Axle counting device

Abstract

To improve an axle counting device to enhance a function of avoiding false determination at an end part of an axle detector caused by repetition of forward and backward movement of a vehicle without increasing a determination reference value.SOLUTION: Counters 23, 24 and 25 are provided at A1, A2 and A3 sensors provided on an end part in a target section of a track, respectively so as to count the forward and backward movement of a wheel-set based on axle detection signals A1, A2 and A3 corresponding to the counters. An A1-A2 continuance counter 51 and an A2-A3 continuance counter 52 are provided to count the number of times of monotonously and continuously updating a count value done by only one of a pair of counters (23, 24) and a pair of counters (24, 25) among the counters 23, 24 and 25. Values of these continuance counters and a prescribed determination reference value are compared to one another to determine the presence / absence of a failure relating to the A1, A2 and A3 sensors.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This invention relates to an axle counting device which is useful for determining whether or not a train is present on a section of railway track, more particularly to an axle counting device which counts the axles (wheel sets) involved in entering and exiting the section being monitored and counted based on the output of an axle detector installed at the end of the section, and still more particularly to a means for detecting faults in the axle detector. [Background technology]

[0002] Railway axle counting devices, also known as axle counters, basically count the number of axles that have entered a target section and the number of axles that have exited the section. The term "axle counting device" may refer to the axle detector that detects when an axle passes (comes or leaves) the axle detector, or it may refer to only the components that do not include the axle detector. However, in this application, any device that includes a component that counts the number of axles based on the axle detection results by the axle detector or the axle detector is considered to be an axle counting device. In other words, any device that counts the number of axles according to the coming and going of the axles at one end of the target section falls within the scope of the present application.

[0003] First, axle detectors and axle detectors are referred to as axle detectors and wheel detectors. Axle detectors also include axle detector devices, axle detectors, wheel ...

[0004] If the pair of transmitter and receiver is clearly defined, then basically that pair is used as the axle detector; however, since the number of transmitters and receivers does not have to be the same (for example, see Patent Document 1), in that case, importance is given to the receiver that produces the detection result and that is used as the axle detector. The axle detector operates axle detectors, usually several, arranged at one of several ends of a track section, and obtains the axle detection state and axle detection result from each axle detector to detect whether an axle passes (comes or goes) at the corresponding end. Some even detect the direction of travel (forward or backward).

[0005] Some such axle detectors are designed to detect the presence or absence of a fault in each axle detector based on the signal level, pulse expression state, etc. (see, for example, Patent Documents 1 to 3), but instead of or in addition to such instantaneous sensor fault detection, so-called time-dependent sensor fault detection methods have also been proposed that detect the presence or absence of a fault in an axle detector based on time-dependent factors such as the number of pulse counts (count value) when the wheel set is sensed. An axle counting device equipped with such a sensor failure detection method will now be described by way of a specific example.

[0006] FIG. 7 is a block diagram of the overall configuration of an axle counting device 20 installed for a target section 8 of the track, FIG. 8(a) is an enlarged view of one end of the target section 8, and FIG. 8(b) is a schematic diagram of a vehicle equipped with four wheel sets (axles), a side view of a typical railway vehicle. In this configuration example (see Figure 7), an axle detector 11 (section end unit) is installed at one of both ends of a target section 8 of the rail (railroad track) near the first adjacent section, and an axle detector 31 (section end unit) is installed at one of both ends of the target section 8 near the second adjacent section, and based on these detection signals A1, A2, A3, an axle counting device 20 determines whether a train is present in the target section 8 (21, 22), determines whether there is a sensor failure associated with the axle detector 11 (23-26), and determines whether there is a sensor failure associated with the axle detector 31 (33-36).

[0007] The axle detector 11 is equipped with multiple axle detectors arranged in the longitudinal direction of the rail. In this example (see Figures 7 and 8(a)), three axle detectors, A1 sensor, A2 sensor, and A3 sensor, are arranged in a row in the longitudinal direction of the rail in close proximity to each other such that the axle detection ranges shown by thin dotted lines partially overlap those of the adjacent sensors (see Figure 8(a)). There is also provided a sensor failure detection unit 12 which detects failures in the axle detectors to the extent possible before counting by monitoring the signal levels and pulse expression states of the axle detection signal A1 from the A1 sensor, the axle detection signal A2 from the A2 sensor, and the axle detection signal A3 from the A3 sensor; however, a detailed description of this will be omitted here. Although the axle detector 31 and the sensor failure detection unit 32 are installed in different locations, they may be similar to the axle detector 11 and the sensor failure detection unit 12, and therefore repeated explanations will be omitted.

[0008] The axle counting device 20 (see Figs. 7 and 8(a)) comprises an ingress / egress difference calculation unit 21 that calculates the ingress / egress difference, which is the difference between the number of entering axles and the number of exiting axles, for all ends, and a determination unit 22 that determines whether a train is present in the target section 8 based on the ingress / egress difference, and determines that a train is not present in the target section 8 if the condition [ingress / egress difference="0"] is satisfied for the target section 8, and determines that a train is present otherwise. The axle counting device 20 also comprises an A1 counter 23 that counts pulses for the axle detection signal A1 of the axle detector 11, an A2 counter 24 that counts pulses for the axle detection signal A2 of the axle detector 11, and an A3 counter 25 that counts pulses for the axle detection signal A3 of the axle detector 11, in order to calculate the number of entering axles and the number of exiting axles for the ends where the axle detector 11 is installed.

[0009] Furthermore, the axle counting device 20 also has a sensor failure determination means 26 which determines whether the axle detectors (A1, A2, A3 sensors) of the axle detector 11 are normal or faulty based on the count values ​​of those counters 23 to 25, i.e., after counting. In addition, the axle counting device 20 is equipped with counters 33, 34, 35 similar to the counters 23, 24, 25 in order to calculate the number of entering axles and the number of exiting axles relating to the end where the axle detector 31 is installed, and further equipped with a sensor failure determination means 36 similar to the sensor failure determination means 26, but detailed explanations of these will be omitted to avoid repetition.

[0010] The judgment criteria by the sensor failure judgment means 26 (see Figure 8 (a)) are as follows: the absolute value of the difference between the count value of the A1 counter 23 and the count value of the A2 counter 24 is |A1-A2|, the absolute value of the difference between the count value of the A1 counter 23 and the count value of the A3 counter 25 is |A1-A3|, and the absolute value of the difference between the count value of the A2 counter 24 and the count value of the A3 counter 25 is |A2-A3|.If [|A1-A2| ≧ 3 or |A1-A3| ≧ 3 or |A2-A3| ≧ 3] is established, it is judged as "abnormal", and if not, it is judged as "normal". Below, three examples of operation when this criterion is applied will be explained.

[0011] [Operational mode 1 of the prior art] First, an operation example in which the A1 sensor, A2 sensor, and A3 sensor of the axle detector 11 installed at the boundary between the first adjacent section and the target section 8 are all operating normally will be described.

[0012] FIG. 8 shows the operating state when the vehicle simply drives from the first adjacent section to the target section 8 without turning back, with the A1 sensor, A2 sensor, and A3 sensor all operating normally, where (a) is a block diagram of the main parts, (b) is a diagram of the arrangement of the vehicle and the wheelsets, and (c) is a transition diagram relating to the counting states of the A1 counter 23, A2 counter 24, and A3 counter 25, as well as the differences and judgments obtained based on them.

[0013] In this case, when a wheel of the vehicle axle 1 passes through the detection range of the A1 sensor, the value of the A1 counter 23 increases by "1", when a wheel of the vehicle axle 1 passes through the detection range of the A2 sensor, the value of the A2 counter 24 increases by "1", and when a wheel of the vehicle axle 1 passes through the detection range of the A3 sensor, the value of the A3 counter 25 increases by "1". In addition, when the wheel of the vehicle axle 2 passes through the detection range of the A1 sensor, the value of the A1 counter 23 is increased by another "1", when the wheel of the vehicle axle 2 passes through the detection range of the A2 sensor, the value of the A2 counter 24 is increased by another "1", and when the wheel of the vehicle axle 2 passes through the detection range of the A3 sensor, the value of the A3 counter 25 is increased by another "1".

[0014] Then, to avoid tedious repetition, in short, when the wheel set 3 of the vehicle passes the axle detector 11, the values ​​of the counters 23, 24, 25 are further incremented by "1" each with a time lag due to the passage. Furthermore, when the wheel set 4 of the vehicle passes the axle detector 11, the values ​​of the counters 23, 24, 25 are further incremented by "1" each with a time lag due to the passage. If the passing train is made up of multiple cars, the above counting operation is repeated for each car. For simplicity, however, the following description will be given for the case where there is a single car.

[0015] Then (see the top three rows of Figure 8(c)), as a vehicle passes through the detection range of axle detector 11, the A1 counter value, i.e., the value of counter 23, the A2 counter value, i.e., the value of counter 24, and the A3 counter value, i.e., the value of counter 25, become "1", "1", "1" in that order along with the passing time difference of axle 1, then "2", "2", "2" in that order along with the passing time difference of axle 2, then "3", "3", "3" in that order along with the passing time difference of axle 3, and finally "4", "4", "4" in that order along with the passing time difference of axle 4. In Figure 8 and other figures, the axle detector 11 is enlarged for convenience of illustration, so the distance between sensors A1 and A3 appears to be close to the distance between axles 1 and 2. However, in reality, the distance between sensors A1 and A3 is orders of magnitude smaller than the distance between axles 1 and 2.

[0016] Each time the A1, A2, and A3 counter values ​​change in this way, the values ​​of the difference |A1-A2|, the difference |A1-A3|, and the difference |A2-A3| change from "0" to "1," but then quickly return to "0" (see the three lines from the fourth to the sixth row in Figure 8(c)). In this way, since none of the counter value differences |A1-A2|, |A1-A3|, and |A2-A3| reaches the judgment reference value of "3", the sensor failure judgment means 26 makes an appropriate judgment of "normal" (see Figure 8(a) and the bottom line of Figure 8(c)).

[0017] [Operational mode 2 of the prior art] Next, we will explain an example of operation when only the A1 sensor among the A1, A2, and A3 sensors in the axle detector 11 installed on the boundary between the first adjacent section and the target section 8 fails and the axle detection signal A1 no longer changes.

[0018] FIG. 9 shows the operating state when the vehicle simply drives from the first adjacent section to the target section 8 without turning back when the A1 sensor has failed, where (a) is a block diagram of the main parts, (b) is a diagram of the arrangement of the vehicle and the wheelsets, and (c) is a transition diagram relating to the counting states of the A1 counter 23, the A2 counter 24, and the A3 counter 25, as well as the differences and judgments obtained based on them.

[0019] In this case, when the vehicle's wheelsets 1 to 4 simply pass the axle detector 11, the axle detection signal A1 for the faulty A1 sensor does not change, so the value of the A1 counter 23 remains at its initial value "0" (see the top row of Figure 9(c)). In contrast, the values ​​of the normal A2 counter 24 and A3 counter 25 increase by "1" each time a set of wheels 1 to 4 passes by, with the time difference due to the passage. Then (see the second and third rows of FIG. 9(c)), as a vehicle passes through the detection range of the axle detector 11, the A2 and A3 counter values ​​change in sequence from "1", "1", to "2", "2", to "3", "3", to "4", "4", with the time difference due to the passage of the set of wheels.

[0020] Each time the A1, A2, and A3 counter values ​​change in this way, the difference |A2-A3| goes from "0" to "1" and then returns to "0" (see the first line in the sixth row of FIG. 9(c)). However, the difference |A1-A2| and the difference |A1-A3| go from "0" to "1" and then continue to increase to "2", "3", and "4" without returning to "0" (see the two lines from the fourth row to the fifth row of FIG. 9(c)). When the difference |A1-A2|, which increases faster, reaches the judgment reference value of "3" (see the fourth row of FIG. 9(c)), the sensor failure judgment means 26 makes an appropriate judgment of "abnormal" (see FIG. 9(a) and the bottom row of FIG. 9(c)). In the same way, the failure of the A2 sensor or the A3 sensor is detected when three axles have passed.

[0021] [Operational mode 3 of the prior art] Finally, we will explain the operation when a vehicle travels from the first adjacent section to the target section 8, assuming that the A1 sensor, A2 sensor, and A3 sensor of the axle detector 11 installed at the boundary between the first adjacent section and the target section 8 are all operating normally, and the front wheel set 1 of the vehicle turns around twice just before the A1 sensor, entering and leaving only the detection range of the A1 sensor. Figure 10 shows the operating state of the axle counting device 20 when a vehicle arrives or leaves, where (a) is a block diagram of the main parts, and (b) is a transition diagram related to the counting states of the A1 counter 23, the A2 counter 24, and the A3 counter 25, as well as the differences and judgments obtained based on them.

[0022] In this case, each time the vehicle's wheel set 1 moves forward and enters the detection range of the A1 sensor, the value of the A1 counter 23 increases by "1", so that the A1 counter value becomes "1" during the first forward movement, "2" during the subsequent reverse movement 1 and forward movement, "3" during the subsequent reverse movement 2 and forward movement, and "4", "5", and "6" during further forward movement (see the two rows in the first and second rows of Figure 10(b)). On the other hand, the A2 counter 24 and the A3 counter 25 do not change until the period of reverse 2 when the wheel set 1 is not approaching, and they only increase when the wheel set 1 enters the detection range of the A1 sensor during the subsequent forward movement. Therefore, after the A1 counter value reaches "3", the A2 counter value becomes "1", and after a short delay the A3 counter value also becomes "1" (see the third and fourth two lines in Figure 10(b)).

[0023] Therefore, when the A1 counter value reaches the judgment reference value of "3", the difference |A1-A2| and the difference |A1-A3| both become "3" (see the fifth and sixth two lines in Figure 10(b)), and the sensor failure judgment means 26 judges the sensor to be "abnormal" (see Figure 10(a) and the bottom line in Figure 10(b)), but this judgment result is incorrect. As a simple measure to delay and suppress the issuance of such erroneous judgments, it may be possible to adopt a value greater than "3," such as "4" or "5," as the judgment reference value to be compared with the difference |A1-A2|, the difference |A1-A3|, and the difference |A2-A3| when making a judgment by the sensor failure judgment means 26. [Prior art documents] [Patent documents]

[0024] [Patent Document 1] JP 2018-091694 A [Patent Document 2] JP 2018-167715 A [Patent Document 3] JP 2019-131084 A Summary of the Invention [Problem to be solved by the invention]

[0025] However, if the judgment reference value is increased to avoid erroneous judgments due to repeated advances and retreats of the vehicle at the end of the axle detector, there is the inconvenience of delaying the timing of making an appropriate judgment when detecting a sensor failure, which is its original purpose. In particular, if the judgment reference value is greater than the number of wheelsets of the vehicle, the timing of the sensor failure judgment will be delayed until the arrival or passing of the next vehicle. Therefore, the technical challenge is to improve the function of avoiding erroneous judgments due to repeated advances and retreats of the vehicle at the end of the axle detector without increasing the judgment reference value. [Means for solving the problem]

[0026] The axle counting device of the present invention (Solution 1) has been devised to solve such problems, and is characterized in that a number of counters are provided corresponding to a number of axle detectors installed at the ends of a target section of track, each of which counts the arrival and departure of axles based on an axle detection signal sent from a corresponding one of the axle detectors, and a continuous counter is provided which measures the number of times that only one of a pair of counters among the multiple counters has monotonically and continuously updated its count value, and the value of the continuous counter is compared with a predetermined judgment reference value to determine the presence or absence of a fault related to the axle detector.

[0027] In addition, the axle counting device of the present invention (Solution Means 2) is an axle counting device of Solution Means 1 above, characterized in that the pair of counters are counters among the multiple counters that are located adjacent to each other in the longitudinal direction of the track.

[0028] Furthermore, the axle counting device of the present invention (Solution Means 3) is the axle counting device of the above-mentioned Solution Means 1 and 2, characterized in that the judgment reference value is an integer "3". Effect of the Invention

[0029] In such an axle counting device of the present invention (Solutions 1 and 2), instead of monitoring the count values ​​of multiple counters corresponding to each axle detector and immediately determining whether there is a fault by calculating the difference, a continuous counter is added for each pair of multiple counters, and a fault is determined by checking whether a one-sided change in the count values, i.e., a significantly biased count state, has occurred. This improves the function of avoiding erroneous determinations due to repeated advances and retreats of the vehicle at the end of the axle detector, without increasing the determination standard value.

[0030] In addition, in the axle counting device of the present invention (Solution 3), by setting the judgment reference value to "3", it is possible to reconcile, at a practical level, the desire to advance the timing of detection of sensor failure and the conflicting desire to increase the number of repeated vehicle advances and retreats that can avoid erroneous judgments caused by repeated vehicle advances and retreats at the end of the axle detector. [Brief description of the drawings]

[0031] [Figure 1] 1A is a block diagram of a main part of the configuration of an axle counting device according to a first embodiment of the present invention, and FIG. 1B is a flowchart showing a part relating to one of the continuous counter value update method and the failure determination method. [Diagram 2] 13(a) and 13(b) are diagrams showing the transition of counting states. [Diagram 3] 13(a) and 13(b) are diagrams showing the transition of counting states. [Figure 4] 13(a) and 13(b) are diagrams showing the transition of counting states. [Diagram 5] FIG. 1A is a block diagram of a main part of the first embodiment, and FIG. 1B is a block diagram of a main part showing an example of a configuration having two sensors (axle detectors). [Figure 6] FIG. 1A is a block diagram of a main portion showing an example of a configuration having four sensors (axle detectors), and FIG. 1B is a block diagram of a main portion showing an example of a configuration having five sensors (axle detectors). [Figure 7] FIG. 1 is a block diagram of the overall configuration of a conventional axle counting device. [Figure 8] The figures show the operating state when all sensors are in a normal state and a vehicle simply passes by, where (a) is a block diagram of the main parts, (b) is a diagram showing the arrangement of the vehicle and the wheelsets, and (c) is a diagram showing the transition of the counting state. [Figure 9] The figures show the operating state when a vehicle simply passes through with some sensors broken, where (a) is a block diagram of the main parts, (b) is a diagram of the arrangement of the vehicle and wheelsets, and (c) is a transition diagram of the counting state. [Figure 10] The figures show the operating state when all sensors are in the normal state and the vehicle turns around twice on the entry side before passing through, (a) being a block diagram of the main parts and (b) being a transition diagram of the counting state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Specific embodiments for carrying out such an axle counting device of the present invention will be described with reference to the following Examples 1 to 4. Example 1 shown in Figures 1 to 5(a) embodies all of the above-mentioned solutions 1 to 3 (claims 1 to 3 as originally filed), and Example 2 shown in Figure 5(b), Example 3 shown in Figure 6(a), and Example 4 shown in Figure 6(b) are modifications of Example 1. In addition, in illustrating these, block diagrams and transition tables are used extensively for simplification, etc. Also, since much of what has been described in the Background Art section is common to each embodiment, duplicated explanations will be omitted, and the following description will focus on the differences from the prior art. EXAMPLES

[0033] The specific configuration of the first embodiment of the axle counting device of the present invention will be described with reference to the drawings. Fig. 1 shows the configuration of an axle counting device 50, where (a) is a block diagram of the main parts, and (b) is a flow chart showing half of the method of updating the values ​​of the continuous counters 51 and 52 and the method of determining a fault based on the counter values ​​(i.e., the part performed when the A1 counter 23 counts up). Fig. 5(a) shows the main configuration of the axle counting device 50.

[0034] The axle counting device 50 (see FIG. 1(a)) is an improvement of the axle counting device 20 described above, and like the axle counting device 20, it inherits the A1 counter 23 that counts pulses for the axle detection signal A1 of the A1 sensor of the axle detector 11 installed at one end of the target section of the track, the A2 counter 24 that counts pulses for the axle detection signal A2 of the axle detector 11, and the A3 counter 25 that counts pulses for the axle detection signal A3 of the axle detector 11. It also includes a sensor failure determination means 53 that is a modified version of the sensor failure determination means 26. Note that other components that were in the axle counting device 20, such as the input / output difference calculation unit 21, the determination unit 22, and the elements 33 to 36 corresponding to the other end of the target section, are omitted because they are not essential.

[0035] In addition, an A1-A2 continuity counter 51 and an A2-A3 continuity counter 52 are newly introduced into the axle counting device 50. The A1-A2 consecutive counter 51 is intended to count the number of times that only one of a pair of A1 counters 23 and A2 counters 24 associated with an A1 sensor and an A2 sensor located adjacent to each other in the longitudinal direction of the track updates its count value monotonically and consecutively. The A2-A3 consecutive counter 52 is intended to count the number of times that only one of a pair of A2 counters 24 and A3 counters 25 associated with an A2 sensor and an A3 sensor located adjacent to each other in the longitudinal direction of the track updates its count value monotonically and consecutively.

[0036] The sensor failure determination means 53 compares the value of the A1-A2 consecutive counter 51 with the judgment reference value integer value "3" to determine the presence or absence of a failure related to the A1 sensor (axle detector) and the A2 sensor (axle detector). Specifically (see FIG. 1(b)), after checking the values ​​of the A1 counter 23 and the A2 counter 24, the means 53 compares the value of the A1-A2 consecutive counter 51 with the judgment reference value integer value "3" (step S5) at any time (steps S1 to S4), and if the value of the A1-A2 consecutive counter 51 is equal to or greater than the judgment reference value integer value "3" (Y in step S5), the means 53 determines that a failure has occurred in the axle detectors (A1, A2 sensors) of the axle detector 11 (step S6).

[0037] The sensor failure determination means 53 also compares the value of the A2-A3 continuity counter 52 with the judgment reference integer value "3" to determine whether or not there is a failure related to the A2 sensor (axle detector) and the A3 sensor (axle detector). Although repeated illustration is omitted, specifically, after checking the values ​​of the A2 counter 24 and the A3 counter 25, the value of the A2-A3 continuity counter 52 is compared with the judgment reference integer value "3" at any time, and if the value of the A2-A3 continuity counter 52 is equal to or greater than the judgment reference integer value "3", a determination is made that a failure has occurred in the axle detectors (A2, A3 sensors) of the axle detector 11.

[0038] Furthermore, the process in which the sensor failure determination means 53 updates the value of the A1-A2 consecutive counter 51 can be realized relatively easily by using the A1 counter memory and the A2 counter memory secured in an appropriate data holding means such as an internal memory or register not shown in FIG. 1(a). Then, in addition to the A1 and A2 counter memories, all of the counters 23 to 25, 51, and 52 mentioned above are initialized to have their values ​​unified to "0", and then a process begins to update the value of the A1-A2 consecutive counter 51 (see Figure 1(b)).

[0039] Specifically (steps S1 to S4), when there is no change in the value of the A1 counter 23, the A1-A2 consecutive counter 51 is not updated in response to the change in the value of the A1 counter 23 (N in step S1), and the value of the A1-A2 consecutive counter 51 is updated (steps S2 to S4) only when there is a change in the value of the A1 counter 23, specifically when the value increases (+1) (Y in step S1). The content of the update is classified into two cases depending on whether the value of the A2 counter 24 coincides with the value of the A2 counter memory or not (step S2).

[0040] If they do not match (N in step S2), this means that the value of the A1 counter 23 has increased after the value of the A2 counter 24 has increased. In other words, this does not mean that the A1 counter 23 is continuing to count up monotonically by itself. In this case (step S3), the A1-A2 consecutive counter 51 is initialized again, and its value is set to "0." In addition, in preparation for future determinations, the value of the A2 counter 24 is substituted and held in the A2 counter memory for future reference.

[0041] On the other hand, if the value of the A2 counter 24 and the value of the A2 counter memory match in the above case classification (Y in step S2), the value of the A1 counter 23 has increased before the value of the A2 counter 24 has increased. In other words, this corresponds to the case where the A1 counter 23 continues to count up monotonically by itself. In this case (step S4), the value of the A1-A2 consecutive counter 51 is updated. Specifically, in order to measure the number of times the A1 counter 23 monotonically increases without an increment of the A2 counter 24, the value of the A1-A2 consecutive counter 51 is incremented (+1).

[0042] The above explanation (see Figure 1(b)) details how the axle counting device 50 uses the A1-A2 consecutive counter 51 and the A2 counter memory to detect when the value of the A1 counter 23 has monotonically increased without an intervening increase in the value of the A2 counter 24. Since the A1 sensor and A1 counter 23 and the A2 sensor and A2 counter 24 are in a symmetrical relationship with respect to the A1-A2 consecutive counter 51, we will omit the presentation of a drawing in which "A1 counter..." and "A2 counter..." are interchanged in steps S1 to S3 of Figure 1(b) and repeated detailed explanations will be omitted, but the following can be said. In other words, the axle counting device 50 is also capable of detecting a monotonically increasing value of the A2 counter 24 without an intervening increase in the value of the A1 counter 23 by utilizing the A1-A2 consecutive counter 51 or another counter memory.

[0043] Also, although illustrations and repeated detailed explanations are omitted, the axle counting device 50 is also adapted to detect a monotonous increase in the value of the A3 counter 25 without an increase in the value of the A2 counter 24 by utilizing an A2-A3 consecutive counter 52 and a further counter memory. Furthermore, although illustrations and repeated detailed explanations will be omitted, the axle counting device 50 is also configured to detect when the value of the A2 counter 24 increases monotonically without an increase in the value of the A3 counter 25 by utilizing an A2-A3 consecutive counter 52, etc.

[0044] The usage and operation of the axle counting device of the first embodiment will be described with reference to Figures 2(a) to 4(b), each of which is a transition diagram of the counting state. Hereinafter, similarly to the latter half of the operation explanation of the axle counting device 20 already described, the operation state of the axle counting device 50 accompanying the passage (coming and going) of vehicles will be briefly explained.

[0045] [Operation mode 1 of embodiment 1] Figure 2(a) is a transition diagram showing, in a chronological list, the vehicle driving state, the changing states of the values ​​of the A1 counter 23, the A2 counter 24 and the A3 counter 25, the changing states of the values ​​of the A1-A2 consecutive counter 51 and the A2-A3 consecutive counter 52, the fault determination conditions and the determination results when the vehicle simply drives from the first adjacent section to the target section 8 without turning back, with the A1 sensor, A2 sensor and A3 sensor of the axle detector 11 installed at the boundary between the first adjacent section and the target section 8 all operating normally.

[0046] When the A1, A2, and A3 sensors of the axle detector 11 installed at the boundary between the first adjacent section and the target section 8 are all operating normally (all sensors normal), and the vehicle simply travels from the first adjacent section to the target section 8 without turning back (vehicle normal forward movement, see the top row of FIG. 2(a)), the A1 counter 23, A2 counter 24, and A3 counter 25 all increase in value by "1" from the initial value "0" each time the axles 1 to 4 pass, with a time difference due to the passage. Then (see the three rows from the second to fourth rows of FIG. 2(a)), as the vehicle passes through the detection range of the axle detector 11, the A1, A2, and A3 counter values ​​change in order from "1", "1", "1" with the time difference due to the passage of the axles, to "2", "2", "2", "3", "3", "4", "4", "4".

[0047] When the A1, A2, A3 counter values ​​change in this way, both the A1-A2 consecutive counter 51 and the A2-A3 consecutive counter 52 continue to take the value "0" (see the two lines from the fifth to sixth rows in FIG. 2(a)). Therefore, the failure determination condition (see the one line in the seventh row in FIG. 2(a)) is not satisfied, specifically, the logical formula {(value of the A1-A2 consecutive counter) ≧ 3 or (A2-A3 consecutive counter) ≧ 3} is not satisfied, so the sensor failure determination means 53 makes an appropriate determination of "normal" (see the one line in the bottom row in FIG. 2(a)). In this manner, an appropriate decision is made regarding normal vehicle forward movement when all sensors are in a normal state.

[0048] [Operation mode 2 of embodiment 1] Next, in the state where the A1 sensor in the axle detector 11 is broken and the other A2 and A3 sensors are operating normally (A1 sensor broken), when the vehicle simply runs from the first adjacent section to the target section 8 without turning back (vehicle normal forward movement, see the top row of FIG. 2(b)), the value of the broken A1 counter 23 remains unchanged at the initial value of "0" (see the second row of FIG. 2(b)), whereas the A2 counter 24 and the A3 counter 25 increase in value by "1" from the initial value of "0" each time the axles 1 to 4 pass, with a time difference due to the passage. Then (see the third to fourth rows of FIG. 2(b)), in response to the vehicle passing through the detection range of the axle detector 11, the A2 and A3 counter values ​​change to "1", "1", "2", "2", "3", "3", and "4", "4", in that order, with a time difference due to the passage of the axles.

[0049] When the A1, A2, and A3 counter values ​​change in this way, the A2-A3 consecutive counter 52 continues to take the value "0" (see the sixth row in FIG. 2(b)), but the value of the A1-A2 consecutive counter 51 increases from "0" to "1", "2", and "3" (see the fifth row in FIG. 2(b)). When the value of the A1-A2 consecutive counter 51 reaches "3", the failure determination condition (see the seventh row in FIG. 2(b)) is established. Specifically, the logical formula {(value of the A1-A2 consecutive counter) ≧ 3 or (A2-A3 consecutive counter) ≧ 3} is established, and the sensor failure determination means 53 appropriately determines that the sensor is "abnormal" (see the right side of the bottom row in FIG. 2(b)). In this way, an appropriate decision can be made as to whether the vehicle will move forward normally even when the A1 sensor has failed.

[0050] [Operation mode 3 of embodiment 1] Furthermore, when the A1, A2, and A3 sensors of the axle detector 11 are all operating normally (all sensors normal), if the vehicle's wheel set 1 enters and exits (comes and goes) only the wheel set detection range of the A1 sensor twice when the vehicle moves from the first adjacent section to the target section 8 (the vehicle retreats twice near the A1 sensor, see the top row of Figure 3(a)), the A1 counter 23 will increase in value by "1" from its initial value of "0" each time the wheel set 1 advances or retreats and approaches, and will reach "3" when the wheel set 1 passes (see the second row of Figure 3(a)).

[0051] During that time, the A2 counter 24 and the A3 counter 25 maintain their initial values ​​of "0" (see the third and fourth rows in FIG. 3(a)). Then, according to such changes in the A1, A2, A3 counter values, when the A1 counter value becomes "2", the value of the A1-A2 consecutive counter 51 changes from the initial value "0" to "1", and when the A1 counter value becomes "3", the value of the A1-A2 consecutive counter 51 becomes "2" (see the first line in the fifth row of FIG. 3(a)). Note that the A2-A3 consecutive counter 52 maintains its initial value of "0" (see the first line in the sixth row of FIG. 3(a)).

[0052] Then, if the vehicle continues to move forward without turning back, the values ​​of both the A2 counter 24 and the A3 counter 25 will become "1" each time the wheelset 1 passes, with a time difference due to the passage (see the third and fourth rows in Figure 3(a)). Furthermore, since the A2 counter value is updated from "0" to "1" after the A1 counter value becomes "3", the value of the A1-A2 consecutive counter 51 is reinitialized to "0" (see the first line in the fifth row of FIG. 3(a)). Even at this time, the A2-A3 consecutive counter 52 continues to maintain its initial value of "0" (see the first line in the sixth row of FIG. 3(a)).

[0053] From then on, as the vehicle continues to move forward, each time the following axles 2-4, in addition to the axle 1, pass the axle detector 11, the A1, A2, and A3 counter values ​​are incremented by "1" with the time difference due to the passage. Then (see the three rows from the second to fourth rows in Figure 3(a)), the A1, A2, and A3 counter values ​​become "4", "2", and "2" in that order with the time difference due to the passage of the axles, and when there is a following vehicle and it also passes, they become "5", "3", and "3", and then "6", "4", and "4", and so on. When the A1, A2, and A3 counter values ​​change in this manner, the maximum value of the A1-A2 consecutive counter 51 remains at “2”, and the A2-A3 consecutive counter 52 continues to have a value of “0” (see the two lines from the fifth to sixth rows in FIG. 3(a)).

[0054] Therefore, the failure judgment condition (see the seventh line in FIG. 3(a)) is not satisfied; specifically, the logical expression {(value of the A1-A2 consecutive counter) ≧ 3 or (value of the A2-A3 consecutive counter) ≧ 3} is not satisfied, so the sensor failure judgment means 53 makes the appropriate judgment of “normal” (see the bottom line in FIG. 3(a)). In this way, in the axle counting device 50, if the A1, A2, and A3 sensors are all normal, even if the vehicle turns around twice on the entry side before passing through, an appropriate judgment will be made, unlike the operation of the axle counting device 20 already described.

[0055] [Operation mode 4 of embodiment 1] Furthermore, the following explanation of the operation also supports the idea that the fact that a "normal" judgment is made when the vehicle enters and passes through the intersection by turning around twice does not impair the failure detection function. First, we will explain the operation when the A1 sensor in the axle detector 11 fails while the other A2 and A3 sensors are operating normally (A1 sensor failure), and when the vehicle moves from the first adjacent section to the target section 8, the wheel set 1 of the vehicle enters and exits (comes and leaves) only the wheel set detection range of the A1 sensor twice (the vehicle backs up twice near the A1 sensor, see the top row of Figure 3(b)).

[0056] In this case, the value of the faulty A1 counter 23 remains unchanged at its initial value of "0" (see the first line in the second row of FIG. 3(b)), whereas the A2 counter 24 and A3 counter 25 increase in value by "1" from their initial value of "0" each time axles 1 to 4 pass by, with the time difference due to the passage. Then (see the two rows from the third row to the fourth row of FIG. 3(b)), as the vehicle passes through the detection range of the axle detector 11, the A2 and A3 counter values ​​change in sequence from "1", "1" to "2", "2", "3", "3", and "4", "4" with the time difference due to the passage of the axles.

[0057] When the A1, A2, and A3 counter values ​​change in this way, the A2-A3 consecutive counter 52 continues to take the value "0" (see the sixth row in FIG. 3(b)), but the value of the A1-A2 consecutive counter 51 increases from "0" to "1", "2", and "3" (see the fifth row in FIG. 3(b)). When the value of the A1-A2 consecutive counter 51 reaches "3", the failure determination condition (see the seventh row in FIG. 3(b)) is established. Specifically, the logical formula {(the value of the A1-A2 consecutive counter) ≧ 3 or (the value of the A2-A3 consecutive counter) ≧ 3} is established, and the sensor failure determination means 53 appropriately determines that the sensor is "abnormal" (see the right side of the bottom row in FIG. 3(b)). In this way, appropriate judgment can be made even when the vehicle moves forward or backward twice when the A1 sensor is in a faulty state.

[0058] [Operation mode 5 of embodiment 1] Next, we will explain the operation when the A2 sensor in the axle detector 11 fails while the other A1 and A3 sensors are operating normally (A2 sensor failure), and when the vehicle moves from the first adjacent section to the target section 8, the wheel set 1 of the vehicle enters and exits (comes and leaves) only the wheel set detection range of the A1 sensor twice (the vehicle reverses twice near the A1 sensor, see the top row of Figure 4(a)).

[0059] In this case, the value of the A2 counter 24 corresponding to the faulty A2 sensor remains unchanged at the initial value "0" until the end (see the first line in the third row of FIG. 4(a)). In contrast, the A1 counter 23 increases in value by "1" from its initial value of "0" each time the wheel set 1 moves forward or backward and approaches, and reaches "3" when the wheel set 1 passes (see the first line in the second row of Figure 4(a)). During that time, the A3 counter 25 maintains its initial value of "0" (see the first line of the fourth row in FIG. 4(a)).

[0060] Then, according to such changes in the A1, A2, and A3 counter values, when the A1 counter value becomes "2", the value of the A1-A2 consecutive counter 51 changes from the initial value "0" to "1", and when the A1 counter value becomes "3", the value of the A1-A2 consecutive counter 51 becomes "2" (see the first line in the fifth row of FIG. 4(a)). The A2-A3 consecutive counter 52 maintains its initial value of "0" (see the first line in the sixth row of FIG. 4(a)). Then, when the vehicle continues to move forward without turning back, the value of the A3 counter 25 becomes "1" as the wheelset 1 passes (see the first line in the fourth row of FIG. 4(a)).

[0061] From then on, as the vehicle continues to move forward, each time the following axles 2 to 4, in addition to the axle 1, pass the axle detector 11, the A1 and A3 counter values ​​are incremented by "1" with the time difference due to the passage. However, the A2 counter value remains at "0". Then (see the second and fourth rows of Figure 4(a)), the A1 and A3 counter values ​​become "4" and "2", respectively, depending on the time difference between the passing of the wheelsets. When there is a following vehicle and it also passes, the values ​​become "5" and "3", then "6" and "4", and so on.

[0062] In the case where the A1, A2, and A3 counter values ​​change in this way, when the A1 counter value becomes "4", the value of the A1-A2 consecutive counter 51 becomes "3" (see the two lines in the second and fifth rows of FIG. 4(a)). In this case, the failure determination condition (see the one line in the seventh row of FIG. 4(a)) is satisfied, specifically, the logical formula {(value of the A1-A2 consecutive counter) ≧ 3 or (value of the A2-A3 consecutive counter) ≧ 3} is satisfied, and the sensor failure determination means 53 makes an appropriate determination of "abnormality" (see the right side part of the one line in the bottom row of FIG. 4(a)). In this way, appropriate judgment is made even when the vehicle advances and retreats twice under the A2 sensor failure condition. Note that the value of the A2-A3 continuity counter 52 also reaches "3" when the following vehicle passes.

[0063] [Operation mode 6 of embodiment 1] Furthermore, the operation will be described in the case where the A3 sensor in the axle detector 11 fails while the other A1 and A2 sensors are operating normally (A3 sensor failure), and when the vehicle moves from the first adjacent section to the target section 8, the wheel set 1 of the vehicle enters and exits (comes and leaves) only the wheel set detection range of the A1 sensor twice (the vehicle reverses twice near the A1 sensor, see the top row of Figure 4(b)).

[0064] In this case, too, the A1 counter 23 increases by "1" from the initial value "0" to "3" (see the first line in the second row of FIG. 4(b)), and the A2 counter 24 and the A3 counter 25 maintain their initial value "0" (see the two lines in the third and fourth rows of FIG. 4(b)), just like when all sensors are normal or when the A2 sensor is faulty, until the wheelset 1 of the vehicle enters and exits the wheelset detection range of the A1 sensor twice and then passes the A1 sensor (see FIG. 3(a) and FIG. 4(a)). After that, the A2 counter value immediately changes from the initial value "0" to "1" as the wheelset 1 continues to pass, but the value of the A3 counter 25 corresponding to the faulty A3 sensor remains unchanged and maintains its initial value "0".

[0065] Then, each time axles 2 to 4 pass following axle 1, the A1 and A2 counter values ​​are incremented by "1" with the time difference due to the passage. Then (see the two rows from the second to third row in FIG. 4(b)), as a vehicle passes through the detection range of axle detector 11, the A1 and A2 counter values ​​change from the above-mentioned "3" and "1" to "4" and "2" with the time difference due to the passage of the axles, and if there is a following vehicle and it also passes, they change to "5" and "3", then to "6" and "4", and so on. During this time, the A3 counter value remains unchanged and maintains its initial value of "0."

[0066] When the A1, A2, and A3 counter values ​​change in this way, the value of the A1-A2 consecutive counter 51 (see the first line in the fifth row of FIG. 3(a)) becomes "2" when the A1 counter value becomes "3", but immediately thereafter, the A2 counter value changes to "1", and the value is returned to "0". After that, the A1 and A2 counter values ​​increase alternately, so the A1-A2 consecutive counter 51 maintains the value "0". In contrast, the value of the A2-A3 consecutive counter 52 (see the first line of the sixth row in FIG. 4(b)) becomes “1” when the A2 counter value continues to increase from “0” to “2” while the A3 counter value remains unchanged.

[0067] Furthermore (see the sixth row in FIG. 4(b)), the A2 counter value increases to "3" and then "4" while the A3 counter value remains unchanged, and accordingly the value of the A2-A3 consecutive counter 52 also increases to "2" and then "3". When the value of the A2-A3 consecutive counter 52 reaches "3", the failure determination condition (see the seventh row in FIG. 4(b)) is established; specifically, the logical formula {(value of the A1-A2 consecutive counter) ≧ 3 or (value of the A2-A3 consecutive counter) ≧ 3} is established, and the sensor failure determination means 53 makes an appropriate determination of "abnormal" (see the right-hand portion of the bottom row in FIG. 4(b)). In this way, appropriate judgment can be made even when the vehicle moves forward and backward twice when the A3 sensor is in a fault state.

[0068] From these six operating modes, it is clear that the axle counting device 50 of the first embodiment of the present invention is designed to give a "normal" judgment when the vehicle enters and passes through by turning around twice, without impairing the failure detection function.

[0069] [Additional points based on Example 1] As is clear from the above-described operational example, when only the A1 sensor among the A1, A2, and A3 sensors fails, the value of the A1-A2 consecutive counter 51 corresponding to the A1 sensor becomes equal to or greater than the judgment reference value of "3" as a vehicle passes, but the value of the A2-A3 consecutive counter 52 not corresponding to the A1 sensor does not reach the judgment reference value. In addition, when only the A3 sensor among the A1, A2, and A3 sensors fails, the value of the A2-A3 consecutive counter 52 corresponding to the A3 sensor becomes equal to or exceeds the judgment reference value as the vehicle passes, but the value of the A1-A2 consecutive counter 51 not corresponding to the A3 sensor does not reach the judgment reference value.

[0070] Furthermore, when only the A2 sensor among the A1, A2, and A3 sensors fails, the value of the A1-A2 consecutive counter 51 and the value of the A2-A3 consecutive counter 52 corresponding to the A2 sensor become equal to or greater than the judgment reference value as the vehicle passes. Therefore, it is expected that incorporating or adding a means to the axle counting device 50 that estimates that a failure has occurred in a sensor that is the input sensor of the reference counter of the continuous counter whose value is equal to or greater than the judgment reference value, but is not the input sensor of the reference counter of the continuous counter whose value is equal to or less than the judgment reference value, will be useful for failure diagnosis and repair work. EXAMPLES

[0071] The axle counting device of the present invention, the block diagram of the essential parts of which is shown in FIG. 5(b), differs from the axle counting device 50 of the above-mentioned embodiment 1 (see FIG. 5(a)) in that the axle detector includes two sensors (axle detectors), an A1 sensor and an A2 sensor, and correspondingly, the continuous counter includes only one A1-A2 continuous counter, and the logical formula of the failure determination condition also includes only one comparison formula, {(value of the A1-A2 continuous counter) ≧ 3}. In this case, the number of sensors is the minimum of two, and redundancy is small, but the axle counting device 50 of the first embodiment functions similarly. EXAMPLES

[0072] The axle counting device of the present invention, the block diagram of the essential parts of which is shown in FIG. 6(a), differs from the above-mentioned embodiment 1 in that the axle detector includes four sensors (axle detectors) A1, A2, A3, and A4 sensors, and correspondingly, the consecutive counters include three consecutive counters, an A1-A2 consecutive counter, an A2-A3 consecutive counter, and an A3-A4 consecutive counter, and the logical formula of the failure determination condition also includes three comparison formulas {(value of the A1-A2 consecutive counter) ≧ 3 or (value of the A2-A3 consecutive counter) ≧ 3 or (value of the A3-A4 consecutive counter) ≧ 3}. In this case, the number of sensors is increased to four, increasing redundancy. EXAMPLES

[0073] The axle counting device of the present invention, the block diagram of the essential parts of which is shown in FIG. 6(b), differs from the above-mentioned embodiments 1 and 3 in that the axle detector includes five sensors (axle detectors) A1, A2, A3, A4 and A5 sensors, and correspondingly, the consecutive counters include four counters, an A1-A2 consecutive counter, an A2-A3 consecutive counter, an A3-A4 consecutive counter and an A4-A5 consecutive counter, and the logical formula of the failure determination condition includes four comparison formulas {(value of the A1-A2 consecutive counter) ≧ 3 or (value of the A2-A3 consecutive counter) ≧ 3 or (value of the A3-A4 consecutive counter) ≧ 3 or (value of the A4-A5 consecutive counter) ≧ 3}. In this case, there are five sensors, further increasing the redundancy.

[0074] [others] In the above embodiment, the sensor failure detection unit 12 described above was not provided, but since the sensor failure detection unit 12 of the instantaneous sensor failure detection method and the sensor failure determination means 53 of the time-dependent sensor failure detection method are not exclusive, the sensor failure detection unit 12 may be provided in addition to the sensor failure determination means 53. Furthermore, the input / output difference calculation unit 21 and the determination unit 22 may be provided in the same device, and in that case, the input / output difference calculation unit 21 and the like may refer to the counters 23 to 25 and the like. [Industrial Applicability]

[0075] The axle counting device of the present invention is not limited to application to target sections having two ends as shown in the above embodiment, but can also be applied to target sections having three or more ends. [Explanation of symbols]

[0076] 8...Target section (railway), 11...Axle detector, A1, A2, A3...Axle detection signal, A1 sensor, A2 sensor, A3 sensor...Axle detector, 12...Sensor failure detection unit (before counting), 20...Axle counting device, 21...Input / output difference calculation section, 22...Judgment section, 23...A1 counter, 24...A2 counter, 25...A3 counter, 26...sensor failure determination means (after counting), 31: Axle detector, 32: Sensor failure detection unit (before counting) 33...A1 counter, 34...A2 counter, 35...A3 counter, 36...sensor failure determination means (after counting), 50...Axle counting device, 51...A1-A2 continuous counter, 52...A2-A3 continuous counter, 53...Sensor failure determination means (after counting)

Claims

1. An axle counting device comprising: a plurality of counters corresponding to a plurality of axle detectors installed at the ends of a target section of track; each of the counters counts the coming and going of axles based on an axle detection signal sent from a corresponding one of the axle detectors; a continuous counter is provided for counting the number of times that only one of a pair of the plurality of counters has monotonically and continuously updated its count value; and the value of the continuous counter is compared with a predetermined judgment reference value to determine the presence or absence of a fault related to the axle detector.

2. 2. The axle counting device according to claim 1, wherein said pair of counters is a pair of counters which are adjacent to each other in the longitudinal direction of said track among said plurality of counters.

3. 3. The axle counting device according to claim 1, wherein the judgment reference value is an integer "3".

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