JP2012186878A - Signal receiving device for train control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal receiving device for train control that can properly determine whether the received signal is a regular signal, and can surely prevent an improper control by the false detection of the signal.SOLUTION: The signal receiving device includes: a signal generation means 1 that carries out diffusion modulation of a prescribed frequency signal based on the car information and outputs it as a spectrum diffusion signal; a pickup coil 2 that is supplied with the spectrum diffusion signal from a signal generation means 1; a signal detecting means 3 that detects a receiving level of a receiving signal sent to a secondary side of the pickup coil 2 by electromagnetic coupling of a wayside coil 9 installed along a track on which a train 5 runs and the pickup coil 2; and a determination means 4 that calculates a Q value of a peak frequency of the received signal, when the receiving level larger than the threshold set beforehand is detected by a signal detecting means 3, and when the Q value is within the range of upper and lower limit values, determines that the receiving signal is the regular signal by the electromagnetic coupling by the wayside coil 9 and the pickup coil 2.

Description

  The present invention relates to a train control signal receiver, and more particularly to a technique for determining whether or not a received signal is a regular signal for train control.

  Conventionally, train control devices such as ATS and ATC transmit signals from the vehicle upper side to the ground side by electromagnetically coupling the vehicle upper element mounted on the train and the ground element arranged along the track, In addition to performing predetermined control on the ground side, a signal is transmitted from the ground side to the upper side of the vehicle and predetermined control is performed on the upper side of the vehicle. And, a receiving device on the vehicle upper side (hereinafter referred to as “train control signal receiving device”) generally uses a frequency changing method as a method for detecting a signal from the ground side. In order to ensure versatility that can also be used as a receiver, and to ensure that signals can be received even if the resonance frequency of the ground element fluctuates, a spread spectrum method is adopted as a signal transmission method. Along with this, the method for detecting a signal from the ground side has been shifted from a frequency change method to a method corresponding to a signal by a spread spectrum method.

  As a train control signal receiving apparatus to which this type of signal detection method corresponding to a signal by a spread spectrum method is applied, for example, there is one described in Patent Document 1 or the like. In the train control signal receiving apparatus on the vehicle upper side described in Patent Document 1, when the train passes over the ground element, the vehicle upper element and the ground element are electromagnetically coupled, and at this time, the signal is transmitted from the secondary side of the vehicle upper element. The received signal shows a frequency distribution having a peak at a frequency corresponding to the frequency of the ground unit. The train control signal receiving device is configured to determine that the train control signal from the ground unit is received when the reception level at the peak frequency exceeds a certain level. Thus, the conventional train control signal receiving device is configured to detect the presence or absence of a train control signal by electromagnetic coupling with the ground unit based on whether or not the reception level exceeds a predetermined level.

JP 2007-28877 A

  However, in the conventional train control signal receiving apparatus mounted on the upper side of the vehicle described in the above-mentioned Patent Document 1 or the like, for example, impulse noise having the same frequency as the resonance frequency of the ground element or a frequency approximate thereto is received. In some cases, the reception level of the reception signal may locally increase in the vicinity of the resonance frequency of the ground element. In addition, if there is an object such as a steel plate on the track or a reinforcing bar in the reinforced concrete floor (slab) under the track, the reception level of the received signal will be increased when the train upper element passes over the object. It may increase overall over the entire frequency of the received signal. Therefore, since the conventional train control signal receiving apparatus simply detects the train control signal based on whether the reception level exceeds a predetermined level, it is caused by impulse noise, iron plates on the track, etc. If the reception level rises, there is a risk that it may be judged that a signal for train control has been received even though the car upper and the ground are not electromagnetically coupled. There is a problem that it may invite inappropriate control.

  The present invention has been made paying attention to the above problems, and even in an environment where there is a possibility that the reception level will increase due to impulse noise from the outside, an iron plate on the orbit, etc., the received signal is normal. It is an object of the present invention to provide a train control signal receiving apparatus that can appropriately determine whether or not a signal is present and can reliably prevent inappropriate control due to erroneous detection of the signal.

  In order to achieve the above object, a signal receiving apparatus for train control according to the present invention comprises a signal generating means for spreading and modulating a predetermined frequency signal based on on-board information and outputting it as a spread spectrum signal, and the signal generating means. Received from the vehicle upper member to which the spread spectrum signal from the vehicle is supplied, and to the secondary side of the vehicle upper member by electromagnetic coupling between the ground member provided along the trajectory of the train and the vehicle upper member. A signal detection means for detecting a reception level of the signal; and when a reception level equal to or higher than a predetermined threshold is detected by the signal detection means, a Q value of a peak frequency of the reception signal is calculated, and the Q value is And determining means for determining that the received signal is a normal signal due to electromagnetic coupling between the ground element and the vehicle element when it is within a predetermined upper and lower limit value range. .

  With such a configuration, the reception level of the reception signal sent to the secondary side of the vehicle upper element is detected by electromagnetic coupling between the vehicle upper element and the ground element, and the reception level equal to or higher than a predetermined threshold is detected by the signal detection. When detected by the means, the Q value of the peak frequency is calculated, and when this Q value is within a predetermined upper and lower limit value range, the received signal is a normal signal due to electromagnetic coupling between the ground element and the vehicle upper element. It is determined that it is a signal.

  According to the train control signal receiving apparatus of the present invention, when the calculated Q value is within a predetermined upper and lower limit value when a reception level equal to or higher than the threshold is detected, It can be determined that the received signal sent to the side is a normal signal due to electromagnetic coupling between the ground element and the vehicle upper element. Therefore, by appropriately setting the range of the Q value for determining that it is a regular signal, for example, a disturbance with a high Q value caused by impulse noise from the outside, or the like is laid on the ground side. Even when a disturbance having a low Q value due to an iron plate or the like is generated, it is not erroneously determined that a regular signal has been received. In this way, it is possible to provide a train control signal receiving apparatus that can reliably prevent erroneous signal detection and can perform appropriate control.

It is a schematic block diagram which shows one Embodiment of the signal receiving apparatus for train control which concerns on this invention. In this embodiment, it is a graph which shows the waveform of a reception level when a reception level rises by the electromagnetic coupling of a vehicle upper child and a ground child. In this embodiment, it is a graph which shows the waveform of a reception level when the reception level near the resonant frequency of a ground element rises by impulse noise. In this embodiment, it is a graph which shows the waveform of a reception level when a reception level raises with an iron plate etc. FIG. It is a flowchart which shows control operation of the signal receiving apparatus for train control which concerns on this embodiment.

Hereinafter, an embodiment of a signal receiving apparatus for train control according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an embodiment of the train control signal receiving apparatus.
In FIG. 1, a signal receiving device for train control of this embodiment includes a signal generating means 1 for outputting a spread spectrum signal, a vehicle upper 2 to which the spread spectrum signal is supplied, a signal detecting means 3, and a judging means. 4. In this embodiment, the train control signal receiving device also constitutes the onboard device 10 of the train control device that controls the train 5, and the signal generating means 1 and the onboard child 2 are generally used. It also constitutes a train control signal transmission device in the on-board device 10.

  The signal generating means 1 spreads and modulates a predetermined frequency signal based on the on-board information and outputs it as a spread spectrum signal. The signal generating means 1 is provided in the on-board device 10 mounted on the train 5 and modulates the signal. And a signal generating circuit 7 and a first connecting transformer 8.

  The modulator 6 generates on-board information to be sent from the vehicle upper element 2 to the ground element 9 provided along the trajectory traveled by the train, and is connected to the signal generating circuit 7. The on-vehicle information is output to the signal generation circuit 7.

  The signal generation circuit 7 spreads and modulates a predetermined frequency signal based on the on-board information output from the modulator 6 and outputs a spread spectrum signal. For example, as shown as a transmission signal in FIG. 4 to be described later, this spread spectrum signal has a wide band so as to include a frequency band used for train control centered on a resonance frequency f (eg, 103 kHz) of the ground unit 9. Shows the spread frequency characteristics.

  The first connection transformer 8 is connected to the signal generation circuit 7 and outputs the spread spectrum signal output from the signal generation circuit 7 to the vehicle upper element 2.

  The vehicle upper 2 is supplied with a spread spectrum signal from the signal generating means 1, and includes a primary side coil 2 a and a secondary side coil 2 b, and is provided at a lower end of the train 5. It has been. The primary coil 2 a of the vehicle upper 2 is connected to the signal generation circuit 7 via the first connection transformer 8. The secondary coil 2b of the vehicle upper 2 is connected to the primary side of the second connection transformer 11 described later. The spread spectrum signal generated by the signal generating means 1 is sent to the ground side via the primary coil 2a of the vehicle upper 2 and also sent to the secondary coil 2b. When the train 5 passes over the ground element 9, the vehicle upper element 2 and the ground element 9 are electromagnetically coupled. At this time, a received signal (spread spectrum) sent from the secondary coil 2 b of the vehicle upper element 2 to the second connection transformer 11. Signal) shows a frequency distribution having a peak at a frequency corresponding to the resonance frequency of the ground element 9, and its spectral energy density changes.

  The signal detection means 3 detects the reception level of the received signal sent to the secondary coil 2b of the vehicle upper element 2 by electromagnetic coupling between the vehicle upper element 2 and the ground element 9, and the second connecting transformer 11 And an A / D conversion circuit 12, an FFT operation processing unit 13, and a signal detection unit 14.

  As described above, the second connection transformer 11 is connected to the secondary coil 2b of the vehicle upper 2 and outputs a signal from the secondary coil 2b of the vehicle upper 2 to the A / D conversion circuit 12. To do.

  The A / D conversion circuit 12 is connected to the secondary side of the second connection transformer 11 and converts an analog signal obtained from the secondary side of the second connection transformer 11 into a digital signal.

  The FFT calculation processing unit 13 samples the reception signal converted into a digital signal by the A / D conversion circuit 12 at a predetermined time, performs frequency analysis, calculates a reception level for each frequency, and outputs the signal to the signal detection unit 14. Output.

  The signal detection unit 14 presets a minimum operation level as a threshold for detecting the presence / absence of a reception signal from the ground in the same manner as in the past, and a reception exceeding the minimum operation level in the output signal of the FFT operation processing unit 13 It detects whether or not there is a level signal. The signal detection unit 14 is connected to the determination unit 4 and outputs a signal having a reception level for each frequency from the FFT calculation processing unit 13 to the determination unit 4 when a reception level equal to or higher than the minimum operation level is detected.

  The determination unit 4 calculates the Q value of the peak frequency f0 of the received signal when the reception level equal to or higher than the minimum operation level (threshold) is detected by the signal detection unit 3, and this Q value is determined in advance. When it is within the range of the lower limit value, the received signal is determined to be a normal signal due to electromagnetic coupling between the ground element 9 and the vehicle upper element 2. Specifically, the determination unit 4 is constituted by, for example, a CPU, detects a peak frequency f0 based on a signal output from the signal detection unit 14, and calculates a Q value of the peak frequency f0. The peak frequency f0 is a frequency indicating the maximum reception level among the reception levels for each frequency of the reception signal calculated by the FFT calculation processing unit 13, and coincides with the resonance frequency f (for example, 103 kHz) that the ground unit 9 has. . In addition, since the resonance frequency f of the ground element 9 may fluctuate slightly due to aging of the ground element 9 or the like, the peak frequency f0 also varies slightly according to the fluctuation. Further, the determination means 4 calculates, for example, the difference between the detected peak frequency f0 and the previously stored resonance frequency f of the ground element 9, and this difference is the slight fluctuation of the resonance frequency f of the ground element 9 described above. It is configured to determine whether or not it is within an allowable value determined in consideration of the above. For example, the determination means 4 calculates the Q value as described above when the difference from the resonance frequency f of the ground element 9 stored in advance is equal to or less than the allowable value, and if the difference exceeds the allowable value, the Q value It is configured to determine that noise has been received without this.

Here, the Q value is a value indicating the sharpness of the peak frequency f0. The higher the Q value, the higher the sharpness, and the smaller the Q value, the lower the sharpness. The Q value is a value generally defined based on the frequencies f1 and f2 (the frequencies near the top and bottom of the peak frequency f0) corresponding to the reception level that is 3 dBv lower than the reception level of the peak frequency f0 and the peak frequency f0. It is represented by the formula of
Q = f0 / (f2-f1)... Formula (1)
The lower limit value Qmin of the Q value is appropriately set corresponding to a disturbance with low sharpness caused by an iron plate or the like on the track, and the upper limit value Qmax of the Q value is a sharpness value caused by impulse noise or the like. Appropriately set for high disturbances.

  In the present embodiment, the determination unit 4 is configured to calculate the Q value based on the data table instead of directly calculating the Q value by the general method based on the formula (1). Specifically, as shown in FIG. 2, the determination means 4 determines the difference between the reception level at the peak frequency f0 and the reception level at frequencies near the top and bottom (f1, f2) separated from the peak frequency f0 by a predetermined frequency df. Each of the values (α, β) is calculated, and the Q value corresponding to the difference value calculated based on the data in the data table that stores the data indicating the correspondence relationship between the Q value and the difference value in advance is obtained. Has been. Here, the predetermined frequency df can be arbitrarily set according to the frequency resolution of the FFT arithmetic processing unit 13 or the like, and is set to 1 kHz, for example. With such a configuration, the determination unit 4 in this embodiment is configured such that the difference value α between the reception level at the peak frequency f0 and the reception level at the frequency f1, and the difference value between the reception level at the peak frequency f0 and the reception level at the frequency f2. β is obtained, the obtained difference values are added, and the Q value associated with the added value (α + β) is read from the data table to obtain the Q value.

  As shown in FIG. 2, when the calculated Q value is within the range between the lower limit value Qmin and the upper limit value Qmax, the determination means 4 determines that a regular signal has been input, for example, output control not shown. The determination result is output to the section. And this output control part outputs the control signal with respect to predetermined apparatuses, such as a drive motor and a brake of a train, based on the determination result obtained from the determination means 4.

  In addition, as shown in FIG. 3, when the calculated Q value is larger than the upper limit value Qmax, the determination means 4 is externally the same frequency as the resonance frequency of the ground element 9 (the center frequency of the spread spectrum signal) or an approximation thereof. Frequency impulse noise is received, it is determined that the reception level of the received signal has increased due to the impulse noise, and the received signal is determined to be an abnormal signal. In this case, for example, the reception signal is not output to the above-described output control unit, and inappropriate train control due to the abnormal signal is prevented. Although not shown, when impulse noise having a frequency significantly different from the resonance frequency f of the ground element 9 is generated, the determination means 4 uses the detected peak frequency f0 and the ground element stored in advance as described above. It is determined that the received signal is an abnormal signal without detecting that the difference from the resonance frequency f of 9 exceeds the allowable value and calculating the Q value.

  Then, as shown in FIG. 4, when the calculated Q value is smaller than the lower limit value Qmin, the determination means 4 has an overall reception level increased by an object other than the ground element 9 such as an iron plate on the orbit. It is determined that the received signal is an abnormal signal, and inappropriate control of the train is prevented as in the case where the Q value is larger than the upper limit value Qmax.

  A plurality of the above-mentioned ground elements 9 provided along the trajectory are provided at predetermined locations in the trajectory with a predetermined interval. The ground unit 9 is configured to output the spread spectrum signal generated by the signal generating means 1 of the on-board device 10 to the ground device 20 when electromagnetically coupled to the on-board unit 2. The ground device 20 recognizes on-board information based on the spread spectrum signal output from the signal generation circuit 7, and this on-board information is used for controlling various trains 5. The ground element 9 is constituted by a resonance circuit. With this configuration, when the ground element 9 and the vehicle upper element 2 are electromagnetically coupled, the spectrum of the received signal (spread spectrum signal) sent from the secondary coil 2b of the vehicle upper element 2 to the second connection transformer The energy density is changed corresponding to the resonance frequency of the ground element 9. The on-board device 10 recognizes a signal from the ground element 9 based on the spread spectrum signal received from the secondary coil 2b of the on-board element 2, and the signal from the ground element 9 is the output control unit described above. And used for predetermined device control such as a drive motor and a brake of the train 5.

  Next, the control operation of the train control signal receiving apparatus according to the present embodiment will be described with reference to the flowchart shown in FIG. In the following description, it is assumed that the difference between the frequency of the impulse noise and the resonance frequency f of the ground element 9 is within an allowable value determined in consideration of the slight variation of the resonance frequency f of the ground element 9 described above. explain.

  When the on-board device 10 is turned on by starting operation of the train 5 (STEP 1; Yes), the modulator 6 generates predetermined on-board information and outputs it to the signal generation circuit 7. Based on the on-board information from the modulator 6, the signal generation circuit 7 generates a spread spectrum signal obtained by spreading and modulating a predetermined frequency signal (STEP 2), and sends it to the on-board element 2 via the first connection transformer 8. Output (STEP 3). Then, when the vehicle upper element 2 is electromagnetically coupled to the ground element 9 by the traveling of the train 5, the spread spectrum signal is received by the ground element 9, and the received spread spectrum signal is output to the ground device 20, It is used as on-board information for train control in the apparatus 20. When a reception signal is input from the secondary coil 2 b of the vehicle upper element 2, the reception signal is output to the A / D conversion circuit 12 via the second connection transformer 11, and is output by the A / D conversion circuit 12. Converted to a digital signal. Then, the digitally converted received signal is sampled at a certain time interval by the FFT arithmetic processing unit 13 and subjected to frequency analysis processing. The output of the FFT arithmetic processing unit 13 is detected by the signal detecting unit 14 and received. When the level is equal to or higher than the threshold value (STEP 4; Yes), a signal of the reception level for each frequency from the FFT calculation processing unit 13 is output to the determination unit 4. Next, the determination unit 4 detects the peak frequency f0, and compares the received level at the detected peak frequency f0 with the received level at frequencies near the top and bottom (f1, f2) separated from the peak frequency f0 by a predetermined frequency df. The difference values (α, β) are calculated, the difference values (α, β) are added, and the Q value corresponding to the difference value (α + β) calculated by the addition is calculated based on the data in the data table. (STEP 5). If the Q value is equal to or greater than the lower limit value Qmin (STEP 6; Yes), the process proceeds to the next step. In STEP 7, if the Q value is equal to or less than the upper limit value Qmax (STEP 7; Yes), the received signal is a ground signal. It is determined that the signal is a regular signal due to electromagnetic coupling with the vehicle top (STEP 8), and a signal is output to the above-described output control unit so as to control the vehicle upper side based on the received signal (STEP 9). When the power of the on-board device 10 is not cut off, the process returns to STEP 2 (STEP 10; No), and when the power of the on-board device 10 is cut off, the control operation ends (STEP 10; Yes). Further, if the Q value is smaller than the lower limit value Qmin in STEP 6 (STEP 6; No), it is determined that the signal is erroneously detected due to an iron plate or the like on the track (STEP 11), and if the Q value is larger than the upper limit value Qmax in STEP 7 ( (STEP 7; No) is determined as a signal misdetection caused by impulse noise from outside (STEP 12), and in any case (STEP 6; No, and STEP 7; No), the received signal is an electromagnetic wave between the ground element and the vehicle upper element. It is determined that the signal is not a regular signal due to coupling (STEP 13), and the process proceeds to STEP 10. Even when the reception level is lower than the threshold value in STEP 4 (STEP 4; No), it is determined that the received signal is not a normal signal due to electromagnetic coupling between the ground element and the vehicle upper element (STEP 13). Proceed to STEP 10.

  Note that, as in the present embodiment, the determination unit 4 is configured to indirectly calculate the Q value based on the data table, so that the frequency resolution performance of the FFT processing unit 13 is low and the reception level of the peak frequency f0 is low. Even when it is not possible to calculate a frequency corresponding to a reception level that is 3 dBv lower than that, an extremely high Q value can be calculated like impulse noise. As described above, the train control signal receiving apparatus according to the present embodiment can use the low-resolution FFT arithmetic processing unit 13 that is relatively low in cost, and therefore calculates an extremely high Q value without increasing the cost. Can do.

  In all the descriptions above, the determination unit 4 has been described with a configuration in which the Q value is indirectly calculated based on the data table. However, the determination unit 4 is not limited to this and corresponds to a reception level that is 3 dBv lower than the reception level of the peak frequency f0. The configuration may be such that the Q value is directly calculated based on the equation (1) using the high-resolution FFT calculation processing unit 13 capable of calculating the frequency.

1 Signal generating means 2 Car upper 2b Secondary side of the car upper (secondary coil of the car upper)
3 Signal detection means 4 Judgment means 5 Train 9 Ground unit

Claims (2)

A signal generating means for spreading and modulating a predetermined frequency signal based on on-vehicle information and outputting it as a spread spectrum signal;
A vehicle upper arm to which a spread spectrum signal from the signal generating means is supplied,
A signal detection means for detecting a reception level of a reception signal sent to a secondary side of the vehicle upper element by electromagnetic coupling between a ground element provided along a track traveled by a train and the vehicle upper element;
When a reception level equal to or higher than a predetermined threshold is detected by the signal detection means, the Q value of the peak frequency of the reception signal is calculated, and the Q value is within a predetermined upper and lower limit value range Determining means for determining that the received signal is a regular signal due to electromagnetic coupling between the ground element and the vehicle upper element;
A signal receiver for train control, comprising:   The determination means calculates a difference value between a reception level at the peak frequency and a reception level at a frequency separated from the peak frequency by a predetermined frequency, and stores in advance data indicating a correspondence relationship between the Q value and the difference value The train control signal receiving apparatus according to claim 1, wherein a Q value corresponding to the calculated difference value is obtained based on the data in the data table.

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