TW202128476A - A balise for a railway track - Google Patents

Abstract

A balise such as a Eurobalise for a railway track having planar dielectric circuit substrate design with a rectangular receiver loop antenna and a rectangular transmitter loop antenna formed on said circuit substrate, wherein an input flux to the receiver loop antenna is conform with a predetermined input flux in a balise active reference area and an output field from the transmitter loop antenna is conform with a field from a predetermined current encircling said balise active reference area, and wherein the receiver loop antenna and the transmitter loop antenna having a separation of at least two times a thickness of the dielectric substrate.

Description

On-ground sensors for railway tracks

Field of invention

The present invention relates to an above-ground sensor, which is an electronic above-ground sensor usually located between rails as part of an automatic train protection system. In particular, the present invention relates to a ground sensor in the European Railway Traffic Management System, ERTMS, which is the so-called Eurobalise. This ground sensor constitutes an integrated part of the European train control system, and is specified for the function and design of a European standard called "FFFIS for Eurobalise". The sensor on a European standard shall comply with the standardization document "SUBSET-036: Specification for Eurobalises".

Background of the invention

Ground sensors are arranged along the railway track to send information from the track side to passing trains, and the trains activate the traffic safety control on the railway tracks by The automatic monitoring system on the moving train (railway vehicle) uses this information. This automatic monitoring system is defined as an ATP (Automatic Train Protection) system, which can be operated in accordance with the European standard ERTMS, for example. The link between the ground sensor and an ATP antenna on the train is based on magnetic coupling, which means that when the antenna is located above or near the ground sensor, the ground sensor and the ATP antenna It constitutes an air transformer. The link is bidirectional, the downlink transmits power from the transmitter on the railway vehicle to the ground sensor through the magnetic induction of the receiver loop antenna of the ground sensor, and the uplink is The data is transmitted to the ATP system mounted on the railway vehicle by the following method: using the transmitter loop antenna through the ground sensor transmitter, the ground sensor transmitter is received by the receiver loop The electricity is to be powered.

The FFFIS used for the sensor on the European standard specifies the intensity and characteristics of the electromagnetic fields generated by the sensor on the European standard and the on-board antenna in the train by first defining two reference loops of predetermined size. Therefore, the European standard ground sensor is required to have an effective reference area of 358 mm×488 mm for a standard-sized European ground sensor; and an effective reference area of 200 mm×390 mm for a reduced size. European ground sensor. The standard stipulates that the fields generated by the sensor and on-board antenna on the European standard should be consistent with the fields generated by one of the reference loops. This means that the physical size of the European ground sensor must be largely equivalent to the reference loops defined by the standard. In a known European ground sensor, a receiver loop antenna and a transmitter loop antenna are basically coaxially arranged on the bottom and top of a printed circuit board, respectively. Basically, each loop has been overlapped so that the two loop antennas can meet the size requirements.

The essence of the transmission link is that the two ground sensor loop antennas should be close to each other because both of them interact with the same antenna function on the train. However, if they are placed closer to each other, there will be more capacitive and inductive coupling between them. This will have the effect of tuning the transmitter circuit and receiver circuit again away from the desired resonance frequencies, and the links become inefficient. Therefore, the used thickness of the sensor on the European standard is thicker than that of the standard circuit board. In order to alleviate the problems of coupling and re-tuning, the above-mentioned known European ground sensor uses a circuit board about 3.2 mm thick, that is, about twice the thickness of today's standard thickness circuit board. A large loop separation is achieved in the known design, which means that there is less coupling between the receiver loop antenna and the transmitter loop antenna. However, this thickness makes the circuit board bulky and expensive.

Summary of the invention

Generally speaking, the present invention provides a ground sensor in which the performance of a receiver loop antenna and a transmitter loop antenna meets the effective reference area of a ground sensor relative to a predetermined nominal size. In addition, the above-ground sensor should allow it to be integrated in an ATP system, thereby complying with the requirements usually defined in a relevant standardized document. The standard European standard ground sensor transmission system, SUB-036, Issue 3.1.0, is incorporated into the present invention for reference.

In particular, the above-ground sensor of the present invention will be fixedly installed between the rails of a railway track to wirelessly send data to at least one vehicle antenna of a railway vehicle on the railway track, wherein the above-ground sensor includes : A substantially planar dielectric circuit substrate. When the above-ground sensor is fixedly arranged between two rails, the dielectric circuit substrate has a first side facing upward and a second side facing downward, wherein the circuit substrate Has a substantially flat substrate thickness; a substantially rectangular receiver loop antenna is formed on the circuit substrate and has a receiver loop center trace along which a receiver loop physical length is defined, where to An input flux of the receiver loop antenna conforms to a predetermined input flux in the effective reference area of an on-ground sensor, and wherein the receiver loop antenna is configured so that when a railway vehicle is in the vicinity of the above-ground sensor , Wirelessly receive operating energy from a vehicle transmitter in the railway vehicle; the receiver circuit is connected to the receiver loop antenna by a receiver feed connection, and is configured to receive from the receiver loop antenna The operating energy; a substantially rectangular transmitter loop antenna is formed on the circuit substrate and has a transmitter circular central trace along which a physical length of the transmitter loop is defined, where from the transmitter An output field of the loop antenna conforms to a field from a predetermined current surrounding the effective reference area of the ground sensor, and the transmitter loop antenna is configured to wirelessly ground when a railway vehicle is in the vicinity of the ground sensor The data is transmitted to a vehicle receiver in the railway vehicle; the transmitter circuit is connected to the transmitter loop antenna by a transmitter feed connection, and is configured to feed a transmission signal including the data to The transmitter loop antenna; the receiver loop center trace and the transmitter loop center trace have an average separation interval that is at least twice the thickness of the substrate.

The loop separation achieved in this way can improve material efficiency and achieve weight reduction by using a relatively thin circuit substrate (circuit board) material. One-tenth of an inch (2.5 mm) or preferably, one-sixteenth of an inch (1.6 mm) will be sufficient. Recent simulations have shown that, contrary to what people expected, placing the receiver loop antenna inside the transmitter loop antenna in a coplanar manner will produce a certain degree of compliance with the antenna performance of the ground-based inductor. Tolerate the impact, such as it still meets the requirements of the standardization. Specifically, the simulations show that the field strength compliance requirement is achievable according to the European standard on-ground sensor specifications, that is, using separate receiver and transmitter loops on the same plane on one side of the circuit substrate. It should be noted that in the case of a coplanar layout, the physical dimensions of at least one of the receiver loop and transmitter loop, such as the size along a center trace, will have to be significantly different from those in the standardized document The size of the effective reference area of the sensor on the European landmark stated in.

For the definition of the present invention, the concept of the central trace, that is, an imaginary path essentially located in the middle of an antenna loop, is a reasonable approximation of the current path in a loop antenna, although the current The actual lateral distribution may deviate slightly from the middle, but usually towards an inner edge of the loop.

When the physical length of the receiver loop is substantially equal to one-tenth or more of the wavelength of the operating frequency of the receiver loop antenna as defined in free space propagation, the current distribution in the receiver loop antenna is not The uniform phenomenon requires special attention to achieve the compliance of the sensor on the ground. This is the case for standard size or reduced size European standard ground sensors. One-tenth or longer of a wavelength should be understood to define a range related to each operating frequency being considered (for a European landmark sensor, a very narrow frequency band at approximately 27 MHz In) a starting point with an accuracy of +/- 10%.

An advantageous method for overcoming the phenomenon of poor current distribution is to provide the receiver loop antenna with two, three, four or more loop segments. The other gaps are separated, except for a gap necessary for the feed connection of a loop antenna. Each of the at least one gap is bridged by a respective capacitor to provide a uniform current distribution in the receiver loop antenna. At least in the case of a sensor on a European standard, the capacitor can be a discrete capacitor component that is soldered to the adjacent end of the ring segment formed as a printed (etched) on a circuit board Conductor pattern. In the case where the at least one gap is substantially positioned on a line of symmetry of the receiver loop antenna and/or is substantially equidistantly positioned along the receiver loop antenna, this arrangement of segments and gaps will Becomes particularly effective.

Several different arrangements of the receiver loop antenna and the transmitter loop antenna can be implemented on a printed circuit substrate of the above-ground sensor, each of which has a set of advantages and possible trade-offs. Both the receiver loop antenna and the transmitter loop antenna can be formed on the circuit substrate in such a way that one is located inside the other. This means that an inner edge of one loop is wide enough to surround an outer edge of another loop, even if the loops are on opposite sides of the circuit substrate. It has been found that it can be advantageous to form the receiver loop antenna inside the transmitter loop antenna.

In order to have good performance, at least one of the receiver loop antenna and the transmitter loop antenna can be arranged on both sides of the circuit substrate, and it is better to make it overlap itself. An alternative is to provide the receiver loop antenna on only one side of the side of the circuit substrate. If this is the case, it is better to provide the receiver loop antenna on the second side because this tends to increase Performance gain. Especially in the latter arrangement, the transmitter loop antenna is preferably arranged only on one side surface of the sides of the circuit substrate, preferably on the first side surface. The transmitter loop antenna and the receiver loop antenna provided only on opposite sides of the circuit substrate can give a particularly advantageous geometry, wherein the thickness of the dielectric substrate and the loop in the plane of the dielectric substrate Both path spacing contribute to a relatively large overall loop spacing. In order to obtain these good characteristics, the thickness of the substrate should be less than or equal to one tenth of an inch.

For the ground sensor disclosed here, a predetermined loop size range can be defined as a difference between the physical length of the receiver loop and the physical length of the transmitter loop, which is at least 20 mm, Preferably it is 40 mm.

As pointed out in this article, the effective reference area of the ground sensor is a rectangle of 358 mm by 488 mm or 200 mm by 390 mm, which is basically concentric and coplanar with the receiver loop antenna and the transmitter loop antenna Relationship. The substantially concentric and coplanar relationship should be understood to generally include an approximation, because in some cases the receiver loop antenna and the transmitter loop antenna are not only located on the same side of the circuit substrate. In terms of the effective reference area of the ground sensor, a compliance condition for the receiver loop antenna and the transmitter loop antenna is +/- 1.5 dB, respectively.

Although other systematic methods are conceivable, the above-ground sensor of the present invention is usually a receiver loop antenna and its transmitter loop antenna are grouped and configured to comply with the European standard ground-based sensor transmission system, SUB-SET-036, The ground sensor for Issue 3.1.0.

Detailed description of the preferred embodiment The drawings are focused on the circuit of an on-ground sensor, which is usually provided with a weatherproof housing (not shown in the figure), the weatherproof housing has fastenings for fixing on a railway member. The drawings are not drawn to scale.

Figure 1 shows an on-ground sensor 1, in this case a European landmark on-ground sensor, which is arranged at a fixed position between the tracks 2a of a railway track. The above-ground sensor is usually attached to the sleeper 2b of the railway track, and may form a group of the above-ground sensor 1. A function of the ground sensor 1 is to wirelessly send data to at least one conventional vehicle antenna (not shown in the figure) of a railway vehicle (not shown in the figure) running on the railway track.

Fig. 2 shows in a simplified manner a functional block diagram of an on-ground sensor 1 of the type involved in the present invention. The ground sensor 1 has a conductive receiver loop antenna 3, and the receiver loop antenna 3 is configured to receive magnetic induction from a vehicle transmitter antenna ( Not shown in the figure) power. The magnetic field generated by the transmitter antenna causes a current to flow in the receiver loop antenna 3. The current is rectified in a receiver 4 and the related energy is stored in an energy storage 5. This energy is used to power the consumer circuit of the above-ground inductor, for example, to power a resonant circuit 6 in a transmitter 7 of the above-ground inductor. The ground sensor further includes a conductive transmitter loop antenna 8, which is configured to be fed by the resonant circuit 6, so that when the vehicle passes the ground sensor, data is sent from a controller 9 via its vehicle antenna to The railway vehicle. The controller 9 (which is not part of the invention) has a serial link input 10 and an input from a predetermined telegraph unit 11 having a programming interface 12.

Figures 3 and 4 show a conventional type of dielectric circuit board 13 which is substantially planar, also called a circuit board. When the ground sensor 1 is positioned at a fixed position between the two rails 2b, it has a first side surface 14 facing upward and a second side surface 15 facing downward. The circuit substrate 13 has a substantially uniform substrate thickness of about 1.6 or 2.5 mm, and is usually so thin that it cannot provide sufficient spacing for loop antennas overlapping each other on opposite sides of the substrate to meet standardized ground sensors such as European standards. These strict requirements for ground sensors. Since the above-ground sensors form part of the railway safety system, their design tends to be conservative. However, as noted, one of the latest designs uses overlapping conductive patterns on the opposite side of an ultra-thick circuit board to provide appropriately spaced receiver and transmitter loops. There is one on each side and has the same predetermined size.

Figures 3 and 4 further show a substantially rectangular receiver loop antenna 16. The rectangular receiver loop antenna 16 is formed on the circuit substrate 13 and has a receiver loop center trace along the The trace defines the physical length of the receiver loop, where an input flux to the receiver loop antenna corresponds to a predetermined input flux in the effective reference area of an on-ground sensor, and where the receiver loop antenna 16 It is configured to wirelessly receive operating energy from a vehicle transmitter of the railway vehicle when a railway vehicle is in the vicinity of the ground sensor, and the receiver circuit 4 is connected to the railway vehicle by a receiver feed connection 17 The receiver loop antenna 16 is configured to receive the operating energy from the receiver loop antenna 16. A substantially rectangular transmitter loop antenna 18 is formed on the circuit substrate 13 and has a transmitter loop center trace along which a transmitter loop physical length is defined, wherein from the transmitter loop antenna An output field of 18 corresponds to a field from a predetermined current surrounding the effective reference area of the ground sensor, and the transmitter loop antenna 18 is configured to wirelessly ground when a railway vehicle is in the vicinity of the ground sensor. The data is transmitted to a vehicle receiver in the railway vehicle, and the transmitter circuit 7 is connected to the transmitter loop antenna by a transmitter feed connection 19, and is configured to transmit a signal including the data Feed to the transmitter loop antenna 18.

The receiver loop antenna and the transmitter loop antenna are separated to limit the coupling between them, so that the receiver loop center trace and the transmitter loop center trace have an average distance of at least the gap. Twice the thickness of the electrical substrate. In Figures 3 and 4, since the receiver loop antenna is arranged inside the transmitter loop antenna, but on an opposite side of the transmitter loop antenna, the interval between a loop is substantially larger than the intermediate loop antenna. Twice the thickness of the electrical substrate. As shown in the figure, there is also a separation gap between the two loops in the plane of the circuit substrate.

The sensors on the European standard in FIGS. 3 and 4 are of standard size or reduced size. This means that when the operating frequency of the receiver loop antenna is 27.095 MHz, according to the definition in free space propagation, the physical length of the receiver loop is essentially one-tenth or more of a wavelength. Under this relationship between physical length and wavelength, the above-ground inductor of the present invention, in the form of a capacitor 20 included in the receiver loop antenna 16, provides a means for a uniform current distribution. This is an advantageous way to overcome the phenomenon of poor current distribution. In the illustrated example, the loop antenna is configured to have four loop segments 21, 22, 23, 24, the four loop fractal segments separated by separate gaps away from the receiver feed connection 17 . Each gap is bridged by a capacitor 25, 26, 27 to present a uniform current distribution in the receiver loop antenna. For this European standard ground sensor, the capacitors 25, 26, 27 may be discrete capacitor components, which are welded to the adjacent ends of the ring segments 21, 22, 23, 24. In the case where the at least one gap is positioned substantially on a line of symmetry of the receiver loop antenna and/or is positioned substantially equidistantly along the receiver loop antenna, this arrangement of segments and gaps will Becomes particularly effective. It should be noted that the feed connections 17 and 19 may or may not overlap.

Figures 5a-5h respectively show several different arrangements of the receiver loop antenna 16 and the transmitter loop antenna 18 on a printed circuit board 13 of the above-ground inductor. This is shown by the part labeled A-A in FIG. 4. The views of Figures 5b-5h correspond to the views of Figure 5a, but show different designs of the conductive traces of the loops. It should be noted that there is an aperture in the circuit substrate inside the loop antenna of Figure 4, which provides a relatively narrow substrate portion for Figures 5a-5h, which depicts the different loop geometries, each Each has a set of advantages and possible trade-offs. Both the receiver loop antenna and the transmitter loop antenna can be formed one inside the other on the circuit substrate. This means that an inner edge of one loop is wide enough to surround an outer edge of another loop, even if the loops are on opposite sides of the circuit substrate. It has been found to be advantageous to form the receiver loop antenna inside the transmitter loop antenna. The center traces of the receiver and transmitter loops are represented by 28 and 29, respectively.

If a loop antenna is formed by conductive patterns on both sides of the dielectric circuit substrate, a conductive via (not shown in the figure) penetrating the substrate is usually used in various positions to connect to The conductive patterns of the loop antenna on the opposite sides of the substrate. Preferably, this will be the case in Figures 5c, 5d, and 5g.

For the sensor on the European landmark disclosed in FIGS. 3 and 4, a predetermined loop size range is defined as a difference between the physical length of the receiver loop and the physical length of the transmitter loop . In this example, the range is greater than 40 mm, and for a standard-sized European standard ground sensor, the total length of the loop is about 1692 mm. For a reduced-sized European standard ground sensor, the loop’s The total length is approximately 1180 mm.

The effective reference area of the sensor on the European standard is a rectangle of 358 mm by 488 mm, or 200 mm by 390 mm, which basically has a concentric and coplanar relationship with the receiver loop antenna and the transmitter loop antenna . The substantially concentric and coplanar relationship should be understood to generally include an approximate situation, because in some cases the receiver loop antenna and the transmitter loop antenna are not only located on the same side of the circuit substrate. In terms of the effective reference area of the ground sensor, a compliance condition for the receiver loop antenna and the transmitter loop antenna is +/- 1.5 dB, respectively. The European standard ground sensor of this embodiment has assembled its receiver loop antenna and its transmitter loop antenna to conform to the European standard ground sensor transmission system, SUBSET-036, Issue 3.1.0.

Although the description is mainly for the European standard ground sensor, the inventor foresaw that the applicability of the ground sensor of the present invention complies with the ERTMS/ETCS, Interface'G' Specification, SUBSET- on February 24, 2012. 100, Issue 2.0.0.

1: Ground sensor 2a: Orbit 2a: sleeper 3.16: Receiver loop antenna 4: receiver 5: Energy storage 6: Resonant circuit 7: Launcher 8, 18: transmitter loop antenna 9: Controller 11: Telegraph unit 12: Planning interface 13: Dielectric circuit substrate 14: First side 15: second side 17: Receiver feed connection 19: Transmitter feed connection 21, 22, 23, 24: ring segment 25, 26, 27: Capacitor 28: Center trace of the receiver loop 29: Center trace of transmitter loop

Figure 1 shows how the ground sensor is traditionally installed on the sleeper of a railway track.

Figure 2 shows a functional block diagram of an on-ground sensor according to the present invention.

Figure 3 shows a bottom view of a simplified circuit layout of a ground sensor according to an embodiment of the invention.

Figure 4 shows a top view of a simplified circuit layout of a ground sensor according to an embodiment of the invention.

Figures 5a-5h show alternative printed circuit layout diagrams of the loop antenna according to the present invention in cross-sectional views.

1: Ground sensor

3: receiver loop antenna

4: receiver

5: Energy storage

6: Resonant circuit

7: Launcher

8: Transmitter loop antenna

9: Controller

11: Telegraph unit

12: Planning interface

Claims (16)

An on-ground sensor, which will be fixedly placed between the tracks of a railway track to wirelessly send data to at least one vehicle antenna of a railway vehicle on the railway track. The on-ground sensor includes: A substantially planar dielectric circuit substrate. When the above-ground sensor is fixedly arranged between the two tracks, the dielectric circuit substrate has a first side facing upward and a second side facing downward, wherein the The circuit substrate has a substantially flat substrate thickness; A substantially rectangular receiver loop antenna, which is formed on the circuit substrate and has a receiver loop center trace along which a receiver loop physical length is defined, where the distance to the receiver loop antenna An input flux conforms to a predetermined input flux in the effective reference area of an on-ground sensor, and the receiver loop antenna is configured to receive wirelessly from a railway vehicle in the vicinity of the on-ground sensor The operating energy of a vehicle transmitter in a railway vehicle, The receiver circuit is connected to the receiver loop antenna by a receiver feed connection, and is configured to receive the operating energy from the receiver loop antenna, A substantially rectangular transmitter loop antenna, which is formed on the circuit substrate and has a transmitter loop center trace along which a transmitter loop physical length is defined. An output field corresponds to a field from a predetermined current surrounding the effective reference area of the ground sensor, and the transmitter loop antenna is configured to wirelessly transmit data to the ground sensor when a railway vehicle is in the vicinity of the ground sensor One of the vehicle receivers in the railway vehicle, The transmitter circuit is connected to the transmitter loop antenna by a transmitter feed connection, and is configured to feed a transmission signal including the data to the transmitter loop antenna, It is characterized by The receiver loop center trace and the transmitter loop center trace have an average separation distance that is at least twice the thickness of the dielectric substrate. For example, the ground sensor in claim 1, which further includes: As defined in free-space propagation, the physical length of the receiver loop is basically one-tenth or longer of a wavelength at the operating frequency of the receiver loop antenna. For example, the above ground sensor of claim 1 or 2, which further includes: The receiver loop antenna has two, three, four or more loop segments separated by separate gaps away from the receiver's feed connection, Each of the at least one gap is bridged by a separate capacitor to present a uniform current distribution in the receiver loop antenna. For example, the above-ground sensor in any one of Claims 1 to 3, which further includes: The at least one gap is positioned substantially on a line of symmetry of the receiver loop antenna and/or positioned substantially equidistantly along the receiver loop antenna. For example, the above-ground sensor in any one of Claims 1 to 4, which further includes: Both the receiver loop antenna and the transmitter loop antenna are formed on the circuit board in such a way that one is inside the other. For example, the ground sensor in claim 5, which further includes: The receiver loop antenna is formed inside the transmitter loop antenna. For example, the above-ground sensor in any one of Claims 1 to 6, which further includes: The receiver loop antenna is formed on both sides of the circuit substrate, and it is preferable that it overlaps itself. For example, the above-ground sensor in any one of Claims 1 to 7, which further includes: The transmitter loop antenna is formed on both sides of the circuit substrate, and preferably it can overlap itself. For example, the above-ground sensor in any one of Claims 1 to 6, which further includes: The receiver loop antenna is provided only on one of the side surfaces of the circuit substrate, preferably on the second side surface. For example, the above-ground sensor in any one of Claims 1 to 6, which further includes: The transmitter loop antenna is provided only on one of the side surfaces of the circuit substrate, preferably on the first side surface. Such as the above ground sensors of claim 1 to 6 or 9 to 10, it further includes: The transmitter loop antenna and the receiver loop antenna are only arranged on opposite sides of the circuit substrate. For example, the above-ground sensor in any one of Claims 1 to 11, which further includes: The thickness of the substrate is less than or equal to one tenth of an inch. For example, the above-ground sensor in any one of Claims 1 to 12, which further includes: The predetermined loop size range is defined as a difference between the physical length of the receiver loop and the physical length of the transmitter loop, and the value is at least 20 mm, preferably 40 mm. For example, the above-ground sensor of any one of claim items 1 to 13, which further includes: The effective reference area of the ground sensor is a rectangle of 358 mm by 488 mm, or 200 mm by 390 mm, which basically has a concentric and coplanar relationship with the receiver loop antenna and the transmitter loop antenna. For example, the above-ground sensor of any one of claim items 1 to 14, which further includes: A compliance condition for the receiver loop antenna and the transmitter loop antenna is +/- 1.5 dB, respectively. For example, the above-ground sensor of any one of claim items 1 to 15, which further includes: The ground sensor, its receiver loop antenna and its transmitter loop antenna are assembled according to the European standard ground sensor transmission system, SUBSET-036, Issue 3.1.0.

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