Railway freight vehicle shunting and marshaling method and system based on UWB positioning technology

Abstract

The present invention relates to a method and system for shunting and marshaling railway freight vehicles based on UWB positioning technology, wherein the method comprises the following steps: obtaining the time when the pulse signal emitted by the positioning tag arrives at each positioning base station; obtaining the coordinates of each positioning base station; obtaining the coordinates of the positioning tag according to the time when the pulse signal emitted by the positioning tag arrives at each positioning base station and the coordinates of each positioning base station; and shunting and marshaling according to the coordinates of the positioning tag. The present invention can obtain the real-time position of the locomotive and the vehicle in real time, and when the locomotive and the vehicle to be marshaled are close, real-time feedback is given to the locomotive cab to ensure that the vehicle docking speed is lower than the set range, thereby ensuring shunting safety.

Description

Technical Field

[0001] The present invention relates to the field of positioning technology, and in particular to a railway freight vehicle shunting and marshaling method and system based on UWB positioning technology. Background Art

[0002] Freight shunting yards have long used manual planning for marshaling. Even if information software is used, it is only manually arranged and the dispatch order is printed in real time. It is impossible to obtain the location and trajectory information of vehicles and inspection and maintenance personnel in real time. Freight trains will stop on the track according to the dispatch. The parking track and number will change at any time according to the dispatch situation. Inspection personnel will also inspect the designated trains in the designated time period and route to check the train situation. Therefore, there is an urgent need to automatically obtain locomotive and vehicle location information and control it. At the same time, there are also shunting systems based on satellite positioning systems such as GPS / Beidou, but due to the characteristics of satellite positioning, there are defects such as dependence on differential positioning stations, contact network occlusion, and positioning cycle not meeting the vehicle coupling, which cannot meet the actual needs of freight shunting yards.

[0003] Therefore, how to design a method and system for railway freight vehicle shunting and marshaling based on UWB positioning technology that can obtain the real-time position of locomotives and vehicles in real time, and provide real-time feedback to the locomotive cab when the locomotive and the vehicle to be assembled are approaching, to ensure that the vehicle docking speed is lower than the set range and ensure shunting safety, has become a technical problem to be solved in this field. Summary of the invention

[0004] The purpose of the present invention is to provide a railway freight vehicle shunting and marshaling method and system based on UWB positioning technology. The present invention can obtain the real-time position of the locomotive and the vehicle in real time, and when the locomotive and the vehicle to be marshaled are close, provide real-time feedback to the locomotive cab to ensure that the vehicle docking speed is lower than the set range, thereby ensuring shunting safety.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A railway freight vehicle shunting and marshaling method based on UWB positioning technology, the method comprising the following steps:

[0007] Obtain the time when the pulse signal emitted by the positioning tag arrives at each positioning base station;

[0008] Obtain the coordinates of each positioning base station;

[0009] The coordinates of the positioning tag are obtained according to the time when the pulse signal emitted by the positioning tag reaches each positioning base station and the coordinates of each positioning base station;

[0010] Shunting and marshaling are performed according to the coordinates of the positioning tags.

[0011] Optionally, obtaining the coordinates of the positioning tag according to the time when the pulse signal emitted by the positioning tag reaches each positioning base station and the coordinates of each positioning base station specifically includes:

[0012] The coordinates of the positioning label are obtained according to the following formula:

[0013]

[0014] Among them, d i,1 is the distance from the ith positioning base station to the first positioning base station, c is the propagation speed of the UWB electromagnetic wave, Δt i is the time it takes for the pulse signal emitted by the positioning tag to reach each positioning base station, d i is the distance from the positioning tag to the i-th positioning base station, i is a positive integer, d1 is the distance from the positioning tag to the first positioning base station, (x i ,y i ) is the coordinate of the ith positioning base station, (x1,y1) is the coordinate of the first positioning base station, and (x,y) is the coordinate of the positioning base station.

[0015] Optionally, also include:

[0016] The positioning error is corrected using the geometric precision factor; the calculation formula of the geometric precision factor is as follows:

[0017]

[0018] Where GDOP is the geometric dilution of precision, is the variance of the positioning error in the x direction, is the variance of the positioning error in the y direction.

[0019] Optionally, also include:

[0020] The time when the pulse signal emitted by the positioning tag reaches each positioning base station and the coordinates of each positioning base station are filtered, smoothed, coordinate transformed, position presented and data stored.

[0021] Optionally, also include:

[0022] Filter out the location information outside the location area, including:

[0023] Determine whether the reflection, refraction and other distance information data of the positioning tag position outputs pseudo-range, and the output coordinates are within the positioning area;

[0024] If yes, then filter out the location information;

[0025] If not, keep it.

[0026] The present invention also provides a railway freight vehicle shunting and marshaling system based on UWB positioning technology, the system comprising:

[0027] Several positioning base stations, UWB engine servers, positioning tags and control centers;

[0028] Among them, several positioning base stations are arranged around the freight station to receive the pulse signals emitted by the positioning tags;

[0029] The positioning tag is matched and installed on the locomotive head and the vehicle to be assembled, and is used to transmit a pulse signal. The positioning tag has a unique ID identification;

[0030] Several of the positioning base stations are connected and communicated with a UWB engine server deployed in a control center via a communication base station;

[0031] The UWB engine server is deployed and configured according to the positioning data transmitted by the positioning base station through the communication base station through the running positioning acquisition program and electronic map program, and then the positioning data is processed by the system service program to obtain the coordinates of the positioning tag;

[0032] The control center is connected to the UWB engine server and is used for shunting and marshaling according to the coordinates of the positioning tags.

[0033] Optionally, the positioning tag is powered by a battery and fixed by magnetism.

[0034] Optionally, it also includes: a positioning data acquisition / storage server, which is used to perform algorithm filtering, smoothing, coordinate transformation, position presentation, and data storage on the positioning data.

[0035] Optionally, it further includes: a screening module, which is used to screen out the positioning information outside the positioning area, specifically including:

[0036] Determine whether the reflection, refraction and other distance information data of the positioning tag position outputs pseudo-range, and the output coordinates are within the positioning area;

[0037] If yes, then filter out the location information;

[0038] If not, keep it.

[0039] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0040] The present invention provides a railway freight vehicle shunting and marshaling method and system based on UWB positioning technology. The present invention is based on UWB technology, relies on two-dimensional precise ranging within the coverage range of multiple base stations and triangulation positioning principles, realizes accurate positioning of shunting locomotives and coupled carriages, and then determines the position of the target train on the train running track. At the marshaling station, the train stop position can be ensured to be accurate, and it can be further determined whether the target train is complete to ensure that the target train is complete. UWB technology can give the track range occupied by the train more accurately than other positioning methods, avoid multipath and pseudo-range problems caused by contact rails, vehicles, etc. above the station, thereby ensuring that the shunting marshaling has a better operating environment and realizing intelligent shunting. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 A flow chart of a railway freight vehicle shunting and marshaling method based on UWB positioning technology provided in Example 1 of the present invention;

[0043] Figure 2 A positioning map for positioning base stations and target nodes;

[0044] Figure 3 This is a layout diagram of a railway freight vehicle shunting and marshaling system based on UWB positioning technology provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In order to improve production safety and achieve accurate and rapid management of shunting and marshaling, freight shunting yards have an urgent need to obtain the real-time position and relative distance information of locomotives and freight cars. Freight trains will stop on the track according to the dispatch, and the track and number of parking tracks will change at any time according to the dispatch situation. In order to achieve the above safety goals, it is necessary to accurately locate the locomotive and each freight car in real time, but the ownership of the cars belongs to different units, and it is impossible to install positioning devices on all cars.

[0047] When the positioning target cannot be equipped with a positioning device, it is necessary to monitor the running speed of the moving locomotive (front) and freight car when it is combined with the stationary freight car, and provide real-time feedback to the locomotive to ensure that the relative speed is lower than the set threshold when docking.

[0048] The purpose of the present invention is to provide a method and system for shunting and marshaling railway freight vehicles based on UWB positioning technology. The present invention can obtain the real-time position of locomotives and vehicles in real time, and when the locomotive and the vehicle to be marshaled are close, it can provide real-time feedback to the locomotive cab to ensure that the vehicle docking speed is lower than the set range and ensure shunting safety. In addition, the present invention uses UWB technology to accurately determine the vehicle position in real time by deploying a limited number of base stations at railway stations, thereby improving the scientific nature of vehicle reception, marshaling, vehicle preparation, and maintenance inspection, and improving shunting safety and management efficiency. The track where the locomotive and train are located can be accurately determined.

[0049] The key terms related to the present invention are explained as follows:

[0050] 1. UWB (Ultra Wide Band)

[0051] 2. Track - refers to the numbered tracks in the railway station, which are used to determine the specific location where the train stops.

[0052] 3. Shunting - organizing vehicles into trains or groups according to relevant regulations.

[0053] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0054] Embodiment 1:

[0055] See also Figure 1 The present invention provides a railway freight vehicle shunting and marshaling method based on UWB positioning technology, the method comprising the following steps:

[0056] S1: When the locomotive and the vehicles to be assembled enter the positioning area, the time when the pulse signal emitted by the positioning tag arrives at each positioning base station is obtained;

[0057] S2: Obtain the coordinates of each positioning base station;

[0058] S3: Obtaining the coordinates of the positioning tag according to the time when the pulse signal emitted by the positioning tag reaches each positioning base station and the coordinates of each positioning base station;

[0059] S4: Perform shunting and marshaling according to the coordinates of the positioning tags.

[0060] In step S3, obtaining the coordinates of the positioning tag according to the time when the pulse signal emitted by the positioning tag reaches each positioning base station and the coordinates of each positioning base station specifically includes:

[0061] The coordinates of the positioning label are obtained according to the following formula:

[0062]

[0063] Among them, d i,1 is the distance from the ith positioning base station to the first positioning base station, c is the propagation speed of the UWB electromagnetic wave, Δt i is the time it takes for the pulse signal emitted by the positioning tag to reach each positioning base station, d i is the distance from the positioning tag to the i-th positioning base station, i is a positive integer, d1 is the distance from the positioning tag to the first positioning base station, (x i ,y i ) is the coordinate of the ith positioning base station, (x1,y1) is the coordinate of the first positioning base station, and (x,y) is the coordinate of the positioning base station.

[0064] Will Shifting, we get:

[0065] d i =d i,1 +d1 (2);

[0066] Square both sides of formula (2) to obtain:

[0067]

[0068] Expanding formula (3), we get:

[0069]

[0070] The main principle of two-dimensional positioning is TDOA, that is, the coordinates of the positioning tag are calculated by measuring the distance difference between the positioning tag and n base stations with known position coordinates.

[0071] The distance difference actually draws a hyperbola, and multiple hyperbola equations (at least 3 base stations) are required to determine the solution.

[0072] From formula (4), we can get:

[0073]

[0074] Since solving nonlinear equations is inconvenient in the program, the formula needs to be further sorted out.

[0075] Substitute the location coordinates of multiple base stations installed at the station one by one

[0076] Let i = 1, then d 1,1 =0, we get:

[0077]

[0078] Formula (5) - Formula (6), we get:

[0079]

[0080] Rearranging the formula, we get:

[0081]

[0082] make:

[0083]

[0084] The following formula (10) can be obtained:

[0085]

[0086] Because the station area must be completely included in the rectangle formed by the base stations, at least four base stations must be installed in the station, and the position is calculated by calculating the three arrival time differences.

[0087] When i=2,3,

[0088]

[0089]

[0090] Dividing formula (11) by formula (12) yields the linear relationship between the coordinates x and y of the locomotive and vehicle:

[0091]

[0092] Therefore, we get:

[0093]

[0094] make:

[0095]

[0096] Then we have:

[0097] y=a0x+a1 (16)

[0098] Substitute formula (16) into the following formula (17):

[0099] have to:

[0100]

[0101] Transformed into:

[0102]

[0103] make:

[0104]

[0105] Then we have:

[0106]

[0107] Squaring both sides gives:

[0108]

[0109] Expand formula (22) to get:

[0110]

[0111] Transformed into:

[0112]

[0113] make:

[0114]

[0115] Using the above formula, two solutions can be obtained. However, for the locomotive and coupled vehicle that actually need to be located, there is only one real position coordinate. Therefore, the value beyond the measurement range can be regarded as an invalid solution, relying on the geographic information of the known station. If the two solutions are close and reasonable, take their middle value. The valid solution obtained will be regarded as the real position of the vehicle to be located.

[0116] The positioning results generated based on the above scheme will produce errors due to factors such as distance measurement. That is, the premise of the above algorithm is to obtain the coordinate information of 4-5 UWB positioning base stations deployed at the shunting station. The selection of the positions of the four base stations, because the shunting system needs to accurately obtain the positions of the locomotive and the coupled vehicles, if the distance deviates, it will cause serious errors in the shunting marshalling behavior. After adding the fifth base station, the best positioning accuracy can be obtained by selecting the optimal solution among multiple triangles. Therefore, it also includes:

[0117] The positioning error is corrected using the geometric precision factor; the calculation formula of the geometric precision factor is as follows:

[0118]

[0119] Where GDOP is the geometric dilution of precision, is the variance of the positioning error in the x direction, is the variance of the positioning error in the y direction.

[0120] It should be noted that before deploying the base station, the key point coordinates of the shunting area are accurately measured, such as the four corners of the rectangular area, the center point, and the spacing between the tracks. The key point coordinates are used as known positions in advance, and the base stations to be deployed are placed at the four pre-selected corners. At the same time, the additional base stations are simulated by software, and the optimal placement is obtained through the effectiveness of the geometric configuration of the above base stations.

[0121] like Figure 2 As shown in the figure, S is the target node, A, B, and O are base stations. When α1=α2=α3, the positions of the base stations will overlap or be close, and the estimation of the target node will be inaccurate. When the target node is far away from the base station, α1-α3, α3-α2, and α1-α2 will become smaller, resulting in an increase in the positioning error. If the base station O and the target node S are fixed, and the distance between base stations A, B and O is increased, the positioning error will be reduced.

[0122] Specifically, the present invention also includes:

[0123] The time when the pulse signal emitted by the positioning tag reaches each positioning base station and the coordinates of each positioning base station are filtered, smoothed, coordinate transformed, position presented and data stored.

[0124] Additionally, it includes:

[0125] Filter out the location information outside the location area, including:

[0126] Determine whether the reflection, refraction and other distance information data of the positioning tag position outputs pseudo-range, and the output coordinates are within the positioning area;

[0127] If yes, then filter out the location information;

[0128] If not, keep it.

[0129] It should be noted that UWB positioning usually covers the rectangular or polygonal area surrounded by multiple base stations, and does not adopt the location information outside the area. However, due to the characteristics of wireless signal transmission, the UWB signal of the vehicle outside the boundary will be received by the positioning base station. If the reflection, refraction and other distance information data output pseudo-range, and the output coordinates are within the area, this part of the data needs to be thrown out to avoid misjudgment of the shunting system. Comparing the output coordinates with the inside and outside of the positioning triangle area and determining the number of valid calculation points received can effectively filter out the locomotive and vehicle positioning information outside the rectangular or polygonal area surrounded by multiple base stations.

[0130] Moreover, in the present invention, the locomotive and the coupled carriage obtained by UWB ranging are coordinates (Xuwb, Yuwb), which are converted into shunting system coordinates (Xobj, Yn), where Xobj is the identification distance of the track where the tag is located, and Yn is the track number. The track number and the Y axis of the actual positioning coordinate are realized by setting the track center distance.

[0131] By setting the track center distance on the UWB engine server side, the track number of the locomotive and carriage can be accurately determined based on the station positioning situation. The system can be flexibly deployed at stations with various terrain conditions and numbers of tracks. It only needs to change the track center distance and determination threshold on the server side.

[0132] Embodiment 2:

[0133] See also Figure 3 The present invention provides a railway freight vehicle shunting and marshaling system based on UWB positioning technology, the system comprising:

[0134] Several positioning base stations, UWB engine servers, positioning tags and control centers;

[0135] Among them, several positioning base stations are arranged around the freight station to receive the pulse signals emitted by the positioning tags;

[0136] The positioning tag is matched and installed on the locomotive head and the vehicle to be assembled, and is used to transmit a pulse signal. The positioning tag has a unique ID identification;

[0137] Several of the positioning base stations are connected and communicated with a UWB engine server deployed in a control center via a communication base station;

[0138] The UWB engine server is deployed and configured according to the positioning data transmitted by the positioning base station through the communication base station through the running positioning acquisition program and electronic map program, and then the positioning data is processed by the system service program to obtain the coordinates of the positioning tag;

[0139] The control center is connected to the UWB engine server and is used for shunting and marshaling according to the coordinates of the positioning tags.

[0140] Specifically, the positioning tag is powered by a battery and fixed by magnetic attraction.

[0141] Specifically, it also includes: a positioning data acquisition / storage server, which is used to perform algorithm filtering, smoothing, coordinate transformation, position presentation, and data storage on the positioning data.

[0142] Specifically, it also includes: a screening module, which is used to screen out the positioning information outside the positioning area, specifically including:

[0143] Determine whether the reflection, refraction and other distance information data of the positioning tag position outputs pseudo-range, and the output coordinates are within the positioning area;

[0144] If yes, then filter out the location information;

[0145] If not, keep it.

[0146] like Figure 3 As shown in the figure, the data of the positioning base station is connected to the Ethernet of the station, and the data is fed into the positioning acquisition server. The vehicle positioning card and the base station realize real-time and accurate positioning through UWB radio frequency pulses. Since the positioning data needs to be filtered by algorithms, smoothed, coordinate transformed, presented, and stored, a positioning data acquisition / storage server is placed in the control center to process the data in real time and upload it to the background system according to the agreed format and fields.

[0147] The present invention realizes a precise real-time parking lot positioning system by deploying UWB positioning base stations around the parking lot. It can locate vehicles entering the parking lot in real time and transmit the location back to the monitoring center, and has the ability to monitor the entire parking lot. The tag card sends a UWB signal to the outside once, and all base stations within the tag positioning distance will receive the wireless signal. If there are two base stations with known coordinates receiving the signal, the distance interval between the tag and the base station is different, so the time nodes of the two receiving the signal are different. According to the mathematical relationship, the point with a constant to the two known points must be on the hyperbola with these two points as the focus.

[0148] The positioning target sends signals to multiple base stations, starts timing from the first base station that receives the signal, and records the time when the signal arrives at the remaining base stations. These times are the time differences between the first node that receives the signal and the arrival of the signals from the remaining nodes. Based on these time differences, a set of hyperbolic equations can be listed. The target position will be located on a branch of the hyperbola with the two receiving base stations as the focus. Two or more hyperbolic equations are required to determine the two-dimensional coordinates of the target, and the intersection of the two hyperbolas is the two-dimensional position coordinates of the positioning target. Therefore, a positioning point requires at least 3 base stations. Under normal circumstances, two hyperbolas will intersect at two points, but the point that does not meet the requirements can be eliminated using the known geographical location.

[0149] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0150] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A railway freight vehicle shunting and marshaling method based on UWB positioning technology, characterized in that: The following steps are involved: Obtain the time when the pulse signal emitted by the positioning tag arrives at each positioning base station; Obtain the coordinates of each positioning base station; The coordinates of the positioning tag are obtained according to the time when the pulse signal emitted by the positioning tag reaches each positioning base station and the coordinates of each positioning base station; Perform shunting and marshaling according to the coordinates of the positioning tags; Also includes: The positioning error is corrected using the geometric precision factor; the calculation formula of the geometric precision factor is as follows: Where GDOP is the geometric dilution of precision, is the variance of the positioning error in the x direction, is the variance of the positioning error in the y direction; Also includes: Filter out the location information outside the location area, including: Determine whether the reflection, refraction and other distance information data of the positioning tag position outputs pseudo-range, and the output coordinates are within the positioning area; If yes, then filter out the location information; If not, keep it; Also includes: The time when the pulse signal emitted by the positioning tag reaches each positioning base station and the coordinates of each positioning base station are filtered, smoothed, coordinate transformed, position presented and data stored.

2. The railway freight vehicle shunting and marshaling method based on UWB positioning technology according to claim 1 is characterized in that: The step of obtaining the coordinates of the positioning tag according to the time when the pulse signal emitted by the positioning tag reaches each positioning base station and the coordinates of each positioning base station specifically includes: The coordinates of the positioning label are obtained according to the following formula: Among them, d i,1 is the distance from the ith positioning base station to the first positioning base station, c is the propagation speed of the UWB electromagnetic wave, Δt i is the time it takes for the pulse signal emitted by the positioning tag to reach each positioning base station, d i is the distance from the positioning tag to the i-th positioning base station, i is a positive integer, d1 is the distance from the positioning tag to the first positioning base station, (x i ,y i ) is the coordinate of the ith positioning base station, (x1,y1) is the coordinate of the first positioning base station, and (x,y) is the coordinate of the positioning base station.

3. A railway freight vehicle shunting and marshaling system based on UWB positioning technology, characterized in that: include: Several positioning base stations, UWB engine servers, positioning tags and control centers; Among them, several positioning base stations are arranged around the freight station to receive the pulse signals emitted by the positioning tags; The positioning tag is matched and installed on the locomotive head and the vehicle to be assembled, and is used to transmit a pulse signal. The positioning tag has a unique ID identification; Several of the positioning base stations are connected and communicated with a UWB engine server deployed in a control center via a communication base station; The UWB engine server is deployed and configured according to the positioning data transmitted by the positioning base station through the communication base station through the running positioning acquisition program and electronic map program, and then the positioning data is processed by the system service program to obtain the coordinates of the positioning tag; The control center is connected to the UWB engine server and is used to perform train shunting and marshaling according to the coordinates of the positioning tag; Also includes: The positioning error is corrected using the geometric precision factor; the calculation formula of the geometric precision factor is as follows: Where GDOP is the geometric dilution of precision, is the variance of the positioning error in the x direction, is the variance of the positioning error in the y direction; It also includes: a screening module, which is used to screen out the positioning information outside the positioning area, specifically including: Determine whether the reflection, refraction and other distance information data of the positioning tag position outputs pseudo-range, and the output coordinates are within the positioning area; If yes, then filter out the location information; If not, keep it; It also includes: a positioning data acquisition / storage server, which is used to perform algorithm filtering, smoothing, coordinate transformation, position presentation, and data storage on the positioning data.

4. The railway freight vehicle shunting and marshaling system based on UWB positioning technology according to claim 3 is characterized in that: The positioning tag is powered by a battery and fixed by magnetic attraction.

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