JP5158729B2 - Detection apparatus and detection method for detecting deformation state of tire of traveling vehicle - Google Patents

Description

  The present invention relates to a detection device and a detection method for detecting a deformation state of a tire of a traveling vehicle.

Generally, a tire of a traveling vehicle is worn according to the traveling state, or flattened according to a load amount or an unbalanced load of luggage.
In particular, traveling vehicles such as AGVs (Auto Guided Vehicles) and forklifts used in factories and warehouses are often operated continuously day and night, and if you are unaware of such tire deformation, There are problems in safety during traveling, such as inaccurate traveling control based on the number of rotations of the tire, or an unexpected accident due to deformation of the tire.
For this reason, various detection devices and detection methods for detecting the deformation state of the tire have been proposed.

For example, there exists a thing of patent document 1 as a detection apparatus which detects abrasion of a tire.
In this detection device, the number of rotations of the tire required to pass through a measurement section of a predetermined length is counted, and compared with the number of rotations in the case of a tire without wear, whether or not the tire is worn is determined. Determined.

On the other hand, as a detection method for detecting tire flatness due to uneven load or the like, for example, there is a detection method using a weight meter such as a strain sensor.
In this detection method, a strain sensor is provided in the vicinity of each tire of the traveling vehicle, and the load weight applied to each tire is calculated based on the output of each strain sensor to estimate the degree of flatness of the tire.

Japanese Utility Model Publication No. 4-86505

However, in the detection apparatus described in Patent Document 1, it is necessary to provide a very long measurement section in order to increase the detection accuracy, and an apparatus for identifying the measurement section is also required, which complicates the configuration. In addition, in this detection device, since the traveling vehicle travels over such a long measurement section, it takes a long time to detect and it is assumed that all tires are uniformly worn, so that the wear of each tire is detected. It is difficult to detect the deformation state of the tire efficiently and accurately.
Further, in the detection method using the weighing scale, it is necessary to prepare a large number of relatively expensive strain sensors and provide them in the vicinity of each tire, and the configuration becomes complicated and the cost is high.

  Further, even if the above-described detection of tire wear or detection of tire flatness due to uneven load has been proposed, the deformation state of the tire is due to wear or flattening due to uneven load or the like. No detection device or detection method has yet been realized that can distinguish and detect whether or not.

  Therefore, the present invention has been made in view of such circumstances, and a detection device and a detection method capable of detecting a deformation state of a tire of a traveling vehicle efficiently and accurately with a simple configuration. It is an issue to provide.

In order to solve the above problems, the present invention is a detection device that detects a deformation state of a tire of a traveling vehicle, and is an imaging device that is mounted on the traveling vehicle and captures an image of a predetermined pattern provided on a road surface in a detection area. Storage means for storing, as a reference image, an image of the predetermined pattern previously captured by the imaging means in the detection area before deformation of the tire, the image captured in the detection area, and the storage And a determination unit that compares the reference image stored in the unit and determines the deformation state of the tire based on a change in a predetermined pattern in the two images. Is.
According to this invention, the image of the predetermined pattern imaged by the imaging unit in the detection area is compared with the reference image stored in the storage unit, and the deformation state of the tire is determined based on the change of the predetermined pattern in the two images. Since it is configured to be determined, a measurement section and a device for identifying the section or an expensive strain sensor as in the prior art are not required, and the tire deformation state is detected in a simple configuration and in a short time. be able to.

In the above-described configuration, the predetermined pattern includes a plurality of marks provided on the road surface, and the determination unit includes an image of the mark imaged in the detection area and a reference of the mark stored in the storage unit It is preferable to compare the images and determine the deformation state of the tire based on the change in the distance between the centers of the marks in the two images.
According to the invention of this configuration, the image of the mark imaged in the detection area is compared with the reference image stored in the storage unit, and based on the change in the exact distance between the centers of the marks in the two images. Since the tire deformation state is determined, the tire deformation state can be accurately detected.

In the above configuration, the traveling vehicle is a transport vehicle that transports a load loaded on a loading platform, and the transport vehicle is equipped with a load detection unit that detects the presence or absence of the load on the loading platform, and the storage device includes Further, tire information related to the usage state of the tire is stored, and the determination means determines that the tire deformation state is due to an unbalanced load due to the luggage based on the output of the luggage detection means and the tire information of the storage means. It is preferable to determine whether the tire is due to wear of the tire.
According to the invention of this configuration, in the transport vehicle, since the tire deformation state is determined based on the output of the luggage detection means and the tire information, a tire that has not been realized in the prior art. It is possible to determine whether the deformation state is due to flattening due to an unbalanced load on the load or due to tire wear.

In the above configuration, the traveling vehicle is an AGV having an automatic traveling function, and the detection area is located in a stop area of the AGV, and the determination means stops the AGV in the stop area. It is preferable that the deformation state of the tire is determined when the tire is being operated.
According to the invention of this configuration, it is possible to efficiently detect the deformation state of the tire in the detection area that is the stop area between the stop of the travel such as when the destination of the AGV arrives or when the battery is charged.

  In order to solve the above problems, the present invention provides a detection method for detecting a deformation state of a tire of a traveling vehicle, wherein the traveling vehicle before the deformation of the tire is detected on a road surface provided with a predetermined pattern. In the detection area, an image of the predetermined pattern is captured by an imaging unit mounted on the traveling vehicle, the captured image is stored as a reference image in a storage unit, and the deformation state of the tire is detected. Therefore, the traveling vehicle is moved again to the detection area, and the image of the predetermined pattern is captured again by the imaging unit in the detection area. The captured image and the basic image stored in the storage unit And detecting a deformation state of the tire based on a change in a predetermined pattern in the two images, and Those were.

  According to the present invention, it is possible to provide a detection device and a detection method capable of detecting a deformation state of a tire of a traveling vehicle efficiently and accurately with a simple configuration.

(A) is a side view showing a configuration example of the detection device according to the first embodiment of the present invention, (B) is a perspective view showing the arrangement relationship of the imaging means, tires and a predetermined pattern of (A). . It is a flowchart which shows the detection method in the detection apparatus of FIG. (A) is a side view (upper) of the traveling vehicle before deformation of the tire, and a top view (lower) of the predetermined pattern viewed from the imaging means in this state, and (B) is a uniform wear of the four tires. A side view (upper) of the traveling vehicle, and a top view (lower) of the predetermined pattern viewed from the imaging means in this state, (C) is a side view (upper) of the traveling vehicle with two tires worn, It is the top view (lower) which looked at the predetermined pattern from the image pick-up means in this state, (D) is the side view (upper) of the traveling vehicle where one tire was worn, and the upper surface which looked at the predetermined pattern from the image pick-up means in this state It is a figure (bottom). (A) is a side view (upper) of the traveling vehicle before the deformation of the tire, and a top view (lower) of the predetermined pattern viewed from the imaging means in this state. A side view (upper) of a traveling vehicle in which the tires are flattened uniformly, and a top view (lower) of a predetermined pattern viewed from the imaging means in this state, (C) shows two tires due to the uneven load of the loaded luggage Is a side view (upper) of a traveling vehicle in which the vehicle is flattened, and a top view (bottom) in which a predetermined pattern is viewed from the imaging means in this state, and (D) is a flattened one tire due to a partial load of the loaded luggage It is the side view (upper) of a traveling vehicle, and the top view (lower) which looked at the predetermined pattern from the imaging means in this state. It is a side view which shows the structural example of the detection apparatus by 2nd Example of this invention.

  Hereinafter, preferred embodiments of a detection apparatus and a detection method for detecting a deformation state of a tire of a traveling vehicle according to the present invention will be described with reference to the drawings.

(First embodiment)
As shown in FIGS. 1A and 1B, the detection apparatus 1 according to the present invention includes an imaging unit 2, a storage unit 3, a determination unit 4, and a display unit 9.
The image pickup means 2 is mounted on the traveling vehicle 5 and picks up an image of a predetermined pattern 7 provided on the road surface 8 in the detection area P, and is composed of, for example, a CCD camera. The imaging means 2 is fixed inside the traveling vehicle.
The storage unit 3 stores, as a reference image, an image of the predetermined pattern 7 captured in advance by the imaging unit 2 in the detection area P before the deformation of the tire 6, and includes, for example, a memory.
The determination unit 4 compares the image captured in the detection area P with the reference image stored in the storage unit 3, and determines the deformation state of the tire 6 based on the change of the predetermined pattern 7 in the two images. To do.
The display means 9 displays the determination result of the deformation state of the tire 6 by the determination means 4, and is composed of a display, for example.

  Next, with reference to FIGS. 2 and 3, the operation of the detection device 1 of the present invention and a detection method for detecting the deformation state of the tire 6 will be described.

First, the traveling vehicle 5 before the deformation of the tire 6 is moved to the detection area P (see step S1 in FIG. 2). Here, as shown in FIG. 1B, the predetermined pattern 7 includes four square marks 7A to 7D.
Next, in the detection area P, an image of a predetermined pattern 7 is captured by the imaging unit 2, and the captured image is stored in the storage unit 3 as a reference image (see step S2 in FIG. 2). For example, the storage unit 3 stores images of four marks 7A to 7D as reference images as shown in the dotted frame in the lower diagram of FIG.

Thereafter, in order to detect the deformation state of the tire 6 of the traveling vehicle 5 that has traveled, the traveling vehicle 5 is moved again to the detection area P (see step S3 in FIG. 2).
Next, in the detection area P, the image of the predetermined pattern 7 is captured again by the imaging unit 2, the captured image is compared with the basic image stored in the storage unit 3, and the predetermined image in the two images is compared. Based on the change of the pattern 7, the deformation state of the tire 6 is determined (see step S4 in FIG. 2).
In this determination, the determination unit 4 uses the center coordinates A (Xa, Ya), B (Xb, Yb), C (Xc, Yc), and D (Xd, Yd) of the marks 7A to 7D of the captured images. The distances between the centers AB = Lab, BC = Lbc, CD = Lcd, and DA = Lda are calculated, compared with those in the basic image, and the deformation state of the tire is determined based on the change in the distance.

For example, in the case of a traveling vehicle in which the four tires 6A to 6D are worn almost uniformly, the distances between the imaging unit 2 and the marks 7A to 7D are shorter than before the tire is deformed.
For this reason, in the detection area P, an image in which the intervals of the marks 7A to 7D are uniformly wide as shown in the dotted frame in the lower diagram of FIG.
Therefore, the determination means 4 detects that the distances AB = Lab, BC = Lbc, CD = Lcd, and DA = Lda in this image have all changed by a predetermined rate longer than that of the basic image, It is determined that the four tires 6A to 6D are worn.

Similarly, in the case of a traveling vehicle in which the two tires 6A and 6B are worn, the distance between the imaging means 2 and the marks 7A and 7B is shorter than before the tire is deformed.
Accordingly, the determination unit 4 detects the changes in the distances AB = Lab, BC = Lbc, and DA = Lda in the captured image as shown by the dotted frame in the lower diagram of FIG. , 6B is determined to be worn.

Similarly, in the case of a traveling vehicle in which one tire 6A is worn, each distance between the imaging means 2 and the mark 7A is shorter than before the tire is deformed.
Therefore, the determination means 4 detects that the tire 6A is worn by detecting changes in the distance AB = Lab and DA = Lda in the captured image as shown in the dotted frame in the lower diagram of FIG. judge.

As described above, according to the invention according to the first embodiment, only by comparing the image of the predetermined pattern 7 captured by the imaging unit 2 in the detection area P with the reference image stored in the storage unit 3, the tire Therefore, the measurement section and the device for identifying it or an expensive strain sensor as in the prior art are unnecessary, and the deformation state of the tire 6 is detected in a simple configuration and in a short time. be able to.
In addition, since the marks 7A to 7D are used as the predetermined pattern 7 and the deformation state of the tire 6 is determined based on a change in the exact distance between the centers of the two images, the tire 6 can be accurately The deformation state can be detected.

(Second embodiment)
By the way, as can be seen by comparing the images in FIGS. 3A to 3D and FIGS. 4A to 4D, the deformation state of the tires 6A to 6D can be determined only by changing the predetermined patterns 7A to 7D. It may be difficult to determine whether it is due to wear or due to flattening such as uneven load.
Therefore, in order to avoid such a case, the detection apparatus 1 ′ of the second embodiment includes the luggage detection means 10 for detecting whether the traveling vehicle 5 has the luggage 11 on the loading platform, as shown in FIG. The storage means 3 is configured to store tire information regarding the usage state of the tire 6. Therefore, only this point will be described.
Here, the baggage detection unit 10 includes a known sensor such as a proximity sensor, a photoelectric sensor, and a pressure sensor, for example, and outputs a baggage detection signal to the determination unit 4 when the baggage 11 is on the loading platform.
The tire information is information that can be used to know the usage state of the tire 6, and includes, for example, a tire replacement time and a usage time.

When there is no output from the luggage detection means 10, the determination means 4 determines that the deformation state of the tire 6 is due to wear in the same manner as in the first embodiment.
On the other hand, when the determination unit 4 determines that the tire 6 is almost not used (the tire 6 is new) based on the tire information stored in the storage unit 3 when there is an output from the luggage detection unit 10, the tire 6 It is determined that the deformation state is due to flatness.
If the determination unit 4 determines that the output from the baggage detection unit 10 is present and that the tire 6 is considerably used based on the tire information (the tire 6 is considerably old), the deformation state of the tire 6 is determined. Is determined to be due to both wear and flatness.

  The preferred embodiments of the present invention have been described above, but the configuration of the present invention is not limited to these embodiments.

For example, the traveling vehicle 5 is not limited at all, and may be, for example, an AGV having an automatic traveling function.
In the case of this AGV (Auto Guided Vehicle), the detection area P is set as the stop area of the AGV, and the determination means 4 is configured to determine the deformation state of the tire 6 when the AGV is stopped in the stop area. It is preferable.
According to this configuration, since the deformation state of the tire 6 is determined in the detection area P that is a stop area between the stop of travel such as when the destination of the AGV arrives or when the battery is charged, the deformation state of the tire 6 is determined. Can be detected efficiently.

  For example, the predetermined pattern 7 is not limited to the plurality of marks 7 </ b> A to 7 </ b> D, and can be a dot-like figure or a line-like figure as long as the change of the image taken by the imaging unit 2 with respect to the reference image is known. Further, it may be composed of a polygonal figure, a figure having a curved shape, or the like.

The mark 7 is the four marks 7A to 7D, but is not limited to this, and it is sufficient if there are at least two marks. It goes without saying that the deformation state of the tire 6 can be more accurately determined by increasing the number of marks 7.
Moreover, it is preferable that the mark 7 is provided on the road surface 8 so as to correspond to the number of tires 6 and the arrangement position thereof. For example, in the above-described embodiment, the marks 7 </ b> A to 7 </ b> D are provided on the road surface 8 so as to correspond to the tires 6 </ b> A to 6 </ b> D disposed at the four corners of the traveling vehicle 5.

  The configurations of the imaging unit 2, the storage unit 3, the determination unit 4, the display unit 9, and the package detection unit 10 in the detection devices 1 and 1 'are all examples.

DESCRIPTION OF SYMBOLS 1, 1 'Detection apparatus 2 Imaging means 3 Storage means 4 Determination means 5 Traveling vehicle 6, 6A-6D Tire 7, 7A-7D Predetermined pattern 8 Road surface 9 Display means 10 Luggage detection means 11 Luggage P detection area

Claims (5)

A detection device for detecting a deformation state of a tire of a traveling vehicle,
An image pickup means mounted on the traveling vehicle for picking up an image of a predetermined pattern provided on a road surface in a detection area;
Storage means for storing, as a reference image, an image of the predetermined pattern previously captured by the imaging means in the detection area before the deformation of the tire;
A determination unit that compares the image captured in the detection area with the reference image stored in the storage unit and determines a deformation state of the tire based on a change in a predetermined pattern in the two images; A detection apparatus comprising: The predetermined pattern comprises a plurality of marks provided on the road surface,
The determination unit compares the image of the mark imaged in the detection area with the reference image of the mark stored in the storage unit, and changes the distance between the centers of the marks in the two images. The detection device according to claim 1, wherein the deformation state of the tire is determined based on the determination. The traveling vehicle is a transport vehicle for transporting a load loaded on a cargo bed,
The transport vehicle is equipped with load detection means for detecting the presence or absence of the load on the loading platform,
The storage means further stores tire information relating to the usage state of the tire,
The determination means determines whether the deformation state of the tire is due to an unbalanced load due to the load or due to wear of the tire based on the output of the load detection means and the tire information of the storage means. The detection device according to claim 1 or 2, wherein The traveling vehicle is an AGV having an automatic traveling function,
The detection area is located in the stop area of the AGV,
The detection device according to any one of claims 1 to 3, wherein the determination unit determines a deformation state of the tire when the AGV is stopped in the stop area. . A detection method for detecting a deformation state of a tire of a traveling vehicle,
The traveling vehicle before deformation of the tire is moved to a detection area where a predetermined pattern is provided on the road surface,
In the detection area, an image of the predetermined pattern is captured by an imaging unit mounted on the traveling vehicle, and the captured image is stored in a storage unit as a reference image;
In order to detect the deformation state of the tire, the traveling vehicle is moved again to the detection area,
In the detection area, the image of the predetermined pattern is captured again by the imaging unit, the captured image is compared with the basic image stored in the storage unit, and a change in the predetermined pattern in the two images is detected. And detecting a deformation state of the tire based on the detection method.

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