Speed ​​measurement and positioning simulation system for ultra-high-speed maglev trains

Abstract

The present invention provides a speed measurement and positioning simulation system for ultra-high-speed maglev trains, comprising an electromagnetic analytical model and a signal processing unit. The electromagnetic analytical model includes first and second zero-flux coil assemblies, an excitation receiving module, an excitation receiving compensation module, and a calculation module. The excitation coil and the excitation compensation coil are connected in reverse series. The calculation module is used to calculate a first receiving induced voltage of the excitation receiving module and a second receiving induced voltage of the excitation receiving compensation module based on the excitation currents of the excitation coil and the excitation compensation coil, the train's motion posture, and the train's motion speed. The signal processing unit is connected to the excitation receiving module and the excitation receiving compensation module, respectively, and is used to measure the speed and position the train based on the first receiving induced voltage and the second receiving induced voltage. The technical solution of the present invention is applied to solve the technical problems of the existing speed measurement and positioning equipment, such as complexity, low measurement accuracy, and poor anti-interference ability.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic levitation trains, and in particular to a speed measurement and positioning simulation system for ultra-high-speed magnetic levitation trains. Background Art

[0002] Ultra-high-speed maglev trains, part of a rail transit system, require speed detection and monitoring during operation. This provides the traction control system and train operation control system with position and speed information at any given moment. This information is crucial for controlling acceleration and deceleration, regulating routes, and enabling emergency stops in the event of a fault. To ensure safe train operation, speed measurement and positioning methods require redundancy.

[0003] The target positioning and speed measurement system of the ultra-high-speed low-vacuum tube maglev transportation system (T-Flight) is divided into two parts: the ground positioning and speed measurement system and the on-board positioning and speed measurement system. Among them, the ground positioning and speed measurement system provides the traction control system and operation control system with the train's position and speed information at any time; the on-board positioning and speed measurement system is completely independent of the ground positioning and speed measurement system. Under normal operating conditions, it provides the train's positioning and speed measurement information to the on-board operation control unit and is used to display the current position and speed to passengers. In the event of a failure of the ground positioning and speed measurement system, it serves as a backup guarantee and emergency plan to guide emergency stops.

[0004] Currently, a variety of technologies exist for positioning and speed measurement, including cross-induction loops, Doppler radar, interrogation-transponders, and pulse-width coding. Cross-induction loop technology, however, requires complex instrumentation and equipment, imposes stringent construction requirements, and requires special handling at intersections, making operation and ongoing maintenance more challenging. Doppler radar suffers from large errors at high speeds. Interrogation-transponders and pulse-width coding are suitable for absolute positioning and eliminating accumulated errors, but are less suitable for speed measurement. Summary of the Invention

[0005] The present invention provides a speed measurement and positioning simulation system for an ultra-high-speed maglev train, which can solve the technical problems in the prior art of complex speed measurement and positioning equipment, low measurement accuracy and poor anti-interference ability.

[0006] The present invention provides a speed measurement and positioning simulation system for an ultra-high-speed maglev train, the speed measurement and positioning simulation system for an ultra-high-speed maglev train comprising: an electromagnetic analytical model, the electromagnetic analytical model comprising a first zero-magnetic flux coil component, a second zero-magnetic flux coil component, an excitation receiving module, an excitation receiving compensation module and a calculation module, the first zero-magnetic flux coil component and the second zero-magnetic flux coil component being arranged relative to each other, the first zero-magnetic flux coil component being connected to the second zero-magnetic flux coil component, the excitation receiving module comprising an excitation coil, a first receiving coil and a second receiving coil, the excitation coil being arranged on the first zero-magnetic flux coil component, the first receiving coil and the second receiving coil being connected in series, the first receiving coil and the second receiving coil being arranged symmetrically relative to the center line of the excitation coil, the first receiving coil and the second receiving coil being arranged at intervals on the second zero-magnetic flux coil component, the excitation receiving compensation module being arranged at intervals from the excitation receiving module, the excitation receiving compensation module comprising an excitation compensation ... A receiving compensation coil and a second receiving compensation coil, the excitation compensation coil is arranged on the first zero magnetic flux coil assembly, the first receiving compensation coil and the second receiving compensation coil are connected in series, the first receiving compensation coil and the second receiving compensation coil are symmetrically arranged relative to the center line of the excitation compensation coil, the first receiving compensation coil and the second receiving compensation coil are arranged at intervals on the second zero magnetic flux coil assembly, the excitation coil and the excitation compensation coil are connected in series in reverse, the calculation module is used to calculate and obtain the first receiving induced voltage of the excitation receiving module and the second receiving induced voltage of the excitation receiving compensation module according to the excitation current of the excitation coil and the excitation compensation coil, the motion posture of the train and the motion speed of the train; a signal processing unit, the signal processing unit is connected to the excitation receiving module and the excitation receiving compensation module respectively, the signal processing unit is used to complete the speed measurement and positioning of the train according to the first receiving induced voltage of the excitation receiving module and the second receiving induced voltage of the excitation receiving compensation module.

[0007] Furthermore, the calculation module includes a zero-flux coil counting system analytical model, a first interference analytical model, and a second interference analytical model. The zero-flux coil counting system analytical model is used to calculate and obtain the first effective voltage signal of the excitation receiving module and the second effective voltage signal of the excitation receiving compensation module. The first interference analytical model is used to calculate and obtain the first interference signal of the propulsion coil to the excitation coil and the second interference signal of the propulsion coil to the excitation compensation coil. The second interference analytical model is used to calculate and obtain the third interference signal of the propulsion coil to the first receiving coil and the second receiving coil of the excitation receiving module and the fourth interference signal of the propulsion coil to the first receiving compensation coil and the second receiving compensation coil of the excitation receiving compensation module.

[0008] Furthermore, the spacing between the excitation coil and the excitation compensation coil, the spacing between the first receiving coil and the first receiving compensation coil, and the spacing between the second receiving coil and the second receiving compensation coil are all 2τ, where τ is the pole pitch of the train propulsion coil.

[0009] Furthermore, the distance between the first receiving coil and the second receiving coil is The distance between the first receiving compensation coil and the second receiving compensation coil is

[0010] Furthermore, the longitudinal distance between the longitudinal centers of the excitation coil and the excitation compensation coil and the center of the vehicle body is 0.1τ.

[0011] Furthermore, the signal processing unit includes a signal processing circuit and a digital processor, the signal processing circuit is used to process the first received induced voltage and the second received induced voltage to output a square wave voltage difference signal, and the digital processor is used to calculate and obtain the speed and displacement of the train based on the square wave voltage difference signal.

[0012] Furthermore, the signal processing circuit includes a subtraction circuit and a zero-crossing detection circuit, the subtraction circuit is used to perform a difference operation on the first received induced voltage and the second received induced voltage to obtain a sinusoidal voltage difference signal, and the zero-crossing detection circuit is used to convert the sinusoidal voltage difference signal into a square wave voltage difference signal.

[0013] Furthermore, the signal processing circuit also includes an overvoltage protection unit and a filtering circuit. The overvoltage protection unit is used to limit the signal whose pressure in the first received induced voltage and the second received induced voltage exceeds the set pressure threshold range, and the filtering circuit is used to filter out the signal whose frequency in the sinusoidal voltage value signal exceeds the set frequency threshold range.

[0014] Furthermore, the digital processor includes a trigger, a counter, a timer and an operation unit. The trigger is used to trigger according to the square wave voltage difference signal, the counter is used to record the number of times the trigger is triggered, the timer is used to record the trigger time interval of the trigger, and the operation unit is used to calculate and obtain the speed and displacement of the train based on the interval between adjacent zero flux coils, the number of triggers and the trigger time interval.

[0015] Furthermore, the train speed v i According to The train displacement S can be calculated according to S = iL, where L is the distance between adjacent zero flux coils, T i is the time interval between the i-th trigger count and the i-1-th trigger count.

[0016] Applying the technical solution of this invention, a speed measurement and positioning simulation system for ultra-high-speed maglev trains is provided. Compared with existing technologies, this system boasts a simpler structure and, through the introduction of an excitation reception compensation module, effectively reduces interference, ensuring that speed measurement and positioning accuracy remain within permitted limits. Furthermore, by fully coupling zero-flux coil counting electromagnetic analysis with signal processing circuit simulation, it effectively and accurately analyzes speed measurement and positioning across the full speed range of high-speed trains. The flexible model establishment and fast solution speed provide support for the design of zero-flux speed measurement and positioning systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are included to provide a further understanding of the embodiments of the present invention, constitute a part of the specification, illustrate the embodiments of the present invention, and together with the description, explain the principles of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0018] Figure 1 A schematic structural diagram of a speed measurement and positioning simulation system for an ultra-high-speed maglev train according to a specific embodiment of the present invention is shown;

[0019] Figure 2 A circuit diagram of a speed measurement and positioning simulation system for an ultra-high-speed maglev train according to a specific embodiment of the present invention is shown;

[0020] Figure 3 A wiring diagram of an electromagnetic analytical model provided according to a specific embodiment of the present invention is shown;

[0021] Figure 4 A schematic diagram of the composition of an electromagnetic analytical model provided according to a specific embodiment of the present invention is shown;

[0022] Figure 5 A schematic diagram showing the connection between the excitation coil and the excitation compensation coil provided according to a specific embodiment of the present invention is shown;

[0023] Figure 6 A schematic diagram showing the connection between a receiving coil and a receiving compensation coil provided according to a specific embodiment of the present invention is shown;

[0024] Figure 7 shows a longitudinal view of an electromagnetic analytical model provided according to a specific embodiment of the present invention;

[0025] Figure 8 shows a guide view of an electromagnetic analytical model provided according to a specific embodiment of the present invention;

[0026] Figure 9A schematic diagram showing the principle of speed measurement and positioning of an ultra-high-speed maglev train provided according to a specific embodiment of the present invention is shown.

[0027] Figure 10 A schematic diagram of an overvoltage protection circuit provided according to a specific embodiment of the present invention is shown;

[0028] Figure 11 A schematic diagram of a subtractor circuit provided according to a specific embodiment of the present invention is shown;

[0029] Figure 12 shows a schematic diagram of a low-pass filter provided according to a specific embodiment of the present invention;

[0030] Figure 13 A schematic diagram of a zero-crossing detection circuit provided according to a specific embodiment of the present invention is shown. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0033] Unless otherwise specifically stated, the relative arrangement of the parts and steps, the numerical expressions and the numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0034] like Figures 1 to 13 As shown, according to a specific embodiment of the present invention, a speed measurement and positioning simulation system for an ultra-high-speed maglev train is provided, and the speed measurement and positioning simulation system for an ultra-high-speed maglev train includes an electromagnetic analytical model and a signal processing unit, the electromagnetic analytical model includes a first zero magnetic flux coil component, a second zero magnetic flux coil component, an excitation receiving module, an excitation receiving compensation module and a calculation module, the first zero magnetic flux coil component and the second zero magnetic flux coil component are arranged relative to each other, the first zero magnetic flux coil component is connected to the second zero magnetic flux coil component, the excitation receiving module includes an excitation coil, a first receiving coil and a second receiving coil, the excitation coil is arranged on the first zero magnetic flux coil component, the first receiving coil and the second receiving coil are connected in series, the first receiving coil and the second receiving coil are symmetrically arranged relative to the center line of the excitation coil, the first receiving coil and the second receiving coil are arranged at intervals on the second zero magnetic flux coil component, the excitation receiving compensation module is arranged at intervals from the excitation receiving module, and the excitation receiving compensation module is arranged at intervals from the excitation receiving module. The module includes an excitation compensation coil, a first receiving compensation coil and a second receiving compensation coil. The excitation compensation coil is arranged on the first zero magnetic flux coil assembly. The first receiving compensation coil and the second receiving compensation coil are connected in series. The first receiving compensation coil and the second receiving compensation coil are symmetrically arranged relative to the center line of the excitation compensation coil. The first receiving compensation coil and the second receiving compensation coil are arranged at intervals on the second zero magnetic flux coil assembly. The excitation coil and the excitation compensation coil are connected in series in reverse. The calculation module is used to calculate the first receiving induced voltage of the excitation receiving module and the second receiving induced voltage of the excitation receiving compensation module according to the excitation current of the excitation coil and the excitation compensation coil, the motion posture of the train and the motion speed of the train. The signal processing unit is connected to the excitation receiving module and the excitation receiving compensation module respectively. The signal processing unit is used to complete the speed measurement and positioning of the train according to the first receiving induced voltage of the excitation receiving module and the second receiving induced voltage of the excitation receiving compensation module.

[0035] By applying this configuration, a speed measurement and positioning simulation system for an ultra-high-speed magnetic levitation train is provided. The speed measurement and positioning simulation system sets an electromagnetic analytical model and a signal processing unit. Direct current is passed through the excitation coil and the excitation compensation coil as the bogie moves forward, generating an induced current on the first zero-flux coil assembly on the same side. The induced current on the first zero-flux coil assembly on the same side flows into the second zero-flux coil assembly on the opposite side. The second zero-flux coil assembly on the opposite side generates a magnetic field in the surrounding space. The magnetic field changes at the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module generate induced electromotive force on the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module. The receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module have a phase difference in voltage signals due to different spatial arrangements. The signal processing unit completes the speed measurement and positioning of the train according to the first receiving induced voltage of the excitation receiving module and the second receiving induced voltage of the excitation receiving compensation module. Compared with existing technologies, the speed measurement and positioning simulation system provided by this invention boasts a simpler structure. By incorporating an excitation-receiving compensation module, it effectively reduces interference and ensures that speed measurement and positioning accuracy remains within acceptable limits. Furthermore, the fully coupled simulation of zero-flux coil counting electromagnetic analysis and signal processing circuitry enables efficient and accurate analysis of speed measurement and positioning across the full speed range of high-speed trains. This flexible modeling and rapid solution provide support for the design of zero-flux speed measurement and positioning systems.

[0036] Furthermore, in the present invention, in order to obtain the speed and displacement of the train, the signal processing unit can be configured to include a signal processing circuit and a digital processor, the signal processing circuit is used to process the first received induced voltage and the second received induced voltage to output a square wave voltage difference signal, and the digital processor is used to calculate and obtain the speed and displacement of the train based on the square wave voltage difference signal.

[0037] In the present invention, to improve the calculation accuracy of train speed and position, the calculation module can be configured to include a zero-flux coil counting system analytical model, a first interference analytical model, and a second interference analytical model. The zero-flux coil counting system analytical model is used to calculate and obtain the first effective voltage signal of the excitation receiving module and the second effective voltage signal of the excitation receiving compensation module. The first interference analytical model is used to calculate and obtain the first interference signal of the propulsion coil on the excitation coil and the second interference signal of the propulsion coil on the excitation compensation coil. The second interference analytical model is used to calculate and obtain the third interference signal of the propulsion coil on the first receiving coil and the second receiving coil of the excitation receiving module, and the fourth interference signal of the propulsion coil on the first receiving compensation coil and the second receiving compensation coil of the excitation receiving compensation module. The first effective voltage signal, the first interference signal, and the third interference signal together constitute the first received induced voltage signal, and the second effective voltage signal, the second interference signal, and the fourth interference signal together constitute the second received induced voltage signal.

[0038] Specifically, if Figure 1 As shown in Figure 1, the speed measurement and positioning simulation system for ultra-high-speed maglev trains includes an electromagnetic analytical model, a signal processing circuit, and a digital processor. This system takes external interference into account and calculates the interference signal and the effective signal. The electromagnetic analytical model inputs the interference and effective signals via a controlled voltage source into the signal processing circuit, which converts them into square wave signals. The square wave signals are then input into the digital processor to complete the speed measurement and positioning functions. Table 1 lists the simulation ports of the electromagnetic analytical model.

[0039] Table 1 Port meaning description

[0040] Port Name Port meaning Port Name Port meaning <![CDATA[V y ]]> Running speed alpha Yaw angle beta Roll angle sita Pitch angle <![CDATA[I 励磁 ]]> Excitation current

[0041] The electromagnetic analytical model's velocity port (Vy) and attitude ports (alpha, beta, and sita) simulate different train speeds and motion attitudes. The excitation current port simulates the current flowing in the excitation coil, accounting for interference from the propulsion coil and current ripple in the excitation coil power supply. These ports ensure the simulation model can handle diverse operating conditions and complex interference conditions.

[0042] Figure 2 This is a simulation model built using MATLAB / Simulink for zero-flux velocity measurement and positioning of a superconducting electric suspension system. The electromagnetic analytical model calculates the electromagnetic models of the ground propulsion coil, excitation coil, zero-flux coil, and receiving coil, obtaining the voltage values ​​of the signals on the receiving coil and receiving compensation coil. The induced voltage on the receiving coil and receiving compensation coil mainly comes from two parts: the effective signal generated by the coil and the interference signal from the ground propulsion coil. Based on this, a Simulink analytical model of the zero-flux coil counting system, a Simulink analytical model of the interference of the propulsion coil on the receiving coil and receiving compensation coil, and a Simulink analytical model of the interference of the propulsion coil on the excitation coil and excitation coil compensation coil were constructed. All three Simulink models have six-degree-of-freedom analytical capabilities.

[0043] The Simulink analytical model of the zero-flux coil counting system takes into account the interference of the propulsion coil on the excitation coil and the excitation compensation coil, calculates the interference current into the working current of the excitation coil, and then calculates the induced electromotive force on the receiving coil.

[0044] The Simulink analytical model of the interference of the propulsion coil on the receiving coil and the receiving compensation coil can calculate the induced voltage generated by the magnetic field generated by the propulsion coil on the receiving coil and the receiving compensation coil under complex conditions such as roll, yaw, and pitch. This voltage is regarded as the interference of the ground coil on the zero-flux speed measurement and positioning system.

[0045] The Simulink analytical model of the interference of the propulsion coil on the excitation coil and the excitation coil compensation coil can calculate the induced voltage generated on the excitation coil and the excitation coil compensation coil by the magnetic field generated by the ground propulsion coil under complex conditions. This induced voltage will be superimposed on the DC excitation voltage and form a corresponding alternating magnetic field, thereby affecting the induced voltage on the receiving coil.

[0046] In the signal processing circuit, a controlled voltage source is used to simulate the induced voltage generated on the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module, which serves as the input of the subtraction circuit. The filter circuit has the function of filtering out high-frequency noise. The zero-crossing detection circuit converts the signal waveform into a zero-crossing flip-flop square wave signal, and then uses a rising delay trigger and a counter to count the number of trains passing through the zero flux coil. Combined with the digital processor, the functions of suspension coil counting, positioning, and speed measurement are realized.

[0047] Specifically, in the present invention, the first zero flux coil assembly and the second zero flux coil assembly are both composed of a plurality of zero flux coils, and the first receiving coil and the second receiving coil are symmetrically arranged relative to the center line of the excitation coil, and the relative positions of the three are fixed, and the three coils constitute an excitation receiving module. The first receiving compensation coil and the second receiving compensation coil are symmetrically arranged relative to the center line of the excitation compensation coil, and the relative positions of the three are fixed, and the three coils also constitute an excitation receiving module. The first receiving coil, the second receiving coil, and the first receiving compensation coil are exactly the same as the second receiving compensation coil and can be replaced with each other. The excitation coil and the excitation compensation coil are exactly the same and can be replaced with each other. As other embodiments of the present invention, multiple excitation receiving compensation modules can also be provided, and the speed and displacement of the train can be measured by one, two or more such excitation receiving modules.

[0048] In an ideal scenario, with no train deflection and no interference, any excitation-receiving module combined with signal processing can accurately measure speed and position. However, in actual train operation, the speed and position accuracy of a single excitation-receiving module can deteriorate or even become unusable due to changes in the train's running posture and interference from ground propulsion modules. The introduction of excitation and receiving compensation coils can effectively reduce interference and ensure that speed and position accuracy remains within acceptable limits.

[0049] In the present invention, Figure 4As shown, the train's propulsion coil has a pole pitch of τ, and a spacing of 2τ creates a 360° phase difference from the propulsion coil. Therefore, setting the spacing between the excitation coil and the excitation compensation coil to 2τ results in the same induced electromotive force. Reversing the excitation coil and the excitation compensation coil can cancel out the back EMF generated by the propulsion coil on the transmitting coil. Similarly, if the currents in the excitation coil and the excitation compensation coil are equal in magnitude and opposite in direction, the back EMFs generated by the excitation coil and the excitation compensation coil at a distance of 2τ on the propulsion coil are equal in magnitude and opposite in direction, thus canceling each other out. As a specific embodiment of the present invention, the pole pitch τ of the propulsion coil is 1.5m, and the excitation coil and the excitation compensation coil are placed 3m apart and connected in reverse series. This can eliminate both the back EMF effects of the propulsion coil on the transmitting coil and the back EMF effects of the transmitting coil on the propulsion coil. Figure 5 A schematic diagram of the power supply for the excitation coil and the excitation compensation coil is shown.

[0050] Furthermore, in the present invention, in the ground propulsion coil space magnetic field, the length of the 2nd harmonic period is 2τ / 2, the length of the 5th harmonic polar period is 2τ / 5, and the length of the 7th harmonic polar period is 2τ / 7. When the vehicle body posture does not deflect, the spacing between the first receiving coil and the first receiving compensation coil and the spacing between the second receiving coil and the second receiving compensation coil are both set to 2τ. This method can ensure that the induced voltage received at every moment is completely consistent. Figure 6 As shown, the first receiving coil and the second receiving coil are connected in series as a group and connected to the signal processing unit. The first receiving compensation coil and the second receiving compensation coil are also connected in series as a group and connected to the signal processing unit. This can completely eliminate the impact of the propulsion coil harmonics on the receiving coils. As a specific embodiment of the present invention, the pole pitch τ of the propulsion coil is 1.5m, and the spacing between the first receiving coil and the first receiving compensation coil, as well as the spacing between the second receiving coil and the second receiving compensation coil, is set to 3m.

[0051] When the vehicle deflects, the interference signal theoretically cannot be completely canceled out. Analysis of the interference signal frequency shows that the 3rd multiplication frequency of the interference signal is half the actual received signal; the 6th multiplication frequency is the same frequency as the actual received signal. Therefore, the design should minimize the 3rd multiplication frequency interference, ensuring that the 6th multiplication frequency interference and the actual received signal do not cancel each other out after cancellation.

[0052] The period of the received signal based on the zero flux coil counting method is the zero flux coil spacing Q divided by the speed, and the signal frequency is Where 3Q = τ.

[0053] The triple frequency generated by the propulsion coil on the receiving coil (specifically including the first receiving coil, the second receiving coil, the first receiving compensation coil and the second receiving compensation coil) is

[0054] The 6-fold frequency generated by the propulsion coil on the receiving coil (specifically including the first receiving coil, the second receiving coil, the first receiving compensation coil and the second receiving compensation coil) is

[0055] Since the initial phase of the 3-fold frequency interference signal on the receiving coil changes with distance along the longitudinal direction, the speed of change of the initial phase is That is, the phase changes by 360° for every change in distance τ.

[0056] The third harmonic voltage in the time domain is generated by the magnetic field of the second harmonic of the space magnetic field. The pole distance of the second harmonic space magnetic field is Two pole pitches form a pair of poles with a phase difference of 360° (2π), so the speed at which the initial phase of the triple frequency changes with the spatial position is Therefore, when constructing the simulation model, the distance between the first receiving coil and the second receiving coil is set to The distance between the first receiving compensation coil and the second receiving compensation coil is set to When , the third harmonics on the first receiving coil and the second receiving coil are in opposite phases and cancel each other out; the third harmonics on the first receiving compensation coil and the second receiving compensation coil are in opposite phases and cancel each other out.

[0057] As a specific embodiment of the present invention, the pole pitch τ of the propulsion coil is 1.5 m, the spacing between the first receiving coil and the second receiving coil is set to 1.5 m, and the spacing between the first receiving compensation coil and the second receiving compensation coil is set to 1.5 m, so that the third harmonics on the two receiving coils have opposite phases and cancel each other out.

[0058] Furthermore, in the present invention, the distance between the first receiving coil and the second receiving coil is The distance between the first receiving compensation coil and the second receiving compensation coil is The relative phase difference of the 6th harmonic on it is fixed, but the phase difference between the 6th harmonic in the interference and the effective signal is related to the initial position of the receiving coil and the receiving compensation coil. The initial phase of the 6th harmonic of the propulsion coil on the receiving coil changes with the distance between the excitation coil-excitation compensation coil and the center of the vehicle body. The 5th harmonic of the spatial magnetic field is opposite to the direction of train movement, and the 7th harmonic is in the same direction as the train movement, so both can generate 6-fold frequency induced voltage on the receiving coil and the receiving compensation coil, but the 5th harmonic magnetic field is greater than the 7th harmonic magnetic field. The 5th harmonic magnetic field is dominant, and its harmonic pole pitch is Therefore, the 6-fold initial phase change frequency generated is After analysis, it is found that when the longitudinal center of the excitation coil and the excitation compensation coil is 0.1τ away from the center of the vehicle body, the phase difference between the effective signal and the interference signal is close to 90°, where the longitudinal center of the excitation coil and the excitation compensation coil refers to the midpoint of the excitation coil and the excitation compensation coil along the longitudinal direction.

[0059] As a specific embodiment of the present invention, the pole pitch τ of the propulsion coil is 1.5m, the harmonic pole pitch of the 5th harmonic magnetic field is 0.3m, and the 6th harmonic initial phase change frequency generated is After analysis, it is found that when the longitudinal center of the excitation coil-excitation compensation coil is 150 mm (0.1τ) away from the center of the vehicle body, the phase difference between the effective signal and the interference signal is close to 90°. Figure 8 This diagram shows the relative position of the zero-flux positioning speed measurement system and the zero-flux coil when installed on a vehicle. At a levitation height of 34mm, the transmitting and receiving coils align with the centerline of the superconducting coil, and their vertical orientation aligns with the centerline of the zero-flux upper coil.

[0060] In the present invention, the signal processing circuit includes a subtraction circuit and a zero-crossing detection circuit. The subtraction circuit is used to perform a difference operation on the first received induced voltage and the second received induced voltage to obtain a sinusoidal voltage difference signal. The zero-crossing detection circuit is used to convert the sinusoidal voltage difference signal into a square wave voltage difference signal.

[0061] In addition, in the present invention, in order to improve the calculation accuracy, the signal processing circuit can be configured to also include an overvoltage protection unit and a filtering circuit. The overvoltage protection unit is used to limit the signal whose pressure in the first received induced voltage and the second received induced voltage exceeds the set pressure threshold range, and the filtering circuit is used to filter out the signal whose frequency in the sinusoidal voltage value signal exceeds the set frequency threshold range.

[0062] Furthermore, in the present invention, the digital processor includes a trigger, a counter, a timer, and an arithmetic unit. The trigger is used to trigger according to the square wave voltage difference signal. The counter is used to record the number of triggers of the trigger. The timer is used to record the trigger time interval of the trigger. The arithmetic unit is used to calculate and obtain the speed and displacement of the train according to the interval between adjacent zero flux coils, the number of triggers, and the trigger time interval. Among them, the speed of the train v i According to Where L is the distance between adjacent zero flux coils, T i is the time interval between the i-th trigger count and the i-1-th trigger count. The train displacement S can be calculated according to S=iL.

[0063] In order to have a further understanding of the present invention, the following Figures 1 to 13 The speed measurement and positioning simulation system for ultra-high-speed maglev trains provided by the present invention is described in detail.

[0064] like Figures 1 to 13 As shown, according to a specific embodiment of the present invention, a speed measurement and positioning simulation system for an ultra-high-speed maglev train is provided, the speed measurement and positioning system includes an electromagnetic analytical model and a signal processing unit, the electromagnetic analytical model includes a first zero-flux coil component, a second zero-flux coil component, an excitation receiving module, an excitation receiving compensation module and a calculation module, the first zero-flux coil component and the second zero-flux coil component are arranged relative to each other, the first zero-flux coil component is connected to the second zero-flux coil component, the excitation receiving module includes an excitation coil, a first receiving coil and a second receiving coil, the excitation coil is arranged on the first zero-flux coil component, the first receiving coil and the second receiving coil are connected in series, the first receiving coil and the second receiving coil are symmetrically arranged relative to the center line of the excitation coil, the first receiving coil and the second receiving coil are arranged at intervals on the second zero-flux coil component, the excitation receiving compensation module is arranged at intervals from the excitation receiving module, and the excitation receiving compensation module includes an excitation coil A compensation coil, a first receiving compensation coil and a second receiving compensation coil, an excitation compensation coil is arranged on the first zero magnetic flux coil assembly, the first receiving compensation coil and the second receiving compensation coil are connected in series, the first receiving compensation coil and the second receiving compensation coil are symmetrically arranged relative to the center line of the excitation compensation coil, the first receiving compensation coil and the second receiving compensation coil are arranged at intervals on the second zero magnetic flux coil assembly, the excitation coil and the excitation compensation coil are connected in series in reverse, the calculation module is used to calculate the first receiving induced voltage of the excitation receiving module and the second receiving induced voltage of the excitation receiving compensation module according to the excitation current of the excitation coil and the excitation compensation coil, the motion posture of the train and the motion speed of the train, the signal processing unit is connected to the excitation receiving module and the excitation receiving compensation module respectively, and the signal processing unit is used to complete the speed measurement and positioning of the train according to the first receiving induced voltage of the excitation receiving module and the second receiving induced voltage of the excitation receiving compensation module.

[0065] The calculation module includes a zero-flux coil counting system analytical model, a first interference analytical model, and a second interference analytical model. The zero-flux coil counting system analytical model is used to calculate and obtain the first effective voltage signal of the excitation receiving module and the second effective voltage signal of the excitation receiving compensation module. The first interference analytical model is used to calculate and obtain the first interference signal of the propulsion coil on the excitation coil and the second interference signal of the propulsion coil on the excitation compensation coil. The second interference analytical model is used to calculate and obtain the third interference signal of the propulsion coil on the first receiving coil and the second receiving coil of the excitation receiving module, and the fourth interference signal of the propulsion coil on the first receiving compensation coil and the second receiving compensation coil of the excitation receiving compensation module. The first effective voltage signal, the first interference signal, and the third interference signal together constitute the first receiving induced voltage signal, and the second effective voltage signal, the second interference signal, and the fourth interference signal together constitute the second receiving induced voltage signal.

[0066] The signal processing unit includes a signal processing circuit and a digital processor. The signal processing circuit processes the first and second received induced voltages to output a square wave voltage difference signal. The digital processor calculates the train's speed and displacement based on the square wave voltage difference signal. The signal processing circuit includes a subtraction circuit, a zero-crossing detection circuit, an overvoltage protection unit, and a filtering circuit. The subtraction circuit performs a difference calculation on the first and second received induced voltages to obtain a sinusoidal voltage difference signal. The zero-crossing detection circuit converts the sinusoidal voltage difference signal into a square wave voltage difference signal. The overvoltage protection unit limits the amplitude of the first and second received induced voltages if their pressure exceeds a set pressure threshold. The filtering circuit filters out signals in the sinusoidal voltage signal whose frequency exceeds a set frequency threshold. The digital processor includes a trigger, a counter, a timer, and an arithmetic unit. The trigger is triggered by the square wave voltage difference signal. The counter records the number of trigger triggers. The timer records the trigger trigger interval. The arithmetic unit calculates the train's speed and displacement based on the spacing between adjacent zero flux coils, the number of triggers, and the trigger interval.

[0067] As the bogie moves forward, direct current is passed through the excitation coil and the excitation compensation coil. As the bogie moves forward, an induced current is generated on the first zero flux coil assembly on the same side. The induced current on the first zero flux coil assembly on the same side flows into the second zero flux coil assembly on the opposite side. The second zero flux coil assembly on the opposite side generates a magnetic field in the surrounding space. The magnetic field changes at the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module generate induced electromotive force on the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module. The receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module have a phase difference in voltage signals due to different spatial arrangements. The intersection of the induced voltage signal of the receiving coil of the excitation receiving module and the induced voltage signal of the receiving compensation coil on the excitation receiving compensation module is used to obtain a square wave waveform. The position and speed information of the train are finally calculated based on the analysis of the square wave waveform. The basic working principle is as follows: Figure 9 shown.

[0068] The overvoltage protection circuit needs to ensure that the normal working signal of the receiving coil can be fully input to the subsequent circuit, but it must be able to play a peak clipping role for signals with larger amplitudes or impacts. In this embodiment, the voltage expression of the overvoltage protection circuit is (V i is the input voltage, V o is the output voltage).

[0069] The subtraction circuit can perform difference operations on multiple input signals in different proportions. Figure 11The circuit shown is a common subtractor circuit. The operational relationship between the input and output of the subtractor circuit is: Among them, V2 is the induced voltage signal of the receiving compensation coil on the second zero flux coil assembly, V1 is the induced voltage signal of the receiving coil on the first zero flux coil assembly, R f , R1 are both adjustment resistors, among which R can be selected according to actual needs. f , R1 value, when the voltage difference signal is too small, you can increase R f / R1 value to achieve signal amplification.

[0070] The filter circuit is used to filter out the signal whose frequency exceeds the set frequency threshold range in the sinusoidal voltage value signal. In the present invention, a second-order low-pass filter is designed according to the design process of the Butterworth low-pass filter. The circuit schematic diagram is shown in FIG. Figure 12 shown.

[0071] The transfer function of the filter circuit is:

[0072] The circuit gain is

[0073] Among them, R1, R2, and R3 are resistors, C1 and C2 are capacitors, and s is the transfer function.

[0074] The zero-crossing detection circuit uses a zero-crossing comparator to detect whether an input value is zero. The principle is to connect one input terminal of the integrated operational amplifier to ground and the other input terminal to the input voltage for voltage comparison. The output voltage jumps near the zero-crossing point of the input voltage. Figure 13 This is the zero-crossing detection circuit used in this embodiment.

[0075] The expression of the zero-crossing detection circuit is:

[0076] The functions of trigger, counter and timer are realized by digital processor DSP, which uses the rising edge of input signal to trigger. The counter counts the number of triggers, and the timer counts the time interval between triggers. Assume that the time interval of the i-th count is T i , the interval between adjacent zero flux coils is 0.5m, then the current speed v i for The displacement is Therefore, the speed and displacement of the train are calculated based on the interval between adjacent zero flux coils, the number of triggering times and the triggering time interval.

[0077] In summary, the present invention provides a speed measurement and positioning simulation system for ultra-high-speed maglev trains. The signal processing circuit of the zero-flux speed measurement and positioning device in actual work is established as a Simulink model, which together with the electromagnetic analysis model of the excitation-receiving module constitutes a simulation model for zero-flux speed measurement and positioning of superconducting electric suspension systems. The simulation model fully considers the actual working conditions of the zero-flux speed measurement and positioning device, realizes the full coupling simulation of the zero-flux coil counting electromagnetic analysis and the signal processing circuit, can ensure the accuracy of the calculation results, and is more in line with reality. In this speed measurement and positioning simulation system, the model is flexible in construction and can be calculated for different operating conditions and complex interference conditions. In addition, the model solution speed is fast, which provides support for the design of the zero-flux speed measurement and positioning system, and can be further applied to the fields of magnetic levitation rocket sleds, electromagnetic catapults, and magnetic levitation space booster launches.

[0078] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0079] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0080] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0081] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A speed measurement and positioning simulation system for ultra-high-speed maglev trains, characterized in that: The speed measurement and positioning simulation system for ultra-high-speed maglev trains includes: An electromagnetic analytical model, the electromagnetic analytical model includes a first zero-magnetic flux coil component, a second zero-magnetic flux coil component, an excitation receiving module, an excitation receiving compensation module and a calculation module, the first zero-magnetic flux coil component and the second zero-magnetic flux coil component are arranged relative to each other, the first zero-magnetic flux coil component is connected to the second zero-magnetic flux coil component, the excitation receiving module includes an excitation coil, a first receiving coil and a second receiving coil, the excitation coil is arranged on the first zero-magnetic flux coil component, the first receiving coil and the second receiving coil are connected in series, the first receiving coil and the second receiving coil are symmetrically arranged relative to the center line of the excitation coil, the first receiving coil and the second receiving coil are arranged at intervals on the second zero-magnetic flux coil component, and the excitation receiving compensation module is arranged at intervals from the excitation receiving module The excitation receiving compensation module includes an excitation compensation coil, a first receiving compensation coil, and a second receiving compensation coil. The excitation compensation coil is arranged on the first zero magnetic flux coil assembly. The first receiving compensation coil and the second receiving compensation coil are connected in series. The first receiving compensation coil and the second receiving compensation coil are symmetrically arranged relative to the center line of the excitation compensation coil. The first receiving compensation coil and the second receiving compensation coil are arranged at intervals on the second zero magnetic flux coil assembly. The excitation coil and the excitation compensation coil are connected in series in reverse order. The calculation module is used to calculate and obtain a first receiving induced voltage of the excitation receiving module and a second receiving induced voltage of the excitation receiving compensation module according to the excitation current of the excitation coil and the excitation compensation coil, the motion posture of the train, and the motion speed of the train; A signal processing unit is connected to the excitation receiving module and the excitation receiving compensation module respectively. The signal processing unit is used to complete the speed measurement and positioning of the train according to the first receiving induced voltage of the excitation receiving module and the second receiving induced voltage of the excitation receiving compensation module. The spacing between the first receiving coil and the second receiving coil is The distance between the first receiving compensation coil and the second receiving compensation coil is τ is the pole pitch of the train propulsion coil.

2. The speed measurement and positioning simulation system for ultra-high-speed maglev trains according to claim 1, characterized in that: The calculation module includes a zero-flux coil counting system analytical model, a first interference analytical model, and a second interference analytical model. The zero-flux coil counting system analytical model is used to calculate and obtain the first effective voltage signal of the excitation receiving module and the second effective voltage signal of the excitation receiving compensation module. The first interference analytical model is used to calculate and obtain the first interference signal of the propulsion coil on the excitation coil and the second interference signal of the propulsion coil on the excitation compensation coil. The second interference analytical model is used to calculate and obtain the third interference signal of the propulsion coil on the first receiving coil and the second receiving coil of the excitation receiving module and the fourth interference signal of the propulsion coil on the first receiving compensation coil and the second receiving compensation coil of the excitation receiving compensation module.

3. The speed measurement and positioning simulation system for ultra-high-speed maglev trains according to claim 1, characterized in that: The spacing between the excitation coil and the excitation compensation coil, the spacing between the first receiving coil and the first receiving compensation coil, and the spacing between the second receiving coil and the second receiving compensation coil are all 2τ, where τ is the pole pitch of the train propulsion coil.

4. The speed measurement and positioning simulation system for ultra-high-speed maglev trains according to claim 3, characterized in that: The longitudinal distance between the longitudinal centers of the excitation coil and the excitation compensation coil and the center of the vehicle body is 0.1τ.

5. The speed measurement and positioning simulation system for ultra-high-speed maglev trains according to any one of claims 1 to 4, characterized in that: The signal processing unit includes a signal processing circuit and a digital processor. The signal processing circuit is used to process the first received induced voltage and the second received induced voltage to output a square wave voltage difference signal. The digital processor is used to calculate and obtain the speed and displacement of the train based on the square wave voltage difference signal.

6. The speed measurement and positioning simulation system for ultra-high-speed maglev trains according to claim 5, characterized in that: The signal processing circuit includes a subtraction circuit and a zero-crossing detection circuit. The subtraction circuit is used to perform a difference operation on the first received induced voltage and the second received induced voltage to obtain a sinusoidal voltage difference signal. The zero-crossing detection circuit is used to convert the sinusoidal voltage difference signal into a square wave voltage difference signal.

7. The speed measurement and positioning simulation system for ultra-high-speed maglev trains according to claim 6, characterized in that: The signal processing circuit also includes an overvoltage protection unit and a filtering circuit. The overvoltage protection unit is used to limit the signals in the first received induced voltage and the second received induced voltage whose pressure exceeds the set pressure threshold range, and the filtering circuit is used to filter out the signals in the sinusoidal voltage difference signal whose frequency exceeds the set frequency threshold range.

8. The speed measurement and positioning simulation system for ultra-high-speed maglev trains according to claim 5, characterized in that: The digital processor includes a trigger, a counter, a timer and an arithmetic unit. The trigger is used to be triggered according to the square wave voltage difference signal. The counter is used to record the number of times the trigger is triggered. The timer is used to record the trigger time interval of the trigger. The arithmetic unit is used to calculate and obtain the speed and displacement of the train based on the interval between adjacent zero flux coils, the number of triggers and the trigger time interval.

9. The speed measurement and positioning simulation system for ultra-high-speed maglev trains according to claim 8, characterized in that: The speed v of the train i According to The displacement S of the train can be calculated according to S=iL, where L is the interval between adjacent zero flux coils, T i is the time interval between the i-th trigger count and the i-1-th trigger count.

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