High-speed magnetic suspension system positioning and speed measuring device and method based on frequency detection

Abstract

The invention provides a high-speed magnetic suspension system positioning and speed measuring device and method based on frequency detection. The device comprises a vehicle-mounted light source assembly arranged at a vehicle-mounted end, and a ground detection assembly and a control unit which are arranged at a ground end, the vehicle-mounted light source assembly comprises a plurality of laser emitters which are sequentially arranged at equal intervals in the train running direction. Each laser emitter is used for emitting laser with the same wavelength but different frequencies; wherein the laser is a square wave pulse signal; the ground detection assembly comprises a plurality of ground detectors which are sequentially arranged at equal intervals in the running direction of the train; the ground detector in the light source coverage area is used for receiving laser emitted by the corresponding laser emitter and sending the laser to the control unit; the control unit is used for acquiring the absolute position of the ground detector corresponding to the frequency of the received laser; the distance acquisition module is used for acquiring the distance between the laser transmitter corresponding to the frequency of the received laser and the laser transmitter at the starting end; and acquiring the position and speed of the train.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-speed magnetic suspension technology, and in particular to a high-speed magnetic suspension system positioning and speed measuring device and method based on frequency detection. BACKGROUND

[0002] The high-speed magnetic suspension system needs a high-precision positioning and speed measuring system under the control of a superconducting synchronous motor at high speed. The system has high speed, short control cycle, and high requirements for the precision, time delay and reliability of the positioning and speed measuring system. Therefore, a positioning and speed measuring system with high precision, low time delay and high reliability is needed in a strong electromagnetic interference environment.

[0003] Currently, there are two positioning and speed measuring methods in the application of the high-speed magnetic suspension system:

[0004] One is to detect the wavelength of the fiber grating. In this method, a plurality of fiber Bragg gratings are engraved on the sensing grating. The fiber Bragg grating is continuously stressed by the vehicle-mounted permanent magnet on the sensing fiber on the track, so that the wavelength of the fiber Bragg grating changes continuously. The position and speed of the train are calculated by detecting the wavelength change. However, this method has the following disadvantages: 1. High cost: At least 5 fiber Bragg gratings need to be engraved on the track along the line; 2. Large time delay: The wavelength of the fiber needs to be detected at the terminal, and the calculation time delay is large; 3. Large error, difficult to apply in engineering: The stress on the fiber Bragg grating is constantly changing due to the continuous adjustment of the posture of the high-speed magnetic levitation train during operation, resulting in large error and difficulty in engineering application; 4. System power-on start, no initial position.

[0005] The second is the laser range finder method. In this method, a laser range finder is mounted on the vehicle, and a convex-concave change or a triangular structure is provided on the ground. When the train passes, the vehicle-mounted laser range finder obtains the distance change and measures the position and speed of the train. However, this method has the following disadvantages: 1. High cost: The convex-concave change or triangular structure needs to be arranged along the track; 2. Large time delay: In the high-speed magnetic suspension system, the position and speed signals of the train need to be transmitted to the ground traction system, and the transmission time delay is large through the vehicle-ground wireless communication system; 3. System power-on start, no initial position. SUMMARY

[0006] The present application provides a high-speed magnetic suspension system positioning and speed measuring device and method based on frequency detection, which can solve the above technical problems.

[0007] According to one aspect of the present application, a high-speed magnetic suspension system positioning and speed measuring device based on frequency detection is provided, which comprises a vehicle-mounted light source assembly arranged on the vehicle side and a ground detection assembly arranged on the ground side, and a control unit.

[0008] The vehicle-mounted light source assembly comprises a plurality of laser emitters arranged equidistantly in sequence along the running direction of the train; each of the laser emitters is used for emitting laser of the same wavelength but different frequencies; wherein the laser is a square wave pulse signal.

[0009] The ground detection assembly comprises a plurality of ground detectors arranged equidistantly in sequence along the running direction of the train; the ground detectors in the light source coverage area are used for receiving laser emitted by the corresponding laser emitters and sending to the control unit.

[0010] The control unit is used for obtaining the absolute position of the ground detector corresponding to the frequency of the received laser; obtaining the distance between the laser emitter corresponding to the frequency of the received laser and the laser emitter at the starting end; and further obtaining the position of the train based on the absolute position of the ground detector corresponding to the frequency of the received laser, the distance between the laser emitter corresponding to the frequency of the received laser and the laser emitter at the starting end, and the distance between the laser emitter at the starting end and the center position of the train, and obtaining the speed of the train based on the position of the train; wherein the laser emitter at the starting end is the laser emitter at the foremost end along the running direction of the train.

[0011] Preferably, the position of the train is obtained by the following formula:

[0012] S T =S1+S2-S3

[0013] Wherein, in the case that the laser emitter corresponding to the frequency of the received laser is the laser emitter at the starting end, S2=0; in the case that the laser emitter corresponding to the frequency of the received laser is not the laser emitter at the starting end, S2=(N+1)*A.

[0014] In the formula, S T represents the position of the train, S1 represents the absolute position of the ground detector corresponding to the frequency of the received laser, S2 represents the distance between the laser emitter corresponding to the frequency of the received laser and the laser emitter at the starting end, N represents the number of laser emitters between the laser emitter corresponding to the frequency of the received laser and the laser emitter at the starting end, A represents the interval between two adjacent laser emitters, and S3 represents the distance between the laser emitter at the starting end and the center position of the train.

[0015] Preferably, the speed of the train is obtained by the following formula:

[0016] V T =(S T2 -S T1 ) / t

[0017] In the formula, V T represents the speed of the train, S T1 represents the position of the train at the previous time, and S T2represents the train position after t time from the last time, and t represents time.

[0018] Preferably, the interval between two adjacent ground detectors is less than half the length of the vehicle-mounted light source assembly, and the control unit is further configured to perform redundant switching based on the train position obtained by the covered ground detector.

[0019] Preferably, the ground detector switching is performed when the train position corresponding to the currently covered ground detector is the same as the train position corresponding to the ground detector newly entering the light source coverage area.

[0020] Preferably, the frequency of each laser emitter is sequentially increased by a preset frequency in the forward or reverse direction along the train running direction.

[0021] Preferably, the laser wavelength range of the plurality of laser emitters is 400nm-1300nm, and the laser frequency range is 1MHz-1GHz.

[0022] Preferably, each ground detector includes two photoelectric sensors arranged along the train running direction, and the interval between the two photoelectric sensors is (A*n+A / 2), and the receiving window width of each photoelectric sensor is A / 2, wherein A is the interval between adjacent laser emitters, and n is any positive integer.

[0023] Preferably, the device further comprises a plurality of optical filters, the number of optical filters is the same as the number of receiving windows, each receiving window is provided with an optical filter at the front end, and the wavelength of the optical filter corresponds to the wavelength of the laser emitted by the laser emitter.

[0024] According to another aspect of the present application, a high-speed magnetic levitation system positioning and speed measurement method based on frequency detection is provided, which is used for positioning and speed measurement of any of the above-mentioned devices, and the method comprises:

[0025] During train operation, each laser emitter emits laser of the same wavelength but different frequencies;

[0026] The ground detector in the light source coverage area receives the laser emitted by the corresponding laser emitter and sends it to the control unit;

[0027] The control unit obtains the absolute position of the ground detector corresponding to the frequency of the received laser;

[0028] The control unit obtains the distance between the laser emitter corresponding to the frequency of the received laser and the starting end laser emitter;

[0029] The control unit obtains the position of the train based on the absolute position of the ground detector corresponding to the frequency of the received laser, the distance between the laser transmitter corresponding to the frequency of the received laser and the laser transmitter at the starting end, and the distance between the laser transmitter at the starting end and the center position of the train;

[0030] The control unit obtains the speed of the train based on the position of the train.

[0031] Preferably, when the interval between two adjacent ground detectors is less than half the length of the on-board light source assembly, the control unit simultaneously obtains the train position corresponding to the ground detector currently covered by the train and the train position corresponding to the ground detector newly entering the light source coverage area;

[0032] The control unit determines whether the train position corresponding to the ground detector currently covered by the train is the same as the train position corresponding to the ground detector newly entering the light source coverage area. If yes, the control unit determines that the ground detector newly entering the light source coverage area is normal, and obtains the position of the train through the ground detector newly entering the light source coverage area. If not, the control unit determines that the ground detector newly entering the light source coverage area is abnormal, continues to use the train position corresponding to the ground detector currently covered, and waits for the next ground detector newly entering the light source coverage area to verify.

[0033] By designing different frequency codes, the technical solution of the application realizes structured optical positioning and speed measurement. Compared with the prior art, the application has the following beneficial effects:

[0034] 1. High-precision position detection of not more than A / 2 mm can be realized;

[0035] 2. Extremely low time delay detection of not more than 10 us can be realized;

[0036] 3. Speed measurement range of 0 km / h to 2400 km / h can be realized;

[0037] 4. Redundancy function of the designed system is realized to achieve high reliability of the system. BRIEF DESCRIPTION OF DRAWINGS

[0038] The accompanying drawings included to provide a further understanding of the embodiments of the application and constitute a part of the specification, illustrate the embodiments of the application and together with the text description serve to explain the principles of the application. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor based on these drawings.

[0039] Figure 1 A structural schematic diagram of a frequency detection-based high-speed magnetic levitation system positioning and speed measurement device according to an embodiment of the application is shown.

[0040] Figure 2 a top view of the vehicle-mounted light source assembly is shown; Figure 1 a top view of the vehicle-mounted light source assembly is shown;

[0041] Figure 3 a side view of the vehicle-mounted light source assembly is shown; Figure 1 a side view of the vehicle-mounted light source assembly is shown;

[0042] Figure 4 a side view of the ground detector is shown. Figure 1 a side view of the ground detector is shown.

[0043] Wherein, the above-mentioned drawings include the following reference signs:

[0044] 10, vehicle-mounted light source assembly; 11, laser emitter; 20, ground detection assembly; 21, ground detector; 211, receiving window; 30, control unit. DETAILED DESCRIPTION

[0045] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0046] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0047] The relative arrangement of parts and steps, numerical expressions, and values set forth in these embodiments do not limit the scope of the present application unless otherwise specified. Meanwhile, it should be understood that the sizes of the various parts shown in the drawings are not drawn in actual proportion. The techniques, methods and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the authorized description where appropriate. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0048] As shown in Figures 1-3 The present application provides a high-speed magnetic suspension system positioning and speed measuring device based on frequency detection, which comprises a vehicle-mounted light source assembly 10 arranged at the vehicle end and a ground detection assembly 20 arranged at the ground end, and a control unit 30.

[0049] The vehicle-mounted light source assembly 10 comprises a plurality of laser emitters 11 arranged in equal intervals along the running direction of the train; each laser emitter 11 is used to emit laser beams of the same wavelength but different frequencies; wherein the laser beams are square wave pulse signals.

[0050] The ground detection assembly 20 comprises a plurality of ground detectors 21 arranged in equal intervals along the running direction of the train; the ground detectors 21 in the light source coverage area are used to receive the laser beams emitted by the laser emitters 11 and send them to the control unit 30.

[0051] The control unit 30 is used to obtain the absolute position of the ground detector 21 corresponding to the frequency of the received laser beam; to obtain the distance between the laser emitter 11 corresponding to the frequency of the received laser beam and the laser emitter 11 at the starting end; and to obtain the position of the train based on the absolute position of the ground detector 21 corresponding to the frequency of the received laser beam, the distance between the laser emitter 11 corresponding to the frequency of the received laser beam and the laser emitter 11 at the starting end, and the distance between the laser emitter 11 at the starting end and the center position of the train, and to obtain the speed of the train based on the position of the train; wherein the laser emitter 11 at the starting end is the laser emitter 11 at the front end along the running direction of the train (laser emitter 11 numbered 1). Figure 2

[0052] By designing different frequency codes, the application achieves structured optical positioning and speed measurement. Compared with the prior art, the application has the following beneficial effects:

[0053] ​1. High-precision position detection of no more than A / 2mm can be realized;

[0054] 2. Extremely low time delay detection of no more than 10us can be realized;

[0055] 3. A speed measurement range of 0km / h to 2400km / h can be realized;

[0056] 4. Redundant functions of the system are designed to realize high reliability of the system.

[0057] In the application, the plurality of laser emitters 11 form a light array of light and shade interlaced sectors, and a precise optical environment is constructed, the length of which can be set according to the length of the train. The laser emitter 11 is composed of two laser light sources in a redundant structure, and when one of the light sources fails, the standby light source is automatically started to output through a switching circuit.

[0058] According to an embodiment of the application, the laser of each laser emitter 11 adopts the same wavelength, which can be selected from 400nm to 1300nm, and when used outdoors, the wavelength is limited to 820nm to 1300nm. The laser of each laser emitter 11 adopts different frequencies, and the laser frequency range is 1MHz to 1GHz. In order to facilitate the calculation of the control unit 30 and engineering maintenance, the frequency of each laser emitter 11 is sequentially increased by a preset frequency in the positive direction or the reverse direction along the running direction of the train, that is, the laser frequency can be sequentially increased by B(Hz) from left to right or from right to left.

[0059] According to an embodiment of the application, the interval between two adjacent ground detectors 21 is less than half the length of the vehicle-mounted light source assembly 10, and at this time, the control unit 30 is further configured to perform redundant switching based on the train position obtained by the covered ground detector 21.

[0060] Through the above setting, the vehicle-mounted light source assembly 10 can cover two ground detectors 21 at the same time, realizing the redundant function of the ground detector 21 receiving signal; the interval can also be set to 1 / 3 of the length of the vehicle-mounted light source assembly 10, realizing a 3-to-2 redundant mode, and realizing the redundant function of the ground detector 21 receiving signal.

[0061] According to an embodiment of the application, when the train position corresponding to the current covered ground detector 21 and the train position corresponding to the ground detector 21 newly entering the light source coverage area are the same, the switching of the ground detector 21 is performed.

[0062] According to an embodiment of the application, as Figure 4As shown, each ground detector 21 comprises two photoelectric sensors arranged along the running direction of the train, the interval between the two photoelectric sensors is (A*n+A / 2), and the receiving window 211 of each photoelectric sensor has a width of A / 2, wherein A is the interval between adjacent laser emitters 11, and n is an arbitrary positive integer. The front end of each receiving window 211 is provided with a filter, and the wavelength of the filter corresponds to the wavelength of the laser emitted by the laser emitter 11.

[0063] Through the above arrangement, the two photoelectric sensors constitute a quadrature signal to realize absolute position detection after power-on start; at the same time, the filter reduces environmental interference.

[0064] According to an embodiment of the present application, the control unit 30 receives the signals of the ground detector 21, and calculates the speed and position of the train through the installation position of the ground detector 21 and the frequency of the received laser. The control unit 30 uses FPGA high-speed calculation, and can realize a position detection error of not more than A / 2 mm and a detection time delay of not more than 10 us, and can achieve a speed measurement range of 0 km / h to 2400 km / h.

[0065] Specifically, the position of the train is obtained by the following formula:

[0066] S T =S1+S2-S3

[0067] Wherein, in the case that the laser emitter corresponding to the frequency of the received laser is the starting end laser emitter, S2=0; in the case that the laser emitter corresponding to the frequency of the received laser is not the starting end laser emitter, S2=(N+1)*A.

[0068] In the formula, S T represents the position of the train, S1 represents the absolute position of the ground detector corresponding to the frequency of the received laser, S2 represents the distance between the laser emitter corresponding to the frequency of the received laser and the starting end laser emitter, N represents the number of laser emitters between the laser emitter corresponding to the frequency of the received laser and the starting end laser emitter, A represents the interval between two adjacent laser emitters, and S3 represents the distance between the starting end laser emitter and the center position of the train.

[0069] After the train moves, the position change is calculated with the change of the received laser frequency, and the train speed is calculated by differentiating the position with respect to time, specifically, the speed of the train is obtained by the following formula:

[0070] V T =(S T2 -S T1 ) / t

[0071] In the formula, V TS represents the speed of the train T1 S represents the position of the train at the last time T2 S represents the position of the train after t time from the last time, and t represents time.

[0072] The application also provides a positioning and speed measurement method for a high-speed magnetic suspension system based on frequency detection, which is used for positioning and speed measurement of any of the above devices, and comprises the following steps:

[0073] During the operation of the train, each laser emitter 11 emits laser beams of the same wavelength but different frequencies;

[0074] The ground detector 21 in the light source coverage area receives the laser beams emitted by the corresponding laser emitter 11 and sends them to the control unit 30.

[0075] The control unit 30 obtains the absolute position of the ground detector 21 corresponding to the frequency of the received laser beams;

[0076] The control unit 30 obtains the distance between the laser emitter 11 corresponding to the frequency of the received laser beams and the laser emitter 11 at the starting end;

[0077] The control unit 30 obtains the position of the train based on the absolute position of the ground detector 21 corresponding to the frequency of the received laser beams, the distance between the laser emitter 11 corresponding to the frequency of the received laser beams and the laser emitter 11 at the starting end, and the distance between the laser emitter 11 at the starting end and the center position of the train.

[0078] The control unit 30 obtains the speed of the train based on the position of the train.

[0079] According to an embodiment of the application, when the distance between the two adjacent ground detectors 21 is less than half the length of the on-board light source assembly 10, the control unit 30 simultaneously obtains the train position corresponding to the ground detector 21 currently covered by the train and the train position corresponding to the ground detector 21 newly entering the light source coverage area.

[0080] The control unit 30 determines whether the train position corresponding to the ground detector 21 currently covered by the train and the train position corresponding to the ground detector 21 newly entering the light source coverage area are the same, if yes, the control unit 30 determines that the ground detector 21 newly entering the light source coverage area is normal, and obtains the position of the train through the ground detector 21 newly entering the light source coverage area; otherwise, the control unit 30 determines that the ground detector 21 newly entering the light source coverage area is abnormal, continues to use the train position corresponding to the ground detector 21 currently covered, and waits for the next ground detector 21 newly entering the light source coverage area for verification.

[0081] For example, the train currently covers the ground detector 21 as R1, and the ground detector 21R2 newly enters the light source coverage area, at which time the control unit 30 calculates the position S of the train by simultaneously feeding back the signals of the two ground detectors 21 C1 And S C2 During the train movement S (mm), the control unit 30 checks whether the two positions S C1 And S C2 If the same, it is considered that the newly entered ground detector 21R2 is normal, and the position data is calculated by the newly entered ground detector 21R2; otherwise, it is considered that the newly entered ground detector 21R2 is abnormal, and the calculation result of the ground detector 21R1 is continued to be used, and the next newly entered ground detector 21 is waited for checking.

[0082] In summary, the application provides a high-speed magnetic suspension system positioning and speed measuring device and method based on frequency detection, which has the following beneficial effects compared with the prior art:

[0083] 1. High-precision position detection of not more than A / 2mm can be realized;

[0084] 2. Extremely low time delay detection of not more than 10us can be realized;

[0085] 3. Speed measurement range of 0km / h to 2400km / h can be realized;

[0086] 4. Redundancy function of the designed system is realized to achieve high reliability of the system.

[0087] The part of the application not described in detail is the technology known to those skilled in the art.

[0088] In the description of the application, it should be understood that the orientation words such as "front, rear, upper, lower, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and in the absence of the opposite description, these orientation words do not indicate and imply that the indicated device or element must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection scope of the application; the orientation words "inner, outer" refer to the inner and outer relative to the contour of each component.

[0089] For purposes of the description hereinafter, spatial or directional terms, for example, "above", "below", "upper", "lower", and the like, can be used, and relate to the device as illustrated in the figures. However, it is to be understood that no absolute or relative orientation of the device is intended or implied, unless specifically described as such. Terms concerning attachments, coupling and the like, such as "connected" and "coupled" and the like, are to be construed in accordance with their normal meanings, that is, as referring to an indirect or direct connection or coupling. Any reference to "comprising" or "containing" is to be construed as meaning "comprising or containing, but not limited to". Any reference to "comprising" or "containing" is to be construed as meaning "comprising or containing, but not limited to".

[0090] In addition, it should be pointed out that the use of the terms "first", "second" and the like, to describe various elements, is merely intended to differentiate the elements from one another, and does not connote any special order or order of precedence, unless otherwise specifically indicated. Thus, the use of the terms "first", "second" and the like, is not intended to limit the scope of the present application, and is not intended to connote any special order or order of precedence.

[0091] The preferred embodiments herein disclosed are not intended to limit or restrict the scope of the application, but merely convey the best mode contemplated by the inventors of carrying out the claimed application. Any modifications, variations or changes within the spirit and scope of the application as disclosed herein will be considered to fall within the scope of the application.

Claims

1. A positioning and velocity measurement device for a high-speed maglev system based on frequency detection, characterized in that, The device comprises a vehicle-mounted light source assembly arranged at a vehicle-mounted end, a ground detection assembly arranged at a ground end, and a control unit; The vehicle-mounted light source assembly comprises a plurality of laser emitters arranged at equal intervals along a train running direction; each laser emitter is used to emit laser beams of the same wavelength but different frequencies; wherein the laser beams are square wave pulse signals; The ground detection assembly comprises a plurality of ground detectors arranged at equal intervals along the train running direction; the ground detectors in a light source coverage area are used to receive laser beams emitted by the laser emitters and send the laser beams to the control unit; The control unit is used to obtain the absolute position of the ground detector corresponding to the frequency of the received laser beams; obtain the distance between the laser emitter corresponding to the frequency of the received laser beams and the laser emitter at a starting end; and obtain the position of the train based on the absolute position of the ground detector corresponding to the frequency of the received laser beams, the distance between the laser emitter corresponding to the frequency of the received laser beams and the laser emitter at the starting end, and the distance between the laser emitter at the starting end and the center position of the train, and obtain the speed of the train based on the position of the train; wherein the laser emitter at the starting end is the laser emitter at the foremost end along the train running direction.

2. The apparatus of claim 1, wherein, The position of the train is obtained by the following formula: S T = S1 + S2 - S3 Wherein, when the laser emitter corresponding to the frequency of the received laser beams is the laser emitter at the starting end, S2=0; when the laser emitter corresponding to the frequency of the received laser beams is not the laser emitter at the starting end, S2=(N+1)*A; In the formula, S T S1 represents the absolute position of the ground detector corresponding to the frequency of the received laser, S2 represents the distance between the laser transmitter corresponding to the frequency of the received laser and the laser transmitter at the starting end, N represents the number of laser transmitters between the laser transmitter corresponding to the frequency of the received laser and the laser transmitter at the starting end, A represents the spacing between the two adjacent laser transmitters, and S3 represents the distance between the laser transmitter at the starting end and the center position of the train.

3. The apparatus of claim 1 or 2, wherein, The speed of the train is obtained by the following formula: V T = (S T2 -S T1 ) / t In the formula, V T denotes the speed of the train, S T1 denotes the position of the train at the previous time, S T2 denotes the position of the train after t time from the previous time, and t denotes time.

4. The apparatus of any one of claims 1-3, wherein, The distance between two adjacent ground detectors is less than half the length of the vehicle-mounted light source assembly; at this time, the control unit is further used to perform redundant switching based on the position of the train obtained by the covered ground detectors.

5. The apparatus of claim 4, wherein, When the position of the train corresponding to the currently covered ground detector is the same as the position of the train corresponding to the ground detector newly entering the light source coverage area, switching of the ground detector is performed.

6. The apparatus of claim 1, wherein, The frequency of each laser emitter is increased by a preset frequency along the positive or negative direction of the train running direction.

7. The apparatus of claim 1, wherein, The wavelength range of the laser beams of the plurality of laser emitters is 400nm-1300nm, and the frequency range of the laser beams is 1MHz-1GHz.

8. The apparatus of claim 1, wherein, Each ground detector comprises two photoelectric sensors arranged along the train running direction, and the distance between the two photoelectric sensors is (A*n+A / 2); the receiving window width of each photoelectric sensor is A / 2, wherein A is the interval between adjacent laser emitters, and n is any positive integer.

9. The device of claim 8, further comprising a plurality of optical filters, the number of optical filters being the same as the number of receiving windows, and each receiving window is provided with an optical filter at the front end, and the wavelength of the optical filter corresponds to the wavelength of the laser beams emitted by the laser emitters.

10. A positioning and speed measurement method for a high-speed magnetic levitation system based on frequency detection, characterized in that, The method is used for positioning and speed measurement of the device of any one of claims 1-9, and the method comprises: During train operation, each laser emitter emits laser beams of the same wavelength but different frequencies respectively; The ground detector in the light source coverage area receives the laser emitted by the corresponding laser emitter and sends to the control unit; The control unit obtains the absolute position of the ground detector corresponding to the frequency of the received laser; The control unit obtains the distance between the laser emitter corresponding to the frequency of the received laser and the laser emitter at the starting end; The control unit obtains the position of the train based on the absolute position of the ground detector corresponding to the frequency of the received laser, the distance between the laser emitter corresponding to the frequency of the received laser and the laser emitter at the starting end, and the distance between the laser emitter at the starting end and the center position of the train; The control unit obtains the speed of the train based on the position of the train.

11. The method of claim 10, wherein, When the interval between the two adjacent ground detectors is less than half the length of the on-board light source assembly, the control unit simultaneously obtains the train position corresponding to the ground detector currently covered by the train and the train position corresponding to the ground detector newly entering the light source coverage area; The control unit determines whether the train position corresponding to the ground detector currently covered by the train and the train position corresponding to the ground detector newly entering the light source coverage area are the same. If yes, the control unit determines that the ground detector newly entering the light source coverage area is normal, and obtains the position of the train through the ground detector newly entering the light source coverage area; otherwise, the control unit determines that the ground detector newly entering the light source coverage area is abnormal, continues to use the train position corresponding to the ground detector currently covered, and waits for the next ground detector newly entering the light source coverage area to check.

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