Mileage Positioning Method for Maglev Track Detection Equipment Combining Eddy Current Detection and Inertial Navigation

Abstract

The present invention relates to the field of precision engineering measurement technology, and discloses a mileage positioning method for a maglev track detection device combining eddy current detection and inertial navigation, including: S1, synchronizing the time of the eddy current detection sensor and the inertial navigation, and outputting eddy current detection data and inertial navigation data with time information; S2, obtaining the initial attitude of the maglev track detection device, and calculating the initial attitude according to different conditions from the designed alignment, the GNSS positioning system or the static inertial navigation data obtained in S1; S3, decoding the eddy current detection data obtained in S1 to obtain the absolute position, etc.; The mileage positioning method of the high-speed maglev track detection device combining eddy current detection and inertial navigation can achieve non-contact mileage positioning; high-precision mileage positioning results can still be obtained in environments such as tunnels where GNSS signals cannot be received; MEMS inertial navigation can be used, and the sensor device has a small volume, low price, and low power consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of precision engineering measurement, and particularly relates to a mileage positioning method for a maglev track detection device combining eddy current detection and inertial navigation. Background Art

[0002] A high-speed maglev train is a new type of ground vehicle that runs at high speed without contact with the track. Its track consists of prestressed concrete beams, connectors, functional components, and long stators with tooth-slot structures spliced in segments. During the operation of the high-speed maglev train, the geometric parameters of the track will change due to factors such as bolt loosening, foundation settlement, and external forces. This change directly affects the safety, stability, and comfort of vehicle operation. To reduce the impact of the track on train operation, it is very important to maintain the good condition of the track and conduct regular inspection and maintenance of the track. After detecting diseases in the high-speed maglev track, it is also necessary to determine the specific mileage, that is, mileage positioning.

[0003] Mileage positioning is to mark the specific position of the detection data of the high-speed maglev track detection device on the line. Mileage deviation will lead to incorrect positioning of the high-speed maglev track unevenness detection data, affect the accuracy of the high-speed maglev track condition assessment, and increase the labor intensity of track maintenance. For the detection of high-speed maglev track unevenness, since the detection device is mounted on the high-speed maglev track train and the high-speed maglev track train does not contact the track, a non-contact mileage positioning method must be adopted.

[0004] In the existing wheel-rail railway track detection system, mileage measurement mostly adopts the method of mileage accumulation, such as an optical encoder. However, the optical encoder is not suitable for non-contact detection systems. When the high-speed maglev train runs, it does not contact the track, resulting in no wheel pair rotating in contact with the track to drive the optical encoder to work. Another commonly used GNSS positioning method can obtain relatively high-precision mileage, but in environments where GNSS signals are blocked, such as tunnels, the positioning mileage cannot be obtained, and it is greatly affected by the environment. At present, there is still a lack of a mileage positioning method for high-speed maglev track detection devices with strong applicability, and the sensors used in the mileage must be small and lightweight to avoid adverse effects on the normal driving of the train. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a mileage positioning method for a maglev track detection device combining eddy current detection and inertial navigation, which realizes non-contact mileage positioning of the maglev track detection device.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] Eddy current detection and inertial navigation combined maglev track detection equipment mileage positioning method, including: S1, the eddy current detection sensor and inertial navigation are time synchronized, and eddy current detection data and inertial navigation data with time information are output; S2, obtaining the initial attitude of the maglev track detection equipment, according to different conditions, the initial attitude is calculated from the designed alignment, GNSS positioning system or the static inertial navigation data obtained in S1; S3, decoding the eddy current detection data obtained in S1 to obtain the absolute position; S4, mechanically arranging the inertial navigation with the inertial navigation data obtained in S1 and the initial attitude obtained in S2 to obtain the position, speed and attitude of the inertial navigation; S5, performing combined navigation calculation on the eddy current detection absolute position obtained in S3 and the inertial navigation mechanical arrangement result obtained in S4; S6, calculating the mileage of the maglev track detection equipment from the speed obtained in S4, and the formula is:

[0008] ;

[0009] Among them, is the current mileage, is the starting mileage.

[0010] In the present invention, preferably, in S1, the time synchronization system of the maglev track detection equipment sends time information to the eddy current detection sensor and the industrial control computer of the inertial navigation through the serial port. After receiving the signal, the eddy current detection sensor and the inertial navigation write the time information into each frame data field of their output, accurate to milliseconds.

[0011] In the present invention, preferably, S2 includes: S21, if there is a designed alignment for the maglev track, obtain the heading angle from the horizontal curve and the pitch angle from the vertical curve; S22, if there is no designed alignment for the maglev track and the maglev track detection equipment is connected to the GNSS positioning and speed measurement system, then use the GNSS speed to obtain the attitude; S23, if there is no designed alignment for the maglev track and the maglev track detection equipment is not connected to the GNSS positioning and speed measurement system, then use inertial navigation static alignment to obtain the attitude.

[0012] In the present invention, preferably, in S21, obtaining the heading angle from the horizontal curve, and the formula is:

[0013] ;

[0014] In the formula, represents the heading angle, represents the curve deflection, represents the radius of the curve starting point, represents the radius of the curve ending point, represents the distance of the high-speed maglev track equipment from the curve starting point, represents the total length of the curve, represents the curve deflection angle;

[0015] Obtain the pitch angle from the vertical curve, and the formula is:

[0016] ;

[0017] In the formula, represents the pitch angle, is the front slope gradient angle, is the rear slope gradient angle, is the total length of the slope section, is the distance of the high-speed maglev track detection equipment from the starting point of the slope section.

[0018] In the present invention, preferably, in the S22, the formula for obtaining the attitude using GNSS speed is:

[0019]

[0020] In the formula, represents the heading angle, represents the pitch angle, represents the north-direction speed of the high-speed maglev track detection equipment, represents the east-direction speed of the high-speed maglev track detection equipment, represents the zenith-direction speed of the high-speed maglev track detection equipment.

[0021] In the present invention, preferably, in the S23, the high-speed maglev track detection equipment needs to be stationary for a preset time, and the observed data of the accelerometer and gyroscope are subjected to error compensation and mean value processing. After processing, the observed data of the accelerometer is , and after processing, the observed data of the gyroscope is , and the attitude direction cosine matrix is obtained. From , the heading angle and the pitch angle are obtained;

[0022] The attitude direction cosine matrix is obtained according to the following formula:

[0023] ;

[0024] In the formula, represents the gravitational acceleration, represents the modulus of the angular velocity of the earth's rotation.

[0025] In the present invention, preferably, the S3 includes: S31, calculating the plane coordinates from the rough mileage and the forward calculation unified model curve element parameters, and obtaining the elevation from the vertical curve elevation rigorous calculation model to obtain the calculated position coordinates ; S32, comparing the absolute position coordinates with the calculated position coordinates Compare them. If the difference between the two is less than the preset threshold, then send the absolute position coordinates to the host computer; otherwise, eliminate the absolute position coordinates as outliers.

[0026] In the present invention, preferably, the eddy current detection sensor is 12 detection coils. The data of the 12 detection coils are divided into 6 groups of voltage data according to every two detection coils as a group. A signal is obtained for the voltage data of each group of coils through a voltage comparator. The eddy current detection sensor obtains a total of 6 groups of signals. The 6 groups of signals form a code, which is compared with the code-position database to obtain the current absolute position of the high-speed maglev track detection equipment, denoted as ; the preset threshold in S32 is 0.05 m.

[0027] In the present invention, preferably, in S4, the inertial navigation data includes triaxial accelerometer data and triaxial gyroscope data, and the position of the inertial navigation is denoted as .

[0028] In the present invention, preferably, S5 includes: S51, when the pushing distance of the high-speed maglev track detection equipment exceeds 200 meters, take the absolute position obtained by the host computer once, and fuse the absolute position and the position of the inertial navigation through Kalman filtering. The observation equation is:

[0029] ;

[0030] Among them, represents the observation vector, represents the lever arm conversion radian matrix, represents the absolute position, represents the position of the inertial navigation, represents the error of the absolute position obtained by the eddy current detection sensor in S2, is the position vector from the inertial navigation center to the high-speed maglev track detection equipment in the system, is the cosine matrix for transforming the sensor coordinate system to the navigation coordinate system represents the position error vector, represents the attitude error vector; S52, further constrain the inertial navigation by using the heading angle locking constraint method; S53, perform Kalman filtering combined navigation solution to obtain the final position, speed and attitude of the high-speed maglev track detection equipment.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. The mileage positioning method of the high-speed maglev track detection equipment combining eddy current detection and inertial navigation can achieve contactless mileage positioning.

[0033] 2. This mileage positioning method can still obtain high-precision mileage positioning results in environments such as tunnels where GNSS signals cannot be received.

[0034] 3. This mileage positioning method can use MEMS inertial navigation, and the sensor equipment has a small volume, low price, and low power consumption. Description of the Drawings

[0035] Figure 1 It is a flowchart of the mileage positioning method of the maglev track detection equipment combining eddy current detection and inertial navigation according to an embodiment of the present invention.

[0036] Figure 2 It is a flowchart of S2 in the mileage positioning method of the maglev track detection equipment combining eddy current detection and inertial navigation according to an embodiment of the present invention.

[0037] Figure 3 It is a flowchart of S3 in the mileage positioning method of the maglev track detection equipment combining eddy current detection and inertial navigation according to an embodiment of the present invention.

[0038] Figure 4 It is a schematic structural diagram of the eddy current detection sensor in the mileage positioning method of the maglev track detection equipment combining eddy current detection and inertial navigation according to an embodiment of the present invention.

[0039] Figure 5 It is a flowchart of S5 in the mileage positioning method of the maglev track detection equipment combining eddy current detection and inertial navigation according to an embodiment of the present invention. Detailed Embodiments

[0040] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0041] It should be noted that when a component is referred to as being "fixed to" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the specification of this invention are only for the purpose of describing specific embodiments and are not intended to limit the invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0043] Please refer to Figure 1 , a mileage positioning method for a maglev track detection equipment combining eddy current detection and inertial navigation is provided in a preferred embodiment of the present invention. The absolute position of the high-speed maglev track detection equipment is obtained by using the eddy current detection method, and the inertial navigation is assisted in data calculation by using the Kalman filter-based method. The mileage of the high-speed maglev track detection equipment is calculated from the speed obtained by the fusion calculation, so as to accurately judge the position where the high-speed maglev track disease occurs, including:

[0044] S1. Synchronize the time of the eddy current detection sensor and the inertial navigation, and output the eddy current detection data and inertial navigation data with time information.

[0045] The high-speed maglev track is installed with a positioning sign board, which is composed of a copper-clad layer and a narrow slit. When the eddy current detection sensor is facing the positioning sign board, different voltage values are generated. The eddy current detection sensor and the inertial navigation are synchronously time-served by the time synchronization system of the track detection equipment. The time synchronization control system sends time information to the industrial control computers of the eddy current detection sensor and the inertial navigation through the serial port. After receiving the signal, the eddy current detection sensor and the inertial navigation write the time information into each frame of data field they output, accurate to milliseconds, so as to synchronize the time of the eddy current detection sensor and the inertial navigation, and keep consistent with the maglev track detection equipment, and output the eddy current detection sensor data and inertial navigation data with synchronous time information.

[0046] S2. Obtain the initial attitude of the maglev track detection equipment. According to different conditions, the initial attitude is calculated from the designed alignment, the GNSS positioning system or the static inertial navigation data obtained in S1.

[0047] When there is a designed alignment for the maglev track, obtain the heading angle from the horizontal curve and the pitch angle from the vertical curve; when the maglev track detection equipment is connected to the Beidou positioning and speed measurement system and in a non-GNSS denial environment, use the GNSS speed to obtain the attitude; when there is no designed alignment and no GNSS positioning and speed measurement information, use inertial navigation static alignment to obtain the attitude.

[0048] Preferably, as Figure 2 shown, S2 includes:

[0049] S21. When there is a designed alignment for the high-speed maglev track, obtain the heading angle from the horizontal curve, as shown in the following formula:

[0050]

[0051] In the formula, represents the course angle, represents the curve deflection, represents the radius of the starting point of the curve, represents the radius of the ending point of the curve, represents the distance of the high-speed maglev track equipment from the starting point of the curve, represents the total length of the curve, represents the curve deflection angle;

[0052] Obtain the pitch angle from the vertical curve as follows:

[0053]

[0054] In the formula, represents the pitch angle, is the slope angle of the front slope, is the slope angle of the rear slope, is the total length of the slope section, is the distance of the high-speed maglev track detection equipment from the starting point of the slope section.

[0055] S22. When the high-speed maglev track detection equipment is connected to the Beidou GNSS positioning and velocity measurement system, the initial attitude angle can be obtained according to the following formula:

[0056]

[0057] In the formula, represents the north direction velocity of the high-speed maglev track detection equipment, represents the east direction velocity of the high-speed maglev track detection equipment, represents the zenith direction velocity of the high-speed maglev track detection equipment.

[0058] S23. When there is no designed alignment and no GNSS positioning and velocity measurement information (that is, the maglev track detection equipment is not connected to the GNSS positioning and velocity measurement system), the high-speed maglev track detection equipment needs to be stationary for 5 minutes, and the observed data of the accelerometer and gyroscope are subjected to error compensation and mean processing. The processed observed data of the accelerometer is , and the processed observed data of the gyroscope is , and the attitude direction cosine matrix is obtained according to the following formula , and the course angle can be obtained by conversion and the pitch angle ;

[0059]

[0060] In the formula, represents the acceleration due to gravity, Represents the modulus of the angular velocity of the Earth's rotation.

[0061] S3, Decode the eddy current detection data obtained in S1 to obtain the absolute position.

[0062] As Figure 4 shown, the eddy current detection sensor is 12 detection coils. Divide the data of the 12 detection coils in the S1 eddy current sensor data into 6 groups of voltage data according to every two detection coils as a group. A signal is obtained for each group of coil voltage data through a voltage comparator. The eddy current detection sensor obtains a total of 6 groups of signals. The 6 groups of signals form a code, which is compared with the code-position database to obtain the current absolute position of the high-speed maglev track detection equipment, denoted as .

[0063] Preferably, as Figure 3 shown, S3 includes:

[0064] S31, Calculate the plane coordinate value from the rough mileage and the parameters of the unified model curve element of the forward calculation , and obtain the elevation from the strict calculation model of the vertical curve elevation ;

[0065] S32, Compare the absolute position coordinates of the high-speed maglev track detection equipment with the calculated position coordinates . If it is less than the preset threshold, send the absolute position coordinates to the upper computer, otherwise eliminate them as outliers. Preferably, the preset threshold is set to 0.05 m here, and the preset threshold can be set to other values according to the accuracy requirements.

[0066] S4, Perform mechanical arrangement of the inertial navigation based on the inertial navigation data obtained in S1 and the initial attitude obtained in S2 to obtain the position, speed and attitude of the inertial navigation.

[0067] The inertial navigation data obtained in S1 consists of three-axis accelerometer data and three-axis gyroscope data. Perform mechanical arrangement on the inertial navigation data obtained in S1 and the initial attitude of the high-speed maglev track detection equipment obtained in S2 to obtain the position, speed and attitude of the inertial navigation. The position is denoted as .

[0068] S5, Perform combined navigation solution on the eddy current detection absolute position obtained in S3 and the inertial navigation mechanical arrangement result obtained in S4.

[0069] Preferably, as Figure 5 shown, S5 includes:

[0070] S51, When the pushing distance of the high-speed maglev track detection equipment exceeds 200 meters, take the absolute position obtained from the upper computer of S3 once, and compare this position with the inertial navigation mechanical arrangement result of S4 Fusion is performed through Kalman filtering, and the observation equation is as follows:

[0071]

[0072] Among them, represents the observation vector, represents the lever-arm conversion radian matrix, represents the error in obtaining the absolute position by the S2 eddy current detection sensor, is the position vector from the inertial navigation center to the high-speed maglev track detection equipment in the is the sensor coordinate system the cosine matrix for the transformation from the coordinate system to the navigation coordinate system and respectively represent the position error and the attitude error vectors.

[0073] S52. The heading angle of the high-speed maglev track detection equipment can be obtained by the method of S2, and the inertial navigation is further constrained by using the heading angle locking constraint method.

[0074] S53. The final position, speed, and attitude of the high-speed maglev track detection equipment are obtained through Kalman filter integrated navigation solution, where the speed at time is denoted as

[0075] S6. The mileage of the maglev track detection equipment is deduced from the speed obtained by S4.

[0076] The mileage of the high-speed maglev track detection equipment is deduced from the speed obtained in S5, and the formula for speed-deduced mileage is:

[0077]

[0078] Among them, is the current mileage, is the starting mileage.

[0079] The above description is a detailed description of the preferred and feasible embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. Any equivalent changes or modifications made under the technical spirit disclosed by the present invention shall fall within the scope of the patent covered by the present invention.

Claims

1. A mileage positioning method for magnetic levitation track detection equipment combining eddy current detection and inertial navigation, characterized in that: include: S1, the eddy current detection sensor is synchronized with the inertial navigation time, and outputs eddy current detection data and inertial navigation data with time information; the high-speed maglev track is installed with a positioning mark plate, which is composed of a copper coating layer and a narrow gap. When the eddy current detection sensor is facing the positioning mark plate, different voltage values ​​are generated; S2, the initial attitude of the maglev track detection equipment is obtained. Depending on the conditions, the initial attitude is calculated by the design line shape, GNSS positioning system or the static inertial navigation data obtained in S1; S3, decoding the eddy current detection data obtained in S1 to obtain the absolute position; S4, mechanically arranges the inertial navigation data obtained by S1 and the initial attitude obtained by S2 to obtain the position, speed and attitude of the inertial navigation; S5, performing combined navigation solution on the eddy current detection absolute position obtained by S3 and the inertial navigation mechanical arrangement result obtained by S4; S6, calculate the mileage of the maglev track inspection equipment based on the speed obtained in S4, the formula is: ； in, is the current mileage, The starting mileage.

2. The mileage positioning method for magnetic levitation track detection equipment combining eddy current detection and inertial navigation according to claim 1 is characterized in that: In S1, the time synchronization system of the maglev track detection equipment sends time information to the industrial computer of the eddy current detection sensor and the inertial navigation through the serial port. After receiving the signal, the eddy current detection sensor and the inertial navigation write the time information in each frame data field of their output, accurate to milliseconds.

3. The mileage positioning method for magnetic levitation track detection equipment combining eddy current detection and inertial navigation according to claim 2 is characterized in that: The S2 includes: S21, if the maglev track has a designed linear shape, obtain the heading angle from the horizontal curve and obtain the pitch angle from the vertical curve; S22, if the maglev track does not have a designed linear shape, and the maglev track detection equipment is connected to the GNSS positioning and speed measurement system, the GNSS speed is used to obtain the attitude; S23: If the maglev track does not have a designed linear shape and the maglev track detection equipment is not connected to the GNSS positioning and speed measurement system, the inertial navigation static alignment is used to obtain the attitude.

4. The mileage positioning method for magnetic levitation track detection equipment combining eddy current detection and inertial navigation according to claim 3 is characterized in that: In S21, the heading angle is obtained from the flat curve, and the formula is: ； In the formula, represents the heading angle, Indicates the curve bias, Indicates the radius of the starting point of the curve. represents the radius of the curve end point, Indicates the distance between the high-speed maglev track equipment and the starting point of the curve. represents the total length of the curve, Indicates the curve deflection angle; The pitch angle is obtained from the vertical curve using the formula: ； In the formula, represents the pitch angle, is the front slope angle, is the back slope angle, is the total length of the slope section, The distance between the high-speed maglev track detection equipment and the starting point of the slope section.

5. The mileage positioning method for magnetic levitation track detection equipment combining eddy current detection and inertial navigation according to claim 3 is characterized in that: In S22, the formula for obtaining the attitude using the GNSS velocity is: In the formula, represents the heading angle, represents the pitch angle, Indicates the north direction speed of the high-speed maglev track detection equipment. Indicates the east direction speed of the high-speed maglev track detection equipment. Indicates the zenith speed of the high-speed maglev track detection equipment.

6. The mileage positioning method for magnetic levitation track detection equipment combining eddy current detection and inertial navigation according to claim 3 is characterized in that: In S23, the high-speed maglev track detection equipment needs to be stationary for a preset time, and the observation data of the accelerometer and the gyroscope are error compensated and averaged. The accelerometer observation data is processed to , after processing, the gyroscope observation data is , find the attitude direction cosine matrix ,Depend on Convert to get heading angle and pitch angle ; The attitude direction cosine matrix is ​​obtained as follows: : ； In the formula, represents the acceleration due to gravity, The magnitude of the Earth's rotational velocity.

7. The mileage positioning method for magnetic levitation track detection equipment combining eddy current detection and inertial navigation according to claim 3 is characterized in that: The S3 includes: S31, calculate plane coordinates by rough mileage and correct calculation of unified model curve element parameters , the elevation is obtained by the rigorous calculation model of the vertical curve elevation , get the calculated position coordinates ; S32, the absolute position coordinates and calculate the position coordinates If the difference between the two is less than the preset threshold, the absolute position coordinates are Send to the host computer, otherwise the absolute position coordinates Removed as outliers.

8. The mileage positioning method for magnetic levitation track detection equipment combining eddy current detection and inertial navigation according to claim 7 is characterized in that: The eddy current detection sensor has 12 detection coils. The data of the 12 detection coils are divided into 6 groups of voltage data according to the principle that every two detection coils are a group. The voltage data of each group of coils obtains a signal through a voltage comparator. The eddy current detection sensor obtains a total of 6 groups of signals. The 6 groups of signals form a code, which is compared with the code-position database to obtain the current absolute position of the high-speed maglev track detection equipment, which is recorded as ; The preset threshold in S32 is 0.05m.

9. The mileage positioning method for magnetic levitation track detection equipment combining eddy current detection and inertial navigation according to claim 8 is characterized in that: In S4, the inertial navigation data includes three-axis accelerometer data and three-axis gyroscope data, and the position of the inertial navigation is recorded as .

10. The mileage positioning method for magnetic levitation track detection equipment combining eddy current detection and inertial navigation according to claim 9 is characterized in that: The S5 includes: S51, when the high-speed maglev track detection equipment pushes the distance exceeding 200 meters, take the absolute position obtained by the host computer once, and fuse the absolute position with the position of the inertial navigation through Kalman filtering. The observation equation is: ； in, represents the observation vector, represents the lever arm conversion radian matrix, Indicates absolute position, represents the position of the inertial navigation system, Indicates the error of the eddy current detection sensor in S2 in obtaining the absolute position, for The position vector from the inertial navigation center to the high-speed maglev track detection equipment in the system, is the sensor coordinate system Transform to navigation coordinate system The cosine matrix of the system, represents the position error vector, represents the attitude error vector; S52, using a heading angle locking constraint method to further constrain the inertial navigation; S53, Kalman filter combined navigation solution obtains the final position, speed and attitude of the high-speed maglev track detection equipment.

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