness to external disturbances.

[0093] Equivalent control law: (10); where the definitions of each variable are consistent with those above; the equivalent control law ensures that when the system is on the sliding surface, it can maintain sliding motion and achieve fixed-time convergence under preset performance constraints. The design of the approach control law introduces an anti-saturation auxiliary system output. To compensate for the effects of input saturation, a nonlinear approach term is added to accelerate the speed at which the sliding surface is reached. (11).

[0094] in, This is the fifth parameter to be designed; to achieve fixed-time convergence, , , The gain of the switching term can be increased to enhance robustness and speed up convergence, but it will exacerbate chattering; decreasing it can reduce chattering, but it may reduce anti-interference capability. It needs to be manually tuned according to the actual system.

[0095] Adding the equivalent control law to the approaching control law yields the complete expression for the actual control voltage. This control law has the following characteristics: ① By using a preset performance function and unconstrained mapping, it ensures that the tracking error of the levitation gap always meets the preset dynamic constraints; ② The design of nonlinear power terms and piecewise continuous functions in the sliding surface ensures that the system state can converge to the equilibrium point within a fixed time, while avoiding the singularity problem of traditional terminal sliding mode; ③ The introduction of an anti-saturation auxiliary system allows the control law to function effectively even when the input voltage is limited, avoiding performance degradation caused by actuator saturation; ④ The control law has a clear structure, low computational complexity, and is easy to implement on an embedded platform.

[0096] The designed closed-loop control structure of the suspension system based on the preset performance framework is as follows: Figure 5 As shown in the figure, the signal transmission relationships between the preset performance function, unconstrained mapping, sliding surface, anti-saturation auxiliary system, and control law modules are clearly illustrated.

[0097] Step S15: Adjust the voltage across the electromagnet coil according to the actual control voltage to control the suspension gap.

[0098] This step focuses on high real-time performance and ease of maintenance, proposing a solution that integrates a high-performance real-time controller, synchronous data transmission, and fast power drive. The non-singular terminal sliding mode fixed-time preset performance control algorithm designed in this application is embedded into the high-speed magnetic levitation controller. The generated actual control voltage needs to be converted into an actual physical signal and applied to both ends of the levitation electromagnet coil to achieve precise adjustment of the levitation gap. The specific implementation process is as follows:

[0099] The control algorithm for generating the actual control voltage is discretized using the forward Euler method, and the discretized control algorithm is embedded into the suspension controller. This controller uses a DSP28335 as the main control chip, whose powerful floating-point operation capabilities, abundant peripheral resources, and high optimization for real-time control ensure efficient execution of the control law. Based on the suspension controller, real-time communication is established with the suspension operation platform via the Controller Area Network (CAN) bus. During the experiment, the operation platform collects sensor data such as suspension gap, acceleration, and current, which are then packaged and uploaded at high speed to the host computer via the CAN bus. The host computer is responsible for data storage, visualization, and offline analysis, providing support for system performance evaluation and parameter optimization. Based on the sensor data, the suspension controller executes the discretized control algorithm and outputs the actual control voltage to adjust the voltage across the electromagnet coil to control the suspension gap.

[0100] In this way, the actual control voltage u When applied to the electromagnet coil, the coil current is changed. i In turn, the electromagnetic force is regulated. f e , making the suspension gap Dynamically adjust to the target value. Under input saturation conditions, the output of the anti-saturation auxiliary system... It participates in control law regulation to ensure that the control voltage is limited within the allowable range of the electromagnet, avoiding performance degradation caused by excessive drive current. The overall architecture balances real-time performance, reliability, and scalability, effectively achieving high-precision and stable control of the magnetic levitation system.

[0101] The beneficial effects of this application are as follows: First, by using the single-point suspension system as the basic unit of the high-speed maglev train suspension system, a high-fidelity dynamic model is constructed, which can accurately characterize the coupling relationship between gap, electromagnetic force, and disturbance, laying a precise model foundation for subsequent control design. Second, by using a preset performance function to quantitatively constrain the transient and steady-state processes of the suspension gap tracking error, it ensures from the source that the error always meets the stringent control requirements of millimeter-level precision for high-speed maglev under high-speed operation conditions. Combined with a mapping function, the constrained error is transformed into an unconstrained free variable, completely solving the problems of complex controller design and high computational difficulty under constrained conditions, greatly simplifying the design of subsequent control laws, and simultaneously achieving decoupling between error constraints and control design, making the design of control strategies more flexible and efficient. The designed sliding surface ensures that the system state converges to the equilibrium point within a fixed time through nonlinear power terms, while the use of piecewise continuous functions avoids the singularity problem of traditional sliding surfaces near the equilibrium point, keeping the control signal smooth and effectively suppressing control chattering. To address the engineering bottleneck of input saturation, an anti-saturation auxiliary system is introduced to compensate for the saturation effect in real time. This ensures that the control law operates effectively within the actuator's limitations, preventing performance degradation or instability caused by input saturation. Furthermore, based on the compensation signal and sliding surface output by the anti-saturation auxiliary system, an actual control voltage containing both an equivalent control law and a reaching control law is generated. This voltage is used to maintain the sliding motion and drive state reaching the sliding surface, respectively. This ensures the core characteristic of unconstrained variables converging within a fixed time while compensating for input saturation effects and rapidly suppressing disturbances. Together, these two technologies output precise and ideal control commands to the levitation system. Finally, the actual control voltage is applied to the electromagnet, enabling the levitation system to achieve high-precision, fast-response levitation gap tracking even under multiple constraints such as track irregularities, external disturbances, and input saturation. This significantly improves the stability and robustness of high-speed maglev trains under complex operating conditions.

[0102] Figure 6The figure shows a comparison of the suspension gap response curves of the fixed-time preset performance control method proposed in this invention with PID control and LQR control under the same operating conditions. As can be seen from the figure, whether in the transient or steady-state process, the suspension system based on the method designed in this invention exhibits improved accuracy, speed, and robustness compared to PID control and LQR control. This superior performance is attributed to: ① The constraint effect of the preset performance function: strictly limiting the tracking error within the preset decay boundary, ensuring no overshoot and rapid convergence in the transient process; ② The design of the fixed-time sliding surface: enabling the system state to converge to the equilibrium point within a fixed time, with the convergence speed independent of the initial state; ③ Compensation of the anti-saturation auxiliary system: adjusting the control command in real time when input saturation occurs, avoiding performance degradation due to voltage limitations; ④ The robustness of the composite control law: the equivalent control maintains the sliding motion, and the approach control-driven state reaches the sliding surface; the synergistic effect of both enhances the system's ability to suppress external disturbances and model uncertainties. In summary, the control method proposed in this invention is significantly superior to traditional PID control and LQR control in terms of overshoot suppression, convergence speed, steady-state accuracy, and disturbance rejection capability, and can meet the high-performance requirements of the suspension system for high-speed maglev trains under complex operating conditions.

[0103] Accordingly, this application also discloses a levitation system control device for a high-speed maglev train, see [link to relevant documentation]. Figure 7 As shown, the device includes:

[0104] Model building module 11 is used to build the target dynamics model of a single-point suspension system;

[0105] The constraint design module 12 is used to define the tracking error of the suspension gap based on the target dynamic model, and to apply time-varying constraints to the dynamic trajectory of the tracking error using a preset performance function to obtain the constraint error.

[0106] The sliding surface design module 13 is used to convert the constraint error into an unconstrained variable through a preset mapping function, and to design a sliding surface containing a nonlinear power term and a piecewise continuous function based on the unconstrained variable.

[0107] The control law design module 14 is used to construct an anti-saturation auxiliary system and generate an actual control voltage based on the compensation signal output by the anti-saturation auxiliary system and the sliding surface; wherein, the anti-saturation auxiliary system is used to compensate for the input saturation effect of the electromagnet; the actual control voltage includes an equivalent control law and a reaching control law, the equivalent control law is used to maintain the unconstrained variable sliding on the sliding surface, and the reaching control law is used to drive the unconstrained variable to reach the sliding surface;

[0108] The control implementation module 15 is used to adjust the voltage across the electromagnet coil according to the actual control voltage to control the suspension gap.

[0109] For more detailed information on the working process of each of the above modules, please refer to the relevant content disclosed in the foregoing embodiments, which will not be repeated here.

[0110] Therefore, the above-described scheme in this embodiment firstly uses the single-point suspension system as the basic unit of the high-speed maglev train suspension system to construct a high-fidelity dynamic model, which can accurately characterize the coupling relationship between gap, electromagnetic force, and disturbance, laying a precise model foundation for subsequent control design. Secondly, by using a preset performance function to quantify and constrain the transient and steady-state processes of the suspension gap tracking error, it ensures from the source that the error always meets the stringent control requirements of millimeter-level precision for high-speed maglev under high-speed operation conditions. Combined with a mapping function, the constrained error is transformed into an unconstrained free variable, completely solving the problems of complex controller design and high computational difficulty under constrained conditions, greatly simplifying the design of subsequent control laws, and simultaneously achieving decoupling between error constraints and control design, making the design of control strategies more flexible and efficient. The designed sliding surface ensures that the system state converges to the equilibrium point within a fixed time through nonlinear power terms, while the use of piecewise continuous functions avoids the singularity problem of traditional sliding surfaces near the equilibrium point, keeping the control signal smooth and effectively suppressing control chattering. To address the engineering bottleneck of input saturation, an anti-saturation auxiliary system is introduced to compensate for the saturation effect in real time. This ensures that the control law operates effectively within the actuator's limitations, preventing performance degradation or instability caused by input saturation. Furthermore, based on the compensation signal and sliding surface output by the anti-saturation auxiliary system, an actual control voltage containing both an equivalent control law and a reaching control law is generated. This voltage is used to maintain the sliding motion and drive state reaching the sliding surface, respectively. This ensures the core characteristic of unconstrained variables converging within a fixed time while compensating for input saturation effects and rapidly suppressing disturbances. Together, these two technologies output precise and ideal control commands to the levitation system. Finally, the actual control voltage is applied to the electromagnet, enabling the levitation system to achieve high-precision, fast-response levitation gap tracking even under multiple constraints such as track irregularities, external disturbances, and input saturation. This significantly improves the stability and robustness of high-speed maglev trains under complex operating conditions.

[0111] Furthermore, embodiments of this application also disclose an electronic device, Figure 8 This is a structural diagram of an electronic device 20 according to an exemplary embodiment. The content of the diagram should not be construed as limiting the scope of this application.

[0112] Figure 8This is a schematic diagram of the structure of an electronic device 20 provided in an embodiment of this application. Specifically, the electronic device 20 may include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 stores a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the levitation system control method for high-speed maglev trains disclosed in any of the foregoing embodiments.

[0113] In this embodiment, the power supply 23 is used to provide operating voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and external devices, and the communication protocol it follows can be any communication protocol applicable to the technical solution of this application, and is not specifically limited here; the input / output interface 25 is used to acquire external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs, and is not specifically limited here.

[0114] In addition, the memory 22, as a carrier for resource storage, can be a read-only memory, random access memory, disk, or optical disk, etc. The resources stored on it can include an operating system 221, computer programs 222, and data 223, etc. The data 223 can include various types of data. The storage method can be temporary storage or permanent storage.

[0115] The operating system 221 is used to manage and control the various hardware devices on the electronic device 20 and the computer program 222, which may be Windows Server, Netware, Unix, Linux, etc. In addition to including a computer program capable of performing the levitation system control method of the high-speed maglev train executed by the electronic device 20 as disclosed in any of the foregoing embodiments, the computer program 222 may further include computer programs capable of performing other specific tasks.

[0116] Furthermore, this application also discloses a computer-readable storage medium, which includes random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, magnetic disks, optical disks, or any other form of storage medium known in the art. The computer program, when executed by a processor, implements the aforementioned levitation system control method for high-speed maglev trains. Specific steps of this method can be found in the corresponding content disclosed in the foregoing embodiments, and will not be repeated here.

[0117] Furthermore, embodiments of this application also provide a computer program product, including a computer program / instruction, which, when executed by a processor, implements any of the above-described methods for controlling the levitation system of a high-speed maglev train.

[0118] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0119] The steps of the levitation system control method or algorithm for high-speed maglev trains described in conjunction with the embodiments disclosed herein can be implemented directly using hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art.

[0120] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0121] The above provides a detailed description of the levitation system control method, device, equipment, and medium for high-speed maglev trains provided by this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only intended to help understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method of controlling a levitation system of a high-speed maglev train, characterized by, include: Construct a target dynamic model for a single-point suspension system; The tracking error of the suspension gap is defined based on the target dynamic model, and a time-varying constraint is applied to the dynamic trajectory of the tracking error using a preset performance function to obtain the constraint error. The constraint error is converted into an unconstrained variable by a preset mapping function, and a sliding surface containing nonlinear power terms and piecewise continuous functions is designed based on the unconstrained variable. An anti-saturation auxiliary system is constructed, and an actual control voltage is generated based on the compensation signal output by the anti-saturation auxiliary system and the sliding surface; wherein, the anti-saturation auxiliary system is used to compensate for the input saturation effect of the electromagnet; the actual control voltage includes an equivalent control law and a reaching control law, the equivalent control law is used to maintain the unconstrained variable sliding on the sliding surface, and the reaching control law is used to drive the unconstrained variable to reach the sliding surface; The voltage across the electromagnet coil is adjusted according to the actual control voltage to control the levitation gap.

2. The method of claim 1, wherein The target dynamic model for constructing the single-point suspension system includes: A dynamic model of a single-point suspension system considering track irregularities is constructed; the system equations of the dynamic model are: ;in, For the mass of the electromagnet, z This is the distance between the magnetic pole surface and the absolute reference plane. t For the current time, for The second derivative, g This is the value of gravitational acceleration. Electromagnetic force, External random disturbance. Permeability, N The number of turns of the electromagnet coil. S The area of ​​the electromagnet poles is denoted as . i The excitation current of the suspending electromagnet, For suspension gap, r The track is not smooth; Define state variables and transform the dynamic model into state-space form to obtain the target dynamic model; wherein, let The system equations of the target dynamics model in state-space form are: ; , , To control the input, The total disturbance caused by external disturbances and track irregularities.

3. The method of claim 2, wherein the method further comprises: Based on the target dynamic model, the tracking error of the suspension gap is defined, and a time-varying constraint is applied to the dynamic trajectory of the tracking error using a preset performance function to obtain the constraint error, including: defining a tracking error for the levitation gap based on the target dynamic model; wherein the tracking error is , for the levitation gap, is a levitation gap reference input value; Design a preset performance function, and use the preset performance function to apply time-varying constraints to the dynamic trajectory of the tracking error to obtain the constraint error; the preset performance function is: ;in, T The transition time from the initial state to the steady state of the preset performance function. t For the current time, Adjusting parameters for curve shape, The initial value of the preset performance function is... This is the final value of the preset performance function.

4. The method of claim 3, wherein the method further comprises: The constraint error is converted into an unconstrained variable by a preset mapping function, including: defining a relative error based on the preset performance function and the constraint error, and setting a corresponding boundary condition for the relative error; the relative error is: , and the boundary condition is: wherein, , is a preset boundary parameter, is an initial value of the tracking error; The preset mapping function is designed, and the relative error is converted into an unconstrained variable through the preset mapping function; the preset mapping function is: wherein, is a symbol switching term, is a first to-be-designed parameter.

5. The method of claim 4, wherein the method further comprises: The sliding surface is designed as follows: ;in, For first-order unconstrained variables, For second-order unconstrained variables, , This is the second parameter to be designed. , For symbolic functions, For the piecewise continuous function, , This is the third parameter to be designed. This is the segmentation threshold.

6. The method of claim 5, wherein the method further comprises: Constructing an anti-saturation auxiliary system, and generating an actual control voltage based on the compensation signal output by the anti-saturation auxiliary system and the sliding surface, including: Define the input saturation deviation and design an anti-saturation auxiliary system based on the input saturation deviation; the input saturation deviation is... , For saturation control input, u For ideal control input; the anti-saturation auxiliary system is: ;in, , This is the fourth parameter to be designed. The output of the anti-saturation auxiliary system, for The first derivative, s The sliding surface, T The transition time from the initial state to the steady state of the preset performance function. As the initial threshold, It is a 2-norm; Designing an equivalent control law: ; Design approaching control law: ; wherein, q is , , , is a fifth to-be-designed parameter; The equivalent control law and the approaching control law are combined, and the actual control voltage is generated based on the compensation signal output by the anti-saturation auxiliary system and the sliding surface.

7. The method of claim 1 to 6, wherein, The step of adjusting the voltage across the electromagnet coil according to the actual control voltage to control the levitation gap includes: The control algorithm for generating the actual control voltage is discretized using the forward Euler method, and the discretized control algorithm is embedded into the suspension controller. Based on the aforementioned levitation controller, it communicates with the levitation operation platform in real time via the controller local area network bus to receive sensor data collected online by the levitation operation platform; Based on the sensor data, the discretized control algorithm is executed by the suspension controller, and the actual control voltage is output to adjust the voltage across the electromagnet coil to control the suspension gap.

8. A levitation system control device for a high-speed maglev train, characterized by comprising: include: The model building module is used to construct the target dynamics model of a single-point suspension system. The constraint design module is used to define the tracking error of the suspension gap based on the target dynamic model, and to apply time-varying constraints to the dynamic trajectory of the tracking error using a preset performance function to obtain the constraint error. The sliding surface design module is used to convert the constraint error into an unconstrained variable through a preset mapping function, and to design a sliding surface containing a nonlinear power term and a piecewise continuous function based on the unconstrained variable. A control law design module is used to construct an anti-saturation auxiliary system and generate an actual control voltage based on the compensation signal output by the anti-saturation auxiliary system and the sliding surface. The anti-saturation auxiliary system is used to compensate for the input saturation effect of the electromagnet. The actual control voltage includes an equivalent control law and a reaching control law. The equivalent control law is used to maintain the unconstrained variable sliding on the sliding surface, and the reaching control law is used to drive the unconstrained variable to reach the sliding surface. The control implementation module is used to adjust the voltage across the electromagnet coil according to the actual control voltage to control the suspension gap.

9. An electronic device, comprising: The electronic device includes a processor and a memory; wherein the memory is used to store a computer program, which is loaded and executed by the processor to implement the levitation system control method for a high-speed maglev train as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, Used to store computer programs; wherein the computer programs, when executed by a processor, implement the levitation system control method for a high-speed maglev train as described in any one of claims 1 to 7.

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