Planar receiving coil module and speed measurement positioning system having the same

Abstract

This invention provides a planar receiving coil module and a speed measurement and positioning system having the same. The planar receiving coil module includes: a PCB coil, which comprises a PCB board and a coil assembly printed on the PCB board; and a shielding unit disposed outside the PCB coil, used to shield against alternating electric fields from interference sources. The technical solution of this invention solves the technical problem that existing coil modules are large in size and unsuitable for installation.

Description

Technical Field

[0001] This invention relates to the field of magnetic levitation train technology, and in particular to a planar receiving coil module and a speed measurement and positioning system having the same. Background Technology

[0002] High-speed maglev trains are a type of rail transit system. During operation, the train's speed needs to be detected and monitored to provide the traction control system and train operation control system with the train's position and speed information at any given time. This is crucial for train acceleration / deceleration control, track adjustment, and emergency braking in case of malfunctions. To ensure safe train operation, the speed measurement and positioning methods require redundant design.

[0003] The target positioning and speed measurement system of the ultra-high-speed low-vacuum pipeline maglev transportation system (T-Flight) is divided into two parts: a ground positioning and speed measurement system and an on-board positioning and speed measurement system. The ground positioning and speed measurement system provides the traction control system and the operation control system with the position and speed information of the train 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 on-board operation control unit with the positioning and speed information of the train 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 and emergency plan to guide emergency stops.

[0004] Currently, transmitting and receiving coils are also used to measure and locate train speeds. However, since existing coil modules are usually large and not suitable for installation, they are not suitable for measuring and locating high-speed maglev trains. Summary of the Invention

[0005] This invention provides a planar receiving coil module and a speed measurement and positioning system having the same, which can solve the technical problem that the coil module is too large and unsuitable for installation in the prior art.

[0006] According to one aspect of the present invention, a planar receiving coil module for zero-flux positioning and speed measurement is provided. The planar receiving coil module includes: a PCB coil, which includes a PCB board and a coil assembly, the coil assembly being printed on the PCB board; and a shielding unit disposed outside the PCB coil, the shielding unit being used to shield the alternating electric field of an interference source.

[0007] Furthermore, the PCB coil includes multiple PCB boards and multiple coil assemblies, with each PCB board corresponding to one of the multiple coil assemblies. The multiple coil assemblies are printed on the multiple PCB boards respectively, and the multiple coil assemblies are connected in sequence.

[0008] Furthermore, the planar receiving coil module also includes a coil housing, which is disposed outside the PCB coil and serves to protect the PCB coil.

[0009] Furthermore, the planar receiving coil module also includes a fixed mounting unit, through which the planar receiving coil module is connected to the train body.

[0010] Furthermore, the coil housing is made of epoxy fiberglass cloth laminate.

[0011] According to another aspect of the present invention, a speed measurement and positioning system for a high-speed maglev train is provided. The system includes: a first zero-flux coil assembly and a second zero-flux coil assembly, both mounted on the train and arranged opposite to each other, connected together; an excitation receiving module, including an excitation coil, a first receiving coil, and a second receiving coil, the excitation coil mounted on the first zero-flux coil assembly, the first and second receiving coils connected in series, symmetrically arranged with respect to the centerline of the excitation coil, and spaced apart on the second zero-flux coil assembly; and an excitation receiving compensation module, spaced apart from the excitation receiving module, including an excitation compensation coil, and... A first receiving compensation coil and a second receiving compensation coil, the excitation compensation coil being disposed on a first zero flux coil assembly, the first receiving compensation coil and the second receiving compensation coil being connected in series, the first receiving compensation coil and the second receiving compensation coil being symmetrically arranged with respect to the center line of the excitation compensation coil, the first receiving compensation coil and the second receiving compensation coil being spaced apart on a second zero flux coil assembly, the first receiving coil, the second receiving coil, the first receiving compensation coil and the second receiving compensation coil being all planar receiving coil modules as described in claims 1 to 5; a power supply, the power supply being used to provide DC power to the excitation coil and the excitation compensation coil, the excitation coil and the excitation compensation coil being connected in reverse series and then connected to the power supply; a signal processing unit, the signal processing unit being connected to the excitation receiving module and the excitation receiving compensation module respectively, the signal processing unit being used to complete the train speed measurement and positioning based on the first receiving induced voltage of the excitation receiving module and the second receiving induced voltage of the excitation receiving compensation module.

[0012] 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.

[0013] Furthermore, 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: The longitudinal distance between the longitudinal center of the excitation coil and the excitation compensation coil and the center of the vehicle body is 0.1τ.

[0014] Furthermore, the signal processing unit includes a signal processing circuit and a digital processor. The signal processing circuit processes the first received induced voltage and the second received induced voltage to output a square wave voltage difference signal. The digital processor calculates and obtains the speed and displacement of the train based on the square wave voltage difference signal.

[0015] Furthermore, the digital processor includes a trigger, a counter, a timer, and an arithmetic unit. The trigger is used to activate based on the square wave voltage difference signal. The counter is used to record the number of times the trigger is activated. The timer is used to record the trigger time interval. The arithmetic unit is used to calculate and obtain the train's speed and displacement based on the interval between adjacent zero flux coils, the number of activations, and the trigger time interval.

[0016] The present invention provides a planar receiving coil module for zero-flux positioning and speed measurement. This planar receiving coil module achieves miniaturization by printing the coil assembly on a PCB board, which facilitates installation and reduces weight. Furthermore, by providing a shielding unit outside the PCB coil 100, the alternating electric field generated by interference sources can be effectively confined to a certain space. Attached Figure Description

[0017] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0018] Figure 1 A schematic diagram of a planar receiving coil module according to a specific embodiment of the present invention is shown;

[0019] Figure 2 A schematic diagram of a speed measurement and positioning system for ultra-high-speed maglev trains according to a specific embodiment of the present invention is shown.

[0020] Figure 3 A schematic diagram of the principle of a speed measurement and positioning system for ultra-high-speed maglev trains according to a specific embodiment of the present invention is shown.

[0021] Figure 4 A wiring diagram of the excitation coil and the excitation compensation coil according to a specific embodiment of the present invention is shown;

[0022] Figure 5 A wiring diagram of a first receiving coil, a second receiving coil, a first receiving compensation coil, and a second receiving compensation coil according to a specific embodiment of the present invention is shown.

[0023] Figure 6 A longitudinal view of a speed measurement and positioning system for a high-speed maglev train according to a specific embodiment of the present invention is shown.

[0024] Figure 7 A directional view of a speed measurement and positioning system for a high-speed maglev train according to a specific embodiment of the present invention is shown.

[0025] Figures 8a to 8c Three views of an excitation coil (excitation compensation coil) provided according to a specific embodiment of the present invention are shown;

[0026] Figures 9a to 9c A three-view diagram of a first receiving coil (second receiving coil / first receiving compensation coil / second receiving compensation coil) according to a specific embodiment of the present invention is shown;

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

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

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

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

[0031] Figure 14 A schematic diagram illustrating the principle of speed measurement and positioning for ultra-high-speed maglev trains according to a specific embodiment of the present invention is shown.

[0032] The above figures include the following reference numerals:

[0033] 100, PCB coil; 200, shielding unit; 300, coil housing; 400, fixed mounting unit; 10, first zero flux coil assembly; 20, second zero flux coil assembly; 30, excitation receiving module; 31, excitation coil; 32, first receiving coil; 33, second receiving coil; 40, excitation receiving compensation module; 41, excitation compensation coil; 42, first receiving compensation coil; 43, second receiving compensation coil; 50, power supply; 60, signal processing unit. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. 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 a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. 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.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0036] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0037] like Figure 1As shown, according to a specific embodiment of the present invention, a planar receiving coil module for zero-flux positioning and speed measurement is provided. The planar receiving coil module includes a PCB coil 100 and a shielding unit 200. The PCB coil 100 includes a PCB board and a coil assembly. The coil assembly is printed on the PCB board. The shielding unit 200 is disposed outside the PCB coil 100 and is used to shield the alternating electric field of the interference source.

[0038] This configuration provides a planar receiving coil module for zero-flux positioning and speed measurement. By printing the coil assembly onto a PCB board, this module achieves miniaturization of the receiving coil, facilitating installation and reducing weight. Furthermore, by placing a shielding unit outside the PCB coil 100, the alternating electric field generated by interference sources can be effectively confined to a certain space.

[0039] Furthermore, in this invention, the PCB coil 100 includes multiple PCB boards and multiple coil assemblies, with each PCB board corresponding to one of the multiple coil assemblies. The multiple coil assemblies are printed on the multiple PCB boards and connected sequentially. As a specific embodiment of this invention, the coil assembly consists of multi-turn coils. The PCB board has 125 turns per layer of wiring, and these 125 turns constitute the coil assembly. The PCB coil 100 includes eight PCB layers, a total of 1000 coil turns, and a single-layer wiring area width of 50.6 mm. The PCB board uses FR4 substrate, and the wiring layer copper thickness is 1 oz.

[0040] Furthermore, in this invention, in order to effectively protect the PCB coil and improve its service life, the planar receiving coil module can be configured to also include a coil housing 300, which is disposed outside the PCB coil 100 and is used to protect the PCB coil 100.

[0041] As a specific embodiment of the present invention, the coil housing is made of epoxy fiberglass cloth laminate, which has the characteristics of high structural strength, high heat resistance, and good insulation performance.

[0042] Furthermore, in this invention, to facilitate the installation of the receiving coil module on the vehicle body, the planar receiving coil module can be configured to also include a fixing mounting unit 400, through which the planar receiving coil module is connected to the vehicle body. As a specific embodiment of this invention, the receiving coil module is connected to the train body using 12 M6 hexagonal socket head cap screws. As another embodiment of this invention, the receiving coil module can also be connected to the train body by adhesive bonding.

[0043] According to another aspect of the present invention, a speed measurement and positioning system for a high-speed maglev train is provided. This system includes a first zero-flux coil assembly 10, a second zero-flux coil assembly 20, an excitation receiving module 30, an excitation receiving compensation module 40, a power supply 50, and a signal processing unit 60. Both the first zero-flux coil assembly 10 and the second zero-flux coil assembly 20 are mounted on the train and are arranged opposite to each other. The excitation receiving module 30 includes an excitation coil 31, a first receiving coil 32, and a second receiving coil 33, connected to the first zero flux coil assembly 10. The excitation coil 31 is disposed on the first zero flux coil assembly 10, and the first receiving coil 32 and the second receiving coil 33 are connected in series. The first receiving coil 32 and the second receiving coil 33 are symmetrically arranged with respect to the center line of the excitation coil 31. The first receiving coil 32 and the second receiving coil 33 are spaced apart on the second zero flux coil assembly 20. The excitation receiving compensation module 40 is spaced apart from the excitation receiving module 30. Group 40 includes an excitation compensation coil 41, a first receiving compensation coil 42, and a second receiving compensation coil 43. The excitation compensation coil 41 is disposed on the first zero flux coil assembly 10. The first receiving compensation coil 42 and the second receiving compensation coil 43 are connected in series and are symmetrically arranged with respect to the center line of the excitation compensation coil 41. The first receiving compensation coil 42 and the second receiving compensation coil 43 are spaced apart on the second zero flux coil assembly 20. The first receiving coil 32, the second receiving coil 33, and the first receiving compensation coil 43 are also present. Both coil 42 and the second receiving compensation coil 43 are planar receiving coil modules as described in claims 1 to 5. The power supply 50 is used to provide DC power to the excitation coil 31 and the excitation compensation coil 41. The excitation coil 31 and the excitation compensation coil 41 are connected in reverse series and then connected to the power supply 50. The signal processing unit 60 is connected to the excitation receiving module 30 and the excitation receiving compensation module 40 respectively. The signal processing unit 60 is used to complete the train speed measurement and positioning based on the first receiving induced voltage of the excitation receiving module 30 and the second receiving induced voltage of the excitation receiving compensation module 40.

[0044] This configuration provides a speed measurement and positioning system for ultra-high-speed maglev trains. The system comprises an excitation receiving module and an excitation receiving compensation module. The excitation coil and compensation coil, powered by direct current, move forward with the bogie, inducing a current in the first zero-flux coil assembly on the same side. This induced current flows into the second zero-flux coil assembly on the opposite side, generating a magnetic field in the surrounding space. The change in the magnetic field at the receiving coil of the excitation receiving module and the compensation coil of the excitation receiving compensation module induces an electromotive force in their respective coils. Due to their different spatial arrangements, the voltage signals of the receiving coils of the excitation receiving module and the compensation coil of the excitation receiving compensation module have a phase difference. The signal processing unit completes the train speed measurement and positioning based on the first induced voltage received by the excitation receiving module and the second induced voltage received by the excitation receiving compensation module. Compared with existing technologies, the speed measurement and positioning system provided by this invention has a simple structure, and by introducing an excitation receiving compensation module, it can effectively reduce interference and ensure that the speed measurement and positioning accuracy is within the permissible range. Furthermore, by setting the first receiving coil 32, the second receiving coil 33, the first receiving compensation coil 42, and the second receiving compensation coil 43 all as the planar receiving coil module provided by this invention, the structure can be further simplified, the weight reduced, and the cost lowered.

[0045] Specifically, in this invention, both the first zero-flux coil assembly 10 and the second zero-flux coil assembly 20 are composed of multiple zero-flux coils. The first receiving coil 32 and the second receiving coil 33 are symmetrically arranged with respect to the center line of the excitation coil 31, and their relative positions are fixed. These three coils constitute an excitation receiving module. The first receiving compensation coil 42 and the second receiving compensation coil 43 are symmetrically arranged with respect to the center line of the excitation compensation coil 41, and their relative positions are fixed. These three coils also constitute an excitation receiving module. The first receiving coil 32, the second receiving coil 33, the first receiving compensation coil 42, and the second receiving compensation coil 43 are completely identical and can be interchanged. The excitation coil 31 and the excitation compensation coil 41 are completely identical and can be interchanged.

[0046] Ideally, the train's running attitude remains unchanged, and without considering interference, any single excitation-receiver module, combined with signal processing, can accurately measure speed and locate the train. However, in actual train operation, changes in the train's running attitude and interference from the ground propulsion module affect the speed measurement and positioning accuracy of a single excitation-receiver module, rendering it unusable. Introducing excitation compensation coils and receiver compensation coils can effectively reduce interference and ensure that the speed measurement and positioning accuracy remains within permissible limits.

[0047] In this invention, such as Figure 4As shown, the pole pitch of the train's propulsion coil is τ, and the distance between the propulsion coil and the distance between them is 2τ, resulting in a 360° phase difference. Therefore, by setting the distance between the excitation coil 31 and the excitation compensation coil 41 to 2τ, their induced electromotive forces are consistent. Reversing the connection of the excitation coil 31 and the excitation compensation coil 41 can cancel out the back electromotive force of the propulsion coil on the transmitting coil. Similarly, the currents in the excitation coil 31 and the excitation compensation coil 41 are equal in magnitude and opposite in direction. The 2τ distance between the excitation coil 31 and the excitation compensation coil 41 generates back electromotive forces on the propulsion coil that are equal in magnitude and opposite in direction, thus canceling each other out. In a specific embodiment of the present invention, the pole pitch τ of the propulsion coil is 1.5m, and the excitation coil 31 and the excitation compensation coil 41 are placed 3m apart and connected in series in reverse. This solves both the back electromotive force effect of the propulsion coil on the transmitting coil and the back electromotive force effect of the transmitting coil on the propulsion coil. Figure 4 A power supply schematic diagram of excitation coil 31 and excitation compensation coil 41 is shown.

[0048] Furthermore, in this invention, in the spatial magnetic field of the ground propulsion coil, the second harmonic period length is 2τ / 2, the fifth harmonic pole pitch period length is 2τ / 5, and the seventh harmonic pole pitch period length is 2τ / 7. When the vehicle body attitude does not deflect, the distance between the first receiving coil 32 and the first receiving compensation coil 42, and the distance between the second receiving coil 33 and the second receiving compensation coil 43, are both set to 2τ. This method ensures that the induced voltage received at each moment is completely consistent. Figure 5 As shown, the first receiving coil 32 and the second receiving coil 33 are a group, connected in series and connected to the signal processing unit 60. The first receiving compensation coil 42 and the second receiving compensation coil 43 are a group, connected in series and connected to the signal processing unit 60, which can completely eliminate the influence of the propulsion coil harmonics on the receiving coil. As a specific embodiment of the present invention, the pole pitch τ of the propulsion coil is 1.5m, and the distance between the first receiving coil 32 and the first receiving compensation coil 42, as well as the distance between the second receiving coil 33 and the second receiving compensation coil 43, are both set to 3m.

[0049] When the vehicle body deflects, the interference signal cannot be completely canceled out in theory. Frequency analysis of the interference signal shows that the third harmonic frequency of the interference signal is half of the actual received signal; the sixth harmonic frequency is the same as the actual received signal. Therefore, the design should try to cancel out the third harmonic interference as much as possible, and the sixth harmonic interference should not cancel out the actual received signal after cancellation.

[0050] The period of the signal received using the zero-flux coil counting method is the distance Q between the zero-flux coils divided by the velocity, and the signal frequency is... Where 3Q = τ.

[0051] The third harmonic 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...

[0052] The sixth harmonic 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...

[0053] Since the initial phase of the third harmonic interference signal on the receiving coil changes longitudinally with distance, the rate of change of the initial phase is... That is, the phase changes by 360° for every change in distance τ.

[0054] The third harmonic voltage in the time domain is generated by the magnetic field of the second harmonic of the spatial magnetic field, and the pole distance of the second spatial magnetic field is... The two poles form a pair, with a phase difference of 360° (2π). Therefore, the rate at which the initial phase of the third harmonic changes with spatial position is... Therefore, the spacing between the first receiving coil 32 and the second receiving coil 33 is set to The distance between the first receiving compensation coil 42 and the second receiving compensation coil 43 is set to At the same time, the third harmonics on the first receiving coil 32 and the second receiving coil 33 are out of phase and cancel each other out; the third harmonics on the first receiving compensation coil 42 and the second receiving compensation coil 43 are out of phase and cancel each other out.

[0055] As a specific embodiment of the present invention, the pole pitch τ of the propulsion coil is 1.5m. When the distance between the first receiving coil 32 and the second receiving coil 33 is set to 1.5m, and the distance between the first receiving compensation coil 42 and the second receiving compensation coil 43 is set to 1.5m, the third harmonics on the two receiving coils can be made to be out of phase and cancel each other out.

[0056] Furthermore, the distance between the first receiving coil 32 and the second receiving coil 33 is... The distance between the first receiving compensation coil 42 and the second receiving compensation coil 43 is: The relative phase difference of the 6th harmonic is fixed; however, the phase difference between the 6th harmonic in the interference and the effective signal is related to the initial positions 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 motion, while the 7th harmonic is in the same direction. Therefore, both can induce a 6th harmonic 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 spacing is... Therefore, the frequency of its 6th harmonic initial phase change is: Analysis shows that when the longitudinal center of excitation coil 31 and excitation compensation coil 42 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°. The longitudinal center of excitation coil 31 and excitation compensation coil 42 refers to the midpoint of excitation coil 31 and excitation compensation coil 42 along the longitudinal direction.

[0057] In 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 resulting 6th harmonic initial phase change frequency is... Analysis showed that when the longitudinal center of the excitation coil-excitation compensation coil was 150mm (0.1τ) away from the center of the vehicle body, the phase difference between the effective signal and the interference signal was close to 90°. Figure 6 This diagram shows the relative positions of the zero-flux positioning and speed measurement system and the zero-flux coil when the system is installed on the vehicle. At a levitation height of 34mm, the transmitting and receiving coils are aligned with the centerline of the superconducting coil, and vertically aligned with the centerline of the zero-flux upper coil.

[0058] Furthermore, in this invention, in order to obtain the speed and displacement of the train, the signal processing unit 60 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.

[0059] In this 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.

[0060] Furthermore, in order to improve the calculation accuracy, the signal processing circuit can be configured to include an overvoltage protection unit and a filtering circuit. The overvoltage protection unit is used to limit the amplitude of signals whose pressure exceeds a set pressure threshold range in the first received induced voltage and the second received induced voltage. The filtering circuit is used to filter out signals whose frequency exceeds a set frequency threshold range in the sinusoidal voltage signal.

[0061] Furthermore, in this invention, the digital processor includes a trigger, a counter, a timer, and an arithmetic unit. The trigger is used to activate based on a square wave voltage difference signal. The counter records the number of times the trigger is activated. The timer records the trigger time interval. The arithmetic unit calculates and obtains the train's speed and displacement based on the interval between adjacent zero-flux coils, the number of activations, and the trigger time interval. The train's speed v...i According to Where L is the interval between adjacent zero flux coils, and T i Let S be the time interval between the i-th trigger count and the (i-1)-th trigger count. The train's displacement S can be determined by S = iL.

[0062] To gain a further understanding of the present invention, the following description is provided in conjunction with... Figures 1 to 13 The present invention provides a detailed description of the speed measurement and positioning system for ultra-high-speed maglev trains.

[0063] like Figures 1 to 13 As shown in the figure, a speed measurement and positioning system for a high-speed maglev train is provided according to a specific embodiment of the present invention. The system includes a first zero-flux coil assembly 10, a second zero-flux coil assembly 20, an excitation receiving module 30, an excitation receiving compensation module 40, a power supply 50, and a signal processing unit 60. Both the first zero-flux coil assembly 10 and the second zero-flux coil assembly 20 are mounted on the train and are positioned opposite each other. The first zero-flux coil assembly 10 is connected to the second zero-flux coil assembly 20 via a hinge wire. The excitation receiving module 30 includes an excitation coil 31, a first receiving coil 32, and a second receiving coil 33. The excitation coil 31 is mounted on the first zero-flux coil assembly 10. The first receiving coil 32 and the second receiving coil 33 are connected in series and are symmetrically arranged with respect to the center line of the excitation coil 31. The first receiving coil 32 and the second receiving coil 33 are spaced apart on the second zero-flux coil assembly 20. The excitation receiving module 40 and the excitation receiving module 30 are arranged alternately. The excitation receiving compensation module 40 includes an excitation compensation coil 41, a first receiving compensation coil 42, and a second receiving compensation coil 43. The excitation compensation coil 41 is disposed on the first zero flux coil assembly 10. The first receiving compensation coil 42 and the second receiving compensation coil 43 are connected in series. The first receiving compensation coil 42 and the second receiving compensation coil 43 are symmetrically arranged with respect to the center line of the excitation compensation coil 41. The first receiving compensation coil 42 and the second receiving compensation coil 43 are arranged alternately on the second zero flux coil assembly 20. The power supply 50 is used to provide DC power to the excitation coil 31 and the excitation compensation coil 41. The excitation coil 31 and the excitation compensation coil 41 are connected in reverse series and then connected to the power supply 50. The signal processing unit 60 is connected to the excitation receiving module 30 and the excitation receiving compensation module 40 respectively. The signal processing unit 60 is used to complete the speed measurement and positioning of the train based on the first receiving induced voltage of the excitation receiving module 30 and the second receiving induced voltage of the excitation receiving compensation module 40.

[0064] The first receiving coil 32, the second receiving coil 33, the first receiving compensation coil 42, and the second receiving compensation coil 43 all have the same structure, and are all planar receiving coil modules provided by this invention. Almost no current flows inside the receiving coil during operation, therefore the cross-sectional area of ​​the wire used to wind the receiving coil can be very small. The miniaturized design of the receiving coil facilitates installation and reduces weight. The planar receiving coil module consists of four parts: a PCB coil 100, a shielding unit 200, a fixed mounting unit 400, and a coil housing 300. Signal lines on the PCB are typically 0.2mm to 0.3mm wide, with a wiring width of 0.2mm (approximately 8mil), and the line spacing is consistent with the line width. The PCB has 125 turns per layer, with 8 layers in total, for a total of 1000 coil turns. The width of a single-layer wiring area is 50.6mm. The PCB uses FR4 substrate, and the copper thickness of the wiring layer is 1oz. In this embodiment, shielding aluminum foil is used as the shielding unit 200, and the receiving coil is made of PCB printed circuitry, similar to a parallel plate capacitor. The inter-turn capacitance of conductors in the same layer and the inter-layer capacitance of conductors in different layers result in a large parasitic capacitance between the coil ports. In an alternating electric field, a large potential difference can easily form between the coil ports, mixed with the induced electromotive force. For electric field shielding, a well-grounded metal shield can be used to confine the alternating electric field generated by the interference source to a certain space. The PCB coil is wrapped with a layer of aluminum foil, with a thickness of 0.01mm. Fixing bolts are used as the mounting unit 400. The PCB coil is connected to the vehicle body via 12 M6 hex bolts. In another embodiment of the invention, the coil module can also be mounted on the vehicle body by adhesive bonding. The coil housing 300 is made of epoxy fiberglass laminate, which has high structural strength, high heat resistance, and good insulation properties. The PCB board is 1.6mm thick. Between the PCB board and the receiving coil module housing, there is a layer of aluminum foil wrapping the PCB board, with negligible thickness. The coil housing has a single-sided thickness of 5mm. There are 12 through holes for mounting M6 bolts on the coil housing, which are evenly and reasonably distributed on the coil housing.

[0065] The signal processing unit 60 includes a signal processing circuit and a digital processor. The signal processing circuit processes the first received induced voltage and the second received induced voltage to output a square wave voltage difference signal. The digital processor calculates and obtains 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 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 converts the sinusoidal voltage difference signal into a square wave voltage difference signal. The overvoltage protection unit limits the amplitude of signals in the first and second received induced voltages whose pressure exceeds a set pressure threshold range. The filtering circuit filters out signals in the sinusoidal voltage signal whose frequency exceeds a set frequency threshold range. The digital processor includes a trigger, a counter, a timer, and an arithmetic unit. The trigger is activated based on the square wave voltage difference signal. The counter records the number of trigger activations. The timer records the trigger activation time interval. The arithmetic unit calculates and obtains the train's speed and displacement based on the interval between adjacent zero flux coils, the number of trigger activations, and the trigger activation time interval.

[0066] As the bogie moves forward, the excitation coil and excitation compensation coil, carrying direct current, induce a current in the first zero flux coil assembly on the same side. This induced current flows into the second zero flux coil assembly on the opposite side, generating a magnetic field in the surrounding space. The change in the magnetic field at the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module induces an electromotive force in their respective coils. Due to their different spatial arrangements, the voltage signals of the receiving coils of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module have a phase difference. A square wave waveform is obtained by analyzing the intersection of the induced voltage signals from the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module. The train's position and speed information are then calculated based on the square wave waveform analysis. The induced voltage received by the excitation receiving module and the excitation receiving compensation module passes sequentially through an overvoltage protection circuit, a subtraction circuit, a filtering circuit, a zero-crossing detection circuit, a trigger, a counter, and a timer to calculate the train's position and speed.

[0067] The overvoltage protection circuit needs to ensure that the normal operating signal of the receiving coil can be completely input to the subsequent circuitry, but it also needs to perform peak clipping for signals with larger amplitudes or surges. In this embodiment, the voltage expression of the overvoltage protection circuit is: (V i V is the input voltage. o (This refers to the output voltage).

[0068] Subtraction circuits can perform subtraction operations on multiple input signals at different ratios. Figure 11 The circuit shown is a common subtractor circuit. The operational relationship between the input and output of the subtractor circuit is as follows: Wherein, 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, and R f R1 and R2 are both adjustable resistors, where R2 can be selected according to actual needs. f The value of R1 can be increased when the voltage difference signal is too small. f The value of / R1 is used to amplify the signal.

[0069] The filtering circuit is used to filter out signals in a sinusoidal voltage signal whose frequency exceeds a set frequency threshold range. In this invention, a second-order low-pass filter is designed based on the design process of a Butterworth low-pass filter, and its circuit schematic is shown below. Figure 12 As shown.

[0070] The transfer function of this filter circuit is:

[0071] The circuit gain is

[0072] Where R1, R2, and R3 are resistors, C1 and C2 are capacitors, and s is the transfer function.

[0073] The zero-crossing detection circuit uses a zero-crossing comparator to detect whether an input value is zero. The principle is to ground one input terminal of the integrated operational amplifier and connect the other input terminal to the input voltage for voltage comparison. Near the zero-crossing point of the input voltage, the output voltage changes abruptly. Figure 13 This is the zero-crossing detection circuit used in this embodiment.

[0074] The expression for the zero-crossing detection circuit is:

[0075] The functions of the triggers, counters, and timers are implemented by a digital signal processor (DSP), triggered by the rising edge of the input signal. The counter counts the number of triggers, and the timer measures the trigger time interval. Assume the time interval for the i-th count is T. i If the interval between adjacent zero flux coils is 0.5m, then the velocity v at the current moment is... i for Displacement is Therefore, the train's speed and displacement are calculated based on the interval between adjacent zero flux coils, the number of triggers, and the trigger time interval.

[0076] In summary, this invention provides a planar receiving coil module for zero-flux positioning and velocity measurement. This planar receiving coil module utilizes printed circuit technology to print hundreds or thousands of turns of coil within a multi-layer PCB circuit board. The aluminum foil provides electric field shielding, and the coil housing protects the PCB coil and ensures secure mounting. Compared to conventional receiving coil modules, the planar coil module offers identical performance while significantly reducing module size and weight, and lowering production costs. This planar receiving coil module can be further applied in fields such as magnetic levitation rocket sleds, electromagnetic catapults, and magnetic levitation aerospace propulsion.

[0077] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0078] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0079] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A velocity measurement positioning system for a super high speed maglev train, characterized in that, The speed measurement and positioning system for ultra-high-speed maglev trains includes: A first zero flux coil assembly (10) and a second zero flux coil assembly (20) are provided on the train. The first zero flux coil assembly (10) and the second zero flux coil assembly (20) are arranged opposite to each other. The first zero flux coil assembly (10) and the second zero flux coil assembly (20) are connected. An excitation receiving module (30) includes an excitation coil (31), a first receiving coil (32), and a second receiving coil (33). The excitation coil (31) is disposed on the first zero flux coil assembly (10). The first receiving coil (32) and the second receiving coil (33) are connected in series. The first receiving coil (32) and the second receiving coil (33) are symmetrically arranged with respect to the center line of the excitation coil (31). The first receiving coil (32) and the second receiving coil (33) are spaced apart. On the second zero flux coil assembly (20); an excitation receiving compensation module (40) is provided, which is spaced apart from the excitation receiving module (30). The excitation receiving compensation module (40) includes an excitation compensation coil (41), a first receiving compensation coil (42), and a second receiving compensation coil (43). The excitation compensation coil (41) is provided on the first zero flux coil assembly (10). The first receiving compensation coil (42) and the second receiving compensation coil (43) are connected in series. (42) and the second receiving compensation coil (43) are symmetrically arranged with respect to the center line of the excitation compensation coil (41). The first receiving compensation coil (42) and the second receiving compensation coil (43) are spaced apart on the second zero flux coil assembly (20). The first receiving coil (32), the second receiving coil (33), the first receiving compensation coil (42), and the second receiving compensation coil (43) are all planar receiving coil modules. The planar receiving coil module includes a PCB coil (100) and a shielding unit (20). 0), the PCB coil (100) includes a PCB board and a coil assembly, the coil assembly being printed on the PCB board; the shielding unit (200) is disposed outside the PCB coil (100), the shielding unit (200) being used to shield the alternating electric field of the interference source; the power supply (50) is used to provide DC power to the excitation coil (31) and the excitation compensation coil (41), the excitation coil (31) and the excitation compensation coil (41) being connected in reverse series and then connected to the power supply (50); A signal processing unit (60) is connected to the excitation receiving module (30) and the excitation receiving compensation module (40) respectively. The signal processing unit (60) is used to complete the speed measurement and positioning of the train based on the first receiving induced voltage of the excitation receiving module (30) and the second receiving induced voltage of the excitation receiving compensation module (40). The distance between the excitation coil (31) and the excitation compensation coil (41), the distance between the first receiving coil (32) and the first receiving compensation coil (42), and the distance between the second receiving coil (33) and the second receiving compensation coil (43) are all... ,in, The signal processing unit (60) includes a signal processing circuit and a digital processor, which are the pole pitches of the train propulsion coils. 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.

2. The speed measurement and positioning system for ultra-high-speed maglev trains according to claim 1, characterized in that, The distance between the first receiving coil (32) and the second receiving coil (33) is The distance between the first receiving compensation coil (42) and the second receiving compensation coil (43) is The longitudinal distance between the longitudinal center of the excitation coil (31) and the excitation compensation coil (41) and the center of the vehicle body is... .

3. The speed measurement and positioning system for ultra-high-speed maglev trains according to claim 2, characterized in that, The digital processor includes a trigger, a counter, a timer, and an arithmetic unit. The trigger is used to activate based on the square wave voltage difference signal. The counter is used to record the number of times the trigger is activated. The timer is used to record the trigger time interval. 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 activations, and the trigger time interval.

4. The speed measurement and positioning system for ultra-high-speed maglev trains according to claim 1, characterized in that, The PCB coil (100) includes multiple PCB boards and multiple coil assemblies. The multiple PCB boards and the multiple coil assemblies are arranged in a one-to-one correspondence. The multiple coil assemblies are printed on the multiple PCB boards respectively, and the multiple coil assemblies are connected in sequence.

5. The speed measurement and positioning system for ultra-high-speed maglev trains according to claim 4, characterized in that, The planar receiving coil module also includes a coil housing (300), which is disposed outside the PCB coil (100) and is used to protect the PCB coil (100).

6. The speed measurement and positioning system for ultra-high-speed maglev trains according to claim 5, characterized in that, The planar receiving coil module also includes a fixed mounting unit (400), through which the planar receiving coil module is connected to the train body.

7. The speed measurement and positioning system for ultra-high-speed maglev trains according to claim 6, characterized in that, The coil housing (300) is made of epoxy fiberglass cloth laminate.

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