JP2011209026A - Train speed measuring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a train speed measuring system capable of more correct measurement of ground speed not only during normal travel but also during slip of an axle by acquiring an image using a camera and matching.SOLUTION: A reference mark 2 is put on a rail. The mark is imaged by an imaging camera 5. The recorded image or visual image is subjected to matching, and the reference mark 2 is extracted by an image processing unit 4. An arithmetic unit 3 calculates train speed based on distance information acquired by the reference mark extracted by the image processing unit 4 and time information of a recording frame of the camera. Such measurement of the train speed allows the ground speed to be more correctly measured not only during normal travel but also during slip of the axle.

Description

  The present invention relates to a train speed measurement system for the purpose of measuring a ground speed using an image or video mounted on a vehicle in a train.

  In general, the method of measuring the train speed is mainly performed by a speed generator attached to the drive shaft, and an improved train speed detection method is described in Patent Document 1. According to Patent Document 1, the speed of a train is detected from the number of rotations of a motor by using speed information used in motor drive control separately from a speed generator.

JP 2008-182808 A

  In the conventional train speed measurement system, as described in Patent Document 1, the speed information used in the drive control of the motor and the information from the speed generator attached to the drive shaft are used to train Was to measure the ground speed. In such a measurement system, during normal driving, the axle directly connected to the train motor and speed generator meshes with the rail, and the information from the motor and speed generator correctly indicates the ground speed. There was a problem that an accurate ground speed could not be obtained when the axle was idled during braking.

  The present invention has been made to solve the above-described problems. By acquiring a video using a camera and performing a matching process, the ground is more accurate not only during normal driving but also when the axle is idle. It aims at obtaining the train speed measurement system which can measure speed.

  A train speed measurement system according to the present invention includes a camera that captures a reference mark provided on a track, an image processing unit that performs matching processing on an image or video captured by the camera and extracts the reference mark, and the image And a calculation unit that calculates a train speed based on distance information obtained based on the reference mark extracted by the processing unit and time information of a photographing frame by the camera.

  According to this invention, the image or video captured by the camera is subjected to matching processing to extract the reference mark, and the train speed is calculated based on the distance information obtained based on the reference mark and the time information of the captured frame by the camera. The ground speed can be measured more accurately even when the axle is idle.

It is a functional block diagram showing the structure of the train speed measurement system which concerns on Embodiment 1 of this invention. It is an enlarged view of the reference mark concerning Embodiment 1 of this invention. It is one specific example of the reference mark concerning Embodiment 1 of this invention. It is a functional block diagram showing the structure of the train speed measurement system which concerns on Embodiment 2 of this invention. It is a functional block diagram showing the structure of the train speed measurement system which concerns on Embodiment 3 of this invention. It is an enlarged view of the reference mark which concerns on Embodiment 3 of this invention. It is another specific example of a reference mark.

  Embodiment 1

  A train speed measurement system according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a functional block diagram showing the configuration of a train speed measurement system according to Embodiment 1 of the present invention. In FIG. 1, 1 is a vehicle, 2 is a reference mark provided on a track, 3 is a calculation unit, 4 is an image processing unit, and 5 is a camera. The reference mark 2 includes a mark on the line indicating the reference position and a uniquely assigned number.

  FIG. 2 is an enlarged view of the reference mark 2 according to the first embodiment of the present invention. The reference mark 2 provided on the track is provided on a sleeper 6 laid under the rail 7. FIG. 3 shows one specific example of the reference mark 2 according to the first embodiment of the present invention. The reference mark 2 is composed of a line parallel to the train traveling direction, a line perpendicular to the traveling direction, and numerals. In this example, the reference mark 2 is very simplified, and the difference between the reference mark 2 captured by the camera 5 and the reference mark 2 before and after the reference mark 2 is determined by the identification code assigned to the reference mark 2. Become.

  Next, the operation of the train speed measurement system will be described. The vehicle 1 is equipped with a camera 5 for photographing the reference mark 2. The camera 5 is mounted on the bottom surface of the vehicle 1 so as to face directly below, and photographs the reference mark 2 provided on the track. Shooting is carried out at a fixed interval of an extremely short time for each frame. As a host device of the camera 5, an image processing unit 4 that inputs a signal output from the camera 5 and performs image processing is mounted. The image processing unit 4 extracts information of the reference mark 2 by performing image processing such as image matching processing. If the vehicle 1 is traveling at a low speed and the same reference mark 2 is photographed in a frame over a plurality of shootings, the reference mark 2 is moved by the plurality of shootings. The amount d (distance information) and the time s (time information) required for the movement can be acquired, and the ground speed v = d / s of the vehicle 1 can be calculated in the calculation unit 3 by these.

  In addition, when the vehicle 1 travels at a high speed and the same reference mark 2 does not enter the frame before and after the continuous shooting, the image processing unit 4 uses the identification code attached to the reference mark 2 for each frame. And the ground speed of the vehicle 1 can be calculated. That is, since the camera 5 captures each frame at regular intervals, the number of frames from the frame where a certain reference mark 2 is captured to the frame where the adjacent reference mark 2 is captured is counted. Thus, time information s as a photographing time interval between two adjacent reference marks 2 can be calculated. Here, since the distance L (distance information) between the adjacent reference marks 2 is known when the reference marks 2 are installed, the ground speed v (= L / s) of the vehicle 1 is calculated by these. It can be calculated in part 3.

  As described above, the reference mark 2 in each frame photographed by the camera 5 is read by the image processing unit 4, and the position of the reference mark 2 in each frame in the frame and the identification code of the recognized reference mark 2 are calculated. Since the train speed is low, the calculation unit 3 obtains the ground speed by v = d / s when the same identification code is input between the shooting frames, and the train speed is high. When different identification codes are input, the ground speed is obtained by v = L / s. According to such measurement of the train speed, the ground speed can be measured more accurately not only during normal travel but also when the axle is idle.

  Embodiment 2

  A train speed measurement system according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 4 is a functional block diagram showing the configuration of the train speed measurement system according to the second embodiment of the present invention. The train speed measurement system shown in FIG. 4 has a plurality of measurement systems. Specifically, the first system includes an operation unit 3-1, an image processing unit 4-1, and a camera 5-1, and the second system includes an operation unit 3-2 and an image processing unit 4-2. , The camera 5-2.

  The train speed obtained by the calculation units 3-1 and 3-2 of each measurement system is input to the averaging unit 10, and by averaging the train speeds obtained from the two systems by the averaging unit 10, more accurate Train speed can be determined. In FIG. 4, the calculation unit 3 and the image processing unit 4 are distributed, but only the camera 5 part may be distributed and arranged by increasing the processing capability of these devices.

  Embodiment 3

  A train speed measurement system according to Embodiment 3 of the present invention will be described with reference to FIGS. FIG. 5 is a functional block diagram showing the configuration of the train speed measurement system according to the third embodiment of the present invention. The train speed measurement system shown in FIG. 5 has a plurality of measurement systems, and uses an infrared camera 11 that detects infrared rays in one or a plurality of measurement systems. FIG. 6 is an enlarged view of a reference mark according to Embodiment 3 of the present invention, and a light emitting material is used for the reference mark 20 (the form of the reference mark itself is the same as that of Embodiment 1).

  By using the infrared camera 11 and the reference mark 20 made of a light emitting material, the reference mark 20 can be clearly identified even in bad weather or at night, and the image processing unit 4 can perform image processing such as image matching processing. .

  In the train speed measurement system using one system shown in the first embodiment, the camera 5 may be the infrared camera 11 and the reference mark 2 may be the reference mark 20 made of a luminescent material.

  Further, the reference mark according to the first to third embodiments of the present invention may be a reference mark 21 as shown in FIG. FIG. 7 shows another specific example of the reference mark. Specific information on the track position, for example, marking (character “A”) defined for each specific section of the track is added, and this is extracted by the image processing unit 4. Train position information can be obtained.

  In addition, in the train speed measurement system shown in FIGS. 1, 4, and 5, the speed is detected using the width of the sleepers laid on the track (train traveling direction) instead of the reference mark 2 and the reference mark 20. It may be. That is, the image processing unit 4 can detect the movement of the edge of the sleeper (the edge of the sleeper) on the image from the captured frame, and the train speed can be obtained from the relationship between the movement amount and the frame speed.

DESCRIPTION OF SYMBOLS 1 Vehicle 2, 20, 21 Reference mark 3 Calculation part 4 Image processing part 5 Camera 6 Sleeper 7 Rail 10 Averaging part 11 Infrared camera

Claims (6)

Obtained based on a camera that captures a reference mark provided on the track, an image processing unit that extracts an image or video captured by the camera and extracts the reference mark, and a reference mark extracted by the image processing unit A train speed measurement system comprising: a calculation unit that calculates a train speed based on distance information obtained and time information of a frame taken by a camera. A camera that captures a reference mark provided on a track, an image processing unit that extracts an image or video captured by the camera and extracts the reference mark, and a distance obtained based on the reference mark extracted by the image processing unit It is provided with a plurality of measurement systems having a calculation unit that calculates the train speed based on information and time information of the frame taken by the camera, and an averaging unit that averages the train speed obtained by each measurement system Train speed measurement system. The train speed measurement system according to claim 2, wherein a camera included in a part of the plurality of measurement systems is a camera that detects infrared rays. The train speed measurement system according to claim 3, wherein a light emitting material is used for a reference mark photographed by the camera. The train speed measuring system according to any one of claims 1 to 4, wherein the image processing unit extracts track position information attached to a reference mark to be photographed. The train speed measurement system according to any one of claims 1 to 5, wherein a sleeper laid on a track is used instead of the reference mark.

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