Axle detection device

Abstract

In the event of an axle sensor failure, the system will be controlled to a safer state to improve safety. [Solution] The axle detection device 10 includes an axle sensor 15 that detects the axles of trains passing through each end of the detection target section DT, a presence determination unit 35 that determines the presence of trains in the detection target section DT based on the detection results of two axle sensors 15 that are in a positional relationship as each train enters and exits the detection target section DT, a failure determination unit 40 that determines a failure of the two axle sensors 15 using the detection results of the two axle sensors 15 and the presence / absence determination results in two adjacent sections AD that are close to the two axle sensors 15, and a control unit 45 that controls the entire device 10. When a failure of an axle sensor 15 is detected, the control unit 45 controls the presence determination unit 35 to determine that a train is present in the detection target section DT. As a result, even if an axle sensor 15 fails, the control is made safer, thus improving the safety of the axle detection device 10.

Description

Technical Field

[0001] The present invention relates to an axle detection device that detects the axles of a train and determines the presence / absence of the train on the line.

Background Art

[0002] A railway axle detection device is a device that counts the number of axles passing on the rails on the entry side and the entry / exit side by an axle sensor, and detects the presence / absence of a train on the line in the control section from the axle count value of the axle sensor. The presence of the train is detected from the difference between the axle count value on the entry side and the axle count value on the entry / exit side (see, for example, Patent Document 1). Here, in order to use such an axle detection device as a security device, it is necessary to detect that a failure or abnormality has occurred in each part of the device and control the device to the safe side (put it in a state where a train is detected in the control section), and not perform an operation that becomes a dangerous side when a failure occurs (even though a train has entered the control section, determine that the train is in a non-present state). Note that Patent Document 2 discloses a technique related to failure detection of an axle sensor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to confirm whether the above-mentioned requirements as a safety device are met, we conducted a fault analysis by subdividing the functions and circuits of conventional axle detection devices. As a result, it was found that when an axle sensor fails to detect an axle, there is a risk that the system may incorrectly determine that there is no train (a dangerous event) even though a train is present within the control section. In other words, the axle sensor has two failure modes: one in which it continues to detect axles, and another in which it becomes unable to detect axles. If a failure occurs in the latter mode, the system can be controlled safely (= train present), but if a failure occurs in the latter mode, the axle detection device cannot detect that failure. In particular, if an axle sensor installed on the approach side fails to detect an axle, the system may incorrectly determine that there is no train even though a train is present within the control section of the axle detection device, which poses a major challenge when using the axle detection device as a safety device.

[0005] This invention was made in view of the above-mentioned problems, and its purpose is to improve safety by controlling the axle sensor to the safe side in the event of a malfunction. [Means for solving the problem]

[0006] (Modes of the invention) The following embodiments of the invention are illustrative of the configuration of the present invention and are described in separate sections to facilitate understanding of the diverse configurations of the present invention. Each section does not limit the technical scope of the present invention, and while taking into consideration the best mode for carrying out the invention, the technical scope of the present invention may also include modifications to some of the components of each section, such as substitution, deletion, or addition of other components.

[0007] (1) An axle detection device for determining whether a train is present or absent in a detection target section set between at least two adjacent sections for determining whether a train is present or absent in a track circuit system, comprising at least two axle sensors for detecting the axles of a train passing through each end of the track in the detection target section, and using the detection results of two of the at least two axle sensors that are in a positional relationship as the train enters and exits the detection target section according to the progress of each train, to determine whether a train is present in the detection target section. Axle detection device comprising: a track presence determination unit that determines whether or not a train is present; a fault determination unit that determines a malfunction of the two axle sensors using the detection results of the two axle sensors and the train presence / absence determination results of two adjacent sections that are close to the two axle sensors among the at least two adjacent sections; and a control unit that controls the entire device, wherein the control unit controls the track presence determination unit to determine that a train is present in the detection target section when the fault determination unit determines that either axle sensor is malfunctioning.

[0008] The axle detection device described in this section determines whether a train is present or absent in a detection target section set between at least two adjacent sections where the presence / absence of a train is determined using a track circuit system, and includes at least two axle sensors, a presence determination unit, a fault determination unit, and a control unit. The at least two axle sensors detect the axles of a train passing through each end of the track in the detection target section. If the detection target section is between two adjacent sections, at least one axle sensor is installed at one end of the track in the detection target section on the adjacent section side, and at least one axle sensor is installed at the other end of the track in the detection target section on the adjacent section side. In contrast, if one side of the track in the detection target section is bifurcated, and consequently the detection target section is adjacent to three adjacent sections where the presence / absence of a train is determined using a track circuit system, at least one axle sensor is installed at each of the three ends of the track in the detection target section.

[0009] The train presence detection unit uses the detection results from axle sensors to determine whether or not a train is present in the target section. In this case, the train presence detection unit makes its determination using the detection results of at least two axle sensors that are in a positional relationship with the train as it enters and exits the target section according to the train's movement. That is, if the target section is between two adjacent sections, the axle sensor on one of the adjacent sections becomes the entry-side axle sensor, and the axle sensor on the other adjacent section becomes the exit-side axle sensor, and the detection results of these two axle sensors are used. Even if the target section is adjacent to three adjacent sections, the detection results of two axle sensors that are in a positional relationship with the train as it enters and exits, from among the axle sensors installed at each of the three ends of the track in the target section, are used. The train presence detection unit then determines whether or not a train is present in the target section between them by comparing the detection results of the entry-side axle sensor and the exit-side axle sensor, etc.

[0010] The fault detection unit determines a fault in an axle sensor by using the detection results of the axle sensors and the determination results of whether a train is present or absent in the adjacent section of the track circuit system. At this time, the detection results of the axle sensors are used from two axle sensors that are in the positional relationship of each train entering and exiting the detection target section, as described above. Furthermore, as the determination results of adjacent sections, the determination results of whether a train is present or absent in two adjacent sections that are close to (adjacent to) those two axle sensors, namely the adjacent section close to the entering axle sensor and the adjacent section close to the exiting axle sensor are used.

[0011] The fault detection unit determines that one or both of the two axle sensors are faulty if there is a discrepancy between the estimated presence / absence of a train in the target section, which is estimated from the presence / absence determination results of the adjacent section, and the detection results of the train's axles by each of the two axle sensors. For example, the fault detection unit determines that the entry-side axle sensor is faulty if, despite the presence / absence determination results of the adjacent section close to the entry-side axle sensor indicating that a train has entered the target section, the entry-side axle sensor does not detect the axles of the train entering the target section. This ensures that faults on the side of the axle sensor that is unable to detect axles are reliably detected.

[0012] The control unit is responsible for controlling the entire axle detection system and, as needed, controls each component of the axle detection system. As one such control, if the fault detection unit determines that any axle sensor is faulty, the control unit controls the presence determination unit to determine that a train is present in the detection target section. This ensures that the system is controlled on the safe side, determining that a train is present in the detection target section regardless of whether the axle sensor fails in a way that causes it to continue detecting axles or in a way that causes it to stop detecting axles, thus improving the safety of the axle detection system. Furthermore, since the fault detection of the axle sensors described above can be achieved by incorporating the train presence determination results for adjacent sections of the track circuit system, the system configuration can be simplified and costs can be reduced.

[0013] (2) The axle detection device further comprising a counting unit that counts the number of axles detected by each of the at least two axle sensors, wherein the presence determination unit compares the counting results of the two axle sensors by the counting unit and determines that there is no train in the target section if the counting result of the entry-side axle sensor located on the side from which the train enters the target section is equal to the counting result of the exit-side axle sensor located on the side from which the train exits the target section, and determines that there is a train in the target section if the counting result of the entry-side axle sensor is greater than the counting result of the exit-side axle sensor.

[0014] The axle detection device described in this section further includes a counting unit, which counts the number of axles of a train passing through each end of the track in the detection target section, as detected by at least two axle sensors. The presence determination unit then compares the count results from the counting unit between two axle sensors that are in a positional relationship where each train is entering and exiting the detection target section. As a result, if the count result of the entry-side axle sensor located on the side where the train is entering the detection target section is equal to the count result of the exit-side axle sensor located on the side where the train is exiting the detection target section, it is determined that there is no train in the detection target section. This determination is based on the fact that even if the count value of the entry-side axle sensor increases when a train enters the detection target section, if the count value of the exit-side axle sensor has already increased when the train has exited the detection target section, those count values ​​will always be equal.

[0015] Furthermore, the train presence detection unit determines that a train is present in the target section if the count result from the entry-side axle sensor is greater than the count result from the exit-side axle sensor. This determination is based on the fact that if a train has entered the target section and the count value of the entry-side axle sensor has increased, and the train is still present in the target section and the count value of the exit-side axle sensor has not increased, the count value of the entry-side axle sensor will be greater than that of the exit-side axle sensor. This allows for more accurate determination of whether a train is present or not in the target section.

[0016] (3) In the above item (2), the fault determination unit determines that the approaching axle sensor is faulty if, despite the determination that a train has gone from being present to not present in the approaching axle sensor, one of the two adjacent sections, the count result of the approaching axle sensor by the counting unit does not increase, and also determines that either the approaching axle sensor or the approaching axle sensor is faulty if, despite the determination that a train has gone from being present to not present in the approaching axle sensor, one of the two adjacent sections, the count results of the two axle sensors by the counting unit are not equal.

[0017] The axle detection device described in this section defines the conditions for the fault determination unit to determine the fault of the axle sensor as follows: The fault determination unit determines that the entry-side axle sensor is faulty if, in the entry-side adjacent section adjacent to the entry-side axle sensor, the track circuit system determines that the train has gone from being present to not present, but the count result of the entry-side axle sensor by the counting unit does not increase. This is because, if the train has gone from being present to not present in the entry-side adjacent section, it is presumed that the train has entered the detection target section from the entry-side adjacent section, but the entry-side axle sensor has not detected the axle of the train entering the detection target section, and therefore the entry-side axle sensor is determined to be faulty.

[0018] Furthermore, the fault detection unit determines that either the entry-side axle sensor or the entry-side axle sensor is faulty if, in the adjacent section adjacent to the entry-side axle sensor, the track circuit system determines that the train has gone from being present to being absent, but the count results from the entry-side axle sensor and the entry-side axle sensor by the count unit are not equal. This is because, if the train has gone from being present to being absent in the adjacent section, it is presumed that the train has already moved out of the detection target section and entered the adjacent section (and further moved out of the adjacent section), and the count results from the entry-side axle sensor and the entry-side axle sensor should be equal. However, since these count results are not equal, it is determined that either the entry-side axle sensor or the entry-side axle sensor is faulty. This allows for more accurate detection of faults in the entry-side axle sensor and the entry-side axle sensor.

[0019] (4) In the above item (3), the entry-side adjacent section is adjacent to a second adjacent section on the opposite side from the side adjacent to the detection target section, where the presence / absence of a train is determined by a track circuit system, and the fault determination unit does not determine that the entry-side axle sensor is faulty even if the count result of the entry-side axle sensor by the count unit does not increase despite the entry-side adjacent section determining that the train has changed from being present to being absent, if the presence / absence determination result of the train in the second adjacent section confirms that the train has returned from the entry-side adjacent section to the second adjacent section.

[0020] The axle detection device described in this section utilizes not only the results of train presence determination in adjacent sections adjacent to the detection target section, but also the results of train presence determination in a second adjacent section of the track circuit system, where the approaching adjacent section is adjacent to the detection target section on the opposite side from the side adjacent to the detection target section. In other words, the fault determination unit determines that the approaching axle sensor is faulty if it is determined that the train has changed from being present to not present in the approaching adjacent section, but the count result of the approaching axle sensor by the counting unit does not increase. However, even in such a case, the fault determination unit will not determine that the approaching axle sensor is faulty if it can confirm that the train has returned from the approaching adjacent section to the second adjacent section based on the train presence / non-presence determination result in the second adjacent section adjacent to the approaching adjacent section.

[0021] This is because, when a train changes from being present to being absent in the adjacent section on the entry side, it is assumed that the train has not only entered the detection target section from the adjacent section on the entry side, but also returned from the adjacent section on the entry side to the second adjacent section. If this can be confirmed from the judgment result of the second adjacent section, the system will not determine that the entry side axle sensor is faulty. In other words, the fault detection unit determines that the entry side axle sensor is faulty if, despite the system determining that a train has changed from being present to being absent in the adjacent section on the entry side, the count result of the entry side axle sensor by the counting unit does not increase, and the judgment result of the second adjacent section does not confirm that the train has returned from the adjacent section on the entry side to the second adjacent section. This avoids false detection of faults in the entry side axle sensor and further improves the accuracy of axle sensor fault detection.

[0022] (5) In the above (2), when it can be confirmed from the determination result of the presence / absence of the train in the approaching-side adjacent section close to the approaching-side axle sensor among the two adjacent sections that the train has changed from being present to absent in the detection target section, even if the difference in the count results of the two axle sensors by the counting unit is 1, the line determination unit is made to determine that the train is not present in the detection target section, and the axle detection device adjusts the count results of the two axle sensors by the counting unit to be equal.

[0023] The axle detection device described in this item is designed to perform the following control to address the situation where the axle of the train floats on the axle sensor due to foreign objects such as small stones on the rail, which may prevent the axle from being properly counted. That is, it is rare for such axle floating to occur continuously, and it is also rare for it to occur at the same timing at the two axle sensors on the entry side and the approaching side. Therefore, even if axle floating occurs, it is assumed that the count for one time will not be performed at either the entry-side axle sensor or the approaching-side axle sensor.

[0024] Therefore, the control unit checks whether the train has changed from being present to not being present in the detection target section based on the determination result of the presence / absence of a train using the track circuit method in the approaching adjacent section close to the advancing side axle sensor. As a result, if it is confirmed that the train has changed from being present to not being present in the detection target section, even if the count result of the approaching side axle sensor by the counting unit and the count result of the advancing side axle sensor are not equal, if the difference between these count results is 1, it is determined that axle floating has occurred rather than the train being present or the axle sensor having failed. Then, the control unit controls the on-line determination unit to determine that the train is not present in the detection target section, and adjusts the count results of the two axle sensors so that the count results of the two axle sensors by the counting unit become equal, such as increasing or decreasing 1 from either count result or resetting both count results. Thereby, even if axle floating occurs, it is possible to avoid the influence on the train's on-line determination being continued or the failure of the axle sensor being misdetected, thus reducing the impact on train operation.

[0025] (6) In the above item (1), the control unit is an axle detection device that grasps the traveling direction of the train by using the detection results of the at least two axle sensors and the determination results of the presence / absence of the train in the at least two adjacent sections. The axle detection device described in this item grasps the traveling direction of the train by using the detection results of at least two axle sensors installed at each end of the track in the detection target section and the determination results of the presence / absence of the train in at least two adjacent sections of the track circuit method adjacent to the detection target section.

[0026] In other words, if the control unit confirms that a train has gone from being present to being absent in an adjacent section, and at almost the same time detects an axle at the end of the adjacent section, it determines that the train is moving from the adjacent section towards the detection target section. Also, if the control unit detects an axle at the end of the adjacent section, and at almost the same time confirms that a train has gone from being absent to being present in the adjacent section, it determines that the train is moving from the detection target section towards the adjacent section. As a result, the direction of travel of the train can be easily determined, leading to more accurate determination of whether the train is present or absent, and fault detection of the axle sensor. [Effects of the Invention]

[0027] Because of the above-described configuration, the present invention can improve safety by controlling the vehicle to a safer state in the event of a failure of the axle sensor. [Brief explanation of the drawing]

[0028] [Figure 1] This is a schematic block diagram showing an example of the configuration of an axle detection device according to an embodiment of the present invention. [Figure 2] Figure 1 is a flowchart showing an example of the operation of the axle detection device. [Figure 3] Following Figure 2, this is a flowchart showing an example of the operation of the axle detection device shown in Figure 1. [Figure 4] Figure 1 is an illustrative diagram showing how the train's position changes, illustrating the operation of the axle detection device. [Figure 5] Following on from Figure 4, this is an illustrative diagram showing how the train's position changes, illustrating the operation of the axle detection device shown in Figure 1. [Figure 6] Following on from Figure 5, this is an illustrative diagram showing how the train's position changes, illustrating the operation of the axle detection device shown in Figure 1. [Figure 7] This is an illustrative diagram showing a section of track different from that shown in Figure 1, in which the axle detection device according to an embodiment of the present invention is installed. [Modes for carrying out the invention]

[0029] Hereinafter, embodiments for carrying out the present invention will be described based on the attached drawings. Here, detailed descriptions of parts identical to or corresponding to those in the prior art will be omitted, and throughout the drawings, identical or corresponding parts are indicated by the same reference numerals. Figure 1 schematically shows an example of the configuration of an axle detection device 10 according to an embodiment of the present invention. This axle detection device 10 detects the axles of train 50 in a detection target section DT set between at least two adjacent sections AD that determine the presence or absence of train 50 (see Figures 4 to 6) using a track circuit system, and determines whether train 50 is present or absent. Note that the detection target section DT shown in Figure 1 is set between two adjacent sections AD, which are at least two adjacent sections AD, and one of the adjacent sections AD (left side in the figure) is adjacent to a second adjacent section AD2 that determines the presence or absence of train 50 using a track circuit system.

[0030] As shown in Figure 1, the axle detection device 10 according to an embodiment of the present invention includes an axle sensor 15, an evaluation unit 25, a counting unit 30, a track presence determination unit 35, a fault determination unit 40, and a control unit 45. Of these, the evaluation unit 25, counting unit 30, track presence determination unit 35, fault determination unit 40, and control unit 45, excluding the axle sensor 15, are configured as a data processing unit 20 in this embodiment. The axle sensor 15 detects the axles of trains 50 passing through each end of the track in the detection target section DT. In the embodiment of Figure 1, where the detection target section DT is between two adjacent sections AD, at least two axle sensors 15 are installed.

[0031] Specifically, in order to detect the axles of train 50 passing through the left-hand end of the adjacent section AD in the diagram, at least one axle sensor 15 is installed near that end of the detection target section DT. Also, in order to detect the axles of train 50 passing through the right-hand end of the adjacent section AD in the diagram, at least one axle sensor 15 is installed near that end of the detection target section DT. For the sake of explanation, it is assumed that one axle sensor 15 (15A) is installed near the left-hand end of the detection target section DT in the diagram, and one axle sensor 15 (15B) is installed near the right-hand end of the detection target section DT in the diagram. Furthermore, in order to avoid false detection of failures in the axle sensor 15 failure detection described later, the installation position of each axle sensor 15 is assumed to be within the length of one train set of train 50 from the corresponding adjacent section AD.

[0032] The evaluation unit 25 determines the presence or absence of axles on the train 50 from the electrical signals output by the axle sensors 15. In this embodiment, two evaluation units 25 are provided to make separate determinations for the two axle sensors 15A and 15B. Therefore, although the axle sensor 15 in Figure 1 transmits the axle detection result as an electrical signal, any sensor used in conventional axle detection devices may be used for each axle sensor 10 of the embodiment of the present invention. The count unit 30 counts the number of axles detected by each of the axle sensors 15 via the determination results of each evaluation unit 25. In this embodiment, it counts the number of axles detected by each of the two axle sensors 15A and 15B. That is, each time an axle is detected by each axle sensor 15, the count value of that axle sensor 15 is increased by 1.

[0033] The train presence determination unit 35 uses the detection results of the axle sensors 15 to determine whether or not a train 50 is present in the detection target section DT. More specifically, the train presence determination unit 35 uses the detection results of two axle sensors 15 installed in the detection target section DT that are in a positional relationship with the train 50 as it enters and exits the detection target section DT, according to the train's progress, to make the determination. In this embodiment, since two axle sensors 15A and 15B are installed, depending on the direction of travel of the train 50, one of them becomes the entering axle sensor 15, and the other becomes the exiting axle sensor 15. Hereafter, unless otherwise specified, it is assumed that the train 50 is traveling from left to right in Figure 1, and the axle sensor 15A on the left side of the figure will also be referred to as the entering axle sensor 15A, and the axle sensor 15B on the right side of the figure will also be referred to as the exiting axle sensor 15B. In this case, the track presence determination unit 35 uses the axle detection result from the approaching axle sensor 15A and the axle detection result from the exiting axle sensor 15B to determine whether the train 50 is present in the detection target section DT.

[0034] More specifically, the train presence determination unit 35 compares the count result of the entry-side axle sensor 15A and the count result of the exit-side axle sensor 15B, both obtained by the counting unit 30. In Figure 1, the input of these count results is shown by arrows extending from the counting unit 30 to the train presence determination unit 35. When the count result of the entry-side axle sensor 15A and the count result of the exit-side axle sensor 15B are equal, the unit determines that the train 50 is not present in the detection target section DT. The train presence determination unit 35 also determines that the train 50 is present in the detection target section DT if the count result of the entry-side axle sensor 15A is greater than the count result of the exit-side axle sensor 15B. This method of determining the presence of the train 50 by the train presence determination unit 35 will be explained in more detail later.

[0035] The fault detection unit 40 determines whether there is a fault in the two axle sensors 15, namely the entry-side axle sensor 15A and the exit-side axle sensor 15B, which are in a positional relationship where the train 50 enters and exits the detection target section DT. At this time, the fault detection unit 40 uses the axle detection results from the entry-side axle sensor 15A and the exit-side axle sensor 15B, the determination results of whether the train 50 is present or absent in the two adjacent sections AD adjacent to these two axle sensors 15A and 15B, and the determination results of whether the train 50 is present or absent in the second adjacent section AD2 as determination materials. The axle detection results from the entry-side axle sensor 15A and the exit-side axle sensor 15B are the respective count results of the entry-side axle sensor 15A and the exit-side axle sensor 15B by the count unit 30. In Figure 1, the way in which these count results are input is shown by arrows extending from the count unit 30 to the fault detection unit 40.

[0036] Furthermore, in Figure 1, where train 50 is assumed to be moving from left to right in the diagram, the adjacent section AD adjacent to the entry-side axle sensor 15A is the adjacent section AD on the left side of the diagram, and will hereafter be referred to as the entry-side adjacent section ADin. Also in Figure 1, the adjacent section AD adjacent to the exit-side axle sensor 15B is the adjacent section AD on the right side of the diagram, and will hereafter be referred to as the exit-side adjacent section ADout. In addition, as described above, the second adjacent section AD2 is the section adjacent to the adjacent section AD on the left side of the diagram on the opposite side from the detection target section DT, in other words, it is adjacent to the entry-side adjacent section ADin. In Figure 1, the input of the train 50 presence / absence determination results for each of these adjacent sections ADin, ADout, and AD2 is shown by arrows labeled "Adjacent Section Determination Result," "Adjacent Section Determination Result," and "Second Adjacent Section Determination Result" extending to the fault determination unit 40. As the determination result for each adjacent section ADin, ADout, and AD2, for example, the contact conditions of the output relays of the track circuits in each adjacent section can be input. However, as long as the information ensures safety, it is not limited to relays, and other alternative means may be used.

[0037] The fault detection unit 40 uses the above-mentioned input information to perform fault detection on the entry-side axle sensor 15A and the exit-side axle sensor 15B, for example, as follows. First, the fault detection unit 40 determines that the entry-side axle sensor 15A is faulty if, despite the determination that the train 50 has changed from being present to being absent in the entry-side adjacent section ADin, the count result of the entry-side axle sensor 15A by the count unit 30 does not increase. However, even in such a case, the fault detection unit 40 does not determine that the entry-side axle sensor 15A is faulty if it can be confirmed from the train 50 presence / absence determination result in the second adjacent section AD2 that the train 50 has returned from the entry-side adjacent section ADin to the second adjacent section AD2.

[0038] Furthermore, the fault detection unit 40 determines that either the entry-side axle sensor 15A or the exit-side axle sensor 15B is faulty if, despite the determination that the train 50 has changed from being present to not present in the adjacent exit-side section ADout, the count results from the entry-side axle sensor 15A and the exit-side axle sensor 15B obtained by the count unit 30 are not equal. The fault detection unit 40's method for determining the fault of the axle sensor 15 will be explained in more detail later. The presence determination result of the train 50 in the detection target section DT obtained by the presence determination unit 35 and the fault determination result of the axle sensor 15 obtained by the fault detection unit 40 are output from the data processing unit 20 as signals to drive relays that output these determination results, for example. In this case, the presence determination result of the train 50 and the fault determination result of the axle sensor 15 are output from each of the relays (not shown).

[0039] The control unit 45 controls the entire axle detection device 10 and, for example, performs the following control as needed. Specifically, if the fault determination unit 40 determines that any of the axle sensors 15 is faulty, the control unit 45 controls the presence determination unit 35 to determine that a train 50 is present in the detection target section DT. Furthermore, if a discrepancy occurs between the count results of the entry-side axle sensor 15A and the exit-side axle sensor 15B by the counting unit 30, which is presumed to be caused by axle lift due to foreign objects such as pebbles on the rails, the control unit 45 controls the determination result of the presence determination unit 35 and adjusts the count result of the counting unit 30. In addition, the control unit 45 uses the detection results of each axle sensor 15 and the presence / absence determination results of the train 50 in each adjacent section AD to determine the direction of travel of the train 50. The control unit 45 also mediates the exchange of data between the various components of the data processing unit 20. More specific control details of the control unit 45 will be explained in more detail later.

[0040] Herein, the configuration of the axle detection device 10 according to the embodiment of the present invention is not limited to the block diagram in Figure 1. For example, depending on the configuration and circumstances of the railway section to which it is applied, some of the components shown in Figure 1 may be deleted, modified, or added as appropriate. Furthermore, each component of the data processing unit 20 shown in Figure 1 is divided into functional units, and not into hardware or software units that actually construct the data processing unit 20. Moreover, any hardware and software can be used to construct the data processing unit 20.

[0041] Next, the operation of the axle detection device 10 shown in Figure 1 will be explained following the flow charts shown in Figures 2 and 3. For the configuration of the axle detection device 10, please refer to Figure 1 as appropriate. Note that the flow charts shown in Figures 2 and 3 are examples of the procedure flow for explaining the operation of the axle detection device 10. Therefore, the operation of the axle detection device 10 is not limited to these flow charts, and some of the steps shown in Figures 2 and 3 may be deleted, modified, or added as appropriate, depending on the configuration and circumstances of the axle detection device 10. Also, the flow chart in Figure 2 and the flow chart in Figure 3 are assumed to be connected at connection points A and B, respectively.

[0042] In this explanation following the flowcharts shown in Figures 2 and 3, refer to Figures 4 to 6 as needed. Figures 4 to 6 show train 50 traveling from station A to station B, with the entry-side adjacent section ADin, the detection target section DT, and the exit-side adjacent section ADout set between station A and station B. In these figures, the entry-side adjacent section ADin is also shown as "21T", the detection target section DT as "ABT", and the exit-side adjacent section ADout as "11T". The axle sensor 15 installed at the station A end of the detection target section DT is the entry-side axle sensor 15A, and the axle sensor 15 installed at the station B end of the detection target section DT is the exit-side axle sensor 15B. Furthermore, the data processing unit 20 performs track presence determination and fault determination based on the detection results of the axle sensors 15A and 15B, the determination results in the adjacent entry section ADin (21T), the determination results in the adjacent exit section ADout (11T), and the determination results in the second adjacent section AD2. The determination result in the second adjacent section AD2 here refers, for example, to the track presence / absence determination result at station A.

[0043] S10 (Confirmation of the status of the adjacent section on the approach side): The fault determination unit 40 obtains the occupancy / non-occupancy determination result based on the track circuit system in the adjacent section ADin on the approach side, and confirms the status of the adjacent section ADin on the approach side. S20 (Confirmation of count result of approaching axle sensor): The presence determination unit 35 and fault determination unit 40 obtain the count result of the axles of the train 50 at the approaching axle sensor 15A, which was counted by the counting unit 30, and confirm the count result of the approaching axle sensor 15A. Hereafter, the count result of the approaching axle sensor 15A will be represented as "INc". In this embodiment, the count result of each axle sensor 15 by the counting unit 30 is assumed to be reset to zero in the initial state.

[0044] S30 (Entry side determination 1): The fault determination unit 40 determines whether the entry side adjacent section ADin is unoccupied and whether the count result INc of the entry side axle sensor 15A is zero. If it is determined that both conditions are met (YES), it is assumed that the train 50 has not yet entered either the entry side adjacent section ADin or the detection target section DT, and the system returns to S10 to continue checking the status of the entry side adjacent section ADin. Figure 4(a) shows that the train 50 has not yet entered either the entry side adjacent section ADin or the detection target section DT, and the train 50 is stopped at station A. On the other hand, if at least one of the conditions in step S30 is not met (NO), the system proceeds to S40.

[0045] S40 (Entry side determination part 2): The fault determination unit 40 determines whether the adjacent entry side section ADin is unoccupied and whether the count result INc of the entry side axle sensor 15A is greater than zero. If it is determined that both conditions are met (YES), it is determined that an abnormality has occurred in the track circuit of the adjacent entry side section ADin, and this information is output to the outside, for example, via a relay (not shown). That is, because the count result INc of the entry side axle sensor 15A is greater than zero, it is presumed that the entry side axle sensor 15A has detected train 50 entering the detection target section DT. Despite this, since the presence of train 50 was not detected in the adjacent entry side section ADin, the fault determination unit 40 determines that an abnormality has occurred in the track circuit of the adjacent entry side section ADin. On the other hand, if at least one of the conditions in step S40 is not met (NO), the process proceeds to S50.

[0046] S50 (Entry side determination part 3): The fault determination unit 40 determines whether the adjacent entry side section ADin is occupied and whether the count result INc of the entry side axle sensor 15A is zero. If it is determined that both conditions are met (YES), it is assumed that train 50 is in the adjacent entry side section ADin and that train 50 has not yet entered the detection target section DT, so the process proceeds to S60. The state of train 50 in this case is shown in Figure 4(b). On the other hand, if at least one of the conditions in step S50 is not met (NO), the process proceeds to S80.

[0047] S60 (Entry side determination part 4): The fault determination unit 40 determines whether train 50 has changed from being present to being absent in the adjacent entry side section ADin. If it is determined that train 50 has changed from being present to being absent (YES), then train 50 is no longer present in the adjacent entry side section ADin, and the process proceeds to S70. On the other hand, if it is determined that train 50 has not changed from being present to being absent, and that train 50 is still present in the adjacent entry side section ADin (NO), the process returns to S20 in order to confirm the entry of train 50 from the adjacent entry side section ADin to the detection target section DT.

[0048] S70 (Entry side determination part 5): The fault determination unit 40 determines whether or not train 50 is present in the second adjacent section AD2 adjacent to the entry side adjacent section ADin. If it is determined that train 50 is present in the second adjacent section AD2 (YES), it is assumed that train 50 has returned from the entry side adjacent section ADin to the second adjacent section AD2, and the system returns to S10 to continue checking the state of the entry side adjacent section ADin. On the other hand, if it is determined that train 50 is not present in the second adjacent section AD2 (NO), the system determines that the entry side axle sensor 15A is faulty and outputs this determination result. In other words, if, as a result of the determination in S60, it is determined that train 50 has changed from present to absent in the entry side adjacent section ADin, but as a result of the determination in S50, the count result INc of the entry side axle sensor 15A by the count unit 30 does not increase and remains at zero, the system determines that the entry side axle sensor 15A is faulty. Furthermore, since the fault detection unit 40 has detected a fault in the approach-side axle sensor 15A, the control unit 45 controls the presence detection unit 35 to determine that the train 50 is present in the detection target section DT, and outputs this determination result.

[0049] S80 (Entry side determination 6): The fault determination unit 40 determines whether the adjacent entry side section ADin is occupied and whether the count result INc of the entry side axle sensor 15A is greater than zero. If it is determined that both conditions are met (YES), the system proceeds to S90, assuming that train 50 is present in the detection target section DT. On the other hand, if at least one of the conditions in step S80 is not met (NO), then, taking into account the determination conditions obtained via S30, S40, and S50, the count result INc of the entry side axle sensor 15A is less than zero, regardless of whether train 50 is present in the adjacent entry side section ADin. Therefore, the fault determination unit 40 determines that train 50 is moving in reverse or that the entry side axle sensor 15A is malfunctioning, and outputs this determination result. Furthermore, if the fault detection unit 40 determines that the entry-side axle sensor 15A is faulty, the control unit 45 controls the presence detection unit 35 to determine that the train 50 is present in the detection target section DT, and outputs this determination result.

[0050] S90 (Detection of presence in the target section): Based on the determination in S80, it is confirmed that train 50 is present in the adjacent entry section ADin, and that as train 50 enters the target section DT, the count result INc of the entry-side axle sensor 15A increases from zero and is greater than the count result of the exit-side axle sensor 15B. Therefore, the presence determination unit 35 determines that train 50 is present in the target section DT and outputs this determination result as a signal to control, for example, a relay. Figure 5(a) shows train 50 present in the target section DT.

[0051] S100 (Confirmation of the status of the adjacent section on the advance side): The fault determination unit 40 obtains the occupancy / non-occupancy determination result based on the track circuit system in the adjacent section ADout on the advance side, and confirms the status of the adjacent section ADout on the advance side. S110 (Confirmation of count result of advance side axle sensor): The presence determination unit 35 and the fault determination unit 40 obtain the count result of the axles of the train 50 at the advance side axle sensor 15B, which was counted by the count unit 30, and confirm the count result of the advance side axle sensor 15B. Hereafter, the count result of the advance side axle sensor 15B will be represented as "OUTc".

[0052] S120 (Determination of Advancing Side, Part 1): The fault determination unit 40 determines whether the adjacent section ADout on the advancing side is unoccupied and whether the count result OUTc of the advancing side axle sensor 15B remains smaller than the count result INc of the entering side axle sensor 15A. If it is determined that both conditions are met (YES), it is assumed that the train 50 has not reached the advancing side axle sensor 15B and is still in the detection target section DT, so the system returns to S100 to continue checking the status of the adjacent section ADout on the advancing side. On the other hand, if at least one of the conditions in step S120 is not met (NO), the system proceeds to S130.

[0053] S130 (Determination of departure side, part 2): The fault determination unit 40 determines whether the adjacent departure side section ADout is unoccupied and whether the count result OUTc of the departure side axle sensor 15B is greater than or equal to the count result INc of the entry side axle sensor 15A. If it is determined that both conditions are met (YES), it is determined that an abnormality has occurred in the track circuit of the adjacent departure side section ADout, and this information is output to the outside, for example, via a relay (not shown). That is, since the count result OUTc of the departure side axle sensor 15B is greater than or equal to the count result INc of the entry side axle sensor 15A, it is presumed that the departure side axle sensor 15B has detected train 50 that has moved from the detection target section DT to the adjacent departure side section ADout. Despite this, since the presence of train 50 is not detected in the adjacent departure side section ADout, the fault determination unit 40 determines that an abnormality has occurred in the track circuit of the adjacent departure side section ADout. Conversely, if at least one of the conditions in step S130 is not met (NO), the process proceeds to S140.

[0054] S140 (Determination of departure side, part 3): The fault determination unit 40 determines whether the adjacent section ADout on the departure side is occupied and whether the count result OUTc of the departure side axle sensor 15B is smaller than the count result INc of the entry side axle sensor 15A. If it is determined that both conditions are met (YES), then although train 50 is located in the adjacent section ADout on the departure side, the count result OUTc of the departure side axle sensor 15B has not reached the count result INc of the entry side axle sensor 15A, and the process proceeds to S150. On the other hand, if at least one of the conditions in step S140 is not met (NO), the process proceeds to S160.

[0055] S150 (Determination of the Advancing Side, Part 4): The fault determination unit 40 determines whether the count result OUTc of the advancing side axle sensor 15B is 1 less than the count result INc of the entering side axle sensor 15A, and whether the train 50 has gone from being present to being absent in the adjacent advancing side section ADout. If both conditions are met (YES), it is presumed that an axle count error due to axle lift has occurred in the advancing side axle sensor 15B, and the control unit 45 controls the process to proceed to S180. In other words, although the count result OUTc of the advancing side axle sensor 15B is 1 less than the count result INc of the entering side axle sensor 15A, it has been confirmed that the train 50 has gone from being present to being absent in the adjacent advancing side section ADout, and it is assumed that the train 50 has advanced from the detection target section DT to the adjacent advancing side section ADout and continued further. This situation is shown in Figure 6. For this reason, if the difference in the count results is 1, it is presumed that axle lift has occurred.

[0056] In contrast, if at least one of the conditions in step S150 is not met (NO), it is because the count result OUTc of the advancing axle sensor 15B is 2 or more less than the count result INc of the entering axle sensor 15A, or because the train 50 did not go from being present to not present in the adjacent advancing section ADout. In the former case, the difference between the count result OUTc of the advancing axle sensor 15B and the count result INc of the entering axle sensor 15A is large, making it unlikely to be caused by axle lift, and a malfunction of the entering axle sensor 15A or the advancing axle sensor 15B is determined. Similarly, in the latter case, since it cannot be confirmed that the train 50 has advanced from the detection target section DT to the adjacent advancing section ADout, if there is a difference between the count result OUTc of the advancing axle sensor 15B and the count result INc of the entering axle sensor 15A, a malfunction of the entering axle sensor 15A or the advancing axle sensor 15B is determined. Then, because the fault detection unit 40 has detected a fault in either the entry-side axle sensor 15A or the exit-side axle sensor 15B, the control unit 45 controls the presence detection unit 35 to determine that the train 50 is present in the detection target section DT, and outputs this determination result.

[0057] S160 (Determination of departure side, part 5): The fault determination unit 40 determines whether the adjacent departure side section ADout is occupied and whether the count result OUTc of the departure side axle sensor 15B is greater than the count result INc of the entry side axle sensor 15A. If it is determined that both conditions are met (YES), then although train 50 is located in the adjacent departure side section ADout, the count result OUTc of the departure side axle sensor 15B is greater than the count result INc of the entry side axle sensor 15A, and the process proceeds to S170. On the other hand, if at least one of the conditions in step S160 is not met (NO), the process proceeds to S180, assuming that train 50 is not located in the detection target section DT.

[0058] S170 (Determination of departure side, part 6): The fault determination unit 40 determines whether the count result OUTc of the departure side axle sensor 15B is 1 greater than the count result INc of the entry side axle sensor 15A, and whether the train 50 went from being present to not present in the adjacent departure side section ADout. If both conditions are met (YES), it is presumed that an axle counting error occurred in the entry side axle sensor 15A due to axle lift, and the control unit 45 controls the process to proceed to S180. In other words, although the count result OUTc of the departure side axle sensor 15B is 1 greater than the count result INc of the entry side axle sensor 15A, it has been confirmed that the train 50 went from being present to not present in the adjacent departure side section ADout, and it is assumed that the train 50 departed from the detection target section DT into the adjacent departure side section ADout and continued further (see Figure 6). Therefore, if the difference in the count results is 1, it is presumed that axle lift has occurred.

[0059] In contrast, if at least one of the conditions in step S170 is not met (NO), it is because the count result OUTc of the advancing axle sensor 15B is 2 or more greater than the count result INc of the entering axle sensor 15A, or because the train 50 did not go from being present to not present in the adjacent advancing section ADout. In the former case, the difference between the count result OUTc of the advancing axle sensor 15B and the count result INc of the entering axle sensor 15A is large, making it unlikely to be caused by axle lift, and a malfunction of the entering axle sensor 15A or the advancing axle sensor 15B is determined. Similarly, in the latter case, since it cannot be confirmed that the train 50 has advanced from the detection target section DT to the adjacent advancing section ADout, if there is a difference between the count result OUTc of the advancing axle sensor 15B and the count result INc of the entering axle sensor 15A, a malfunction of the entering axle sensor 15A or the advancing axle sensor 15B is determined. Then, because the fault detection unit 40 has detected a fault in either the entry-side axle sensor 15A or the exit-side axle sensor 15B, the control unit 45 controls the presence detection unit 35 to determine that the train 50 is present in the detection target section DT, and outputs this determination result.

[0060] S180 (Detection of non-occupancy in the detection target section): If the process has progressed from S160 to this step S180, then, taking into account the determination conditions obtained via S120, S130, S140, and S160, it is confirmed that the adjacent section ADout on the exit side is occupied, and that the count result INc of the entry side axle sensor 15A and the count result OUTc of the exit side axle sensor 15B are equal. Here, if the same train 50 has passed both the entry side axle sensor 15A and the exit side axle sensor 15B, then the count results INc and OUTc of those two axle sensors 15A and 15B are equal. Furthermore, the fact that the same train 50 has passed both the entry side axle sensor 15A and the exit side axle sensor 15B indicates that the train 50 entered the detection target section DT but has already advanced to the adjacent section ADout on the exit side. Therefore, the presence determination unit 35 determines that train 50 is not present in the detection target section DT and outputs this determination result.

[0061] Furthermore, if the control unit 45 has controlled the system from S150 or S170 to this step S180, the determination conditions in S150 or S170 have confirmed that the train 50 has moved from the detection target section DT to the adjacent exit section ADout. Therefore, similar to the above, the presence determination unit 35 determines that the train 50 is not present in the detection target section DT and outputs this determination result. Figure 5(b) shows the train 50 moving from the detection target section DT to the adjacent exit section ADout.

[0062] S190 (Count result reset): The control unit 45 resets the count result INc of the entry-side axle sensor 15A and the count result OUTc of the exit-side axle sensor 15B, both calculated by the count unit 30, to zero. Alternatively, instead of resetting both count results, the system may compare the two count results and adjust them to equalize if they are not equal. A case where the two count results are not equal corresponds to, for example, in S150 or S170, when it is estimated that axle lift has occurred and the difference between the count result INc of the entry-side axle sensor 15A and the count result OUTc of the exit-side axle sensor 15B is 1. In this case, the system may subtract 1 from the larger count result or add 1 to the smaller count result to make both count results equal. After step S190, the system returns to S10 to re-check the state of the entry-side adjacent section ADin.

[0063] Herein, the axle detection device 10 according to the embodiment of the present invention described above is not limited to the configuration shown in Figures 1 to 6, and can take various configurations depending on the situation and application. For example, the axle sensor 15 may be installed at each end of the detection target section DT, not just one, but two or more. For example, if two axle sensors 15 are installed at each end of the detection target section DT, the control unit 45 may determine the direction of travel of the train 50 from the difference in the timing of axle detection by the two axle sensors 15. That is, if the timing of axle detection by one axle sensor 15 is earlier than the timing of axle detection by the other axle sensor 15, it is considered that the train 50 is moving from one axle sensor 15 towards the other axle sensor 15. Furthermore, even if one axle sensor 15 is installed at each end of the detection target section DT, the control unit 45 may determine the direction of travel of the train 50 from the timing when an axle is detected by the axle sensor 15 at each end and the timing when the presence or absence of the train 50 is detected in the adjacent section AD of the track circuit system adjacent to the axle sensor 15. In either case, although not specifically mentioned in the explanation of Figures 2 and 3, the control unit 45 may determine the direction of travel of the train 50 as needed.

[0064] Furthermore, the detection target section DT is not limited to being adjacent to two adjacent sections AD of the track circuit system, but may be adjacent to three or more adjacent sections AD of the track circuit system. For example, Figure 7 illustrates a configuration in which the detection target section DT is adjacent to three adjacent sections AD. In Figure 7, the detection target section DT is adjacent to one adjacent section AD on the left side of the figure, and adjacent to two adjacent sections AD on the right side of the figure where the track branches into two. Even in such a case, at least one axle sensor 15 is installed at each of the three ends of the detection target section DT, and the detection results of two of these axle sensors 15 that are in a positional relationship with the train 50 as it enters and exits the detection target section DT according to the progress of each train 50 are used to determine whether the detection target section DT is occupied and to determine if the axle sensor 15 is faulty.

[0065] Furthermore, if the axle detection device 10 cannot use the presence determination result from the second adjacent section AD2 adjacent to the entry-side adjacent section ADin, it may perform the determination without using this result. That is, in S60 of Figure 2, if it is determined that the train 50 has changed from being present to not present in the entry-side adjacent section ADin (YES), it is possible to determine that the entry-side axle sensor 15A has malfunctioned, as described below S70, without going through S70 in Figure 2. Also, in Figures 1 and 4 to 6, the explanation was given using the case where the train 50 is moving from left to right in the figures as an example, but if the train 50 is moving in the opposite direction, the explanation should be interpreted by swapping the entry side and exit side in each figure.

[0066] Now, according to the embodiment of the present invention having the above configuration, the following effects can be obtained. That is, as shown in Figure 1, the axle detection device 10 according to the embodiment of the present invention determines whether a train 50 (see Figures 4 to 6) is present or not in a detection target section DT set between at least two adjacent sections AD that determine whether a train 50 is present or not in a track circuit system, and includes at least two axle sensors 15, a presence determination unit 35, a fault determination unit 40, and a control unit 45. The at least two axle sensors 15 detect the axles of the train 50 passing through each end of the track in the detection target section DT. As shown in Figure 1, when the detection target section DT is between two adjacent sections AD, at least one axle sensor 15 is installed at one end of the track in the detection target section DT on the side of adjacent section AD, and at least one axle sensor 15 is installed at the other end of the track in the detection target section DT on the side of adjacent section AD. In contrast, as shown in Figure 7, if one side of the track in the detection target section DT is bifurcated, and consequently the detection target section DT is adjacent to three adjacent sections AD that determine the presence or absence of train 50 using a track circuit system, then at least one axle sensor 15 is installed at each of the three ends of the track in the detection target section DT.

[0067] The train presence determination unit 35 uses the detection results of the axle sensors 15 to determine whether or not a train 50 is present in the target section DT. At this time, the train presence determination unit 35 makes its determination using the detection results of at least two of the two axle sensors 15 that are in a positional relationship as each train 50 enters and exits the target section DT according to its progress. That is, as shown in Figure 1, if the target section DT is between two adjacent sections AD, the axle sensor 15 on one of the adjacent sections AD becomes the entry-side axle sensor 15A, and the axle sensor 15 on the other adjacent section AD becomes the exit-side axle sensor 15B, so the detection results of these two axle sensors 15A and 15B are used. Even when the detection target section DT is adjacent to three adjacent sections AD as shown in Figure 7, the detection results of two axle sensors 15, which are installed at each of the three ends of the track in the detection target section DT, that are in the positional relationship of the train 50 entering and exiting, are used. The presence determination unit 35 then determines whether or not a train 50 is present in the detection target section DT between them by comparing the detection result of the entering axle sensor 15A and the detection result of the exiting axle sensor 15B, etc.

[0068] The fault detection unit 40 determines a fault in the axle sensor 15 by utilizing the detection result of the axle sensor 15 and the determination result of whether the train 50 is present or absent in the adjacent section AD of the track circuit system. At this time, as the detection result of the axle sensor 15, the detection results of the two axle sensors 15A and 15B, which are in the positional relationship in which each train 50 enters and exits the detection target section DT as described above, are used. Furthermore, as the determination result of the adjacent section AD, the determination results of whether the train 50 is present or absent in the two adjacent sections AD that are close to (adjacent to) the two axle sensors 15A and 15B, namely, the adjacent section ADin that is close to the entering axle sensor 15A and the adjacent section ADout that is close to the exiting axle sensor 15B, are used.

[0069] The fault detection unit 40 determines that one or both of the two axle sensors 15A and 15B are faulty if there is a discrepancy between the estimated presence / absence of a train in the target section DT, which is estimated from the presence / absence determination result of the adjacent section AD, and the detection results of the axles of the train 50 by each of the two axle sensors 15A and 15B. For example, the fault detection unit 40 determines that the presence / absence of a train in the target section DT is faulty if, despite the presence / absence determination result of the adjacent section ADin, which is close to the entry-side axle sensor 15A, the entry-side axle sensor 15A does not detect the axles of the train 50 entering the target section DT (see S50 and S60 in Figure 2). This ensures reliable detection of a fault on the side of the axle sensor 15 that is unable to detect axles.

[0070] The control unit 45 is responsible for controlling the entire axle detection device 10 and controls each component of the axle detection device 10 as needed. As one such control, if the fault determination unit 40 determines that any of the axle sensors 15 has failed, the control unit 45 controls the presence determination unit 35 to determine that a train 50 is present in the detection target section DT. This ensures that even if the axle sensor 15 fails in either a mode where it continues to detect axles or a mode where it can no longer detect axles, the control unit 45 will still determine that a train 50 is present in the detection target section DT, thus improving the safety of the axle detection device 10. Furthermore, since the fault determination of the axle sensors 15 as described above can be achieved by incorporating the train presence determination results for the adjacent section AD of the track circuit system, the device configuration can be simplified and costs can be reduced.

[0071] Furthermore, as shown in Figure 1, the axle detection device 10 according to an embodiment of the present invention further includes a counting unit 30, which counts the number of axles of a train 50 passing through each end of the track in the detection target section DT, as detected by each of at least two axle sensors 15. The presence determination unit 35 then compares the count results INc and OUTc from the counting unit 30 of two axle sensors 15A and 15B, which are in a positional relationship where each train 50 enters and exits the detection target section DT. As a result, if the count result INc of the entry-side axle sensor 15A, which is located on the side where the train 50 enters the detection target section DT, and the count result OUTc of the exit-side axle sensor 15B, which is located on the side where the train 50 exits the detection target section DT, are equal, it is determined that there is no train 50 in the detection target section DT (see S140, S160, and S180 in Figure 3). This determination is based on the fact that even if train 50 enters the detection target section DT and the count value of the entry-side axle sensor 15A increases, if train 50 has already left the detection target section DT and the count value of the exit-side axle sensor 15B has increased, then those count values ​​will always be equal.

[0072] Furthermore, the presence determination unit 35 determines that train 50 is present in the detection target section DT if the count result INc of the entry-side axle sensor 15A is greater than the count result OUTc of the exit-side axle sensor 15B (see S80 and S90 in Figure 2). This determination is based on the fact that if train 50 has entered the detection target section DT and the count value of the entry-side axle sensor 15A has increased, and train 50 is still present in the detection target section DT and the count value of the exit-side axle sensor 15B has not increased, then the count value of the entry-side axle sensor 15A will be greater than that of the exit-side axle sensor 15B. This makes it possible to determine whether train 50 is present or not in the detection target section DT with greater accuracy.

[0073] Furthermore, the axle detection device 10 according to an embodiment of the present invention defines the conditions for fault determination of the axle sensor 15 by the fault determination unit 40 as follows. That is, the fault determination unit 40 determines that the entry-side axle sensor 15A is faulty if, in the entry-side adjacent section ADin which is close to (adjacent to) the entry-side axle sensor 15A, the track circuit method determines that the train 50 has gone from being present to not present, but the count result INc of the entry-side axle sensor 15A by the count unit 30 does not increase (see S50 and S60 in Figure 2). This is because, if the train 50 has gone from being present to not present in the entry-side adjacent section ADin, it is presumed that the train 50 has entered the detection target section DT from the entry-side adjacent section ADin, but since the entry-side axle sensor 15A has not detected the axle of the train 50 entering the detection target section DT, it is determined that the entry-side axle sensor 15A is faulty.

[0074] Furthermore, the fault determination unit 40 determines that either the entry-side axle sensor 15A or the entry-side axle sensor 15B is faulty if, in the entry-side adjacent section ADout adjacent to the entry-side axle sensor 15B, the track circuit system determines that the train 50 has gone from being present to not present, but the count results INc and OUTc of the entry-side axle sensor 15A and the entry-side axle sensor 15B determined by the count unit 30 are not equal (see S140~S170 in Figure 3). This means that if train 50 changes from being present to not present in the adjacent section ADout on the departure side, it is presumed that train 50 has already departed from the detection target section DT and entered the adjacent section ADout on the departure side (and further departed from the adjacent section ADout on the departure side). In this case, the count results INc and OUTc from the entry side axle sensor 15A and the departure side axle sensor 15B should be equal. However, since the count results INc and OUTc are not equal, it is determined that either the entry side axle sensor 15A or the departure side axle sensor 15B is malfunctioning. This allows for more accurate detection of malfunctions in the entry side axle sensor 15A and the departure side axle sensor 15B.

[0075] Furthermore, the axle detection device 10 according to an embodiment of the present invention utilizes not only the results of the train presence determination in the adjacent section AD adjacent to the detection target section DT, but also the results of the train presence determination in the second adjacent section AD2 of the track circuit system, which is adjacent to the entry-side adjacent section ADin on the opposite side from the side adjacent to the detection target section DT. That is, the fault determination unit 40 determines that the entry-side axle sensor 15A is faulty if, despite the determination that the train 50 has gone from being present to not present in the entry-side adjacent section ADin, the count result INc of the entry-side axle sensor 15A by the count unit 30 does not increase. However, even in such a case, if the fault determination unit 40 can confirm from the train presence / non-presence determination result of the train 50 in the second adjacent section AD2 adjacent to the entry-side adjacent section ADin that the train 50 has returned from the entry-side adjacent section ADin to the second adjacent section AD2, it will not determine that the entry-side axle sensor 15A is faulty (see S70 in Figure 2).

[0076] This is because, when train 50 changes from being present to being absent in the adjacent entry section ADin, it is assumed that train 50 has not only entered the detection target section DT from the adjacent entry section ADin, but also returned from the adjacent entry section ADin to the second adjacent section AD2. If this can be confirmed from the judgment result of the second adjacent section AD2, the system will not determine that the entry-side axle sensor 15A is faulty. In other words, the fault determination unit 40 determines that train 50 has changed from being present to being absent in the adjacent entry section ADin, but the count result INc of the entry-side axle sensor 15A by the count unit 30 does not increase, and the judgment result of the second adjacent section AD2 does not confirm that train 50 has returned from the adjacent entry section ADin to the second adjacent section AD2, then the system determines that the entry-side axle sensor 15A is faulty. This makes it possible to avoid false detection of faults in the entry-side axle sensor 15A and to further improve the accuracy of fault detection of the axle sensor 15.

[0077] Furthermore, in the axle detection device 10 according to the embodiment of the present invention, if the axle of the train 50 is lifted off the axle sensor 15 due to foreign matter such as pebbles on the rail, it is assumed that the axle may not be counted properly, and the following control is performed to address this. That is, such axle lifting rarely occurs consecutively, and it is also rare for it to occur at the same time on the two axle sensors 15A and 15B on the entry and exit sides. Therefore, even if axle lifting occurs, it is assumed that one count will not be performed on either the entry side axle sensor 15A or the exit side axle sensor 15B.

[0078] Therefore, the control unit 45 checks whether the train 50 has changed from being present to being absent in the detection target section DT based on the determination result of whether the train 50 is present or absent in the adjacent section ADout on the approaching side, which is close to the approaching axle sensor 15B. If it is confirmed that the train 50 has changed from being present to being absent in the detection target section DT, the control unit 45 determines that even if the count result INc of the approaching axle sensor 15A and the count result OUTc of the approaching axle sensor 15B by the counting unit 30 are not equal, if the difference between these count results is 1, the train 50 is not present or the axle sensor 15 has malfunctioned, but rather axle lift has occurred (see S150 and S170 in Figure 3).

[0079] The control unit 45 then controls the presence determination unit 35 to determine if the train 50 is not present in the detection target section DT (see S180 in Figure 3), and adjusts the count results of the two axle sensors 15A and 15B by increasing or decreasing one of the count results by 1 or resetting both count results so that the count results of the two axle sensors 15A and 15B are equal (see S190 in Figure 3). This makes it possible to avoid the continuation of the presence determination of the train 50 or the false detection of a malfunction in the axle sensor 15 even if axle lift occurs, thereby reducing the impact on train operations.

[0080] In addition, the axle detection device 10 according to an embodiment of the present invention determines the direction of travel of the train 50 by utilizing the detection results of at least two axle sensors 15 installed at each end of the track in the detection target section DT, and the determination results of whether the train 50 is present or absent in at least two adjacent sections AD of the track circuit system adjacent to the detection target section DT. That is, if the control unit 45 confirms that the train 50 has changed from present to absent in an adjacent section AD, and at almost the same time, an axle is detected by the axle sensor 15 installed at the end of the adjacent section AD, the control unit 45 determines that the train 50 is traveling from the adjacent section AD towards the detection target section DT. Also, if the control unit 45 detects an axle by the axle sensor 15 installed at the end of the adjacent section AD, and at almost the same time, it confirms that the train 50 has changed from absent to present in the adjacent section AD, the control unit 45 determines that the train 50 is traveling from the detection target section DT towards the adjacent section AD. This makes it easy to determine the direction of travel of train 50, enabling more accurate determination of whether train 50 is present or absent from the track, as well as fault detection of the axle sensor 15. [Explanation of symbols]

[0081] 10: Axle detection device, 15: Axle sensor, 15A: Approach side axle sensor, 15B: Exit side axle sensor, 30: Counting unit, 35: Track presence determination unit, 40: Fault determination unit, 45: Control unit, 50: Train, DT: Detection target section, AD: Adjacent section, ADin: Approach side adjacent section, ADout: Exit side adjacent section, AD2: Second adjacent section, INc: Count result of approach side axle sensor, OUTc: Count result of exit side axle sensor

Claims

1. An axle detection device that detects the axles of a train to determine whether a train is present or absent in a detection target section set between at least two adjacent sections for determining the presence or absence of a train using a track circuit system, At least two axle sensors for detecting the axles of trains passing through each end of the track in the section to be detected, A train presence determination unit determines whether or not a train is present in the detection target section by utilizing the detection results of two axle sensors, of which at least two axle sensors are in a positional relationship in which the train enters and exits the detection target section according to the progress of each train. A fault determination unit determines a malfunction of the two axle sensors by utilizing the detection results of the two axle sensors and the determination results of whether a train is present or not in two adjacent sections that are close to the two axle sensors, among the at least two adjacent sections. Includes a control unit that controls the entire device, The axle detection device is characterized in that, when the fault determination unit determines that any axle sensor is faulty, the control unit controls the presence determination unit to determine that a train is present in the detection target section.

2. The system further includes a counting unit that counts the number of axles detected by each of the at least two axle sensors, The axle detection device according to claim 1, characterized in that the presence determination unit compares the count results of the two axle sensors by the count unit and determines that there is no train in the target section if the count result of the entry-side axle sensor located on the side the train is entering the target section is equal to the count result of the exit-side axle sensor located on the side the train is leaving the target section, and determines that there is a train in the target section if the count result of the entry-side axle sensor is greater than the count result of the exit-side axle sensor.

3. The axle detection device according to claim 2, characterized in that the fault determination unit determines that the approaching axle sensor is faulty if, despite the determination that a train has gone from being present to not present in the approaching adjacent section of the two adjacent sections that is close to the approaching axle sensor, the count result of the approaching axle sensor by the count unit does not increase, and also determines that either the approaching axle sensor or the approaching axle sensor is faulty if, despite the determination that a train has gone from being present to not present in the approaching adjacent section of the two adjacent sections that is close to the approaching axle sensor, the count results of the two axle sensors by the count unit are not equal.

4. The aforementioned entry-side adjacent section is adjacent to a second adjacent section on the opposite side from the side adjacent to the detection target section, where the presence / absence of a train is determined using a track circuit system. The axle detection device according to claim 3, characterized in that even if the fault determination unit determines that the train has changed from being present to not present in the adjacent section on the approach side, and the count result of the approach side axle sensor by the count unit does not increase, if it can be confirmed from the train presence / absence determination result in the second adjacent section that the train has returned from the adjacent section on the approach side to the second adjacent section, the approach side axle sensor does not determine that the approach side axle sensor is faulty.

5. The axle detection device according to claim 2, characterized in that, if the control unit can confirm that a train has changed from being present to being absent in the detection target section based on the determination result of whether a train is present or absent in the adjacent section on the approaching side, which is close to the advance-side axle sensor, the control unit causes the presence determination unit to determine that a train is not present in the detection target section, even if the difference in the count results of the two axle sensors by the counting unit is 1, and adjusts the count results of the two axle sensors by the counting unit to be equal.

6. The axle detection device according to claim 1, characterized in that the control unit determines the direction of travel of the train by utilizing the detection results of the at least two axle sensors and the determination results of whether the train is present or not in the at least two adjacent sections.

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