Track loop monitoring device

Abstract

The present invention provides a track circuit monitoring device that can determine the phase difference between track voltage and local voltage with high accuracy. [Solution] The track circuit monitoring device 1 is characterized by comprising: a track voltage acquisition unit 1A that acquires a track voltage V111 used for detecting the presence of a track based on the voltage V11 of the section rails; a local voltage acquisition unit 1B that acquires a local voltage V121 used for detecting the presence of a track based on the voltage V12 of the local power distribution line; a phase difference calculation unit 1C that can calculate the phase difference between the track voltage V111 and the local voltage V121 using multiple calculation methods; and a calculation method specification unit 1D that can changely select and specify the calculation method used for calculating the phase difference from among multiple calculation methods for the phase difference calculation unit 1C.

Description

Technical Field

[0001] The present invention relates to a track circuit monitoring device for monitoring a track circuit for detecting an on-line state in a railway.

Background Art

[0002] Conventionally, a track circuit for detecting an on-line state in a railway has been provided. In such a track circuit, the on-line state is detected for each section of a railway rail electrically divided into a plurality of sections. This detection of the on-line state utilizes a configuration in which the section rail of each section is electrically short-circuited via the axle of a train when the train is on-line, and is performed based on measurement of the track voltage in the section rail or the like. By detecting the on-line state by the track circuit, operations such as controlling the operation of trains so that, for example, only one train is on-line in each section become possible, and situations such as multiple trains approaching each other too closely during running can be effectively avoided.

[0003] Here, a track circuit monitoring device for monitoring whether such a track circuit is operating normally is known (see, for example, Patent Document 1). In the device described in Patent Document 1, an alternating voltage is applied to the section rail in the track circuit, and an alternating voltage is also applied to a local distribution line installed near the section rail. Then, the track circuit is monitored based on various parameters including the track voltage of the section rail, the local voltage of the local distribution line, and the phase difference between the two in these applied states. In particular, the phase difference between the track voltage and the local voltage is an important parameter in on-line management.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in track circuits, for example, to avoid interference with the overhead line voltage for pantographs, an AC voltage shifted by dividing the frequency from the commercial frequency is sometimes applied to the section rails, and then the frequency is doubled by the track circuit monitoring device to return it to the original commercial frequency. The voltage waveform of the track voltage acquired by the track circuit monitoring device after frequency division and doubling may be distorted, and if this distortion is large, the accuracy of acquiring the phase difference required by the track circuit monitoring device may decrease. And such a decrease in the accuracy of acquiring the phase difference may lead to difficulties in track presence management by the track circuit monitoring device, which is undesirable.

[0006] Therefore, the present invention aims to provide a track circuit monitoring device that can determine the phase difference between track voltage and local voltage with high accuracy, taking into account the circumstances described above. [Means for solving the problem]

[0007] To solve the above problems, the track circuit monitoring device monitors the state of a track circuit for detecting the presence of a train in a section of a railway rail that is electrically divided into multiple sections, based on the voltage of the section rail to which a first AC voltage is applied and which is electrically short-circuited when a train is present, and the voltage of a local power distribution line installed near the section rail to which a second AC voltage is applied. The track circuit monitoring device is characterized by comprising: a track voltage acquisition unit that acquires the track voltage used for detecting the presence of a train based on the voltage of the section rail; a local voltage acquisition unit that acquires the local voltage used for detecting the presence of a train based on the voltage of the local power distribution line; a phase difference calculation unit that can calculate the phase difference between the track voltage and the local voltage using a plurality of calculation methods; and a calculation method specification unit that can changely select and specify the calculation method used for calculating the phase difference from the plurality of calculation methods to the phase difference calculation unit.

[0008] According to the above-described track circuit monitoring device, the phase difference between the track voltage and the local voltage is determined using a calculation method that can be selected and specified from among multiple calculation methods. This allows for operations such as attempting to obtain the phase difference using multiple calculation methods and deriving the calculation method that yields the phase difference most similar to the measurement result of a portable phase meter used for on-site verification. In addition to operation using a phase meter, a majority-rule operation is also possible, where the number of calculation methods that yield similar results is determined and the set of calculation methods with the largest number of similar results is derived. In the majority-rule operation, one calculation method may be arbitrarily selected from the one or more calculation methods derived and used to obtain the phase difference, or the average value of the results obtained using all one or more calculation methods may be adopted. In any case, by providing a calculation method specification section that allows selection and specification from among multiple calculation methods, it is possible to obtain the most reliable phase difference. In other words, according to the above-described track circuit monitoring device, the phase difference between the track voltage and the local voltage can be determined with high accuracy.

[0009] Here, it is preferable that the plurality of calculation methods include a center crossing calculation method that calculates the phase difference based on the time difference between the time at which the voltage waveform of the orbital voltage intersects with the orbital center voltage, which is the center of the voltage waveform, and the time at which the voltage waveform of the local voltage intersects with the local center voltage, which is the center of the voltage waveform.

[0010] In this configuration, one calculation method employs a center crossing method that uses the orbital center crossing time and local center crossing time, which are easy to grasp when the voltage waveforms of the orbital voltage and local voltage are typical sinusoidal waveforms or similar waveforms with little distortion. In other words, when the voltage waveforms of the orbital voltage and local voltage are typical sinusoidal waveforms or similar waveforms, the calculation method specification unit can specify the center crossing calculation method to effectively obtain the phase difference with high accuracy.

[0011] Furthermore, it is preferable that the plurality of calculation methods include an offset crossing calculation method that calculates the phase difference based on the time difference between the time at which the voltage waveform of the orbital voltage intersects with an orbital offset voltage offset by a predetermined voltage from the center of the voltage waveform, and the time at which the voltage waveform of the local voltage intersects with a local offset voltage offset by a predetermined voltage from the center of the voltage waveform.

[0012] In this configuration, one calculation method employs an offset crossover calculation method that uses the track offset crossover time and local offset crossover time, which are easier to understand while avoiding distortion when distortion occurs near the center of the voltage waveform in the track voltage and local voltage. In other words, when distortion occurs near the center of the voltage waveform, the calculation method specification unit can specify the offset crossover calculation method to effectively obtain the phase difference with high accuracy.

[0013] Furthermore, it is preferable that the plurality of calculation methods include a maximum / minimum calculation method that calculates the phase difference based on the time difference between the orbital maximum time when the voltage waveform of the orbital voltage reaches its maximum value and the local maximum time when the voltage waveform of the local voltage reaches its maximum value, or the time difference between the orbital minimum time when the voltage waveform of the orbital voltage reaches its minimum value and the local minimum time when the voltage waveform of the local voltage reaches its minimum value.

[0014] In this configuration, when distortion is large near the center of the voltage waveform in the orbital voltage and local voltage, a maximum / minimum calculation method using the orbital maximum time, local maximum time, orbital minimum time, and local minimum time is adopted as one calculation method, which makes it easier to grasp while avoiding distortion. In other words, when distortion is large near the center of the voltage waveform, the calculation method specification unit can specify the maximum / minimum calculation method, which allows for effective acquisition of the phase difference with high accuracy.

[0015] Furthermore, it is preferable that the plurality of calculation methods include an average calculation method for calculating the phase difference based on the average value of a first time difference, which is the time difference between the time at the first location on the track in the voltage waveform of the track voltage and the time at the first local location where a change corresponding to the first location on the track occurs in the voltage waveform of the local voltage, and a second time difference, which is the time difference between the time at a second location on the track that is different from the first location on the track in the voltage waveform of the track voltage and the time at the second local location where a change corresponding to the second location on the track occurs in the voltage waveform of the local voltage.

[0016] In this configuration, when the distortion of the voltage waveforms in the orbital voltage and local voltage is random, an average calculation method is employed that improves the accuracy of time difference acquisition by using the average of two time differences. In other words, when the distortion of the voltage waveform is random, the calculation method specification unit can specify the average calculation method, which allows for effective acquisition of the phase difference with high accuracy.

[0017] Furthermore, it is even more preferable that the first track location is a location where the voltage waveform of the track voltage intersects a predetermined track threshold voltage in the rising direction, the first local location is a location where the voltage waveform of the local voltage intersects a predetermined local threshold voltage in the rising direction, the second track location is a location where the voltage waveform of the track voltage intersects the track threshold voltage in the falling direction, and the second local location is a location where the voltage waveform of the local voltage intersects the local threshold voltage in the falling direction.

[0018] With this configuration, when there is a difference in waveform change between the rising and falling directions in the voltage waveforms of the orbital voltage and local voltage, the average calculation method can suppress the influence of such differences and obtain the phase difference.

[0019] Further, it is more preferable that the first position on the track is a position where the voltage waveform of the track voltage reaches the maximum value, the first local position is a position where the voltage waveform of the local voltage reaches the maximum value, the second position on the track is a position where the voltage waveform of the track voltage reaches the minimum value, and the second local position is a position where the voltage waveform of the local voltage reaches the minimum value.

[0020] According to this configuration, when the distortion at the maximum value and the minimum value of the voltage waveforms of the track voltage and the local voltage is small but the waveform change is poor and it is somewhat difficult to specify the maximum / minimum, in the average calculation method, it is possible to suppress the influence of the error in such specification and obtain the phase difference.

[0021] Further, it is preferable that the calculation method specifying unit can set the calculation method specified for the phase difference calculation unit among the plurality of calculation methods in response to a predetermined operation.

[0022] According to this configuration, an operator can calculate the phase difference while manually changing the calculation method, and perform operations such as deriving an optimal calculation method by comparing each calculation result with the measurement result of the phase meter and comparing a plurality of calculation results with each other.

[0023] Further, it further includes a state grasping unit that grasps the on-line state based on the track voltage and the phase difference, and the calculation method specifying unit can set the calculation method specified for the phase difference calculation unit among the plurality of calculation methods for each of the plurality of on-line states in the section, and when a change occurs in the on-line state grasped by the state grasping unit, the calculation method specified for the phase difference calculation unit is switched from the calculation method set for the on-line state before the change to the calculation method set for the on-line state after the change, which is preferable.

[0024] According to this configuration, by presetting an optimal calculation method for the phase difference for each on-line state, the phase difference in each on-line state can be obtained with high accuracy during the operation of the train.

Advantages of the Invention

[0025] According to the above track circuit monitoring device, the phase difference between the track voltage and the local voltage can be obtained with high accuracy.

Brief Description of the Drawings

[0026] [Figure 1] It is a schematic configuration diagram showing an example of a track circuit that is a monitoring target of one embodiment of the track circuit monitoring device. [Figure 2] It is a schematic configuration diagram showing the track circuit monitoring device shown in FIG. 1. [Figure 3] It is a schematic diagram showing the functional blocks of the track circuit monitoring device shown in FIG. 1. [Figure 4] It is a schematic diagram showing two types of center intersection calculation methods and one type of average calculation method which is a modified method among the phase difference calculation methods that can be specified by the calculation method specifying unit. [Figure 5] It is a schematic diagram showing two types of offset intersection calculation methods and one type of average calculation method which is a modified method among the phase difference calculation methods that can be specified by the calculation method specifying unit. [Figure 6] It is a schematic diagram showing two types of maximum / minimum calculation methods and one type of average calculation method which is a modified method among the phase difference calculation methods that can be specified by the calculation method specifying unit. [Figure 7] It is a schematic flowchart showing the flow of processing executed by the track circuit monitoring device shown in FIGS. 1 to 3. [Figure 8] It is a schematic flowchart showing the flow of processing focusing on the setting of the specification rule of the phase difference calculation method for the setting process shown in FIG. 7. [Figure 9] It is a schematic flowchart showing the flow of the monitoring process shown in FIG. 7. [Figure 10] It is an example chart diagram showing how the on-line state is grasped in the state grasping process shown in FIG. 9. [Figure 11] It is a diagram showing the state information generated in the example shown in the chart diagram of FIG. 1 O.

Mode for Carrying Out the Invention

[0027] An embodiment of the track circuit monitoring device will be described below with reference to the drawings.

[0028] Figure 1 is a schematic diagram showing an example of a track circuit that is monitored by one embodiment of the track circuit monitoring device.

[0029] The track circuit L1 shown in Figure 1 is a circuit including a railway rail L1a for detecting the presence of a train on a railway line. The railway rail L1a is divided into a station section A2 that passes through station ST1 and a block section A1 sandwiched between station sections A2. A signal SG1 is installed at the boundary between station section A2 and block section A1. Block section A1 is further divided into multiple sections A11. Each section A11 is provided with a section rail L11, and adjacent sections A11 are electrically separated from each other by the section rails L11. A first AC voltage of 2V to 3V at commercial frequency is applied to the section rail L11 of each section A11 from a first power supply E11. When a train is present in section A11, the section rail L11 is electrically short-circuited by the train's axle, and the voltage of that section rail L11 becomes "0".

[0030] On the other hand, a local power distribution line L12 is installed near the section rail L11, to which a second AC voltage of 100V to 120V at the same commercial frequency as the first AC voltage is applied from a second power supply E12. Furthermore, the section rail L11 is connected to the track coil L131 of the track relay L13 for detecting the presence of a train, and the local power distribution line L12 is connected to the local coil L132 of this track relay L13.

[0031] In track circuit L1, the presence of a train in section A11 is detected when the voltage of section rail L11 becomes "0" and track relay L13 operates. Track circuit L1 also determines the phase difference between the voltages of track coil L131 and local coil L132. If the voltage of section rail L11 is not "0" and track coil L131 is lagging in phase with local coil L132, it is detected that there is no train in section A11, but there is a train in section A11 ahead in the direction of travel. Conversely, if the voltage of section rail L11 is not "0" and track coil L131 is leading in phase with local coil L132, it is detected that there is no train in either section A11 or section A11 ahead in the direction of travel.

[0032] The track circuit monitoring device 1 receives the voltages of the track coil L131 and the local coil L132, that is, the voltage V11 of the section rail L11 and the voltage V12 of the local power distribution line L12, and monitors the track circuit L1 based on these voltages V11 and V12.

[0033] Figure 2 is a schematic diagram showing the track circuit monitoring device shown in Figure 1.

[0034] The track circuit monitoring device 1 is a device that monitors the track circuit L1 shown in Figure 1, and comprises a track voltage processing unit 11, a local voltage processing unit 12, an MPU 13, an RS485 transmission unit 14, a power supply unit 15, an oscillator 16, and a reset IC 17.

[0035] The track voltage processing unit 11 receives the voltage V11 of the section rail L11 shown in Figure 1 and performs signal processing on the said voltage V11.

[0036] The track voltage processing unit 11 includes a track step-down circuit 111, a track isolation amplifier 112, a first track LPF 113, a first track HPF 114, a second track LPF 115, a second track HPF 116, and a track inverting amplifier 117. The track step-down circuit 111 is a circuit that steps down the input section rail voltage V11 to 0.99 times its original value. The track isolation amplifier 112 is a circuit that transmits the stepped-down voltage to the subsequent stage while electrically isolating it from the track step-down circuit 111. In addition, this track isolation amplifier 112 adds a predetermined DC offset to the input voltage. This DC offset is adjusted to an offset value such that the track voltage V111 finally obtained by the track voltage processing unit 11 is always a positive value. The first orbital LPF113 is a low-pass filter that allows input voltages below a predetermined frequency (e.g., 219 Hz) to pass through. The first orbital HPF114, located downstream of the first orbital LPF113, is a high-pass filter that allows input voltages above a predetermined frequency (e.g., 9.95 Hz) to pass through.

[0037] Furthermore, the orbital voltage processing unit 11 is provided with two routes for transmitting the orbital voltage V111 to the MPU 13. One route transmits the orbital voltage V111 obtained via the second orbital LPF 115, the second orbital HPF 116, and the orbital inverting amplifier 117 to the MPU 13. The other route transmits the orbital voltage V111 obtained only via the orbital inverting amplifier 117 to the MPU 13. The second orbital LPF 115 is a low-pass filter that allows input voltages below a predetermined frequency (e.g., 66.32 Hz) to pass through. The second orbital HPF 116 is a high-pass filter that allows input voltages above a predetermined frequency (e.g., 33.66 Hz) to pass through. The orbital inverting amplifier 117 is provided at the final stage of each of the two routes described above and is an inverting amplifier circuit that amplifies the input voltage by a predetermined number (e.g., 5 times) to obtain the orbital voltage V111 and transmits it to the MPU 13.

[0038] The local voltage processing unit 12 receives the voltage V12 of the local power distribution line L12 shown in Figure 1 and performs signal processing on the said voltage V12.

[0039] The local voltage processing unit 12 includes a local step-down circuit 121, a local isolation amplifier 122, a local low-pass filter 123, a local high-pass filter 124, and a local inverting amplifier 125. The local step-down circuit 121 is a circuit that steps down the voltage V12 of the input local distribution line L12 to 0.06 times its original value. The local isolation amplifier 122 is a circuit that transmits the stepped-down voltage to the subsequent stage while electrically isolating it from the local step-down circuit 121. This local isolation amplifier 122 also adds a predetermined DC offset to the input voltage. This DC offset is adjusted to an offset value such that the local voltage V121 finally obtained by the local voltage processing unit 12 is always a positive value. The local low-pass filter 123 is a low-pass filter that allows the input voltage to pass through frequencies below a predetermined frequency (e.g., 219 Hz). The local HPF124, located downstream of the local LPF123, is a high-pass filter that allows input voltages above a predetermined frequency (e.g., 9.95 Hz) to pass through. The local inverting amplifier125 is located at the final stage of the local voltage processing unit12 and is an inverting amplifier circuit that amplifies the input voltage by a predetermined number (e.g., 0.75 times) to obtain the local voltage V121, which is then transmitted to the MPU13.

[0040] The MPU13 is a microprocessor equipped with a CPU (Central Processing Unit), etc. The MPU13 executes various operations, as described later, using programs stored in its internal memory. The MPU13 also includes AD converters 131, 132, and 133, and UARTs 134 and 135.

[0041] AD converter 131 receives an AC waveform with a DC offset of the local voltage V121 from the local inverting amplifier 125 in the local voltage processing unit 12, and converts the analog signal into a digital signal. AD converter 132 receives an AC waveform with a DC offset of the orbital voltage V111 from a route that passes only through the orbital inverting amplifier 117 in the orbital voltage processing unit 11, and converts the analog signal into a digital signal. AD converter 133 receives an AC waveform with a DC offset of the orbital voltage V111 from a route that passes through the second orbital LPF 115, the second orbital HPF 116, and the orbital inverting amplifier 117 in the orbital voltage processing unit 11. AD converter 133 converts the analog signal of the AC waveform thus input into a digital signal.

[0042] UART134 is an interface circuit that converts parallel data to be transmitted to the RS485 transmission unit 14 into serial data, and converts serial data received from the RS485 transmission unit 14 into parallel data. UART134 outputs state information representing the state of the track circuit L1 calculated by the MPU 13 as serial data. In addition, UART134 receives various instruction signals related to the monitoring of the track circuit L1 received by the RS485 transmission unit 14 and outputs them to the MPU 13 as parallel data. UART135 converts parallel data into serial data for serial communication with the PC3 used for various settings. It also converts serial data received from the PC3 into parallel data.

[0043] The RS485 transmission unit 14 outputs information received from the UART 134 to the external device 2. The RS485 transmission unit 14 also outputs various instruction signals received from the external device 2 to the UART 134. In this embodiment, communication between the track circuit monitoring device 1 and the external device 2 is performed using the RS485 standard, but other communication standards, whether wired or wireless, may be used instead.

[0044] The power supply unit 15 converts the power supplied from the power supply 4 into the voltage and other values ​​required by each block of the track circuit monitoring device 1 and supplies them to the device.

[0045] The oscillator 16 is composed of, for example, a crystal oscillator and generates a clock signal for the operation of the MPU 13.

[0046] The reset IC17 is a well-known circuit that monitors when the output voltage of power supply 4 exceeds the operating voltage of MPU13 and activates MPU13 by releasing the reset signal to MPU13.

[0047] External device 2 receives information output by the track circuit monitoring device 1. External device 2 comprises an RS485 transmission unit 21 and a microcontroller circuit 22. The RS485 transmission unit 21 receives information output from the track circuit monitoring device 1. The microcontroller circuit 22 includes a microprocessor and the like, and performs processing based on the information received from the track circuit monitoring device 1, such as internal storage or transmission to a monitoring center.

[0048] PC3 is a computer that serves as a terminal for various settings of the track circuit monitoring device 1. PC3 is connected when necessary for settings and other operations. Power supply 4 supplies power (e.g., 5V DC) to the track circuit monitoring device 1.

[0049] In this embodiment, the following functional blocks are constructed in the track circuit monitoring device 1 described above.

[0050] Figure 3 is a schematic diagram showing the functional blocks of the track circuit monitoring device shown in Figure 1.

[0051] The track circuit monitoring device 1 of this embodiment includes a track voltage acquisition unit 1A, a local voltage acquisition unit 1B, a phase difference calculation unit 1C, a calculation method specification unit 1D, an information generation unit 1E, and an information output unit 1F.

[0052] The track voltage acquisition unit 1A is a functional block constructed by the track voltage processing unit 11 and the AD converters 132 and 133 of the MPU 13. The track voltage acquisition unit 1A acquires the track voltage V111 based on the voltage V11 of the section rail L11. This track voltage acquisition unit 1A has a track offset unit 1A-1 and a track voltage receiving unit 1A-2 as functional blocks. The track offset unit 1A-1 is a functional block constructed by the track voltage processing unit 11 and adds a DC offset to the voltage V11 of the section rail L11. The track voltage receiving unit 1A-2 is a functional block constructed by the AD converters 132 and 133 of the MPU 13 and receives the processed voltage from the track offset unit 1A-1 as the track voltage V111.

[0053] The local voltage acquisition unit 1B is a functional block constructed by the local voltage processing unit 12 and the AD converter 131 of the MPU 13. The local voltage acquisition unit 1B acquires the local voltage V121 based on the voltage V12 of the local power distribution line L12. This local voltage acquisition unit 1B has a local offset unit 1B-1 and a local voltage receiving unit 1B-2 as functional blocks. The local offset unit 1B-1 is a functional block constructed by the local voltage processing unit 12 and adds a DC offset to the voltage V12 of the local power distribution line L12. The local voltage receiving unit 1B-2 is a functional block constructed by the AD converter 131 of the MPU 13 and receives the processed voltage from the local offset unit 1B-1 as the local voltage V121.

[0054] In this embodiment, as described above, a first AC voltage of commercial frequency is applied to the section rail L11 from the first power supply E11. A second AC voltage of the same commercial frequency as the first AC voltage is applied to the local distribution line L12 from the second power supply E12. The periods of the first and second AC voltages are selected from the periods of 1 / 50 second and 1 / 60 second, which are the frequency periods of two types of commercial power supplies in Japan. At this time, the track voltage acquisition unit 1A and the local voltage acquisition unit 1B each use an integer multiple of the least common multiple of the two periods described above as their sampling time, and acquire the track voltage V111 and local voltage V121 based on the sampled values ​​at regular intervals during the sampling time. Specifically, 100 milliseconds, which is an integer multiple (here, 1) of 100 milliseconds, the least common multiple of the 1 / 50 second and 1 / 60 second periods, is adopted as the sampling time. During this 100ms period, the orbital voltage V111 and local voltage V121 are acquired by the orbital voltage acquisition unit 1A and local voltage acquisition unit 1B from 500 sampled values ​​obtained at 0.2ms intervals. In the orbital voltage acquisition unit 1A and local voltage acquisition unit 1B, the orbital voltage V111 and local voltage V121, which have been converted to digital values ​​by the AD converters 131, 132, and 133 of the MPU13, are acquired sequentially at 0.2ms intervals. In addition, the MPU13 collects these orbital voltage V111 and local voltage V121 at 0.2ms intervals every 100ms sampling time, and calculates the amplitude, RMS value, and average value of the voltage waveforms of the orbital voltage V111 and local voltage V121. In this embodiment, the sampling time was set to 100ms, which is the smallest common multiple of the periods of 50Hz and 60Hz, but it does not need to be the smallest common multiple. By setting the sampling time standard to an integer multiple of 100 milliseconds, it is possible to process data in multiples of 5 waveforms in 50Hz regions and multiples of 6 waveforms in 60Hz regions. This allows for measurements without waveform peaks being missing or other artifacts, eliminating the effects of the frequency difference between the two regions. In this example, the sampling period is set to 0.2 milliseconds, but this should be appropriately selected based on the capabilities of the MPU used, the required measurement accuracy, and especially the local crossover time, track crossover time, and the frequency of the input AC voltage, which will be used for phase difference calculations described later.While a shorter sampling period can further increase resolution, it requires the use of MPUs, AD converters, and other components suitable for high-speed operation. The settings should be determined based on factors such as measurement accuracy and cost-effectiveness.

[0055] The phase difference calculation unit 1C is a functional block constructed by the operation of the MPU 13, and it calculates the phase difference θ between the orbital voltage V111 and the local voltage V121. In this embodiment, the phase difference calculation unit 1C is configured to be able to calculate this phase difference using a number of calculation methods, which will be described in detail later.

[0056] The calculation method specification unit 1D is a functional block constructed by the operation of the MPU 13, and specifies to the phase difference calculation unit 1C the calculation method to be used for calculating the phase difference, which can be changed by selecting from multiple available calculation methods.

[0057] In this embodiment, the calculation method specification unit 1D can automatically set which of the nine calculation methods to specify to the phase difference calculation unit 1C by a setting process S100, which will be described later with reference to Figure 8. In addition to this automatic setting, it is also possible to set it manually based on predetermined operations from an operator performing maintenance on the track circuit L1 or the track circuit monitoring device 1. This manual setting by the operator can be performed via the PC3 shown in Figure 2. Furthermore, the calculation method specification unit 1D can set the calculation method to be specified to the phase difference calculation unit 1C for each of the three track occupancy states in the above section A11: occupancy, forward occupancy, and non-occupancy. This setting can also be done in advance by automatic setting via the setting process S100 in Figure 8 or by manual setting by an operator via the PC3. Then, according to the pre-set settings, the calculation method specification unit 1D switches the calculation method specified to the phase difference calculation unit 1C when a change occurs in the occupancy status from the calculation method set for the occupancy status before the change to the calculation method set for the occupancy status after the change.

[0058] The information generation unit 1E is a functional block constructed by the operation of the MPU 13, and generates state information representing the state of the track circuit L1 based on the track voltage V111, local voltage V121, and phase difference θ. This information generation unit 1E has a state recognition unit 1E-1 and a generation unit 1E-2 as functional blocks. The state recognition unit 1E-1 recognizes the occupancy status of section rail L11 based on the track voltage V111 and phase difference θ. This recognition result is sent to the calculation method specification unit 1D, and the calculation method specification unit 1D switches the calculation method according to the occupancy status sent from the state recognition unit 1E-1. The generation unit 1E-2 determines abnormality judgment thresholds for the track voltage V111, local voltage V121, and phase difference θ based on the occupancy status recognized by the state recognition unit 1E-1. Subsequently, the generation unit 1E-2 uses the abnormality determination threshold to determine abnormalities in the orbital voltage V111, local voltage V121, and phase difference, and generates information including the results of the abnormality determination as state information. The generated state information is stored in the internal memory of the MPU 13.

[0059] The information output unit 1F is a functional block constructed by the operation of the MPU 13, and outputs the state information generated by the information generation unit 1E. In this embodiment, the state information is read from the internal memory of the MPU 13 in response to instructions from the external device 2 and output to the external device 2.

[0060] Next, we will explain the phase difference calculation method that can be specified to the phase difference calculation unit 1C in the calculation method specification unit 1D described above.

[0061] Figure 4 is a schematic diagram showing two center crossing calculation methods and one average calculation method, which is a variation thereof, among the phase difference calculation methods that can be specified in the calculation method specification section. The two center crossing calculation methods are shown in Figures 4(A) and 4(B), and the average calculation method is shown in Figure 4(C). In all of Figures 4(A) to 4(C), the orbital voltage V111 is shown as a solid line, and the local voltage V121 is shown as a dashed line. Furthermore, for the sake of simplicity of explanation, both the orbital voltage V111 and the local voltage V121 are depicted as distortion-free sine waves. This is also the case in Figures 5 and 6, which will be described later.

[0062] The center crossing calculation method shown in Figure 4(A) is a rising center crossing calculation method based on the point where the voltage waveforms of the track voltage V111 and local voltage V121 change in the rising direction D11. This rising center crossing calculation method calculates the phase difference based on the time difference Δ11 between the rising track center crossing time T11 and the rising local center crossing time T12. The rising track center crossing time T11 is the time when the voltage waveform of the track voltage V111 intersects with the center of that voltage waveform, specifically the track center voltage Vc1, which is the average voltage obtained by averaging the track voltage V11 over a predetermined period, in the rising direction D11. The rising local center crossing time T12 is the time when the voltage waveform of the local voltage V121 intersects with the center of that voltage waveform, specifically the local center voltage Vc2, which is the average voltage obtained by averaging the local voltage V121 over a predetermined period. In this example, the orbital center voltage Vc1 and the local center voltage Vc2 are equal in voltage. The predetermined period for calculating the average voltage is 100 milliseconds, which is the sampling time mentioned above (an integer multiple of the least common multiple of the 1 / 50 second period and the 1 / 60 second period (1 in this case)). This 100 millisecond period corresponds to 5 cycles of the 1 / 50 second period and 6 cycles of the 1 / 60 second period. Alternatively, the predetermined period for calculating the average voltage may be an integer multiple of the period of the voltage waveform of the local voltage V121, which has less distortion than the orbital voltage V111.

[0063] The center crossing calculation method shown in Figure 4(B) is a falling-down center crossing calculation method based on the point where the voltage waveforms of the track voltage V111 and local voltage V121 change in the falling direction D12. This falling-down center crossing calculation method calculates the phase difference based on the time difference Δ12 between the falling-down track center crossing time T13 and the falling-down local center crossing time T14. The falling-down track center crossing time T13 is the time when the voltage waveform of the track voltage V111 intersects with the track center voltage Vc1, which is the average voltage obtained by averaging the track voltage V111 over a predetermined period, in the falling direction D12. The falling-down local center crossing time T14 is the time when the voltage waveform of the local voltage V121 intersects with the local center voltage Vc2, which is the average voltage obtained by averaging the local voltage V121 over a predetermined period.

[0064] The average calculation method shown in Figure 4(C) is a center-crossed average calculation method that calculates the phase difference based on the average value of the first time difference Δ13 and the second time difference Δ14.

[0065] The first time difference Δ13 is the time difference between the time at the first location P11 in the voltage waveform of the orbital voltage V111 and the time at the first local location P12 in the voltage waveform of the local voltage V121 where a change corresponding to the first location P11 in the orbital voltage V121 occurs. In other words, the first location P11 in the orbital voltage and the first local location P12 are locations where the changes in the increase and decrease of the orbital voltage V111 and the local voltage V121 coincide, including the periods before and after them. In this example, the time at the first location P11 in the orbital voltage is the time T11 when the rising orbital center crosses the center in the rising direction D11, with the orbital center voltage Vc1 being the orbital threshold voltage Vt1. The time at the first local location P12 in the local location is the time T12 when the rising local center crosses the center in the rising direction D11, with the local center voltage Vc2 being the local threshold voltage Vt2. In other words, in this example, the first time difference Δ13 is the time difference Δ11 between the time of the rising track center crossing T11 and the time of the rising local center crossing T12.

[0066] Furthermore, the second time difference Δ14 is the time difference between the time at the second location P13 on the track in the voltage waveform of the track voltage V111, and the time at the second local location P14 on the voltage waveform of the local voltage V121 where a change corresponding to the second location P13 on the track occurs. In other words, the second location P13 on the track and the second local location P14 are locations where the increasing and decreasing directions of the track voltage V111 and the local voltage V121 coincide. The time at the second location P13 on the track is a different time from the time at the first location P11 on the track, and in this example, it is the falling track center intersection time T13 with respect to the falling direction D12, where the track center voltage Vc1 is the track threshold voltage Vt1. Also, the time at the second local location P14 is the falling local center intersection time T14 with respect to the falling direction D12, where the local center voltage Vc2 (i.e., the track center voltage Vc1) is the local threshold voltage Vt2. In other words, in this example, the second time difference Δ14 is the time difference Δ12 between the time of the falling trajectory center crossing T13 and the time of the falling local center crossing T14.

[0067] The method for calculating the center cross-average is a method of calculating the phase difference based on the average value of the first time difference Δ13 and the second time difference Δ14, as explained above.

[0068] Up to this point, as examples of orbital voltage and local voltage, orbital voltage V111 and local voltage V121, whose increasing and decreasing directions coincide, have been presented, and the center crossing calculation method and average calculation method have been explained based on these voltages. However, the orbital voltage and local voltage are not limited to this example, and either voltage may have a waveform that is inverted (reversed) with respect to the orbital center voltage or local center voltage, that is, a voltage that is 180° out of phase with respect to the example in Figure 4. This is also true for Figures 5 and 6 described later.

[0069] In the center crossing calculation method and average calculation method shown in Figure 4, if one of the orbital voltage and local voltage is an inverted voltage waveform, the time difference for determining the phase difference may be calculated based on the following two time points. That is, one time point may be the time when one of the non-inverted / inverted voltage waveforms crosses the center voltage in the rising direction, and the other time point may be the time when the other voltage waveform crosses the center voltage in the falling direction. The phase difference will then be calculated based on the time difference between these two time points when each voltage waveform crosses the center voltage in different directions.

[0070] Furthermore, the time differences Δ11 and Δ12 obtained in the above calculation method, and the average value of the first time difference Δ13 and the second time difference Δ14 are taken as Δt, and once the period T of the local voltage 121 is determined, the phase difference θ is calculated using the formula θ = (360° / T) × Δt. If the calculated phase difference θ has a negative sign, it is a lagging phase corresponding to a train being ahead, and if it has a positive sign, it is a leading phase corresponding to an unoccupied train. Also, when a train is present, the track voltage V111 becomes "0", so the phase difference cannot be calculated, and in this case, the phase difference θ is set to "0°". This calculation method is the same as in Figures 5 and 6 described later.

[0071] Figure 5 is a schematic diagram showing two offset cross calculation methods and one average calculation method, which is a variation thereof, among the phase difference calculation methods that can be specified in the calculation method specification section. Figures 5(A) and 5(B) show the two offset cross average calculation methods, and Figure 5(C) shows the one average calculation method.

[0072] The offset crossover calculation method shown in Figure 5(A) is a rising offset crossover calculation method based on the point where the voltage waveforms of the track voltage V111 and local voltage V121 change in the rising direction D11. This rising offset crossover calculation method calculates the phase difference based on the time difference Δ15 between the rising track offset crossover time T15 and the rising local offset crossover time T16. The rising track offset crossover time T15 is the time when the voltage waveform of the track voltage V111 intersects with the track positive offset voltage Vp1, which is offset by a predetermined voltage in the positive direction from the track center voltage Vc1. The rising local offset crossover time T16 is the time when the voltage waveform of the local voltage V121 intersects with the local positive offset voltage Vp2, which is offset by a predetermined voltage in the positive direction from the local center voltage Vc2. In this example, the orbital center voltage Vc1 and the local center voltage Vc2 are equal voltages, and the orbital positive offset voltage Vp1 and the local positive offset voltage Vp2 are also equal voltages. Furthermore, the offset amounts of the orbital positive offset voltage Vp1 and the local positive offset voltage Vp2 are appropriately adjusted according to the calculated phase difference and the actual waveforms including distortion in the orbital voltage V111 and local voltage V121.

[0073] The offset crossover calculation method shown in Figure 5(B) is a falling-down offset crossover calculation method based on the point where the voltage waveforms of the track voltage V111 and local voltage V121 change in the falling direction D12. This falling-down offset crossover calculation method calculates the phase difference based on the time difference Δ16 between the falling-down track offset crossover time T17 and the falling-down local offset crossover time T18. The falling-down track offset crossover time T17 is the time when the voltage waveform of the track voltage V111 intersects with the track negative offset voltage Vm1, which is offset by a predetermined voltage in the negative direction from the track center voltage Vc1. The falling-down local offset crossover time T18 is the time when the voltage waveform of the local voltage V121 intersects with the local negative offset voltage Vm2, which is offset by a predetermined voltage in the negative direction from the local center voltage Vc2. In this example, the track center voltage Vc1 and the local center voltage Vc2 are equal voltages, and the track negative offset voltage Vm1 and the local negative offset voltage Vm2 are also equal voltages. Furthermore, the offset amounts of the orbital negative offset voltage Vm1 and the local negative offset voltage Vm2 are also adjusted as appropriate according to the calculated phase difference and the actual waveforms of the orbital voltage V111 and local voltage V121.

[0074] The average calculation method shown in Figure 5(C) is an offset cross-average calculation method that calculates the phase difference based on the average value of the first time difference Δ17 and the second time difference Δ18.

[0075] The first time difference Δ17 is the time difference between the time at the first location P15 in the voltage waveform of the orbital voltage V111 and the time at the first local location P16 in the voltage waveform of the local voltage V121 where a change corresponding to the first location P15 in the orbital voltage V121 occurs. In other words, the first location P15 in the orbital voltage and the first local location P16 are locations where the increasing and decreasing directions of the orbital voltage V111 and the local voltage V121 coincide. In this example, the time at the first location P15 in the orbital voltage is the rising orbital offset intersection time T15 with respect to the rising direction D11, where the orbital positive offset voltage Vp1 is the orbital threshold voltage Vt3. Also, the time at the first local location P16 in the local location is the rising local offset intersection time T16 with respect to the rising direction D11, where the local positive offset voltage Vp2 is the local threshold voltage Vt4. In other words, in this example, the first time difference Δ17 is the time difference Δ15 between the rising track offset crossing time T15 and the rising local offset crossing time T16.

[0076] Furthermore, the second time difference Δ18 is the time difference between the time at the second location P17 on the track in the voltage waveform of the track voltage V111, and the time at the second local location P18 on the voltage waveform of the local voltage V121 where a change corresponding to the second location P17 on the track occurs. In other words, the second location P17 on the track and the second local location P18 are locations where the increasing and decreasing directions of the track voltage V111 and the local voltage V121 coincide. The time at the second location P17 on the track is a different time from the time at the first location P15 on the track, and in this example, it is the falling track offset intersection time T17 with respect to the falling direction D12, where the track negative offset voltage Vm1 is the track threshold voltage Vt5. Also, the time at the second local location P18 is the falling local offset intersection time T18 with respect to the falling direction D12, where the local negative offset voltage Vm2 (i.e., the track negative offset voltage Vm1) is the local threshold voltage Vt6. In other words, in this example, the second time difference Δ18 is the time difference Δ16 between the falling trajectory offset intersection time T17 and the falling local offset intersection time T18.

[0077] The offset cross-average calculation method calculates the phase difference based on the average value of the first time difference Δ17 and the second time difference Δ18, as described above.

[0078] Furthermore, in the offset crossover calculation method and average calculation method shown in Figure 5, if one of the orbital voltage and local voltage is an inverted voltage waveform, the time difference for determining the phase difference may be calculated based on the following two times. That is, one time may be the time when one of the non-inverted / inverted voltage waveforms crosses the threshold voltage (positive offset voltage) in the rising direction, and the other time may be the time when the other voltage waveform crosses the threshold voltage (negative offset voltage) in the falling direction. In this way, the phase difference is calculated based on the time difference between two times when each voltage waveform crosses different threshold voltages in different directions.

[0079] Figure 6 is a schematic diagram showing two maximum / minimum calculation methods and one average calculation method, which is a variation thereof, among the phase difference calculation methods that can be specified in the calculation method specification section. The two maximum / minimum calculation methods are shown in Figures 6(A) and 6(B), and the average calculation method is shown in Figure 6(C).

[0080] The maximum / minimum calculation method shown in Figure 6(A) is a maximum calculation method that calculates the phase difference based on the time difference Δ19 between the orbital maximum time T19 and the local maximum time T20. The orbital maximum time T19 is the time when the voltage waveform of the orbital voltage V111 reaches its maximum value, and the local maximum time T20 is the time when the voltage waveform of the local voltage V121 reaches its maximum value.

[0081] The maximum / minimum calculation method shown in Figure 6(B) is a minimum calculation method that calculates the phase difference based on the time difference Δ20 between the orbital minimum time T21 and the local minimum time T22. The orbital minimum time T21 is the time when the voltage waveform of the orbital voltage V111 reaches its minimum value, and the local minimum time T22 is the time when the voltage waveform of the local voltage V121 reaches its minimum value.

[0082] The average calculation method shown in Figure 6(C) is a maximum / minimum average calculation method that calculates the phase difference based on the average value of the first time difference Δ21 and the second time difference Δ22.

[0083] The first time difference Δ21 is the time difference between the time at the first location P19 in the voltage waveform of the orbital voltage V111 and the time at the first local location P20 in the voltage waveform of the local voltage V121, where a change corresponding to the first location P19 in the orbital voltage V121 occurs. In other words, the first location P19 in the orbital voltage and the first local location P20 are locations where the increasing and decreasing directions of the orbital voltage V111 and the local voltage V121 coincide. In this example, the time at the first location P19 in the orbital voltage is the maximum time T19 in the orbital voltage waveform, when the voltage waveform of the orbital voltage V111 reaches its maximum value. Also, the time at the first local location P20 is the maximum local time T20 in the local voltage waveform, when the voltage waveform of the local voltage V121 reaches its maximum value. In other words, in this example, the first time difference Δ21 is the time difference Δ19 between the maximum time T19 in the orbital voltage and the maximum local time T20.

[0084] Furthermore, the second time difference Δ22 is the time difference between the time at the second location P21 in the voltage waveform of the orbital voltage V111 and the time at the second local location P22 in the voltage waveform of the local voltage V121, where a change corresponding to the second location P21 in the orbital voltage V121 occurs. In other words, the second location P21 in the orbital voltage and the second local location P22 are locations where the increase and decrease of the orbital voltage V111 and the local voltage V121 coincide, including the periods before and after them. The time at the second location P21 in the orbital voltage is different from the time at the first location P19 in the orbital voltage, and in this example, it is the minimum time T21 in the orbital voltage waveform when the orbital voltage V111 reaches its minimum value. Also, the time at the second local location P22 is the minimum local time T22 in which the voltage waveform of the local voltage V121 reaches its minimum value. In other words, in this example, the second time difference Δ22 is the time difference Δ20 between the minimum time T21 in the orbital voltage and the minimum local time T22.

[0085] The method for calculating the maximum / minimum average is to calculate the phase difference based on the average value of the first time difference Δ21 and the second time difference Δ22, as explained above.

[0086] Furthermore, in the maximum / minimum calculation method and average calculation method shown in Figure 6, if one of the orbital voltage and local voltage is an inverted voltage waveform, the time difference for determining the phase difference may be calculated based on the following two time points. That is, one time point may be the time when one of the non-inverted / inverted voltage waveforms reaches its maximum value, and the other time point may be the time when the other voltage waveform reaches its minimum value. The phase difference will then be calculated based on the time difference between these two times when different peaks are reached.

[0087] The phase difference calculation unit 1C shown in Figure 3 can calculate the phase difference using the nine calculation methods described with reference to Figures 4 to 6, and the calculation method specification unit 1D selects one of these nine calculation methods and specifies it to the phase difference calculation unit 1C.

[0088] Next, we will explain the processing flow performed by the track circuit monitoring device 1 described so far.

[0089] Figure 7 is a schematic flowchart illustrating the processing flow performed by the track circuit monitoring device shown in Figures 1 to 3.

[0090] The process shown in the flowchart of Figure 7 starts when the track circuit monitoring device 1 is installed on the track circuit L1 and the track circuit monitoring device 1 is activated by power-on. When the process starts, first, a setting determination process S11 is executed to determine whether the execution of various settings for the track circuit monitoring device 1 has been instructed by a predetermined operation of the operator. If the execution of various settings has been instructed (YES determination), the setting process S100 is executed; if not instructed (NO determination), the normal monitoring process S200 for the track circuit L1 is executed. In the setting process S100, various settings are made, including the setting of a specification rule for the phase difference calculation method to the phase difference calculation unit 1C by the calculation method specification unit 1D. Then, in the monitoring process S200, the calculation method specification unit 1D specifies the phase difference calculation method to the phase difference calculation unit 1C based on the specification rule set in the setting process S100, while monitoring of the track circuit L1 is performed.

[0091] Figure 8 is a schematic flowchart illustrating the process of setting the phase difference calculation method, as shown in Figure 7, focusing on the setting of the specification rule. While this setting process also involves other settings besides the phase difference calculation method, only the setting of the phase difference calculation method will be explained below, and the other settings will not be described.

[0092] In this setting process S100, rules are set to specify the optimal calculation method for each of the three occupancy states: occupant, forward occupant, and unoccupied, as a rule for specifying the method of calculating the phase difference. First, in setting process S100, setting acquisition process S101 is executed in which the track voltage acquisition unit 1A and the local voltage acquisition unit 1B acquire the track voltage V111 and the local voltage V121. Next, setting state understanding process S102 is executed based on the acquisition results. In setting state understanding process S102, the state understanding unit 1E-1 understands the occupancy state at that time based on the track voltage V111 and the local voltage V121 acquired in setting acquisition process S101. This understanding of the occupancy state also includes the calculation of the phase difference between the track voltage V111 and the local voltage V121, but this calculation is performed by one calculation method that is arbitrarily determined in advance. Then, the calculation method specification unit 1D executes an unset determination process S103 to determine whether the identified train occupancy status means that the optimal method for calculating the phase difference has not yet been set. If it is not unset, i.e., the optimal method for calculating the phase difference has already been set (NO determination), the process proceeds to the continuation determination process S106 described below. On the other hand, if the optimal method for calculating the phase difference has not been set (YES determination), the all-method phase difference calculation process S104 and the method setting process S105, described below, are executed.

[0093] In the all-method phase difference calculation process S104, the calculation method specification unit 1D sequentially switches and specifies the calculation method, so that the phase difference calculation unit 1C calculates the phase difference between the orbital voltage V111 and the local voltage V121 acquired in the setting acquisition process S101 using all nine of the above calculation methods.

[0094] In the next method setting process S105, the calculation method specification unit 1D sets the optimal calculation method for the occupancy status grasped by the status grasping unit 1E-1, based on the calculation results of all nine calculation methods. The specific method for setting this optimal calculation method will not be specified here, but the following two methods can be given as examples.

[0095] One setting method involves deriving a calculation method that obtains the phase difference most similar to the measurement results from a portable phase meter used for on-site verification. In this method, the phase difference for each occupancy state is measured in advance using the phase meter, and the measurement results from the phase meter are recorded, for example, in the information generation unit 1E. When the phase difference calculation process S104 is completed, the calculation results, along with the measurement results from the phase meter that were recorded in advance as described above, are passed to the calculation method specification unit 1D. The calculation method specification unit 1D then compares the calculation results from all nine calculation methods with the measurement results from the phase meter, and sets the calculation method that obtained the calculation result most similar to the measurement results as the optimal calculation method for the occupancy state recorded in the setting state recognition process S102.

[0096] Another setting method is a majority vote method, which involves determining the number of calculation methods that yield similar results and deriving the set of calculation methods that yields the most similar results. In this method, one calculation method can be arbitrarily selected from the one or more calculation methods derived and set as the optimal calculation method, or all of those one or more calculation methods can be set as the optimal calculation method. In the latter case, when actually acquiring the phase difference, for example, the average value of the acquisition results from the one or more set calculation methods will be adopted as the phase difference calculation result.

[0097] In the method setting process S105, once the optimal calculation method for the phase difference for one occupancy state is set, the next step is to execute the continuation decision process S106, which determines whether or not to continue the setting process S100. In this continuation decision process S106, the continuation decision is made based on whether or not there are any occupancy states for which the optimal calculation method has not been set. If there are occupancy states for which the optimal calculation method has not been set (YES determination), the process returns to the setting acquisition process S101 and the subsequent processes are repeated. On the other hand, if the optimal calculation method has been set for all occupancy states and there are no occupancy states for which the optimal calculation method has not been set (NO determination), the setting process S100 ends. After completion, the process returns to the process shown in Figure 7, and if the setting decision process S11 does not instruct the execution of various settings again (NO determination), the process moves to the monitoring process S200, which will be described below.

[0098] Up to this point, we have described how the setting of the optimal calculation method for each occupancy state is performed automatically by the setting process S100 shown in the flowchart of Figure 8. On the other hand, in this embodiment, the calculation method specification unit 1D can also be manually set by receiving a predetermined operation from an operator via PC3 to specify the calculation method to the phase difference calculation unit 1C. Therefore, it is also possible for an operator to calculate the phase difference by manually switching between nine calculation methods via PC3 and verifying the results, for example, by individual comparison with the measurement results of a phase meter or by comparing the nine calculation results with each other to derive the optimal calculation method. Such manual setting is performed instead of the setting process S100 shown in Figures 7 and 8, but once the setting of the optimal calculation method for all occupancy states is completed, the subsequent processing will move to the monitoring process S200 upon instruction from the operator.

[0099] Figure 9 is a schematic flowchart illustrating the monitoring process shown in Figure 7.

[0100] When the monitoring process S200 starts after either automatic setting by the setting process S100 in Figure 8 or manual setting by receiving predetermined operations from an operator, the calculation method specification unit 1D first executes the initial calculation method specification process S201, which specifies the initial calculation method to the phase difference calculation unit 1C. The initial calculation method is a calculation method specified at an unknown stage before the presence status is determined, and is, for example, one of the nine calculation methods described above that is set as the optimal for non-occupied trains.

[0101] Next, the track voltage acquisition unit 1A and the local voltage acquisition unit 1B execute a monitoring acquisition process S202 to acquire the track voltage V111 and local voltage V121, and the phase difference calculation unit 1C executes a monitoring phase difference calculation process S203 to calculate the phase difference based on the acquisition results. In this monitoring phase difference calculation process S203, the phase difference is calculated using the initial calculation method described above.

[0102] Once the phase difference is calculated, the information generation unit 1E executes the information generation process S204 based on the calculated phase difference and the acquisition results from the monitoring acquisition process S202. This information generation process S204 generates state information representing the state of the track circuit L1 based on the track voltage V111, local voltage V121, and phase difference θ. In this process, the monitoring state recognition process S204a and the generation process S204b are executed. In the monitoring state recognition process S204a, the state recognition unit 1E-1 recognizes the occupancy status of the section rail L11 based on the track voltage V111 and phase difference θ. In the generation process S204b, the generation unit 1E-2 determines abnormality judgment thresholds for the track voltage V111, local voltage V121, and phase difference θ based on the recognized occupancy status. Furthermore, abnormality judgments are performed for the track voltage V111, local voltage V121, and phase difference θ using these abnormality judgment thresholds, and state information including the judgment results is generated. The generated state information is stored in the internal memory of the MPU13.

[0103] Figure 10 is a chart illustrating an example of how the occupancy status is determined by the status recognition process shown in Figure 9, and Figure 11 is a diagram showing the status information generated in the example shown in the chart in Figure 10.

[0104] First, as shown in Figures 10 and 11, the state information J11 generated in the information generation process S204 is generated for each of the multiple sections A11 on the railway rail L1a. The example in Figures 10 and 11 takes one of the multiple sections A11 as an example, and shows how the presence status changes in the order of non-present, present, present ahead, and non-present as the train progresses over time. That is, it shows an example where the train is present when it is non-present in the section A11 ahead and in the section A11 where no train is present, then moves to the section A11 ahead and becomes present ahead, and then moves to the next section A11 and becomes non-present.

[0105] In the monitoring status recognition process S204a, the occupancy status, which changes as described above, is recognized based on the track voltage V111 acquired in the monitoring acquisition process S202 and the phase difference θ calculated in the monitoring phase difference calculation process S203.

[0106] As shown in Figure 10, the track voltage V111 acquired in the monitoring acquisition process S202 is an AC voltage. When section A11 is empty, the track voltage V111 is an AC voltage corresponding to the first AC voltage from the first power supply E11 shown in Figure 1. When section A11 is occupied, the section rail L11 is short-circuited and the amplitude of this track voltage V111 becomes 0V, and when the train is ahead, the waveform of the AC voltage is inverted. Then, when section A11 changes from being occupied ahead to being empty, the waveform is inverted again and the track voltage V111 returns to the original AC voltage. In the monitoring acquisition process S202, the track voltage V111, whose waveform changes in this way as the train moves, is acquired. In the monitoring state recognition process S204a, first, the amplitude (track voltage amplitude value) V111a of this track voltage V111 is calculated. Note that the calculation here may be an RMS value. The track voltage amplitude value V111a is approximately the same when the track is empty and when the track is ahead (1.2V as an example in Figures 10 and 11), and becomes 0V when the track is occupied. Furthermore, when the track changes from being ahead to empty, it momentarily becomes 0V in accordance with the switching operation of the track relay L13 shown in Figure 1.

[0107] Here, the local voltage V121 acquired in the monitoring acquisition process S202 is also an AC voltage, but since it is the voltage of the local power distribution line L12 which is installed separately from the section rail L11, the local voltage V121 is not affected by the movement of the train and maintains a constant AC voltage waveform. For this reason, the local voltage V121 is used as a reference in the calculation of the phase difference θ.

[0108] In the monitoring state recognition process S204a, the amplitude (local voltage amplitude value) V121a is also calculated for this local voltage V121. The local voltage amplitude value V121a for a local voltage V121 whose waveform does not change is approximately constant (110V as an example in Figures 10 and 11).

[0109] After calculating the track voltage amplitude value V111a and the local voltage amplitude value V121a, the monitoring state recognition process S204a recognizes the presence status. For this recognition, the track voltage amplitude value V111a and the phase difference θ calculated in the monitoring phase difference calculation process S203 are used. As shown in Figure 10, the phase difference θ of the track voltage V111 with respect to the local voltage V121 is a predetermined positive phase, for example, a leading phase of +90° when the train is not present, 0° when the train is present, and a predetermined negative phase, for example, a lagging phase of -90° when the train is ahead. In the monitoring state recognition process S204a, first, it is determined whether section A11 is present or not based on whether the track voltage amplitude value V111a is 0V and the phase difference θ is 0°. Also, it is determined whether section A11 is not present or not based on whether the track voltage amplitude value V111a is greater than 0V and the phase difference θ is a leading phase with a positive sign. Furthermore, whether section A11 is ahead of the track is determined by whether the track voltage amplitude value V111a is greater than 0V and the phase difference θ is a lagging phase with a negative sign. Note that the monitoring state recognition process S204a does not evaluate the absolute values ​​of the track voltage amplitude value V111a and the phase difference θ.

[0110] Once the occupancy status is determined in this way, the next step in the generation process S204b is to determine the abnormality determination thresholds for the track voltage amplitude value V111a, the local voltage amplitude value V121a, and the phase difference θ based on the determined occupancy status. In this embodiment, for each of the three occupancy statuses—not occupying, occupying, and forward occupying—the abnormality determination thresholds for the track voltage V111, the local voltage V121, and the phase difference θ are pre-set and stored in the internal memory of the MPU13. In the generation process S204b, the abnormality determination thresholds for the track voltage amplitude value V111a, the local voltage amplitude value V121a, and the phase difference θ corresponding to the determined occupancy status are read from the internal memory to determine each abnormality determination threshold. Subsequently, an abnormality determination is performed based on each of the read abnormality determination thresholds. In the abnormality determination, the track voltage amplitude value V111a, the local voltage amplitude value V121a, and the phase difference θ are each compared with the abnormality determination threshold determined according to the occupancy status to determine the abnormality determination.

[0111] Finally, in generation process S204b, information including the results of the abnormality detection is generated as state information J11. In this embodiment, as shown in Figure 11, the state information J11 includes the occupancy status of section A11, the track voltage amplitude value V111a, the local voltage amplitude value V121a, and the phase difference θ. In addition to these, the results of each abnormality detection are included. The generated state information J11 is stored in the internal memory of the MPU13.

[0112] In the monitoring process S200 shown in Figure 9, after the information generation process S204 described above, a continuation decision process S205 is executed to determine whether or not to continue the monitoring process S200. In this continuation decision process S205, the decision to continue the monitoring process S200 is made based on, for example, whether or not there is an instruction from the operator to interrupt the process or an instruction to shut off the power. If it is determined that the monitoring process S200 will not be continued (NO determination), the monitoring process S200 is terminated. On the other hand, if it is determined that the monitoring process S200 will be continued (YES determination), the calculation method specification unit 1D executes the state change determination process S206.

[0113] In the state change determination process S206, it is determined whether the occupancy status determined in the monitoring state acquisition process S204a is different from the occupancy status determined previously. In the case of the first process following the initial calculation method specification process S201, the occupancy status corresponding to the calculation method specified in the initial calculation method specification process S201 (e.g., not occupying) is compared with the result of the monitoring state acquisition process S204a. If it is determined that the occupancy status is the same as the previous occupancy status (NO determination), the process returns to the monitoring acquisition process S202 and the subsequent processes are repeated. On the other hand, if it is determined that the occupancy status is different from the previous occupancy status (YES determination), the calculation method switching process S207 by the calculation method specification unit 1D is executed.

[0114] In the calculation method switching process S207, the calculation method for the phase difference is switched to the calculation method that is set as optimal for the presence status as determined in the monitoring status acquisition process S204a. For example, if the presence status changes from absent to present, the calculation method for the phase difference is switched from the calculation method that is optimal for absent to the calculation method that is optimal for present. After the calculation method switching process S207 is executed, the process returns to the monitoring acquisition process S202 and the subsequent processes are repeated.

[0115] Through the repetition of the process including the calculation method switching process S207, state information J11 is generated at the aforementioned sampling time (for example, 100 milliseconds) and stored in the internal memory of the MPU13.

[0116] In this embodiment, the state information J11 of the track circuit L1, which is generated and stored in this manner, is output by the information output unit 1F shown in Figure 3 in response to a read request from the external device 2 shown in Figure 2.

[0117] According to the track circuit monitoring device 1 of the embodiment described above, the phase difference between the track voltage V111 and the local voltage V121 is determined by a calculation method that can be changed and specified from among nine calculation methods. This makes it possible to attempt to obtain the phase difference using the nine calculation methods as described above, and to derive the calculation method that can obtain the phase difference most similar to the measurement result of a portable phase meter used for on-site verification. In addition to operation using a phase meter, it is also possible to perform a majority vote operation, such as determining the number of calculation methods that yield similar acquisition results and deriving the set of calculation methods that yields the largest number. In the majority vote operation, one calculation method may be arbitrarily selected from the one or more calculation methods derived and used to obtain the phase difference, or the average value of the acquisition results obtained using all of those one or more calculation methods may be adopted, or the average value of the remaining results after excluding the maximum and minimum acquisition results from one or more calculation methods may be adopted. In any case, by providing a calculation method specification unit 1D that can be changed and specified from among nine calculation methods, it is possible to obtain the most likely phase difference. In other words, the above-described track circuit monitoring device 1 can determine the phase difference between the track voltage V111 and the local voltage V121 with high accuracy. Furthermore, by using the phase difference acquisition result obtained by the set calculation method as a reference, it is possible to check whether there is a discrepancy in the phase difference acquisition result due to changes over time, and thus perform trend monitoring, such as performing maintenance and countermeasures before a malfunction occurs in the track circuit itself.

[0118] In this embodiment, the nine methods for calculating the phase difference include two center crossing calculation methods: the rising center crossing calculation method shown in Figure 4(A) and the falling center crossing calculation method shown in Figure 4(B). The rising center crossing calculation method is a method for calculating the phase difference based on the time difference Δ11 between the rising track center crossing time T11 and the rising local center crossing time T12. The falling center crossing calculation method is a method for calculating the phase difference based on the time difference Δ12 between the falling track center crossing time T13 and the falling local center crossing time T14. In this configuration, the track center crossing times, such as the rising track center crossing time T11 and the falling track center crossing time T13, are easy to grasp when the track voltage V111 is a typical sinusoidal waveform or a similar waveform with little distortion. Similarly, the track center crossing times, such as the rising local center crossing time T12 and the falling local center crossing time T14, are easier to determine when the local voltage V121 is a typical sinusoidal waveform with little distortion or a similar waveform. In other words, with this configuration, when the track voltage V111 and the local voltage V121 are typical sinusoidal waveforms or similar waveforms, the calculation method specification unit 1D can specify the two center crossing calculation methods described above to effectively obtain the phase difference with high accuracy.

[0119] Furthermore, in this embodiment, the nine calculation methods for phase difference include two offset crossing calculation methods: the rising offset crossing calculation method shown in Figure 5(A) and the falling offset crossing calculation method shown in Figure 5(B). The rising offset crossing calculation method is a method for calculating the phase difference based on the time difference Δ15 between the rising track offset crossing time T15 and the rising local offset crossing time T16. The falling offset crossing calculation method is a method for calculating the phase difference based on the time difference Δ16 between the falling track offset crossing time T17 and the falling local offset crossing time T18. In this configuration, the track offset crossing times, such as the rising track offset crossing time T15 and the falling track offset crossing time T17, are easy to grasp while avoiding distortion when distortion occurs near the center of the voltage waveform at the track voltage V111. Similarly, local offset crossover times such as the rising local offset crossover time T16 and the falling local offset crossover time T18 are easier to grasp while avoiding distortion when distortion occurs near the center of the voltage waveform at the local voltage V121. In other words, with this configuration, when distortion occurs near the center of the voltage waveform of each voltage, the calculation method specification unit 1D can specify the two types of offset crossover calculation methods described above, thereby effectively obtaining the phase difference with high accuracy.

[0120] Furthermore, in this embodiment, the nine calculation methods for phase difference include two maximum / minimum calculation methods: the maximum calculation method shown in Figure 6(A) and the minimum calculation method shown in Figure 6(B). The maximum calculation method is a method for calculating the phase difference based on the time difference Δ19 between the orbital maximum time T19 and the local maximum time T20. The minimum calculation method is a method for calculating the phase difference based on the time difference Δ20 between the orbital minimum time T21 and the local minimum time T22. In this configuration, the orbital maximum time T19, local maximum time T20, orbital minimum time T21, and local minimum time T22 are all easy to grasp while avoiding distortion when the distortion near the center of the voltage waveform is large for the orbital voltage V111 and local voltage V121. In other words, with this configuration, when the distortion near the center of the voltage waveform of each voltage is large, the calculation method specification unit 1D can specify the two maximum / minimum calculation methods described above to effectively obtain the phase difference with high accuracy.

[0121] Furthermore, in this embodiment, the nine calculation methods for phase difference include three average calculation methods: the center cross-average calculation method shown in Figure 4(C), the offset cross-average calculation method shown in Figure 5(C), and the maximum / minimum average calculation method shown in Figure 6(C). All three of these average calculation methods are methods for calculating phase difference based on the average values ​​of the first time differences Δ13, Δ17, Δ21 and the second time differences Δ14, Δ18, Δ22 between the track voltage V111 and the local voltage V121. The first time differences Δ13, Δ17, Δ21 are the time differences between the time at the first track locations P11, P15, P19 and the time at the first local locations P12, P16, P20. Furthermore, the second time differences Δ14, Δ18, and Δ22 are the time differences between the time at the second orbital locations P13, P17, and P21 and the time at the second local locations P14, P18, and P22. With this configuration, when the distortion in the orbital voltage V111 and local voltage V121 is random, the accuracy of time difference acquisition can be improved by using the average value of two different time differences. In other words, with this configuration, when the distortion of each voltage waveform is random, the calculation method specification unit 1D can specify the above three average calculation methods to effectively acquire the phase difference with high accuracy.

[0122] Furthermore, in this embodiment, the first trajectory locations P11 and P15 in the center crossing average calculation method in Figure 4(C) and the offset crossing average calculation method in Figure 5(C) are locations that intersect the trajectory threshold voltages Vt1 and Vt3 in the rising direction D11. Also, the first local locations P12 and P16 are locations that intersect the local threshold voltages Vt2 and Vt4 in the rising direction D11. In addition, the second trajectory locations P13 and P17 are locations that intersect the trajectory threshold voltages Vt1 and Vt5 in the falling direction D12, and the second local locations P14 and P18 are locations that intersect the local threshold voltages Vt2 and Vt6 in the falling direction D12. With this configuration, when there is a difference in waveform change between the rising direction D11 and the falling direction D12 in the voltage waveforms of the trajectory voltage V111 and local voltage V121, the phase difference can be obtained while suppressing the influence of such differences in the two average calculation methods described above.

[0123] Furthermore, in this embodiment, in the maximum / minimum average calculation method shown in Figure 6(C), the first track location P19 is the location where the voltage waveform of the track voltage V111 reaches its maximum value, and the first local location P20 is the location where the voltage waveform of the local voltage V121 reaches its maximum value. Also, the second track location P21 is the location where the voltage waveform of the track voltage V111 reaches its minimum value, and the second local location P22 is the location where the voltage waveform of the local voltage V121 reaches its minimum value. With this configuration, when the voltage waveforms of the track voltage V111 and the local voltage V121 have little distortion at their maximum and minimum values, but the waveform changes are minimal and it is somewhat difficult to pinpoint the maximum / minimum, the average calculation method can acquire the phase difference while suppressing the influence of errors in such pinpointing.

[0124] Furthermore, in this embodiment, the calculation method specification unit 1D can be set to specify a calculation method from among nine calculation methods to be used with the phase difference calculation unit 1C through a predetermined operation. With this configuration, the operator can manually change the calculation method to calculate the phase difference, and the optimal calculation method can be derived by comparing each calculation result with the measurement result of the phase meter or by comparing the nine calculation results with each other.

[0125] Furthermore, in this embodiment, the calculation method specified by the calculation method specification unit 1D to the phase difference calculation unit 1C can be set for each of the multiple train occupancy states. When a change occurs in the train occupancy state, the calculation method specification unit 1D switches the calculation method specified to the phase difference calculation unit 1C from the calculation method set for the train occupancy state before the change to the calculation method set for the train occupancy state after the change. With this configuration, by setting the optimal calculation method for the phase difference for each train occupancy state in advance, the phase difference for each train occupancy state can be determined with high accuracy during train operation.

[0126] It should be noted that the embodiments described above merely represent typical forms of track circuit monitoring devices, and the track circuit monitoring device is not limited to these. In other words, the track circuit monitoring device can be implemented in various ways without departing from its core principles.

[0127] For example, in the above embodiment, as an example of a track circuit, a track circuit L1 is provided in which a section rail L11 and a local power distribution line L12 are connected via a track relay L13, and the track relay L13 detects the presence of a train. However, the track circuit is not limited to this, and any circuit that detects the presence of a train based on the voltage of the section rail and the voltage of the local power distribution line is acceptable, regardless of its specific circuit configuration.

[0128] Furthermore, in the above-described embodiment, an example of a track circuit monitoring device is provided in which an information generation unit 1E generates state information J11 of the track circuit L1 and an information output unit 1F outputs the state information J11. However, the track circuit monitoring device is not limited to this, and may also be a device that does not specifically generate or output state information J11, but instead outputs the acquired track voltage, local voltage, and calculated phase difference as they are or stores them in internal memory.

[0129] Furthermore, in the above-described embodiment, as an example of a track circuit monitoring device, a track circuit monitoring device 1 is provided in which a track voltage V111 and a local voltage V121, to which a DC offset is applied so as to always be a positive value, are input to a positive single-supply MPU 13. In this track circuit monitoring device 1, the track center voltage Vc1 and local center voltage Vc2 used for phase difference calculation become voltages corresponding to the DC offset. However, the track circuit monitoring device is not limited to this, and may also be equipped with an MPU with a positive / negative dual-supply specification. In this case, the track voltage and local voltage, which fluctuate in both positive and negative directions around 0V without a DC offset being applied, are input to the MPU, and the track center voltage and local center voltage become 0V.

[0130] Furthermore, in the above-described embodiment, as an example of a phase difference calculation unit and a calculation method specification unit, a phase difference calculation unit 1C capable of calculating the phase difference using nine calculation methods, and a calculation method specification unit 1D that allows selection and specification of a calculation method from among the nine methods for the phase difference calculation unit 1C are provided as examples. However, the phase difference calculation unit and the calculation method specification unit are not limited to these, and the number of calculation methods that can be calculated by the phase difference calculation unit and the number of calculation methods that can be specified by the calculation method specification unit may be any number. Also, the number of calculation methods that can be calculated and the number of calculation methods that can be specified may be the same or different.

[0131] Furthermore, in the above-described embodiment, nine calculation methods are exemplified, including two types of center crossing calculation methods: the rising center crossing calculation method shown in Figure 4(A) and the falling center crossing calculation method shown in Figure 4(B), as an example of multiple calculation methods for the phase difference. However, the multiple calculation methods for the phase difference are not limited to these, and the above-described two types of center crossing calculation methods may not be included. However, as mentioned above, including the above-described two types of center crossing calculation methods in the multiple calculation methods allows for the effective acquisition of the phase difference with high accuracy when the track voltage V111 and local voltage V121 are typical sinusoidal waveforms or similar waveforms. In addition, in the above-described embodiment, two types of center crossing calculation methods, the rising center crossing calculation method and the falling center crossing calculation method, are exemplified as examples of center crossing calculation methods, but only one type may be used. Furthermore, in this embodiment, as an example of a center crossing calculation method, a calculation method is provided in which the orbital center voltage Vc1, which is the average voltage obtained by averaging the orbital voltage V111 over a predetermined period, and the local center voltage Vc2, which is the average voltage obtained by averaging the local voltage V121 over a predetermined period, are set to be equal voltages. However, the center crossing calculation method is not limited to this, and the orbital center voltage and the local center voltage may be different voltages.

[0132] Furthermore, in the above-described embodiment, nine calculation methods are exemplified, including two types of offset crossover calculation methods: the rising offset crossover calculation method shown in Figure 5(A) and the falling offset crossover calculation method shown in Figure 5(B), as an example of multiple calculation methods for phase difference. However, the multiple calculation methods for phase difference are not limited to these, and the above-described two types of offset crossover calculation methods may not be included. However, as mentioned above, including the above-described two types of offset crossover calculation methods in the multiple calculation methods allows for effective acquisition of the phase difference with high accuracy when distortion occurs near the center of the voltage waveforms of the track voltage V111 and local voltage V121. In addition, in the above-described embodiment, two types of offset crossover calculation methods, the rising offset crossover calculation method and the falling offset crossover calculation method, are exemplified, but only one type may be used. Also, in this embodiment, two types of track offset voltages, the track positive offset voltage Vp1 and the track negative offset voltage Vm1, are exemplified as examples of track offset voltages in the offset crossover calculation method, but only one type may be used. Similarly, in this embodiment, two types of local offset voltages are exemplified: a local positive offset voltage Vp2 and a local negative offset voltage Vm2. However, only one of these may be used. Furthermore, examples of orbital offset voltages and local offset voltages include a mutually equal orbital positive offset voltage Vp1 and local positive offset voltage Vp2, and a mutually equal orbital negative offset voltage Vm1 and local negative offset voltage Vm2. However, the orbital offset voltages and local offset voltages are not limited to these, and the orbital offset voltages and local offset voltages may be different voltages.

[0133] Furthermore, in the above-described embodiment, nine calculation methods are exemplified, including two maximum / minimum calculation methods: the maximum calculation method shown in Figure 6(A) and the minimum calculation method shown in Figure 6(B), as an example of multiple calculation methods for the phase difference. However, the multiple calculation methods for the phase difference are not limited to these, and the two maximum / minimum calculation methods described above may not be included. However, as mentioned above, including the two maximum / minimum calculation methods described above in the multiple calculation methods allows for the effective acquisition of the phase difference with high accuracy when there is significant distortion near the center of the voltage waveforms of the orbital voltage V111 and local voltage V121.

[0134] Furthermore, in the above-described embodiment, nine calculation methods are provided as an example of multiple calculation methods for the phase difference, including the following three average calculation methods. Specifically, these nine calculation methods include the center cross-average calculation method in Figure 4(C), the offset cross-average calculation method in Figure 5(C), and the maximum / minimum average calculation method in Figure 6(C). However, the multiple calculation methods for the phase difference are not limited to these, and the above-mentioned three average calculation methods may not be included. However, as mentioned above, including the above-mentioned three average calculation methods in the multiple calculation methods allows for the effective acquisition of the phase difference with high accuracy when the distortion of the orbital voltage V111 and local voltage V121 is random.

[0135] Furthermore, in the above-described embodiment, three types of average calculation methods are illustrated as examples of average calculation methods: the center crossing average calculation method in Figure 4(C), the offset crossing average calculation method in Figure 5(C), and the maximum / minimum average calculation method in Figure 6(C). In these average calculation methods, the phase difference is calculated based on the average value of the first time differences Δ13, Δ17, Δ21 and the second time differences Δ14, Δ18, Δ22 in the orbital voltage V111 and local voltage V121. In the center crossing average calculation method and the offset crossing average calculation method, the first time differences Δ13, Δ17 are the time differences between the times when the orbital voltage V111 and local voltage V121 intersect the orbital threshold voltages Vt1, Vt3 and local threshold voltages Vt2, Vt4 in the rising direction D11. Furthermore, the second time differences Δ14 and Δ18 are the time differences between the times when the orbital voltage V111 and local voltage V121 intersect with the orbital threshold voltages Vt1, Vt5 and local threshold voltages Vt2, Vt6 in the falling direction D12. Also, in the maximum / minimum average calculation method, the first time difference Δ21 is the time difference between the times when the orbital voltage V111 and local voltage V121 reach their maximum values, and the second time difference Δ22 is the time difference between the times when they reach their minimum values. However, the average calculation method is not limited to these three types. Any average calculation method that calculates the phase difference based on the average value of the first time difference and the second time difference in the orbital voltage and local voltage can be arbitrarily set for the first and second time differences. However, as mentioned above, the center crossing average calculation method and the offset crossing average calculation method can obtain the phase difference while suppressing the influence of the difference in waveform change between the rising direction D11 and the falling direction D12. Furthermore, as mentioned above, the maximum / minimum average calculation method allows for obtaining the phase difference while suppressing the influence of errors in identifying the maximum / minimum values, even when waveform changes at the maximum and minimum values ​​are minimal and it is somewhat difficult to pinpoint them.

[0136] Furthermore, in the above-described embodiment, as an example of a calculation method specification unit, a calculation method specification unit 1D is provided in which the calculation method to be specified for the phase difference calculation unit 1C can be set by performing a predetermined operation. However, the calculation method specification unit is not limited to this, and may, for example, have fixed rules for specifying the calculation method for the phase difference calculation unit. However, as mentioned above, by making the calculation method configurable, it is possible to perform operations such as deriving the optimal calculation method through manual work by the operator.

[0137] Furthermore, in the above-described embodiment, as an example of a calculation method specification unit, a calculation method specification unit 1D is provided in which a calculation method for each of multiple train occupancy states can be set, and the calculation method specified to the phase difference calculation unit 1C is switched according to the change in the train occupancy state. However, the calculation method specification unit is not limited to this, and may not switch the calculation method according to the train occupancy state. However, as mentioned above, by switching the calculation method according to the change in the train occupancy state, the phase difference for each train occupancy state can be determined with high accuracy during train operation. [Explanation of symbols]

[0138] 1 Track circuit monitoring device 1A Track voltage acquisition unit 1A-1 Track offset section 1A-2 Track voltage receiving section 1B Local voltage acquisition unit 1B-1 Local offset section 1B-2 Local voltage receiving section 1C Phase difference calculation section 1D calculation method specification section 1E Information generation section 1E-1 Status Monitoring Unit 1E-2 Generation part 1F Information Output Unit 2 External equipment 3 PC 4 Power supply 11. Track Voltage Processing Unit 12 Local voltage processing unit 13 MPU 14,21 RS485 transmission section 15 Power supply section 16 Oscillator 17 Reset IC 22 Microcontroller Circuits 111 Step-down circuit for track 112 Isolation amplifier for track use 113 First orbital LPF 114 HPF for the first orbit 115 Second orbital LPF 116 HPF for the second orbit 117 Inverting amplifier for orbit 121 Local step-down circuit 122 Local isolation amplifier 123 Local LPF 124 Local HPF 125 Local Inverting Amplifier 131, 132, 133 AD converters 134,135 UART A1 Block Section A11 section A2 In-venue section D11 Rising direction D12 Falling direction E11 First Power Supply E12 Second power supply J11 Status Information L1 track circuit L1a Railway Rail L11 Section Rail L12 Local distribution line L13 Track Relay L131 orbital coil L132 Local Coil S11 Setting determination process S100 Setup Process S101 Setting acquisition process S102 Status acquisition process for settings S103 Not set determination process S104 All-method phase difference calculation process S105 Method setting process S106 Continue Decision Processing S200 Monitoring Process S201 Initial calculation method specification process S202 Monitoring acquisition process S203 Phase difference calculation process for monitoring S204 Information generation process S204a Monitoring status acquisition process S204b Generation Process S205 Continue Decision Processing S206 State Change Judgment Process S207 Calculation method switching process ST1 Station SG1 traffic light T11 Time of track center crossing during rising section T12 Time of local center crossing at rising point T13 Downward track center crossing time T14 Falling local center crossing time T15 Rising track offset intersection time T16 Rising local offset crossover time T17 Falling track offset intersection time T18 Falling local offset crossover time T19 Orbit maximum time T20 Local maximum time T21 Orbit minimum time T22 Local minimum time V11 section rail voltage V111 orbital voltage V111a Orbital voltage amplitude value V12 Local distribution line voltage V121 Local Voltage V121a Local voltage amplitude value Vc1 is the orbital center voltage. Vc2 Local Center Voltage Vp1 orbital plus offset voltage Vp2 Local positive offset voltage Vm1 is the negative offset voltage of the orbit. Vm2 Local negative offset voltage Vt1, Vt3, Vt5 Orbital threshold voltages Vt2, Vt4, Vt6 Local threshold voltage P11, P15, P19 Track 1st location P12, P16, P20 Local area 1 P13, P17, P21 Track 2nd location P14, P18, P22 Local area, second location Δ11,Δ12,Δ15,Δ16,Δ19,Δ20 Time difference Δ13, Δ17, Δ21 1st time difference Δ14, Δ18, Δ22 2nd time difference θ phase difference

Claims

1. In a track circuit monitoring device that monitors the state of a track circuit for detecting the presence of a train in a section of a railway track that is electrically divided into multiple sections, based on the voltage of the section rail to which a first AC voltage is applied and which is electrically short-circuited when a train is present, and the voltage of a local power distribution line installed near the section rail to which a second AC voltage is applied, A track voltage acquisition unit that acquires the track voltage used for detecting the occupancy status based on the voltage of the aforementioned section of rail, A local voltage acquisition unit that acquires a local voltage used for detecting the presence of a power line based on the voltage of the local power distribution line, A phase difference calculation unit capable of calculating the phase difference between the orbital voltage and the local voltage using multiple calculation methods, A calculation method specification unit that allows the phase difference calculation unit to select and specify a calculation method to be used for calculating the phase difference from among the plurality of calculation methods, A track circuit monitoring device characterized by being equipped with the following features.

2. The track circuit monitoring device according to claim 1, characterized in that the plurality of calculation methods include a center crossing calculation method that calculates the phase difference based on the time difference between the track center crossing time when the voltage waveform of the track voltage crosses the track center voltage which is the center of the voltage waveform, and the local center crossing time when the voltage waveform of the local voltage crosses the local center voltage which is the center of the voltage waveform.

3. The track circuit monitoring device according to claim 1, characterized in that the plurality of calculation methods include an offset crossing calculation method that calculates the phase difference based on the time difference between the track offset crossing time at which the voltage waveform of the track voltage crosses a track offset voltage offset by a predetermined voltage from the center of the voltage waveform, and the local offset crossing time at which the voltage waveform of the local voltage crosses a local offset voltage offset by a predetermined voltage from the center of the voltage waveform.

4. The track circuit monitoring device according to claim 1, characterized in that the plurality of calculation methods include a maximum / minimum calculation method for calculating the phase difference based on the time difference between the track maximum time when the voltage waveform of the track voltage reaches its maximum value and the local maximum time when the voltage waveform of the local voltage reaches its maximum value, or the time difference between the track minimum time when the voltage waveform of the track voltage reaches its minimum value and the local minimum time when the voltage waveform of the local voltage reaches its minimum value.

5. The track circuit monitoring device according to claim 1, characterized in that the plurality of calculation methods include an average calculation method for calculating the phase difference based on the average value of a first time difference, which is the time difference between the time at the first track location in the voltage waveform of the track voltage and the time at the first local location where a change corresponding to the first track location occurs in the voltage waveform of the local voltage, and a second time difference, which is the time difference between the time at a second track location different from the first track location in the voltage waveform of the track voltage and the time at the second local location where a change corresponding to the second track location occurs in the voltage waveform of the local voltage.

6. The first location of the track is the location where the voltage waveform of the track voltage intersects a predetermined track threshold voltage in the rising direction. The aforementioned first local location is a location where the voltage waveform of the local voltage intersects a predetermined local threshold voltage in the rising direction. The second location of the track is the location where the voltage waveform of the track voltage intersects the track threshold voltage in the falling direction. The track circuit monitoring device according to claim 5, characterized in that the second local location is a location where the voltage waveform of the local voltage intersects the local threshold voltage in the falling edge direction.

7. The first location of the track is the location where the voltage waveform of the track voltage reaches its maximum value. The aforementioned first local location is the location where the voltage waveform of the local voltage reaches its maximum value. The second location of the track is the location where the voltage waveform of the track voltage reaches its minimum value. The track circuit monitoring device according to claim 5, characterized in that the second local location is the location where the voltage waveform of the local voltage reaches its minimum value.

8. The track circuit monitoring device according to claim 1, characterized in that the calculation method specification unit can set the calculation method to be specified to the phase difference calculation unit from among the plurality of calculation methods by receiving a predetermined operation.

9. The system further includes a state recognition unit that recognizes the occupancy status based on the track voltage and the phase difference, The track circuit monitoring device according to claim 1, wherein the calculation method specification unit can set a calculation method to be specified to the phase difference calculation unit from among the multiple calculation methods for each of the multiple occupancy states in the section, and when a change occurs in the occupancy state grasped by the state grasp unit, the calculation method specified to the phase difference calculation unit is switched from the calculation method set for the occupancy state before the change to the calculation method set for the occupancy state after the change.

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