Speed ​​measurement and positioning system based on multi-excitation-receiver module

Abstract

This invention provides a speed measurement and positioning system based on multiple excitation-receiving modules, including first and second zero-flux coil assemblies, multiple excitation receiving modules, a power supply, and a signal processing unit. Each excitation receiving module includes an excitation coil, a first receiving coil, and a second receiving coil. The excitation coil is disposed on the first zero-flux coil assembly, and the first and second receiving coils are connected in series. The first and second receiving coils are symmetrically arranged with respect to the center line of the excitation coil. The power supply provides DC power to the excitation coils of the multiple excitation receiving modules. The excitation coils of the multiple excitation receiving modules are connected in series in reverse order. The signal processing unit is used to complete the speed measurement and positioning of the train based on the received induced voltage of the multiple excitation receiving modules. This invention solves the technical problems of existing speed measurement and positioning equipment being complex, having low measurement accuracy, and poor anti-interference capability.

Description

Technical Field

[0001] This invention relates to the field of magnetic levitation train technology, and in particular to a speed measurement and positioning system based on a multi-excitation-receiving module. 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, several technologies exist for location and speed measurement, including cross-induction loops, Doppler radar, interrogation-responder systems, and pulse width coding. Cross-induction loop technology, in particular, requires complex equipment, has high construction standards, and necessitates special handling of crossing sections, leading to significant operational and maintenance challenges. Doppler radar suffers from large speed measurement errors at high speeds. Interrogation-responder systems and pulse width coding are suitable for absolute positioning and clearing accumulated errors, but less suitable for speed measurement. Summary of the Invention

[0005] This invention provides a speed measurement and positioning system based on a multi-excitation-receiving module, 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] This invention provides a speed measurement and positioning system based on a multi-excitation-receiver module. The system includes: a first zero-flux coil assembly and a second zero-flux coil assembly, both mounted on a train and arranged opposite to each other, connected to each other; and multiple excitation-receiver modules, arranged sequentially at intervals. Each excitation-receiver module includes an excitation coil, a first receiving coil, and a second receiving coil. The excitation coil is located within the first zero-flux coil... On the coil assembly, a first receiving coil and a 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. The first receiving coil and the second receiving coil are spaced apart on the second zero flux coil assembly. A power supply is used to provide DC power to the excitation coils of multiple excitation receiving modules. The excitation coils of multiple excitation receiving modules are connected in series in reverse order and then connected to the power supply. A signal processing unit is connected to multiple excitation receiving modules respectively. The signal processing unit is used to complete the speed measurement and positioning of the train based on the received induced voltage of the multiple excitation receiving modules.

[0007] Furthermore, the spacing between the excitation coils of any two adjacent excitation receiving modules, the spacing between the first receiving coils of any two adjacent excitation receiving modules, and the spacing between the second receiving coils of any two adjacent excitation receiving modules are all 2τ, where τ is the pole pitch of the train propulsion coil.

[0008] Furthermore, the spacing between the first and second receiving coils of any excitation receiving module is...

[0009] Furthermore, the longitudinal distance between the longitudinal center of the excitation coil of the multiple excitation receiving modules and the center of the vehicle body is 0.1τ.

[0010] Furthermore, the signal processing unit includes a signal processing circuit and a digital processor. The signal processing circuit processes multiple received induced voltages to output multiple square wave voltage difference signals, and the digital processor calculates and obtains the train's speed and displacement based on the multiple square wave voltage difference signals.

[0011] Furthermore, the signal processing circuit includes a subtraction circuit and a zero-crossing detection circuit. The subtraction circuit is used to perform a difference operation on any two adjacent received induced voltages among multiple received induced voltages to obtain multiple sinusoidal voltage difference signals. The zero-crossing detection circuit is used to convert the multiple sinusoidal voltage difference signals into multiple square wave voltage difference signals.

[0012] Furthermore, the signal processing circuit also includes 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 among multiple received induced voltages, and the filtering circuit is used to filter out signals whose frequency exceeds a set frequency threshold range among multiple sinusoidal voltage signals.

[0013] Furthermore, the digital processor includes a trigger, a counter, a timer, and an arithmetic unit. The trigger is used to activate based on multiple square wave voltage difference signals. 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.

[0014] Furthermore, the train's speed v i According to Where L is the interval between adjacent zero flux coils, and T i The time interval between the i-th trigger count and the (i-1)-th trigger count is denoted as N, and N is the number of excitation receiving modules.

[0015] Furthermore, the train's displacement S can be calculated using S = iL / N.

[0016] This invention provides a speed measurement and positioning system based on multiple excitation-receiving modules. This system utilizes multiple excitation-receiving modules. The excitation coils of these modules, powered by direct current, move forward with the bogie, inducing a current in a first zero-flux coil assembly on the same side. This induced current flows into a second zero-flux coil assembly on the opposite side, generating a magnetic field. The change in this magnetic field at the receiving coil of each excitation-receiving module induces an electromotive force. Due to the different spatial arrangements of the receiving coils, the voltage signals of the multiple excitation-receiving modules exhibit phase differences. The signal processing unit uses the induced voltages from the multiple excitation-receiving modules to perform train speed measurement and positioning. Compared to existing technologies, the speed measurement and positioning system provided by this invention has a simpler structure, and by introducing multiple excitation-receiving modules, it effectively reduces interference and ensures that the speed measurement and positioning accuracy remains within permissible limits. 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 speed measurement and positioning system based on a multi-excitation-receiving module according to a specific embodiment of the present invention is shown.

[0019] Figure 2 A schematic diagram of the principle of a speed measurement and positioning system based on a multi-excitation-receiving module according to a specific embodiment of the present invention is shown.

[0020] Figure 3 A wiring diagram of the excitation coils of a plurality of excitation receiving modules provided according to a specific embodiment of the present invention is shown;

[0021] Figures 4a to 4c Three views of an excitation coil according to a specific embodiment of the present invention are shown;

[0022] Figures 5a to 5c Three views of a first receiving coil (second receiving coil) provided according to a specific embodiment of the present invention are shown;

[0023] Figure 6 A schematic diagram of an overvoltage protection circuit according to a specific embodiment of the present invention is shown;

[0024] Figure 7 A schematic diagram of a subtractor circuit according to a specific embodiment of the present invention is shown;

[0025] Figure 8 A schematic diagram of a low-pass filter provided according to a specific embodiment of the present invention is shown;

[0026] Figure 9 A schematic diagram of a zero-crossing detection circuit according to a specific embodiment of the present invention is shown;

[0027] Figure 10 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.

[0028] The above figures include the following reference numerals:

[0029] 10. First zero flux coil assembly; 20. Second zero flux coil assembly; 30. Excitation receiving module; 40. Power supply. Detailed Implementation

[0030] 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.

[0031] 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.

[0032] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described 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.

[0033] like Figures 1 to 10As shown in the figure, a speed measurement and positioning system based on a multi-excitation-receiver module is provided according to a specific embodiment of the present invention. This system includes a first zero-flux coil assembly 10, a second zero-flux coil assembly 20, multiple excitation receiving modules 30, a power supply 40, and a signal processing unit. The first zero-flux coil assembly 10 and the second zero-flux coil assembly 20 are both mounted on the train, facing each other and connected. The multiple excitation receiving modules 30 are arranged sequentially at intervals. Each excitation receiving module 30 includes an excitation coil, a first receiving coil, and a second receiving coil. The excitation coil is mounted on the first zero-flux coil assembly 10, and the first and second receiving coils are connected in series. The first and second receiving coils are symmetrically arranged with respect to the center line of the excitation coil. The first and second receiving coils are spaced apart on the second zero-flux coil assembly 20. The power supply 40... The excitation coils of the multiple excitation receiving modules 30 are used to provide DC power to the excitation coils of the multiple excitation receiving modules 30. The excitation coils of the multiple excitation receiving modules 30 are connected in series in reverse order and then connected to the power supply 40. The signal processing unit is connected to the multiple excitation receiving modules 30 respectively. The signal processing unit is used to complete the speed measurement and positioning of the train based on the received induced voltage of the multiple excitation receiving modules 30.

[0034] This configuration provides a speed measurement and positioning system based on multiple excitation-receiving modules. The system uses multiple excitation-receiving modules. The excitation coils of these modules, powered by direct current, move forward with the bogie, inducing a current in a first zero-flux coil assembly on the same side. This induced current flows into a second zero-flux coil assembly on the opposite side, generating a magnetic field. This magnetic field change at the receiving coil of each excitation-receiving module induces an electromotive force (EMF). The different spatial arrangements of the receiving coils result in a phase difference in the voltage signals. The signal processing unit uses the induced voltages from the multiple excitation-receiving modules to perform train speed measurement and positioning. Compared to existing technologies, the speed measurement and positioning system provided by this invention has a simpler structure and, by introducing multiple excitation-receiving modules, effectively reduces interference and ensures that the speed measurement and positioning accuracy remains within permissible limits.

[0035] 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 zero-flux coil assembly 10 is connected to the second zero-flux coil assembly 20 via a hinge line. The first and second receiving coils of any excitation receiving module 30 are symmetrically arranged with respect to the center line of the excitation coil, and their relative positions are fixed. These three coils constitute an excitation receiving module. The first receiving coils of the multiple excitation receiving modules 30 are completely identical and can be interchanged with each other; the second receiving coils of the multiple excitation receiving modules 30 are completely identical and can be interchanged with each other; and the excitation coils of the multiple excitation receiving modules 30 are completely identical and can be interchanged with each other.

[0036] 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 additional excitation-receiver modules can effectively reduce interference and ensure that the speed measurement and positioning accuracy remains within permissible limits.

[0037] In this invention, such as Figure 3 As shown, the pole pitch of the train's propulsion coil is τ, and the distance between the propulsion coils is 2τ, which is 360° out of phase. Therefore, if the distance between the excitation coils of any two adjacent excitation receiving modules 30 is set to 2τ, their induced electromotive forces are consistent. Similarly, the currents of the excitation coils of any two adjacent excitation receiving modules 30 are equal in magnitude and opposite in direction. The back electromotive forces generated on the propulsion coil by the excitation coils of any two adjacent excitation receiving modules 30 separated by a distance of 2τ are equal in magnitude and opposite in direction, thus canceling each other out. As a specific embodiment of the present invention, the pole pitch τ of the propulsion coil is 1.5m, and the excitation coils of any two adjacent excitation receiving modules 30 are placed 3m apart and connected in series in reverse. This solves both the back electromotive force influence of the propulsion coil on the excitation coil and the back electromotive force influence of the excitation coil on the propulsion coil. Figure 3 A schematic diagram of the power supply for the excitation coils of any two adjacent excitation receiving modules 30 is shown.

[0038] 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 coils of any two adjacent excitation receiving modules 30 and the distance between the second receiving coils of any two adjacent excitation receiving modules 30 are both set to 2τ. This method can ensure that the induced voltage received at each moment is completely consistent. The first and second receiving coils of any excitation receiving module 30 are connected in series and then connected to the signal processing unit. As a specific embodiment of this invention, the pole pitch τ of the propulsion coil is 1.5m, and the distance between the first receiving coils of any two adjacent excitation receiving modules 30 and the distance between the second receiving coils of any two adjacent excitation receiving modules 30 are both set to 3m.

[0039] 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.

[0040] 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.

[0041] The third harmonic generated by the propulsion coil on the receiving coil (specifically including the first receiving coil and the second receiving coil) is...

[0042] The sixth harmonic generated by the propulsion coil on the receiving coil (specifically including the first receiving coil and the second receiving coil) is...

[0043] 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.

[0044] 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 and second receiving coils of any excitation receiving module 30 is set to This allows the third harmonics on the first and second receiving coils to be out of phase and cancel each other out.

[0045] As a specific embodiment of the present invention, the pole pitch τ of the propulsion coil is 1.5m. Setting the distance between the first receiving coil and the second receiving coil of any excitation receiving coil 30 to 1.5m can make the third harmonic phases on the two receiving coils opposite and cancel each other out.

[0046] Furthermore, in this invention, the distance between the first receiving coil and the second receiving coil of any excitation receiving module 30 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 position of the receiving coil. The initial phase of the 6th harmonic of the propulsion coil on the receiving coil changes with the distance between the excitation 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, but the 5th harmonic magnetic field is stronger 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 revealed that when the longitudinal center of the excitation coils of the multiple excitation receiving modules 30 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 the excitation coils of the multiple excitation receiving modules 30 refers to the midpoint of the excitation coils of the multiple excitation receiving modules 30 along the longitudinal direction.

[0047] 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 revealed that when the longitudinal center of the excitation coils of the multiple excitation receiving modules 30 is 150mm (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°. At a suspension height of 34mm, the guiding directions of the excitation coils and receiving coils are aligned with the centerline of the superconducting coil, and their vertical directions are aligned with the centerline of the coil above zero magnetic flux.

[0048] 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 multiple received induced voltages to output multiple square wave voltage difference signals, and the digital processor is used to calculate and obtain the speed and displacement of the train based on the multiple square wave voltage difference signals.

[0049] 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 any two adjacent received induced voltages among a plurality of received induced voltages to obtain a plurality of sinusoidal voltage difference signals. The zero-crossing detection circuit is used to convert the plurality of sinusoidal voltage difference signals into a plurality of square wave voltage difference signals.

[0050] 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 among multiple received induced voltages, and the filtering circuit is used to filter out signals whose frequency exceeds a set frequency threshold range among multiple sinusoidal voltage signals.

[0051] 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 multiple square wave voltage difference signals. 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 The time interval between the i-th trigger count and the (i-1)-th trigger count is given, and N is the number of excitation receiving modules 30. The train displacement S can be calculated using S = iL / N.

[0052] To gain a further understanding of the present invention, the following description is provided in conjunction with... Figures 1 to 9 The present invention provides a detailed description of the speed measurement and positioning system based on a multi-excitation-receiving module.

[0053] like Figures 1 to 9As shown in the figure, a speed measurement and positioning system based on a multi-excitation-receiver module is provided according to a specific embodiment of the present invention. This speed measurement and positioning system includes a first zero-flux coil assembly 10, a second zero-flux coil assembly 20, multiple excitation receiving modules 30, a power supply 40, and a signal processing unit. 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 first zero-flux coil assembly 10 is connected to the second zero-flux coil assembly 20 via a hinge wire. The multiple excitation receiving modules 30 are arranged sequentially at intervals. Any excitation receiving module... Each module 30 includes an excitation coil, a first receiving coil, and a second receiving coil. The excitation coil is mounted on the first zero flux coil assembly 10. The first and second receiving coils are connected in series and are symmetrically arranged with respect to the center line of the excitation coil. The first and second receiving coils are spaced apart on the second zero flux coil assembly 20. The power supply 40 provides DC power to the excitation coils of the multiple excitation receiving modules 30. The excitation coils of the multiple excitation receiving modules 30 are connected in series in reverse order and then connected to the power supply 40. The signal processing unit is connected to the multiple excitation receiving modules 30 respectively and is used to complete the speed measurement and positioning of the train based on the received induced voltage of the multiple excitation receiving modules 30.

[0054] The signal processing unit 60 includes a signal processing circuit and a digital processor. The signal processing circuit processes the received induced voltages from multiple excitation receiving modules 30 to output square wave voltage difference signals. The digital processor calculates and obtains the train's speed and displacement based on the multiple square wave voltage difference signals. 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 any two adjacent received induced voltages to obtain multiple sinusoidal voltage difference signals. The zero-crossing detection circuit converts the multiple sinusoidal voltage difference signals into multiple square wave voltage difference signals. The overvoltage protection unit limits the amplitude of signals whose pressure exceeds a set pressure threshold range. The filtering circuit filters out signals whose frequency exceeds a set frequency threshold range from the multiple sinusoidal voltage signals. The digital processor includes a trigger, a counter, a timer, and an arithmetic unit. The trigger is activated based on the multiple square wave voltage difference signals. 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.

[0055] As the bogie moves forward, the excitation coils of multiple excitation receiving modules 30, carrying direct current, induce a current in the first zero-flux coil assembly on the same side. This induced current flows through the hinge line 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 30 induces an electromotive force in its receiving coil. Due to the different spatial arrangement of the receiving coils of the multiple excitation receiving modules, there is a phase difference in the voltage signals. A square wave waveform is obtained by analyzing the intersection of the induced voltage signals from the multiple excitation receiving modules. The position and speed information of the train are then calculated. The induced voltages from the multiple excitation receiving modules are sequentially passed 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.

[0056] 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).

[0057] Subtraction circuits can perform subtraction operations on multiple input signals at different ratios. Figure 10 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. The subtraction circuit performs a difference operation on any two adjacent received induced voltages among the multiple received induced voltages to obtain multiple sinusoidal voltage difference signals. In this embodiment, the speed measurement and positioning system includes three excitation receiving modules. The subtraction circuit performs a difference operation on the first received induced voltage of the first excitation receiving module and the second received induced voltage of the second excitation receiving module to obtain the first sinusoidal voltage difference signal, and performs a difference operation on the second received induced voltage of the second excitation receiving module and the third received induced voltage of the third excitation receiving module to obtain the second sinusoidal voltage difference signal.

[0058] The filtering circuit is used to filter out signals whose frequency exceeds a set frequency threshold from multiple sinusoidal voltage signals. 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 8 As shown.

[0059] The transfer function of this filter circuit is:

[0060] The circuit gain is

[0061] Wherein, R1, R2, and R3 are resistors, C1 and C2 are capacitors, and s is the transfer function. In this embodiment, the speed measurement and positioning system includes three excitation receiving modules. The filtering circuit filters the first sinusoidal voltage difference signal and the second sinusoidal voltage difference signal to remove signals in the difference signal whose frequency exceeds the set frequency threshold range.

[0062] 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 9 This is the zero-crossing detection circuit used in this embodiment.

[0063] The expression for the zero-crossing detection circuit is: In this embodiment, the speed measurement and positioning system includes three excitation receiving modules. The zero-crossing detection circuit converts the first sinusoidal voltage difference signal into a first square wave voltage difference signal and converts the second sinusoidal voltage difference signal into a second square wave voltage difference signal.

[0064] 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, the trigger time interval, and the number of excitation receiving modules. In this embodiment, the first square wave voltage difference signal and the second square wave voltage difference signal simultaneously enter the trigger to activate the trigger, the counter counts the number of triggers, and the timer counts the trigger time interval.

[0065] In summary, this invention provides a speed measurement and positioning system based on multiple excitation-receiving modules. This system utilizes multiple excitation-receiving modules. The excitation coils of these modules, powered by direct current, move forward with the bogie, inducing a current in a first zero-flux coil assembly on the same side. This induced current flows into a second zero-flux coil assembly on the opposite side, generating a magnetic field. The change in this magnetic field at the receiving coil of each excitation-receiving module induces an electromotive force. The different spatial arrangements of the receiving coils in the multiple modules result in a phase difference in their voltage signals. The signal processing unit uses the induced voltages from the multiple excitation-receiving modules to perform train speed measurement and positioning. Compared to existing technologies, the speed measurement and positioning system provided by this invention offers higher positioning accuracy, a wider speed measurement range, stronger anti-interference capabilities, and a simpler structure. Furthermore, by introducing multiple excitation-receiving modules, interference can be effectively reduced, ensuring that the speed measurement and positioning accuracy remains within permissible limits. This system can be further applied to fields such as magnetic levitation rocket skids, electromagnetic catapults, and magnetic levitation aerospace booster launches.

[0066] 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.

[0067] For ease of description, spatial relative terms such as "above," "over," "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 "above" 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.

[0068] 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.

[0069] 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 speed measurement and positioning system based on a multi-excitation-receiving module, characterized in that, The velocity measurement and positioning system based on a multi-excitation-receiver module 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. Multiple excitation receiving modules (30) are arranged sequentially at intervals. Each excitation receiving module (30) 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 (10). 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. The first receiving coil and the second receiving coil are arranged at intervals on the second zero flux coil assembly (20). Power supply (40) is used to provide DC power to the excitation coils of the multiple excitation receiving modules (30). The excitation coils of the multiple excitation receiving modules (30) are connected in series in reverse order and then connected to the power supply (40). The signal processing unit is connected to multiple excitation receiving modules (30) respectively. The signal processing unit is used to complete the speed measurement and positioning of the train based on the received induced voltage of the multiple excitation receiving modules (30).

2. The speed measurement and positioning system based on a multi-excitation-receiving module according to claim 1, characterized in that, The spacing between the excitation coils of any two adjacent excitation receiving modules (30), the spacing between the first receiving coils of any two adjacent excitation receiving modules (30), and the spacing between the second receiving coils of any two adjacent excitation receiving modules (30) are all... ,in, This refers to the pole pitch of the train propulsion coil.

3. The speed measurement and positioning system based on a multi-excitation-receiving module according to claim 2, characterized in that, The spacing between the first and second receiving coils of any of the excitation receiving modules (30) is 1. .

4. The speed measurement and positioning system based on a multi-excitation-receiving module according to claim 3, characterized in that, The longitudinal distance between the longitudinal center of the excitation coil of the plurality of excitation receiving modules (30) and the center of the vehicle body is .

5. The speed measurement and positioning system based on a multi-excitation-receiving module according to any one of claims 1 to 4, characterized in that, The signal processing unit includes a signal processing circuit and a digital processor. The signal processing circuit processes multiple received induced voltages to output multiple square wave voltage difference signals. The digital processor calculates and obtains the speed and displacement of the train based on the multiple square wave voltage difference signals.

6. The speed measurement and positioning system based on a multi-excitation-receiving module according to claim 5, characterized in that, The signal processing circuit includes a subtraction circuit and a zero-crossing detection circuit. The subtraction circuit is used to perform a difference operation on any two adjacent received induced voltages among the plurality of received induced voltages to obtain a plurality of sinusoidal voltage difference signals. The zero-crossing detection circuit is used to convert the plurality of sinusoidal voltage difference signals into a plurality of square wave voltage difference signals.

7. The speed measurement and positioning system based on a multi-excitation-receiving module according to claim 6, characterized in that, 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 whose pressure exceeds a set pressure threshold range among the multiple received induced voltages. The filtering circuit is used to filter out signals whose frequency exceeds a set frequency threshold range among the multiple sinusoidal voltage difference signals.

8. The speed measurement and positioning system based on a multi-excitation-receiving module according to claim 5, characterized in that, The digital processor includes a trigger, a counter, a timer, and an arithmetic unit. The trigger is used to trigger based on multiple square wave voltage difference signals. The counter is used to record the number of times the trigger is triggered. 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 triggers, and the trigger time interval.

9. The speed measurement and positioning system based on a multi-excitation-receiving module according to claim 8, characterized in that, The speed of the train According to ,in, The interval between adjacent zero flux coils, For the first The trigger count and the number The time interval between trigger counts, The number of the excitation receiving modules (30) is denoted as .

10. The speed measurement and positioning system based on a multi-excitation-receiving module according to claim 9, characterized in that, The displacement of the train According to Calculated and obtained.

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