Speed measurement and positioning system for ultra-high speed maglev train

Abstract

The present invention provides a speed measurement and positioning system for a super-high-speed maglev train, which includes first and second zero-flux coil assemblies, an excitation receiving module, an excitation receiving compensation module, a power supply, and a signal processing unit. The excitation receiving module includes an excitation coil, a first receiving coil and a second receiving coil, and the first receiving coil and the second receiving coil are connected in series. The excitation receiving compensation module includes an excitation compensation coil, a first receiving compensation coil and a second receiving compensation coil, and the first receiving compensation coil and the second receiving compensation coil are connected in series. The excitation coil and the excitation compensation coil are connected in reverse series. The signal processing unit is respectively connected to the excitation receiving module and the excitation receiving compensation module, and the signal processing unit is used to complete the speed measurement and positioning of the train according to the first received induced voltage of the excitation receiving module and the second received induced voltage of the excitation receiving compensation module. Applying the technical solution of the present invention can solve the technical problems of complex speed measurement and positioning equipment, low measurement accuracy and poor anti-interference ability in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of maglev trains, and particularly to a speed measurement and positioning system for ultra-high speed maglev trains. Background Art

[0002] The ultra-high speed maglev train belongs to a rail transit system. During operation, it is necessary to detect and monitor the speed of the train, and provide the position information and speed information of the train at any time for the traction control system and the train operation control system, which is of great guiding significance for the train acceleration and deceleration control, operation line regulation or emergency stop due to failure. In order to ensure the safe operation of the train, the speed measurement and positioning method requires 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: the ground positioning and speed measurement system and the vehicle-mounted positioning and speed measurement system. Among them: the ground positioning and speed measurement system provides the position and speed information of the train at any time for the traction control system and the operation control system; the vehicle-mounted 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 for the vehicle-mounted operation control unit and is used to display the current position and speed for passengers. Under the condition of the failure of the ground positioning and speed measurement system, it serves as a backup guarantee and emergency plan for guiding emergency stops.

[0004] Currently, there are various technologies to achieve positioning and speed measurement, including cross induction loops, Doppler radars, interrogator-responders, pulse width coding, etc. Among them, the cross induction loop technology has the problems of complex required instrument equipment, high construction requirements, special treatment required in the line crossing section, and great difficulty in operation and later maintenance. The Doppler radar has the problem of large high-speed speed measurement error. Interrogator-responders and pulse width coding are suitable for absolute positioning and clearing cumulative errors, and are not very suitable for speed measurement. Summary of the Invention

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

[0006] The present invention provides a speed measurement and positioning system for a super high-speed maglev train. The speed measurement and positioning system for a super high-speed maglev train includes: a first zero-flux coil assembly and a second zero-flux coil assembly. Both the first zero-flux coil assembly and the second zero-flux coil assembly are arranged on the train. The first zero-flux coil assembly and the second zero-flux coil assembly are arranged opposite to each other and connected. An excitation receiving module, which includes an excitation coil, a first receiving coil, and a second receiving coil. The excitation coil is arranged on the first zero-flux coil assembly. 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 with respect to the center line of the excitation coil and are spaced apart on the second zero-flux coil assembly. An excitation receiving compensation module, which is spaced apart 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-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 with respect to the center line of the excitation compensation coil and are spaced apart on the second zero-flux coil assembly. A power supply, which is used to provide direct current to the excitation coil and the excitation compensation coil. The excitation coil and the excitation compensation coil are connected in reverse series and then connected to the power supply. A signal processing unit, which is respectively connected to the excitation receiving module and the excitation receiving compensation module. The signal processing unit is used to complete the speed measurement and positioning of the train according to the first received induced voltage of the excitation receiving module and the second received induced voltage of the excitation receiving compensation module.

[0007] Further, the distance between the excitation coil and the excitation compensation coil, the distance between the first receiving coil and the first receiving compensation coil, and the distance 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.

[0008] Further, 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

[0009] Further, 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.

[0010] Further, 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 according to the square wave voltage difference signal.

[0011] Further, the signal processing circuit includes a subtraction circuit and a zero-crossing detection circuit. The subtraction circuit is used to perform a subtraction operation on the first received induced voltage and the second received induced voltage to obtain a sine voltage difference signal, and the zero-crossing detection circuit is used to convert the sine voltage difference signal into a square-wave voltage difference signal.

[0012] Further, the signal processing circuit further includes an overvoltage protection unit and a filtering circuit. The overvoltage protection unit is used to limit the amplitude of 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 signals in the sine voltage value signal whose frequency exceeds the set frequency threshold range.

[0013] Further, 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 trigger times of the trigger, the timer is used to record the trigger time interval of the trigger, and 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 trigger times, and the trigger time interval.

[0014] Further, the speed v of the train i can be obtained according to wherein, L is the interval between adjacent zero-flux coils, and T i is the time interval between the i-th trigger count and the (i - 1)-th trigger count.

[0015] Further, the displacement S of the train can be obtained according to S = iL.

[0016] Applying the technical solution of the present invention, a speed measurement and positioning system for a super-high-speed maglev train is provided. The speed measurement and positioning system is provided with an excitation receiving module and an excitation receiving compensation module. The excitation coil and the excitation compensation coil are energized with direct current and move forward with the bogie, 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, and 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 forces on the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module. Due to the different spatial arrangements of the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module, there is a phase difference in the voltage signals. The signal processing unit completes the speed measurement and positioning of the train according to the first received induced voltage of the excitation receiving module and the second received induced voltage of the excitation receiving compensation module. Compared with the prior art, the speed measurement and positioning system provided by the present invention has a simple structure, and by introducing the excitation receiving compensation module, it can effectively reduce interference and ensure that the speed measurement and positioning accuracy is within the permitted range. Brief Description of the Drawings

[0017] The accompanying drawings included are used to provide a further understanding of the embodiments of the present invention, which form a part of the specification, illustrate the embodiments of the present invention, and, together with the written description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0018] Figure 1 Shows a schematic structural diagram of a speed measurement and positioning system for a high-speed maglev train provided according to a specific embodiment of the present invention;

[0019] Figure 2 Shows a schematic principle diagram of a speed measurement and positioning system for a high-speed maglev train provided according to a specific embodiment of the present invention;

[0020] Figure 3 Shows a schematic wiring diagram of an exciting coil and an exciting compensation coil provided according to a specific embodiment of the present invention;

[0021] Figure 4 Shows a schematic wiring diagram of a first receiving coil, a second receiving coil, a first receiving compensation coil, and a second receiving compensation coil provided according to a specific embodiment of the present invention;

[0022] Figure 5 Shows a longitudinal view of a speed measurement and positioning system for a high-speed maglev train provided according to a specific embodiment of the present invention;

[0023] Figure 6 Shows a guiding view of a speed measurement and positioning system for a high-speed maglev train provided according to a specific embodiment of the present invention;

[0024] Figures 7a to 7c Shows three views of an exciting coil (exciting compensation coil) provided according to a specific embodiment of the present invention;

[0025] Figures 8a to 8c Shows three views of a first receiving coil (second receiving coil / first receiving compensation coil / second receiving compensation coil) provided according to a specific embodiment of the present invention;

[0026] Figure 9 Shows a schematic diagram of an overvoltage protection circuit provided according to a specific embodiment of the present invention;

[0027] Figure 10 Shows a schematic diagram of a subtractor circuit provided according to a specific embodiment of the present invention;

[0028] Figure 11 Shows a schematic diagram of a low-pass filter provided according to a specific embodiment of the present invention;

[0029] Figure 12 Shows a schematic diagram of a zero-crossing detection circuit provided according to a specific embodiment of the present invention;

[0030] Figure 13 Shows a schematic diagram of the principle of speed measurement and positioning for a super-high-speed maglev train provided according to a specific embodiment of the present invention.

[0031] Among them, the above-mentioned drawings include the following reference numerals:

[0032] 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. Specific embodiments

[0033] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0034] It should be noted that the terms used here are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used here, 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 "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0035] Unless otherwise specifically noted, the relative arrangement of components and steps, numerical expressions, and 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 the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, further discussion thereof is not required in subsequent drawings.

[0036] As Figures 1 to 13As shown in the figure, according to a specific embodiment of the present invention, a speed measurement and positioning system for a super-high-speed maglev train is provided. The speed measurement and positioning system for the super-high-speed maglev train 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. The first zero-flux coil assembly 10 and the second zero-flux coil assembly 20 are both arranged on the train. The first zero-flux coil assembly 10 and the second zero-flux coil assembly 20 are arranged opposite to each other and are connected. 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 arranged 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 arranged at intervals on the second zero-flux coil assembly 20. The excitation receiving compensation module 40 is arranged at intervals with 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 arranged 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 at intervals on the second zero-flux coil assembly 20. The power supply 50 is used to provide direct current 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 respectively connected to the excitation receiving module 30 and the excitation receiving compensation module 40. The signal processing unit 60 is used to complete the speed measurement and positioning of the train according to the first received induced voltage of the excitation receiving module 30 and the second received induced voltage of the excitation receiving compensation module 40.

[0037] By applying this configuration method, a speed measurement and positioning system for a super-high-speed maglev train is provided. The speed measurement and positioning system sets up an excitation receiving module and an excitation receiving compensation module. When the excitation coil and the excitation compensation coil are energized with direct current and move forward with the bogie, 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 forces on the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module. Due to the different spatial arrangements of the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module, there is a phase difference in the voltage signals. The signal processing unit completes the speed measurement and positioning of the train based on the first received induced voltage of the excitation receiving module and the second received induced voltage of the excitation receiving compensation module. Compared with the prior art, the speed measurement and positioning system provided by the present invention has a simple structure, and by introducing the excitation receiving compensation module, it can effectively reduce interference and ensure that the speed measurement and positioning accuracy is within the permitted range.

[0038] Specifically, in the present invention, both the first zero-flux coil assembly 10 and the second zero-flux coil assembly 20 are composed of a plurality of 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 form 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 form 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 exactly the same and can be replaced with each other. The excitation coil 31 and the excitation compensation coil 41 are exactly the same and can be replaced with each other.

[0039] Under ideal conditions, the running attitude of the train does not deflect, and at the same time, without considering interference, any excitation-receiving module combined with signal processing can accurately measure speed and position. However, during the actual operation of the train, affected by the change of the train running attitude and the interference of the ground propulsion module on the excitation-receiving module, the speed measurement and positioning accuracy of a single excitation-receiving module deteriorates, and it may even become unusable. Introducing the excitation compensation coil and the receiving compensation coil can effectively reduce interference and ensure that the speed measurement and positioning accuracy is within the permitted range.

[0040] In the present invention, as Figure 3As shown, the pole pitch of the propulsion coil of the train is τ, and the distance between the two coils with a spacing of 2τ from the propulsion coil is 360° out of phase. Therefore, the distance between the excitation coil 31 and the excitation compensation coil 41 is set to 2τ, and their induced electromotive forces are the same. By connecting the excitation coil 31 and the excitation compensation coil 41 in reverse, the counter electromotive force of the propulsion coil on the transmitting coil can be cancelled out. Similarly, the currents in the excitation coil 31 and the excitation compensation coil 41 are equal in magnitude and opposite in direction. The excitation coil 31 and the excitation compensation coil 41 are separated by a distance of 2τ, and the counter electromotive forces generated on the propulsion coil are equal in magnitude and opposite in direction, canceling each other out. As a specific embodiment of the present invention, the pole pitch τ of the propulsion coil is 1.5 m, the excitation coil 31 and the excitation compensation coil 41 are placed 3 m apart and connected in series in reverse, which can not only solve the influence of the counter electromotive force generated by the propulsion coil on the transmitting coil, but also solve the influence of the counter electromotive force of the transmitting coil on the propulsion coil. Figure 3 The power supply schematic diagram of the excitation coil 31 and the excitation compensation coil 41 is shown.

[0041] Furthermore, in the present invention, in the space magnetic field of the ground propulsion coil, the period length of the second harmonic is 2τ / 2, the pole pitch period length of the fifth harmonic is 2τ / 5, and the pole pitch period length of the seventh harmonic is 2τ / 7. When the body attitude does not deflect, the distances between the first receiving coil 32 and the first receiving compensation coil 42 and between the second receiving coil 33 and the second receiving compensation coil 43 are both set to 2τ. This method can ensure that the induced voltages received at each moment are exactly the same. As Figure 4 shown, the first receiving coil 32 and the second receiving coil 33 are in 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 in 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 1.5 m, and the distances between the first receiving coil 32 and the first receiving compensation coil 42 and between the second receiving coil 33 and the second receiving compensation coil 43 are both set to 3 m.

[0042] When the body deflects, theoretically the interference signal cannot be completely cancelled out. By analyzing the frequency of the interference signal, it can be known that the third harmonic frequency of the interference signal is 1 / 2 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 interference of the third harmonic as much as possible, and after cancellation, the interference of the sixth harmonic and the actual received signal do not cancel each other out.

[0043] Based on the zero-flux coil counting method, the period of the received signal is the zero-flux coil spacing Q divided by the speed, and the signal frequency is where 3Q = τ.

[0044] The 3 - times 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

[0045] The 6 - times 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

[0046] Since the initial phase of the 3 - times frequency interference signal on the receiving coil changes longitudinally with distance, the change speed of the initial phase is That is, for every change of τ in distance, the phase changes by 360°.

[0047] The 3rd - harmonic voltage in the time domain is generated by the 2nd - harmonic magnetic field of the spatial magnetic field. The pole pitch of the 2nd - order spatial magnetic field is Two pole pitches form a pair of poles, with a difference of 360° (2π). Therefore, the change speed of the 3 - times frequency initial phase with the spatial position is Therefore, when the distance between the first receiving coil 32 and the second receiving coil 33 is set to and the distance between the first receiving compensation coil 42 and the second receiving compensation coil 43 is set to it can make the 3rd - harmonic phases on the first receiving coil 32 and the second receiving coil 33 opposite to each other and cancel each other out; the 3rd - harmonic phases on the first receiving compensation coil 42 and the second receiving compensation coil 43 are opposite to each other and cancel each other out.

[0048] As a specific embodiment of the present invention, when the pole pitch τ of the propulsion coil is 1.5 m, the distance between the first receiving coil 32 and the second receiving coil 33 is set to 1.5 m, and the distance between the first receiving compensation coil 42 and the second receiving compensation coil 43 is set to 1.5 m, the 3rd - harmonic phases on the two receiving coils can be opposite to each other and cancel each other out.

[0049] Furthermore, in the present invention, the distance between the first receiving coil 32 and the second receiving coil 33 is and the distance between the first receiving compensation coil 42 and the second receiving compensation coil 43 is Then the relative phase difference of the 6 - times harmonic on them is fixed. However, the phase difference between the 6 - times 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 6 - times 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 train movement direction, and the 7th - harmonic is the same as the train movement direction. Therefore, both can generate 6 - times - 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. Taking the 5th - harmonic magnetic field as the main one, its harmonic pole pitch is Therefore, the initial phase change frequency of its sixth harmonic is After analysis, when the longitudinal centers of the excitation coil 31 and the excitation compensation coil 42 are 0.1τ away from the center of the car body, the phase difference between the effective signal and the interference signal is close to 90°. Here, the longitudinal centers of the excitation coil 31 and the excitation compensation coil 42 refer to the midpoints of the excitation coil 31 and the excitation compensation coil 42 along the longitudinal direction.

[0050] As a specific embodiment of the present invention, the pole pitch τ of the propulsion coil is 1.5 m, the harmonic pole pitch of the fifth harmonic magnetic field is 0.3 m, and the initial phase change frequency of its sixth harmonic is After analysis, when the longitudinal center of the excitation coil - excitation compensation coil is 150 mm (0.1τ) away from the center of the car body, the phase difference between the effective signal and the interference signal is close to 90°. Figure 5 It is a diagram of the relative position relationship between the zero - flux positioning and speed - measuring system installed on the vehicle and the zero - flux coil. When the suspension height is 34 mm, the guiding directions of the transmitting coil and the receiving coil are aligned with the center line of the superconducting coil, and the vertical direction is aligned with the center line of the upper zero - flux coil.

[0051] Furthermore, in the present 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 according to the square - wave voltage difference signal.

[0052] 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 subtraction operation on the first received induced voltage and the second received induced voltage to obtain a sine voltage difference signal, and the zero - crossing detection circuit is used to convert the sine voltage difference signal into a square - wave voltage difference signal.

[0053] In addition, in the present invention, in order to improve the calculation accuracy, the signal processing circuit can be configured to further include an over - voltage protection unit and a filtering circuit. The over - voltage protection unit is used to limit the amplitude of 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 sine voltage value signal whose frequency exceeds the set frequency threshold range.

[0054] 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 trigger times of the trigger, the timer is used to record the trigger time interval of the trigger, and 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 trigger times, and the trigger time interval. Among them, the speed v of the traini It can be based on where L is the interval between adjacent zero - flux coils, and T i is the time interval between the i - th trigger count and the (i - 1)-th trigger count. The displacement S of the train can be based on S = iL.

[0055] To further understand the present invention, the following combines Figures 1 to 8c to elaborate in detail on the speed measurement and positioning system for a high - speed maglev train provided by the present invention.

[0056] As Figures 1 to 8c shown, according to a specific embodiment of the present invention, there is provided a speed measurement and positioning system for a high - speed maglev train. The speed measurement and positioning 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. The first zero - flux coil assembly 10 and the second zero - flux coil assembly 20 are both arranged 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 is connected to the second zero - flux coil assembly 20 through a hinge line. 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 arranged 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 arranged at intervals on the second zero - flux coil assembly 20. The excitation receiving compensation module 40 is arranged at an interval 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 arranged 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 at intervals on the second zero - flux coil assembly 20. The power supply 50 is used to provide direct current 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 respectively connected to the excitation receiving module 30 and the excitation receiving compensation module 40. The signal processing unit 60 is used to complete the speed measurement and positioning of the train according to the first received induced voltage of the excitation receiving module 30 and the second received induced voltage of the excitation receiving compensation module 40.

[0057] The signal processing unit 60 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 according to 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 is used to perform a subtraction operation on the first received induced voltage and the second received induced voltage to obtain a sine voltage difference signal. The zero-crossing detection circuit is used to convert the sine voltage difference signal into a square-wave voltage difference signal. The overvoltage protection unit is used to limit the amplitude of the signals in the first received induced voltage and the second received induced voltage whose pressure exceeds the set pressure threshold range. The filtering circuit is used to filter out the signals in the sine voltage value signal whose frequency exceeds the set frequency threshold range. 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.

[0058] As the bogie moves forward, the excitation coil and the excitation compensation coil are energized with direct current. 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 forces on the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module. Due to the different spatial arrangements, there is a phase difference in the voltage signals of the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module. The intersection of the induced voltage signal of the receiving coil on 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 operation is finally calculated by analyzing the square-wave waveform. The received induced voltages of the excitation receiving module and the excitation receiving compensation module pass through an overvoltage protection circuit, a subtraction circuit, a filtering circuit, a zero-crossing detection circuit, a trigger, a counter, and a timer in sequence to realize the calculation of the train position and speed.

[0059] The overvoltage protection circuit needs to ensure that the normal working signal of the receiving coil can be completely input to the subsequent circuit, but for signals or impulses with larger amplitudes, it should be able to play a role in clipping the peaks. In this embodiment, the voltage expression of the overvoltage protection circuit is (V i is the input voltage, V o is the output voltage).

[0060] The subtraction circuit can perform subtraction operations on multiple input signals in different proportions. Figure 10 The circuit shown is a common subtractor circuit. The operational relationship between the input and output of the subtractor circuit is: where, V 2 is the induced voltage signal of the receiving compensation coil on the second zero-flux coil assembly, V 1 is the induced voltage signal of the receiving coil on the first zero-flux coil assembly, R f , R 1 are both adjustable resistors. Among them, the values of R f , R 1 can be selected according to actual needs. When the voltage difference signal is too small, the value of R f / R 1 can be increased to achieve signal amplification.

[0061] The filter circuit is used to filter out the signals in the sine voltage value signal whose frequencies exceed the set frequency threshold range. In the present invention, a second-order low-pass filter is designed according to the design process of the Butterworth low-pass filter, and its circuit schematic diagram is as Figure 11 shown.

[0062] The transfer function of this filter circuit is:

[0063] The circuit gain is

[0064] where, R 1 , R 2 , R 3 are resistors, C 1 , C 2 are capacitors, and s is the transfer function.

[0065] 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. The output voltage jumps near the zero-crossing point of the input voltage. Figure 12 This is the zero-crossing detection circuit used in this embodiment.

[0066] The expression of the zero-crossing detection circuit is:

[0067] The functions of the flip-flop, counter, and timer are implemented by the digital signal processor DSP and are triggered using the rising edge of the input signal. The counter counts the number of trigger times, and the timer measures the trigger time interval. Assuming that the time interval for the i-th count is T i , and the adjacent zero-flux coils are spaced 0.5 m apart, then the speed v i at the current moment is The displacement is Thus, the speed and displacement of the train are calculated based on the intervals between adjacent zero-flux coils, the number of trigger times, and the trigger time intervals.

[0068] In summary, the present invention provides a speed measurement and positioning system for a super-high-speed maglev train. By setting up an excitation receiving module and an excitation receiving compensation module, when the excitation coil and the excitation compensation coil are energized with direct current and move forward with the bogie, 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, and 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 forces on the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module. Due to the different spatial arrangements, there is a phase difference in the voltage signals between the receiving coil of the excitation receiving module and the receiving compensation coil of the excitation receiving compensation module. The signal processing unit completes the speed measurement and positioning of the train based on the first received induced voltage of the excitation receiving module and the second received induced voltage of the excitation receiving compensation module. Compared with the prior art, the speed measurement and positioning system provided by the present invention has high positioning accuracy, a wide speed measurement range, strong anti-interference ability, a simple structure, and by introducing the excitation receiving compensation module, it can effectively reduce interference and ensure that the speed measurement and positioning accuracy are within the permitted range, and can be further applied to fields such as maglev rocket sleds, electromagnetic catapults, and maglev space booster launches.

[0069] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, rear, up, down, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary explanations, these orientation words do not indicate and imply that the devices or elements referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0070] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper", etc. may be used herein to describe the spatial positional relationship of one device or feature to other devices or features as shown in the figures. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both orientations of "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations for the spatial relative descriptions used herein will be made accordingly.

[0071] In addition, it should be noted that the use of terms such as "first" and "second" to define components is only for the convenience of differentiating the corresponding components. Without further statement, the above terms have no special meaning, and thus should not be construed as limiting the scope of protection of the present invention.

[0072] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A speed measurement and positioning system for a super-high-speed maglev train, characterized in that, the speed measurement and positioning system for a super-high-speed maglev train comprises: a first zero-flux coil assembly (10) and a second zero-flux coil assembly (20), both the first zero-flux coil assembly (10) and the second zero-flux coil assembly (20) are arranged on the train, the first zero-flux coil assembly (10) and the second zero-flux coil assembly (20) are arranged opposite to each other, and the first zero-flux coil assembly (10) is connected to the second zero-flux coil assembly (20); an excitation receiving module (30), the excitation receiving module (30) comprises an excitation coil (31), a first receiving coil (32) and a second receiving coil (33), the excitation coil (31) is arranged 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), and the first receiving coil (32) and the second receiving coil (33) are arranged at intervals on the second zero-flux coil assembly (20); an excitation receiving compensation module (40), the excitation receiving compensation module (40) is arranged at an interval from the excitation receiving module (30), the excitation receiving compensation module (40) comprises an excitation compensation coil (41), a first receiving compensation coil (42) and a second receiving compensation coil (43), the excitation compensation coil (41) is arranged 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), and the first receiving compensation coil (42) and the second receiving compensation coil (43) are arranged at intervals on the second zero-flux coil assembly (20); a power supply (50), the power supply (50) is used to provide direct current to the excitation coil (31) and the excitation compensation coil (41), and the excitation coil (31) and the excitation compensation coil (41) are connected in reverse series and then connected to the power supply (50); A signal processing unit (60), the signal processing unit (60) is respectively connected to the excitation receiving module (30) and the excitation receiving compensation module (40), and the signal processing unit (60) is configured to complete the speed measurement and positioning of the train according to the first received induced voltage of the excitation receiving module (30) and the second received induced voltage of the excitation receiving compensation module (40), and 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 τ is the pole pitch of the train propulsion coil.

2. The speed measurement and positioning system for a super-high-speed maglev train according to claim 1, characterized in that, the longitudinal distance between the longitudinal centers of the excitation coil (31) and the excitation compensation coil (41) and the center of the vehicle body is 0.1τ.

3. The speed measurement and positioning system for a super-high-speed maglev train according to claim 1 or 2, characterized in that, the signal processing unit (60) comprises 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 according to the square wave voltage difference signal.

4. The speed measurement and positioning system for a super-high-speed maglev train according to claim 3, wherein, the signal processing circuit includes a subtraction circuit and a zero-crossing detection circuit. The subtraction circuit is used to perform a subtraction operation on the first received induced voltage and the second received induced voltage to obtain a sine voltage difference signal, and the zero-crossing detection circuit is used to convert the sine voltage difference signal into a square-wave voltage difference signal.

5. The speed measurement and positioning system for a super-high-speed maglev train according to claim 4, wherein, the signal processing circuit further includes an overvoltage protection unit and a filtering circuit. The overvoltage protection unit is used to limit the amplitude of 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 sine voltage value signal whose frequency exceeds the set frequency threshold range.

6. The speed measurement and positioning system for a super-high-speed maglev train according to claim 3, wherein, 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, and 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.

7. The speed measurement and positioning system for a super-high-speed maglev train according to claim 6, wherein, The speed v of the train i can be based on where L is the interval between adjacent zero-flux coils, and T i is the time interval between the i-th trigger count and the (i - 1)-th trigger count.

8. The speed measurement and positioning system for a super-high-speed maglev train according to claim 7, wherein, the displacement S of the train can be calculated and obtained according to S = iL.

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