Train control support system and method

Abstract

To provide a method by which a control signal is correctly demodulated even when there is an individual difference between train car or long-term deterioration of an analog element in a path of the control signal received by the train cars.SOLUTION: A train control support system transmits an inspection signal as a simulated control signal to a route having one or a plurality of analogue elements on which a control signal received through a rail on which a train travels flows. For an inspection signal, A / D conversion is performed similarly to a control signal, level calculation is performed based on a parameter, and demodulation of a digital signal is performed. When a comparison result between an actually demodulated inspection signal and an inspection signal of a correct answer as the demodulated inspection signal satisfies a prescribed condition, the train control support system determines a correction value of a level based on a difference between a level of the calculated actual inspection signal and a level of the correct answer. A parameter following the determined correction value is the parameter used for level calculation in the operation of the train.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates generally to train control assistance, for example to on-board security devices for trains. [Background technology]

[0002] In general, a train control system automatically activates the brakes to slow down or stop the train if the train exceeds the speed limit by exchanging signals between ground equipment and on-board equipment.

[0003] The ATC (Automatic Train Control) system is a type of train control system. The ATC system receives and demodulates the ATC signal transmitted from the ground equipment via the rails. The rails, which serve as the signal transmission path, are also used as the return line for the power supplied to the train, so they cause noise when receiving and demodulating the ATC signal.

[0004] Therefore, when the ATC system receives and demodulates the ATC signal, it calculates the level (typically the level of the carrier wave) by digital signal processing. In the digital signal processing, a minimum level threshold is set. If the calculated level falls below the minimum level threshold, the signal-to-noise ratio of the ATC signal cannot be ensured, and as a result, there is a risk that the signal cannot be demodulated correctly.

[0005] For example, Patent Document 1 discloses a track circuit receiving device that automatically adjusts the amount of attenuation for the reception level of a train control signal in each track circuit, thereby keeping the reception level of each track circuit constant. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2001-213315 A Summary of the Invention [Problem to be solved by the invention]

[0007] Generally, ATC systems are designed so that the voltage level of the ATC signal can be read from the level calculated by digital signal processing. For example, if the voltage level is 300mVrms, the level calculated by digital signal processing indicates 3000 digits.

[0008] Parameters are used to calculate the level, but regardless of individual differences between vehicles, the parameters used for level calculation are set to fixed values, which causes variation in the level calculated by digital signal processing when the received ATC signal is demodulated.

[0009] In addition, when the analog elements in the path of the ATC signal received by the vehicle deteriorate over time, the calculated level varies even within the same vehicle (i.e., one vehicle).When the analog elements deteriorate over time, the level calculated by the digital signal processing when demodulating the received ATC signal falls below the minimum level threshold, and the ATC system may erroneously detect that it cannot demodulate the ATC signal.

[0010] According to the technology disclosed in Patent Document 1, even if the ATC signal cannot be demodulated correctly due to a failure of the on-board device, a short circuit or an open circuit in the signal line, etc., the attenuation amount may be automatically corrected for the noise level. If the ATC signal cannot be demodulated correctly, it may have a negative impact on train operation.

[0011] In view of the above problems, an object of the present invention is to correctly demodulate a control signal regardless of individual differences between cars of a train or deterioration over time of analog elements in the path of the control signal received by the car. [Means for solving the problem]

[0012] In order to achieve the above object, a representative train control support system according to the present invention transmits a test signal, which is a simulated control signal, to a path having one or more analog elements along which a control signal received through a rail on which a train runs. The test signal is A / D converted (analog / digital converted) in the same manner as the control signal, and a level is calculated based on set parameters, and the digital signal is demodulated. When a result of a comparison between the actual demodulated test signal and a correct test signal (the correct test signal as the demodulated test signal) satisfies a predetermined condition, the train control support system determines a correction value for the level based on the difference between the calculated level of the actual test signal and the correct level. The parameter according to the determined correction value is the above parameter used for level calculation in train operation. Effect of the Invention

[0013] According to the present invention, it is possible to correctly demodulate a control signal regardless of individual differences between cars of a train or deterioration over time of analog elements in the path of the control signal received by the car.

[0014] Problems, configurations and effects other than those described above will become apparent from the following embodiments. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic configuration diagram of a system including a train control support system according to an embodiment of the present invention. [Diagram 2] 1 is a configuration diagram of an on-board safety device to which a train control support system according to an embodiment of the present invention is applied. [Diagram 3] 3 is a flowchart showing a process from when the on-board safety device shown in FIG. 2 transmits an inspection signal to when a correction value is determined. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] An embodiment for carrying out the present invention will be described.

[0017] FIG. 1 is a schematic configuration diagram of a system including a train control support system according to an embodiment of the present invention.

[0018] The train control support system includes an inspection signal transmitting unit 110 and a correction value determining unit 140. The control signal receiving unit 120 and the control signal demodulating unit 130 are provided, for example, in each of one or more cars constituting a train. At least one of the inspection signal transmitting unit 110 and the correction value determining unit 140 in the train control support system may be provided in each car, or may be provided in a specified car (for example, the leading car).

[0019] The control signal demodulation section 130 includes a filter section 131, an amplifier section 132, a level calculation section 133, and a signal demodulation section 134.

[0020] During on-board inspection, the inspection signal transmitting unit 110 transmits an inspection signal (ATC signal for inspection) to the control signal receiving unit 120, and transmits a telegram of the inspection signal before modulation to the correction value determining unit 140. The inspection signal transmitted is an analog signal. The inspection signal may be transmitted as a digital signal, and D / A conversion (digital / analog conversion) may be performed before it is received by the control signal receiving unit 120, and the analog inspection signal may be input to the control signal receiving unit 120. The inspection signal transmitting unit 110 operates during on-board inspection that is performed before operation. On-board inspection is not performed while the vehicle is in operation.

[0021] The control signal receiving unit 120 is an interface that receives an inspection signal received from the inspection signal transmitting unit 110 during on-board inspection. When the train is in operation, the control signal receiving unit 120 receives an ATC signal (analog signal) flowing on the rail. The control signal receiving unit 120 has one or more analog elements through which the received analog control signal flows, and is configured to A / D convert (analog / digital convert) the analog control signal that has flowed through the one or more analog elements and output it.

[0022] During operation, the control signal demodulation unit 130 extracts the ATC signal (digital signal) received from the control signal receiving unit 120 using an internal filter unit 131, amplifies the lowered level in an amplifier unit 132, and finally calculates the voltage level using digital signal processing in a level calculation unit 133, and demodulates the modulated signal in a signal demodulation unit 134. During inspection, the same processing is performed on the inspection signal (digital signal) received from the control signal receiving unit 120.

[0023] The correction value determination unit 140 determines a correction value so that the voltage level can be read from the level calculated by digital signal processing, based on the message from the test signal transmission unit 110 and the test signal level received from the control signal demodulation unit 130. The correction value determination unit 140 transmits the calculation result to the control signal demodulation unit 130.

[0024] Hereinafter, an on-board safety device to which a train control support system according to an embodiment of the present invention is applied will be described with reference to the drawings.

[0025] FIG. 2 is a configuration diagram of an on-board safety device to which a train control support system according to one embodiment of the present invention is applied.

[0026] The on-board safety device mounted on a train car 201 includes at least some of an on-board inspection device 211, a power receiver 221, a transformer 222, an equipment cable 223, an anti-aliasing filter 224, an A / D converter 225, a signal processing calculation device 231, and a correction value calculation device 241 (for example, the on-board inspection device 211, the signal processing calculation device 231, and the correction value calculation device 241).

[0027] The on-board inspection device 211 transmits an inspection signal simulating an ATC signal during on-board inspection before operation to check that there are no abnormalities or failures in the train. Specific examples of the realization of the on-board inspection device 211 include a method of generating a digital signal generated by software processing using a DSP (Digital Signal Processor) or hardware processing using an FPGA (Field Programmable Gate Array) through D / A conversion, and a method of generating an arbitrary waveform or frequency from a crystal oscillator using a DDS (Direct Digital Synthesizer). Furthermore, the on-board inspection device 211 transmits a telegram of the inspection signal before modulation to the correction value calculation device 241. The on-board inspection device 211 corresponds to the inspection signal transmission unit 110 in FIG. 1.

[0028] The power receiver 221 is a coil that receives the ATC signal, and takes in the current that flows when the axle of the vehicle shorts the track by electromagnetic induction. The ATC signal received by the power receiver 221 is transmitted to the transformer 222.

[0029] The transformer 222 is designed to have the frequency band of the ATC signal as its passband, and performs insulation from the power receiver 221 and transforms the ATC signal according to the windings. The ATC signal is transmitted to the anti-aliasing filter 224 through the equipment cable 223.

[0030] The anti-aliasing filter 224 is a filter for preventing aliasing that occurs during sampling in the downstream A / D converter 225. An alias is a periodic noise that occurs when an analog signal is sampled into digital data and frequency components of half or more of the sampling frequency are mixed in.

[0031] The A / D converter 225 extracts the amplitude of the ATC signal, which is an analog signal, at discrete periods and converts it into digital data represented by codes. This digital data makes it possible to perform digital signal processing.

[0032] The above-mentioned power receiver 221, transformer 222, equipment cable 223, anti-aliasing filter 224, and A / D converter 225 correspond to the control signal receiving unit 120 in Fig. 1. The transformer 222, the equipment cable 223, and the anti-aliasing filter 224 are examples of one or more analog elements.

[0033] The signal processing calculation device 231 extracts the band components of the ATC signal converted to digital data by the A / D converter 225 using a digital filter, amplifies the lowered level, and finally performs message acquisition processing and level calculation processing by demodulation. Specific examples of the implementation of the signal processing calculation device 231 include software processing using a DSP (Digital Signal Processor) and hardware processing using an FPGA (Field Programmable Gate Array). Furthermore, this device 231 has a function of transmitting the demodulation result to the correction value calculation device 241 and a function of calculating the level by digital signal processing based on the correction value received from the correction value calculation device 241. The signal processing calculation device 231 corresponds to the control signal demodulation unit 130 in FIG. 1.

[0034] The correction value calculation device 241 determines a correction value based on the received processing result, and transmits the correction value to the signal processing calculation device 231. Specific examples of the implementation of the correction value calculation device 241 include software processing by a CPU (Central Processing Unit) and hardware processing by an FPGA. The correction value calculation device 241 receives a message before modulation of the inspection signal from the on-board inspection device 211, and receives a message acquisition processing result and a level calculation processing result by demodulation from the signal processing calculation device 231. The correction value calculation device 241 corresponds to the correction value determination unit 140 in FIG. 1.

[0035] Although the signal processing calculation device 231 and the correction value calculation device 241 are shown separately, these devices may be realized as an integrated device (for example, they may be realized as a single element by incorporating the logic of both into an FPGA). In addition, if a DSP and a CPU are used, a separate memory element such as a DPRAM (Dual-Ported Random Access Memory) may be required.

[0036] FIG. 3 is a flowchart showing the process from when the on-board safety device shown in FIG. 2 transmits an inspection signal to when the correction value is determined.

[0037] In step 3-1, the on-board inspection device 211 modulates a message for on-board inspection and transmits it as an inspection signal. The inspection signal passes through the transformer 222, reaches the equipment cable 223, the anti-aliasing filter 224, and the A / D converter 225. The voltage level of the inspection signal at this time is a voltage level that is predetermined and is higher than the minimum level threshold at which the ATC signal can be demodulated. This is because if the voltage level falls below the minimum level threshold, the signal-to-noise ratio of the ATC signal cannot be ensured, and as a result, there is a risk that the signal processing calculation device 231 will not be able to correctly demodulate the signal. In addition, since the voltage level is predetermined, it is possible to compare the signal with predetermined level information held in the correction value calculation device 241. Furthermore, the on-board inspection device 211 transmits the message before modulation of the inspection signal to the correction value calculation device 241.

[0038] The transformer 222 and the anti-aliasing filter 224 are both analog elements, and their characteristics change depending on tolerances and temperature. Similarly, the characteristics of the equipment cable 223 change depending on tolerances and temperature. In other words, even if the same model of vehicle is on the same line, there are individual differences between the vehicles. Also, it is considered that the characteristics of analog elements change depending on temperature and aging even in the same individual vehicle.

[0039] Next, in step 3-2, the A / D converter 225 converts the test signal into digital data and transmits the data.

[0040] Next, in step 3-3, the signal processing calculation device 231 performs a message acquisition process and a level calculation process by demodulation on the ATC signal that has become digital data.

[0041] Next, in step 3-4, the correction value calculation device 241 receives the demodulated data of the inspection signal received from the signal processing calculation device 231 and the calculated level information. Furthermore, the correction value calculation device 241 compares the demodulated data with the message before modulation of the inspection signal. The amount of data used for the comparison varies depending on the case, etc., but it is necessary for the amount of data to achieve the BER (Bit Error Rate) required for each case. From the comparison of the demodulated data with the message before modulation, it is possible to determine whether the BER requirement has been achieved (whether the BER is less than a predetermined value).

[0042] If the BER requirement is not met (step 3-4: No), it means that the requirements for the ATC signal reception and demodulation function are not met. Since there is a possibility that there is an abnormality in the equipment or cables in the ATC system, in step 3-5, the correction value calculation device 241 notifies the driver of the occurrence of the abnormality.

[0043] If the BER requirement is met (step 3-4: Yes), there is no abnormality in the devices or cables on the ATC system, and the requirements for the ATC signal reception and demodulation function are met. In step 3-6, the correction value calculation device 241 compares the level calculation information (information indicating the calculated level) with the level indicated by the predetermined level information held in the correction value calculation device 241 (for example, the level indicated by the received telegram). If there is a difference between the levels, it means that the relationship set at the time of product design, in which the voltage level can be read from the level calculated by digital signal processing, has collapsed. In this case, the correction value calculation device 241 determines a correction value so that the relationship in which the voltage level can be read from the level calculated by digital signal processing is maintained. The correction value calculation device 241 transmits the determined correction value to the signal processing calculation device 231. In addition, in determining the correction value, a correction value that exceeds the range that the correction value can take may be required. In that case, there is a risk that a relationship will not be established that allows the voltage level to be read from the level calculated by digital signal processing, so the correction value calculation device 241 may take into consideration the possibility of an abnormality and notify the driver of the occurrence of the abnormality.

[0044] Next, in step 3-7, the signal processing and calculation device 231 records the received correction value as an amplification parameter.

[0045] During subsequent operations, the level is calculated based on this correction value.

[0046] The following is an example of a summary of the above description. The following summary includes supplementary explanations or explanations of modifications of the above description (for example, explanations regarding functions that may be considered for addition).

[0047] A train control support system is constructed that includes an inspection signal transmitting unit 110 and a correction value determining unit 140. The inspection signal transmitting unit 110 transmits an inspection signal (a simulated control signal) to the control signal receiving unit 120.

[0048] The control signal receiving unit 120 is provided in a train car, receives an analog control signal (e.g., an analog ATC signal) through the rails on which the train runs, has one or more analog elements through which the analog control signal flows, and A / D converts and outputs the analog control signal that has flowed through the one or more analog elements. The control signal demodulating unit 130 in the car receives the digital control signal output from the control signal receiving unit 120, calculates the level of the received digital control signal based on set parameters, and demodulates the digital control signal. The same processing is performed on the inspection signal as on the control signal.

[0049] When a comparison result between the actual demodulated inspection signal output from the control signal demodulation unit 130 and the correct inspection signal as the demodulated inspection signal satisfies a predetermined condition, the correction value determination unit 140 determines a correction value for the level based on the difference between the level of the actual inspection signal calculated by the control signal demodulation unit 130 and the correct level. A parameter according to the determined correction value is a parameter used for level calculation in train operation. The parameter may be the correction value itself, or a value calculated using the correction value may be the parameter. In addition, the "parameter used for level calculation" may be used in the level calculation itself or in a process that affects the level calculation (for example, it may be used in the calculation by the level calculation unit 133 or used for amplification by the amplification unit 132).

[0050] This makes it possible to correctly demodulate the control signal regardless of individual differences between cars in a train or deterioration over time of analog elements in the path of the control signal received by the car.

[0051] The inspection signal transmitting unit 110 may transmit the pre-modulation message to the correction value determining unit 140. The correction value determining unit may identify the correct inspection signal and the correct level from the pre-modulation message. This makes it possible to maintain correct data for the inspection signal to be transmitted even if the inspection signal transmitted by the inspection signal transmitting unit 110 differs, for example, for each inspection. Note that the pre-modulation message may be stored in advance by the correction value determining unit 140 instead of being transmitted from the inspection signal transmitting unit 110 to the correction value determining unit 140 every time an inspection signal is transmitted.

[0052] The above-mentioned "predetermined condition" may be that the bit error rate of the actual demodulated inspection signal relative to the correct inspection signal is less than a predetermined value. This makes it possible to detect a possible abnormality in a portion in the process leading up to the signal demodulation. Note that the "predetermined condition" may be another condition, such as the difference between the feature amount of the actual demodulated inspection signal and the correct feature amount being equal to or less than a certain value, instead of or in addition to the bit error rate being less than a predetermined value.

[0053] The correction value determination unit 140 may issue an anomaly report if the above-mentioned predetermined conditions are not met. This makes it possible to avoid train operation in a situation where there is a risk of an anomaly in a part in the process leading up to signal demodulation. The anomaly report may be issued, for example, by notifying the driver or by notifying a predetermined upper-level computer system of the occurrence of the anomaly.

[0054] The correction value determination unit 140 may issue an anomaly notification if the actual inspection signal level or the determined correction value is not within a predetermined range. Since the A / D converter 225 has a quantization error, the calculated level varies, but if the range of variation is exceeded, it can be determined that there is an anomaly.

[0055] Furthermore, the test signal transmitting unit 110 may transmit level information of the test signal in addition to the message of the test signal before modulation to the correction value determining unit 140. In this case, the test signal transmitting unit 110 does not need to transmit the test signal at a predetermined voltage level, and the correction value determining unit 140 can determine the correction value by comparing the calculated level information received from the control signal demodulating unit 130. However, the level represented by the transmitted level information (level information of the test signal) needs to be a voltage level higher than the minimum level threshold at which the control signal can be demodulated.

[0056] In addition, in determining the correction value performed by the correction value determination unit 140, the level information calculated by the control signal demodulation unit 130 may be received multiple times. It is known that quantization error occurs when the analog voltage is replaced by the closest discrete value in the A / D converter 225. Therefore, if a correction is performed from the level information received once, the subsequent level calculation will be a correction including the quantization error performed during the inspection. Therefore, the influence of the quantization error can be reduced by taking a representative value such as an average value or a median value from the level information received multiple times. That is, the correction value determination unit 140 may determine a correction value for each of the levels calculated multiple times during the same inspection period, calculate a representative value of the obtained correction values, and use the representative value as the final correction value.

[0057] The correction value determining unit 140 may issue an anomaly alert if the actual level of the inspection signal or the determined correction value is not within a predetermined range.

[0058] After step 3-5, step 3-1 may be performed again. That is, after the correction value is determined by the correction value determination unit 140, the test signal transmission unit 110 may transmit the test signal, and the correction value determination unit 140 may check whether the above-mentioned predetermined condition is satisfied for the test signal based on the output from the control signal demodulation unit 130 and whether the calculated level is correct based on the correct level. This makes it possible to check whether the automatic correction of the level functions correctly. In addition, the condition at the time of checking is that the received level information is within a predetermined allowable error range with respect to the predetermined level information held by the correction value calculation device. This is because the received level information varies even when checking after correction due to the presence of a quantization error of the A / D converter.

[0059] The operation after the on-board inspection is finished and the train starts running is as follows. During the train running, the inspection signal transmission unit 110 and the correction value determination unit 140 do not operate. The control signal reception unit 120 and the control signal demodulation unit 130 operate, and the ATC signal flowing through the rail is constantly received and demodulated. During the train running, when the train arrives at the end of the line, it may be necessary to cut off the power supply to the on-board security device once in order to switch between the up and down directions of the line. This is because the specifications of the ATC signal, such as the frequency, change between the up and down directions. If the storage area of ​​the parameters according to the correction value calculated by the correction value determination unit 140 is a non-volatile storage area (for example, a non-volatile memory), the correction value received during the on-board inspection can be used again even if a power cut occurs. The recorded correction value can also be read out during the next on-board inspection.

[0060] The present invention is not limited to the above-described embodiment as it is, and in the implementation stage, the components can be modified and embodied without departing from the gist of the invention. In addition, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, components from different embodiments may be appropriately combined. [Explanation of symbols]

[0061] 110: inspection signal transmitting section, 120: control signal receiving section, 130: control signal demodulating section, 140: correction value determining section

Claims

1. An inspection signal transmitting unit; A correction value determination unit Equipped with a control signal receiving unit in a train car receives an analog control signal through a rail on which the train runs, has one or more analog elements through which the analog control signal flows, and performs A / D conversion (analog / digital conversion) on the analog control signal that flows through the one or more analog elements and outputs the analog control signal; a control signal demodulation unit in the vehicle receives the digital control signal output from the control signal receiving unit, calculates a level of the received digital control signal based on a set parameter, and demodulates the digital control signal; The test signal transmitting unit transmits an analog test signal, which is a test signal that is a simulated control signal, to the control signal receiving unit; the analog inspection signal is received by the control signal receiving unit, passes through the one or more analog elements, is A / D converted, and is output to the control signal demodulating unit, the digital inspection signal output from the control signal receiving unit is received by the control signal demodulating unit, and the control signal demodulating unit performs level calculation and demodulation on the digital inspection signal, the correction value determination unit determines a level correction value based on a difference between a level of the actual inspection signal calculated by the control signal demodulation unit and a correct level when a result of a comparison between the actual demodulated inspection signal output from the control signal demodulation unit and a correct inspection signal as the demodulated inspection signal satisfies a predetermined condition; The parameter according to the determined correction value is the parameter used for level calculation in the operation of the train. Train control assistance system.

2. the test signal transmission unit transmits data representing the correct test signal and a level of the correct answer to the correction value determination unit; The correction value determination unit identifies the correct test signal and the correct level from the data. The train control assistance system according to claim 1.

3. The predetermined condition is that a bit error rate of the actual demodulated check signal with respect to the correct check signal is less than a predetermined value. A train control assistance system according to claim 1 or 2.

4. The correction value determination unit issues an abnormality report when the predetermined condition is not satisfied. A train control assistance system according to any one of claims 1 to 3.

5. The correction value determination unit issues an abnormality report when the actual inspection signal level or the determined correction value is not within a predetermined range. A train control assistance system according to any one of claims 1 to 4.

6. the correction value determination unit determines a correction value for each of the levels calculated a plurality of times during the same inspection period, calculates a representative value of the obtained correction values, and sets the representative value as a final correction value; A train control assistance system according to any one of claims 1 to 5.

7. After the correction value is determined by the correction value determination unit, The inspection signal transmission unit transmits the inspection signal, the correction value determination unit confirms whether or not the predetermined condition is satisfied based on the output from the control signal demodulation unit for the inspection signal, and whether or not the calculated level is correct based on the correct level. A train control assistance system according to any one of claims 1 to 6.

8. A step of receiving an analog control signal through a rail on which a train runs and transmitting an analog test signal, which is a simulated control signal, to a control signal receiving unit through which the analog control signal flows; Steps for level correction having the control signal receiving unit is located in a vehicle of the train, has one or more analog elements through which the received analog control signal flows, and performs A / D conversion (analog / digital conversion) on the analog control signal that flows through the one or more analog elements and outputs the converted signal; a control signal demodulation unit in the vehicle receives the digital control signal output from the control signal receiving unit, calculates a level of the received digital control signal based on a set parameter, and demodulates the digital control signal; the analog inspection signal is received by the control signal receiving unit, passes through the one or more analog elements, is A / D converted, and is output to the control signal demodulating unit, the digital inspection signal output from the control signal receiving unit is received by the control signal demodulating unit, and the control signal demodulating unit performs level calculation and demodulation on the digital inspection signal, In the step of performing level correction, determining a level correction value based on a difference between the actual level of the inspection signal calculated by the control signal demodulation unit and the correct level when a comparison result between the actual demodulated inspection signal output from the control signal demodulation unit and the correct inspection signal as the demodulated inspection signal satisfies a predetermined condition; The parameter according to the determined correction value is the parameter used for level calculation in the operation of the train. Train control assistance method.

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