CN108229628B - A method of train positioning and identification based on three-dimensional magnetic code - Google Patents

Abstract

The invention discloses a train positioning identification method based on a three-dimensional magnetic code. The method adopts the magnetic 'N' pole, 'S' pole and '0' vacancy of the permanent magnet to represent the values 2, 1 and 0 respectively, and the combination constitutes a three-dimensional magnetic code of train positioning information, and then the three-dimensional magnetic code is arranged at certain intervals according to the accuracy requirements. It is pasted along the track, and the information is read and decoded by the electromagnetic induction reading device installed on the train, so as to obtain the coordinate positioning, as well as the speed and acceleration of the train. In the method, the preset position of the train is encoded and combined by three symbols according to the matrix sequence, and the preset sequences of different symbols represent different position information. The most notable feature of this patent is that it has strong environmental adaptability and good reliability, and can be used normally in various harsh environments such as heavy dust, poor light, low temperature, rain and snow weather.

Description

A method of train positioning and identification based on three-dimensional magnetic code

technical field

The invention relates to technologies such as electromagnetic induction and combined coding, and more particularly to a three-dimensional magnetic coding method and its application in the fields of train positioning identification and speed measurement.

Background technique

At present, the maglev train is a new type of vehicle developed by the country after the high-speed rail. It has many advantages such as low energy consumption, fast speed, strong climbing ability, safety, intelligence, and riding comfort. development trend. Therefore, as the preferred system for the development of a new generation of ground transportation in the future, maglev trains have great strategic significance for social and people's livelihood, economic development, and urban layout.

There are many methods for speed measurement and positioning of maglev trains at home and abroad, such as: cross-loop speed measurement and positioning, Doppler radar speed measurement and positioning, microwave speed measurement and positioning, based on inter-track cable speed measurement and positioning, "set distance detection + beacon" speed measurement and positioning, etc. In China, the cross-loop speed measurement and positioning method is mostly used for medium and low-speed maglev trains. However, maglev trains are equipped with strong magnetic field subsystems such as suspension systems, guidance systems, and propulsion systems, and there is a certain degree of electromagnetic interference between them. The cross-circuit speed measurement and positioning method is based on the identification of the train position based on the magnetic field generated by the loop. The electromagnetic fields of the suspension system, the guidance system, the propulsion system, as well as the installation error, train running vibration and other factors will affect the cross-induction loop speed measurement and positioning system. positioning accuracy.

With the steady advancement of the country's rail transit technology innovation and the industrialization of key technical equipment, the development goals of green, safe and intelligent railway equipment have become more and more clear. Vigorously developing maglev train-related technologies will be one of the important development directions in the future. The Advanced Rail Transit Special Project of the National Key R&D Program has successively funded the projects of medium and high-speed maglev trains with a speed of 200 km/h and 400 km/h, and the project of a new generation of high-speed maglev trains with a speed of 600 km/h has also been launched. These have higher precision and intelligent control requirements for the existing train suspension, propulsion, guidance and other systems, which are both a severe challenge and a rare development opportunity for related technologies in the field. At the same time, maglev trains are complex in structure, difficult to control, highly intelligent, and have a large amount of data. The existing train positioning and speed measurement technologies are incompetent for high-speed maglev trains.

The technology of train positioning and speed measurement is also an important basis for realizing the operation control and train scheduling of maglev trains. Especially for a maglev train driven by a long-stator synchronous linear motor, the excitation control of the armature winding is closely related to the positioning of the train. Without accurate positioning technology, there is no reliable long-stator synchronous linear motor control.

On the other hand, the current energy-saving operation and intelligent control technologies of trains require well-functioning systems such as train overspeed protection (ATP), automatic train driving (ATO) and automatic train monitoring (ATS). These systems all need accurate, efficient and reliable train positioning and speed measurement technology. Without accurate train positioning and speed measurement technology, no matter how advanced the optimization algorithm is, the expected effect cannot be achieved.

To sum up, to give full play to the advantages of maglev technology, improve the competitiveness of maglev trains, and also to further realize the energy-saving operation and intelligent control of trains, accurate, efficient and reliable train positioning and speed measurement technology is of great significance.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is: using the trackside beacon positioning method to locate and measure the speed of the maglev train, improve the accuracy of the train's location and speed measurement, and realize the effective monitoring of the train running status.

In order to achieve the above technical goals, the present invention adopts the wayside beacon positioning method to provide a three-dimensional magnetic encoding type train positioning identification method with small size, high reliability and simple coding. The three-dimensional magnetic code is pasted along the track and passed through the vehicle. The probe performs corresponding scanning, decoding and monitoring, which is simpler in structure and lower in cost than the existing train positioning method, and has high precision and is easy to install and maintain.

In order to achieve the above-mentioned technical goals, the present invention specifically adopts the following technical solutions:

The three-dimensional magnetic code adopts a three-layer structure: it includes a base, an information coding layer and a protective layer; the upper part of the information coding layer includes a position detection area and an information identification area, the position detection area is used for the calibration of the position of the magnetic code area, and the information The identification area is used to store information, and the lower part of the information coding layer adopts an n×j matrix sequence; the method includes the following steps:

(1) Data analysis: determine the encoded character type and the three-dimensional magnetic code specification, and convert it into data characters according to the character set;

(2) Data encoding: convert data characters into bit streams, directly convert decimal landmark data into ternary data sequences, form a data codeword sequence for matrix encoding, and then the decoder recognizes and reads the three-dimensional magnetic code data codewords Sequence to obtain the data content of the 3D magnetic code;

(3) error correction coding: the data code word sequence is arranged by partition, and the error correction code word is added to the data code word sequence to form a new sequence information, and the additional prefix sequence information is added at the end of the new sequence information;

(4) construct matrix: put the detection information, positioning information, additional information and codeword module in the sequence generated in step (3) into the matrix sequence;

(5) format and version information: put the format and version information in the sequence generated in step (3) into the information identification area to generate the final three-dimensional magnetic code;

(6) When the train passes through the three-dimensional magnetic code, the magnetic pole information of the three-dimensional magnetic code is read, and the read information is sent to the on-board control unit, and the on-board control unit decodes the information to obtain the real-time status information of the train.

Preferably, the three-dimensional magnetic code magnetic pole information reading method in step (6) is: when the train passes the three-dimensional magnetic code, the matrix sequence of the three-dimensional magnetic code is scanned by the on-board induction coil, and the on-board sensor detects the induction coil generated during the scanning process. The electromagnetic wave is pulsed, and the detection information is transmitted to the vehicle-mounted control unit; the vehicle-mounted control unit judges the polarity of the magnetic pole according to the direction of the pulse wave, performs decoding operation, converts the decoded sequence into binary computer language, and then calls the corresponding road sign from the established information database. Finally, the train displacement is obtained through the adjacent monitoring points, the train displacement is derived to obtain the running speed, and the running speed is derived to obtain the train acceleration.

Preferably, according to the matrix sequence, the road sign information is encoded by matrix combination through three kinds of symbols of permanent magnetic pole 'N', 'S' and non-magnetic '0' vacancy.

Preferably, the protective layer is made of non-magnetic material, which covers the surface of the information coding layer.

Preferably, the position detection area is formed by nesting a larger square magnetic pole ring and a square magnet.

Preferably, the adhesive surface of the base is frosted.

Preferably, the base and the information coding layer are fixed by rivets or grooves, and the edge of the magnetic code is rounded.

Preferably, the protective layer is provided with an information demarcation place, which can identify the serial number and installation position information.

The present invention has the following beneficial effects:

The invention realizes the accurate positioning of the maglev train based on the wayside beacon, realizes the storage of the track position information through the different arrangement order of the three symbols, and has the advantages of simple coding, fast reading, strong adaptability and the like. The running speed of the train can be obtained by derivation of the displacement, and the acceleration of the train can be obtained by derivation of the running speed. Accurate monitoring of train position, speed and acceleration provides the basis for train energy-saving operation and intelligent control.

Description of drawings

FIG. 1 is a top view of the three-dimensional magnetic code maglev train positioning identification structure of the present invention.

FIG. 2 is a cross-sectional view of the coding layer of the three-dimensional magnetic code maglev train positioning mark of the present invention.

FIG. 3 is a left side view of the structure of the three-dimensional magnetic code maglev train positioning identification mark of the present invention.

In the figure: (1) the edge of the magnetic code, (2) and (9) represent the magnetic code protection layer, (3) represent the magnetic code information calibration area, (4) represent the information calibration place, (5) represent the base, (6) And (10) represents a position detection area, (7) an information identification area, (8) an information coding area, and (11) represents a permanent magnet symbol.

Detailed ways

The three-dimensional magnetic coding method and its application technology in the field of positioning and speed measurement of maglev trains are a key technology related to the excitation of stator windings, traction force matching, and energy-saving operation of maglev trains. With the rapid development of rail transit system towards green, safe and intelligent direction, higher requirements are put forward for train positioning technology, such as information collection speed and information accuracy. Based on the information calibration method, the invention uses the three-dimensional magnetic coding identification method to monitor the status information of the maglev train, such as the position, speed, acceleration, etc., and provides a basic basis for the precise control of the maglev train.

The three-dimensional magnetic code identification method of the present invention adopts the 'N' and 'S' polarities of the permanent magnet and the non-magnetic '0' vacancy to form a basic symbol in the information coding area, and performs information coding and storage according to a preset matrix coding method.

The core part of the three-dimensional magnetic code lies in the information encoding method of its coding layer and the reading strategy of the three-dimensional magnetic code.

Three-dimensional magnetic code magnetic pole encoding process:

(1) Data analysis: Determine the character type of the encoding and the three-dimensional magnetic code specification, and convert it into a symbol character according to the corresponding character set; under the condition of a certain specification, the higher the error correction level, the smaller the real data capacity.

(2) Data encoding: convert data characters into bit streams, directly convert decimal landmark data into ternary data sequences, and form a data codeword sequence for matrix encoding for efficient decoding, and then the decoder recognizes and reads The data content of the two-dimensional code can be obtained by using the code word sequence of the three-dimensional magnetic code data.

(3) Error correction coding: Arrange the above codeword sequences by partitions as needed. In order to achieve a higher error tolerance rate of the magnetic code, it is necessary to add error correction codewords in the coding area, and add the error correction codeword to the data codeword sequence. Inside, it becomes a new sequence information, and in addition, additional suffix sequence information is added at the end of the sequence.

(4) Constructing the final data information: Under the condition that the specification is determined, the sequence generated above is put into the blocks in order.

(5) Constructing a matrix: Put the detection information, positioning information, additional information and codeword modules into the corresponding matrix.

(6) Format and version information: The generated format and version information are put into the corresponding information identification area, and the final three-dimensional magnetic pole three-dimensional magnetic code is generated.

The modern train itself has a database of information about the entire line, including the slope of the road section, the curve and the speed limit. It provides the basic technology for realizing the intelligent driving of future trains.

In order to illustrate the present invention more clearly, an information database with a decimal value range of [0-1320000] is established based on the total length of the track route from Beijing South Railway Station to Shanghai Hongqiao Railway Station, which is about 1320 kilometers below. The present invention adopts the magnetic pole 'S' , 'N' and '0' represent the values '2', respectively, and '1' and '0' are encoded as ternary values

The encoding mode of the present invention can also adopt encoding modes such as letters, characters, Chinese characters, etc. The basic method is consistent with the digital mode, and will not be described too much here.

The indicator is set to: 0001 by digital encoding, and the data 1234 567 is encoded in the [0-1320000] information database as an example.

1. Data analysis: The Beijing-Shanghai rail transit line is usually 1320 kilometers long, and the train positioning detection points are set at a distance of one meter. A total of 1,320,001 identification information sequences are required for the entire line. The ternary value is used in the coding area size of 15 × 10 matrix. It can meet the requirements. In addition, the repeated sorting method of the three-dimensional magnetic code is used to achieve a higher level of error correction to ensure the accuracy of the three-dimensional magnetic code.

2. Numerical conversion ternary: 1234 567→2022 2011 1120 1

A 4-bit mode indicator (0001) is added in front of the above-mentioned real numerical sequence to facilitate the storage of encoding mode and additional information, etc. In addition, an eight-bit character is added at the end of the numerical sequence to set the remainder information sequence (0000 0001).

3. Add the symbol sequence: 0001 2022 2011 1120 1000 0000 1

In order to improve the error tolerance rate of the three-dimensional magnetic code and avoid decoding errors, an error correction sequence is added to the coding sequence, and the three-dimensional magnetic symbol is repeated here to form a new sequence.

Error correction processing: form a set of 5×10 ternary sequences according to the above, and then perform error correction processing, that is, repeat the coding of 5×10 ternary sequences, add them to the coding sequence, and combine them into a final coded sequence of 15×10. Among them, a set of ternary sequences are expressed as:

0000 0011 2200 2222 2200 1111 1111 2200 1100 0000 0000 0000 11

Supplementary additional information bits: Add the information identification module and the magnetic code position detection module to obtain it, as shown in Figure 1.

Three-dimensional magnetic code magnetic pole information reading process:

Information sequence acquisition: The train identifier reads the three-dimensional magnetic code data codeword sequence to obtain the road sign information sequence.

Adopt the induction coils in a one-to-one correspondence between the vertical row (vertical ground) and the three-dimensional magnetic code. When the train passes through the three-dimensional magnetic code, the vertical induction coils are scanned in sequence according to the single-row matrix, and the induction coils generate induced electromagnetic waveforms during the scanning process. The electromagnetic pulse of the induction coil is detected by the sensor and transmitted to the control system for magnetic code reading and storage of the information sequence (the electromagnetic wave generated by the magnetic pole 'S' can be set as a forward pulse, and the electromagnetic pulse generated by the magnetic pole 'N' is a reverse pulse, no electromagnetic wave. In addition, the position detection area adopts a nested rectangular ring to generate a pulse signal that is obviously different from the coding area, which is convenient for the decoder to identify the three-dimensional magnetic code and avoid the interference and misreading of external magnetic objects. , because the area of the information identification area is small, the size of the magnetic code is small, so that the storage capacity of the encoding mode and format information of the encoding area is satisfied.

Three-dimensional magnetic code reading: The control system restores the three-dimensional magnetic code matrix sequence to the information sequence.

The above-mentioned strategy control system judges the polarity of the magnetic poles according to the direction of the pulse wave and completes the control sequence set by the system in turn, carries out the decoding operation according to the decoding method set by the system, and then converts it into binary computer language, and the system directly obtains the information from the established information database. It is enough to call the corresponding road condition information, and then provide accurate position information for the train control system. In addition, the train running displacement is obtained through the adjacent monitoring points, and then the running speed can be obtained by derivation of the train displacement, and the running speed can be obtained by derivation. Get the train acceleration. Then it achieves the goal of accurate monitoring of train position, speed and acceleration, and provides a technical basis for train energy-saving operation and intelligent control.

Note: This specific reading method is listed here, only to describe the present invention more concretely and in detail, and does not have a specific reading method.

According to the description of the drawings, the present invention includes three parts: a base, an information coding layer 8, and a magnetic code protection layer 2/9. Among them, the magnetic code protection layer 2/9 directly covers the information coding layer 8 to form a whole, and protects the magnetic code of the information coding layer 8 to prevent it from falling off, damaged or demagnetized; in the information coding layer 8, the road sign information is passed through the permanent magnet. The magnetic pole 'N', 'S' and the non-magnetic '0' vacancy are encoded and stored in a preset magnetic code sequence composed of magnetic codes. The position detection area 6/9 is used to calibrate the position of the magnetic code area, which is convenient for decoding the scanning code information of the vehicle-mounted probe to ensure accurate reading. The information identification area 7 is used to store information such as the format, version, and zero point of the three-dimensional magnetic code.

The three-dimensional magnetic code is provided with a position detection area 6/10 and an information identification area 7 in the information coding area, which are respectively formed by nesting square magnetic pole rings and square magnets, and magnetic sheets with different size of the code element in the coding area are arranged in accordance with a preset specific matrix sequence. arranged in the format. The position detection area 6/10 is used to identify and read the magnetic code area, determine the scanning position of the decoder, improve the anti-interference ability, and ensure the accurate reading of the decoder; the information identification area 7 is used to store the format, version and zero position of the three-dimensional magnetic code. Click for information.

The above-mentioned appearance selects the base 5 and the information coding layer 8 to be fixed by rivets or grooves, and can be rounded at the edge 1 of the magnetic code.

The magnetic code protection layer 2/9 of the patent is provided with an information calibration point 4, which can identify information such as serial number and installation position, which is convenient for engineering installation and maintenance.

The three-dimensional magnetic coding contains the coding information and fault tolerance information of the location. This position is an absolute position, which does not affect each other and does not cause accumulated errors.

The magnetic code layer symbol includes three types: magnetic pole 'N', magnetic pole 'S' and non-magnetic vacancy. The magnetic pole is realized by an axially magnetized circular magnetic sheet (the circular magnetic sheet can be made of cylindrical magnet slices, and the thickness, excitation, etc. can be adjusted according to actual requirements).

The magnetic code element using rare earth permanent magnet material has the advantages of strong magnetism, high positioning accuracy, high readability, and is not easy to demagnetize, and the size of the three-dimensional magnetic code is small.

The surface of the three-dimensional magnetic code is covered with non-magnetic material to prevent the magnetic code from falling off and damaged, and has the effect of preventing the magnetic performance of the magnetic code element from deteriorating due to oxidation, corrosion, impact, etc., and improving the service life.

The three-dimensional magnetic code can be used normally in various harsh environments such as heavy dust, poor light, low temperature, rain and snow, and has certain protective functions.

The logo is frosted on the base design to ensure that the three-dimensional magnetic code is firmly adhered and improves reliability.

The three-dimensional magnetic code is provided with an information mark on the surface of the protective layer, which can identify information such as serial number and installation position, which is convenient for engineering installation and maintenance.

As mentioned above, the present invention uses the trackside beacon positioning method to locate and measure the speed of the maglev train, and the preset detection positions along the track of the maglev train are pasted in an orderly manner according to the set spacing (the specific spacing is determined according to the actual situation). fixed.

According to the above description, install on-board probes at the corresponding positions of the maglev train for corresponding scanning, decoding and monitoring. Every time the train scans a three-dimensional magnetic code, it can read the pre-stored information, and then obtain the train running position information. The running speed of the train is obtained by derivation of the displacement, and the acceleration of the train is obtained by derivation of the running speed. Accurate monitoring of train position, speed and acceleration provides the basis for energy-saving operation and intelligent control of trains.

Claims (7)

1. a train positioning identification method based on a three-dimensional magnetic code, the three-dimensional magnetic code adopts a three-layer structure: comprising a base, an information coding layer and a protective layer; it is characterized in that, The upper part of the information coding layer comprises a position detection area and an information identification area, the position detection area is used for the calibration of the position of the magnetic code area, the information identification area is used for storing information, and a matrix sequence is adopted in the lower part of the information coding layer; The method includes the following steps: (1) Data analysis: determine the type of encoded characters and the specifications of the three-dimensional magnetic code, and convert them into data characters according to the character set; (2) Data encoding: convert data characters into bit streams, directly convert decimal landmark data into ternary data sequences, form a data code word sequence for matrix encoding, and pass the road sign information through the permanent magnetic poles 'N', ' The three symbols S' and non-magnetic '0' vacancies are encoded by matrix combination, and then the decoder recognizes and reads the 3D magnetic code data code word sequence to obtain the data content of the 3D magnetic code; (3) Error correction coding: the data codeword sequence is arranged in partitions, the error correction codeword is added to the data codeword sequence to form a new sequence information, and additional prefix sequence information is added at the end of the new sequence information; (4) Constructing a matrix: put the detection information, positioning information, additional information and codeword modules in the sequence generated in step (3) into the matrix sequence; (5) Format and version information: put the format and version information in the sequence generated in step (3) into the information identification area to generate the final three-dimensional magnetic code; (6) When the train passes the three-dimensional magnetic code, the magnetic pole information of the three-dimensional magnetic code is read, and the read information is sent to the on-board control unit, and the on-board control unit decodes the information to obtain the real-time status information of the train. 2 . The method for identifying train positioning based on a three-dimensional magnetic code according to claim 1 , wherein the method for reading the magnetic pole information of the three-dimensional magnetic code in step (6) is: 2 . When the train passes through the three-dimensional magnetic code, the matrix sequence of the three-dimensional magnetic code is scanned by the on-board induction coil, and the on-board sensor detects the induced electromagnetic wave pulse generated by the induction coil during the scanning process, and transmits the detection information to the on-board control unit; The on-board control unit judges the polarity of the magnetic pole according to the direction of the pulse wave, performs the decoding operation, converts the decoded sequence into binary computer language, then calls the corresponding road sign information from the established information database, and finally obtains the train displacement through the adjacent monitoring points. Derivating the displacement of the train to obtain the running speed, and deriving the running speed to obtain the acceleration of the train. 3 . The method for train positioning and identification based on a three-dimensional magnetic code according to claim 1 , wherein the protective layer is composed of a non-magnetic material, which covers the surface of the information coding layer. 4 . 4 . The method for locating and identifying trains based on a three-dimensional magnetic code according to claim 1 , wherein the position detection area is formed by nesting a larger square magnetic pole ring and a square magnet. 5 . 5 . The three-dimensional magnetic code-based train positioning and identification method according to claim 1 , wherein the adhesive surface of the base is frosted. 6 . 6 . The method for train positioning and identification based on a three-dimensional magnetic code according to claim 1 , wherein the base and the information coding layer are fixed by rivets or grooves, and the edge of the magnetic code is rounded. 7 . 7 . The method for train positioning and identification based on a three-dimensional magnetic code as claimed in claim 1 , wherein the protective layer is provided with an information demarcation place, which can identify serial numbers and installation position information. 8 .

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