JP2012101622A - Railroad-crossing obstacle detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a railroad-crossing obstacle detector having an object tracking function which enables to determine that an object is moving and the moving object is the same object.SOLUTION: The railroad-crossing obstacle detector has the following configuration. A transmitter/receiver transmits radio waves into an area including a railroad cross and receives reflected waves from an object existing inside the area so as to convert them into electric signals. The electric signals are supplied from the transmitter/receiver to a signal processing part. The signal processing part calculates the distance from the transmitter/receiver to the object for each prescribed detection cycle on the basis of the electric signals. The device is configured to set the following state as the condition for determining to be the same object, that is, a distance L2 calculated in the current detection cycle T2 and a distance L0 calculated in the last detection cycle T1 are respectively within a predetermined difference ΔL in the two continuous detection cycles.

Description

  The present invention relates to a level crossing obstacle detection device that detects obstacles left in a level crossing by radio waves such as millimeter waves.

  In recent years, a level crossing obstacle detection device that detects an obstacle left in a level crossing by millimeter waves has been developed. This millimeter-wave type railroad crossing obstacle detection device is disclosed in Patent Document 1, for example, and has an excellent characteristic that it is hardly affected by external conditions such as weather.

  There are other excellent characteristics of the millimeter wave type railroad crossing obstacle detection device. Conventional optical railroad crossing obstacle detection devices detect obstacles by blocking the light of the sensor device, so it is difficult to detect small obstacles such as humans and wheelchairs that can enter the interval between optical axes. There was a problem.

  On the other hand, since the millimeter wave type railroad crossing obstacle detection device transmits a millimeter wave to a monitoring area and detects a reflected wave from the obstacle, it can reliably detect even a small obstacle. Of course, a large obstacle such as an automobile can be detected in the same manner. In addition, the millimeter wave type railroad crossing obstacle detection device sends a millimeter wave so as to cover the entire area of the railroad crossing and detects obstacle foreign matter, so it is different from the conventional optical level crossing obstacle detection device. Thus, no off-axis blind spot occurs in the optical axis monitoring area.

As described above, the millimeter-wave type railroad crossing obstacle detection device has excellent characteristics. However, since the object to be detected is a moving object such as an automobile, a bicycle, or a person, whether or not it is a moving object. Must be detected. In order to detect whether or not it is a moving object, it must be possible to determine that the object is moving and that it is the same object. Patent Document 1 does not disclose such means.
JP-A-2005-234813

  An object of the present invention is to provide a crossing obstacle detection device having an object tracking function capable of determining that an object is moving and that the object is the same object.

  In order to solve the above-described problem, a crossing obstacle detection device according to the present invention includes a transceiver and a signal processing unit. The transceiver transmits a radio wave in an area including a railroad crossing, receives a reflected wave from an object existing in the area, and converts it into an electric signal. The signal processing unit is supplied with the electrical signal from the transmitter / receiver, calculates a distance from the transmitter / receiver to the object based on the electrical signal for each predetermined detection cycle, and in two consecutive detection cycles A condition for determining that the same object is that the distance calculated in the current detection cycle and the distance calculated in the previous detection cycle are within a predetermined difference.

  As described above, in the present invention, the signal processing unit calculates the distance from the transceiver to the object for each predetermined detection period based on the electrical signal supplied from the transceiver, so that an object that can be an obstacle is detected. It can be determined that it is moving. If the distance calculated for each period is the same, it is determined that the obstacle is stopped.

  In addition, the signal processing unit determines that the distance calculated in the current detection cycle and the distance calculated in the previous detection cycle are within a predetermined difference in two consecutive detection cycles. Since it is a condition for determination, it can be determined that the object is the same object at the same time as detecting that the object is moving.

  Furthermore, the movement of an object that can be an obstacle and the same object determination are performed using two data of the distance calculated in the current detection cycle and the distance calculated in the previous detection cycle. Detection can be avoided.

  As described above, according to the present invention, it is possible to provide a crossing obstacle detection device having an object tracking function capable of determining that an object is moving and that it is the same object.

It is a figure showing roughly one embodiment of a level crossing obstacle detection device concerning the present invention. FIG. 2A is a diagram illustrating the operation of the transceiver and the signal processing unit in the crossing obstacle detection device according to the present invention. FIG. 2A illustrates the operation of the transceiver, and FIGS. The operation is shown.

  The level crossing obstacle detection device shown in FIG. 1 detects the presence or absence of an object 10 that can be an obstacle entering the level crossing 4, and includes transceivers 1 and 2, reflectors 11 to 13 and 21 to 23. The signal processing unit 3 is provided. The railroad crossing 4 intersects the line 51 (upward direction) on which the train 61 travels and the line 52 (downward direction) on which the train 62 travels on the same plane, and the circuit breakers 71 and 81 are on both sides corresponding to the doorway. There are provided shut-off rods 72 and 82 which are driven up and down. The illustrated lines 51 and 52 are merely examples, and are not limited thereto. The object 10 includes a person, a wheelchair, a bicycle or a car.

  The transceivers 1 and 2 are disposed at diagonal positions inside the crossing bars 72 and 82 of the circuit breakers 71 and 81 and outside the railroad crossing 4 with the railroad crossing 4 interposed therebetween. The transmitters and receivers 1 and 2 are assigned radiation areas (S11 to S13) and (S21 to S23), respectively, and radio waves are transmitted to these radiation areas (S11 to S13) and (S21 to S23). It transmits periodically and receives the reflected wave from the object 10 in the railroad crossing 4. The radio wave is preferably a millimeter wave band radio wave. As is well known, the millimeter wave is a radio wave having a frequency of 30 to 300 GHz (wavelength of 10 to 1 mm) and has extremely narrow directivity.

  The transceiver 1 is disposed in the vicinity of the corner on the side where the breaker 71 is located. The radiation area (S11 to S13) in charge of the transceiver 1 is an area from the inside of the circuit breaker 71 to adjacent to the radiation area (S21 to S23) of the transceiver 2. The radiation areas (S11 to S13) in charge of the transmitter / receiver 1 are made continuous so as not to generate a spatial blank area.

  The transceiver 2 is disposed in the vicinity of the corner on the side where the circuit breaker 81 is located. The radiation area (S21 to S23) in charge of the transceiver 2 is an area from the area adjacent to the radiation area (S11 to S13) to the inside of the circuit breaker 81. The radiation areas (S21 to S23) handled by the transceiver 2 are also continued so as not to generate a spatial blank area.

  The reflectors 11 to 13 are provided so as to face the transceiver 1 across the railroad crossing 4. These reflectors 11 to 13 reflect radio waves radiated from the transceiver 1 toward the transceiver 1. Another set of reflectors 21 to 23 is provided to face the transmitter / receiver 2 across the railroad crossing 4. The reflectors 21 to 23 reflect the radio waves radiated from the transceiver 2 toward the transceiver 2. When the reflected waves from the reflectors 11 to 13 and 21 to 23 are not detected, it is determined that the transceivers 1 and 2 are in a failure state. This determination is performed by the signal processing unit 3.

  The signal processing unit 3 is connected to the transceivers 1 and 2 and controls the operations of the transceivers 1 and 2 based on the operating condition signal S1 supplied from the outside. The presence or absence of the object 10 is determined using the electrical signal. In addition, a self-diagnosis function for diagnosing the transceivers 1 and 2 based on the reception information of the reflected waves reflected by the reflectors 11 to 13 and 21 to 23 is provided. The signal processing unit 3 is provided in the vicinity of the transceivers 1 and 2 or in a predetermined electrical equipment room. The signal processing unit 3 can be configured by a CPU or a microprocessor (MPU). The detection signal S2 indicating the presence / absence determination of the object 10 and the self-diagnosis result output from the signal processing unit 3 is sent to, for example, a ground control device (not shown) that controls the operation of the railway traffic system, It is used for control such as train stoppage.

  The signal processing unit 3 is supplied with electrical signals from the transceivers 1 and 2, calculates the distance from the transceivers 1 and 2 to the object 10 based on the electrical signals, and in two consecutive detection cycles (detection time), A condition for determining that the object 10 is the same is that the distance calculated this time and the distance calculated last time are within a predetermined difference. Next, this point will be described with reference to FIG.

  First, when the transmitter / receiver 1 is shown as a representative of the transmitter / receivers 1 and 2, as shown in FIG. The operation of radiating radio waves and receiving the reflected waves is periodically repeated so that no blank area is generated. The received reflected wave is converted into an electrical signal in the transceiver 1 and supplied to the signal processing unit 3.

In the signal processing unit 3, distance information (referred to as the same object determination distance) ΔL that is a condition for determining the same object 10 is stored in, for example, a memory. The same object determination distance ΔL is calculated from the detection cycle T (h) and the speed V (m / h) of the object 10 that ensures detection.
ΔL (m) = V (m / h) · T (h)
As required. It is merely an example for realizing the description and contributing to the understanding of the invention. However, assuming that the detection cycle T = 1.5 seconds and the moving speed V (m / h) = 1200 (m / h),
ΔL (m) = 1200 (m / h) · (1.5 / 3600) (h)
= 0.5 (m)
It becomes. Hereinafter, it demonstrates concretely according to this condition.

  The signal processing unit 3 samples the relationship between the distance and the reflection level at the same object determination distance ΔL = 0.5 m in the given detection period T. Assuming that object detection is started from FIG. 2A where the object 10 is at a distance L0 = 18 m, in the first detection cycle T1, as shown in FIG. 2B, at a position at a distance L0 = 18 m. A maximum reflection level (voltage) Rp is obtained. Therefore, as shown in FIG. 2C, in the first detection cycle T1, it is determined that the object 10 is present at the position of the distance L0 = 18 m (◯ mark). In the present invention, since the signal processing unit 3 determines that the same object 10 exists within the range of the same object determination distance ΔL = 0.5 m, the same object determination distance ΔL = 0.5 m from the position of the distance L0 = 18 m. It is determined that the object 10 exists (marked with a circle) even at the position of the distance L2 = 18.5 m within the range.

  In the first detection cycle T1, the relationship between the distance and the reflection level is sampled up to the maximum detection distance L = 32 m in steps of the same object determination distance ΔL = 0.5 m, and then the process proceeds to the next detection cycle T2. Similarly, in the detection cycle T2, the relationship between the distance and the reflection level is sampled. As described above, the detection cycle T1 is 1.5 seconds, and within this detection cycle T1 = 1.5 seconds, the object 10 moves in the direction of the arrow F1 by the same object determination distance ΔL = 0.5 m. I assumed that. Therefore, in the detection cycle T1, the object 10 located at the distance L0 = 18 m moves to the position of the distance L2 = 18.5 m advanced by the same object determination distance ΔL = 0.5 m in the detection cycle T2. Thus, the maximum reflection level Rp is obtained at the position of the distance L2 = 18.5 m. Therefore, the distance L2 = 18.5 m is set as the distance from the transceiver 1 to the object 10, and as shown in FIG. 2C, the object 10 exists at the position of the distance L2 = 18.5m in the detection cycle T2 (◯ Mark). In the present invention, since the signal processing unit 3 determines that the same object 10 exists within the range of the same object determination distance ΔL = 0.5 m, the same object determination distance ΔL = 0 from the position of the distance L2 = 18.5 m. It is determined that the object 10 is present (circle mark) even at a position of distance L2 = 19 m within a range of 0.5 m.

  Thereafter, the same processing is repeated in the detection cycles T3, T4,. Thereby, the movement of the object 10 can be tracked from the position of the distance 0 until the maximum detection distance Lm = 32 m is reached.

  In addition, the signal processing unit has a difference in distance between two consecutive detection periods (T1, T2), (T2, T3), ... (Tn-1, Tn) among the detection periods T1 to Tn. When it is within the determined difference same object determination distance ΔL, it can be determined that the object 10 is moving, and at the same time, it can be determined that it is the same object 10.

  Furthermore, since the movement of the object 10 and the same object determination are performed using the two data of the distance calculated in the current cycle and the distance calculated in the previous cycle, erroneous detection due to radio wave interference can be avoided. .

  Although the description is omitted, the same object tracking process is executed even when the object 10 moves in the direction opposite to the arrow F1, for example, from the position of the distance L0 to the direction of the distance L1. Further, the above-described operation is similarly performed in the transceiver 12. Note that the technology already known in Patent Document 1 or the like can be applied as it is to the distance measuring function by the transceivers 1 and 2 and the signal processing method of the signal processing unit 3.

1, 2 Transceiver 3 Signal processor 10 Object

Claims (1)

A crossing obstacle detection device including a transceiver and a signal processing unit,
The transmitter / receiver transmits a radio wave in a region including a railroad crossing, receives a reflected wave from an object existing in the region, and converts it into an electric signal,
The signal processing unit is supplied with the electrical signal from the transmitter / receiver, calculates a distance from the transmitter / receiver to the object based on the electrical signal for each predetermined detection cycle, and in two consecutive detection cycles The condition for determining the same object is that the distance calculated in the current detection cycle and the distance calculated in the previous detection cycle are within a predetermined difference.
Railroad crossing obstacle detection device.

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