JP5858447B2 - Picking lift safety device - Google Patents

Description

  The present invention relates to a safety device that prevents an operator who has boarded a cab of a picking lift from falling from the cab, and a picking lift including the safety device.

  FIG. 7 shows a picking lift 100 conventionally used. The picking lift 100 is a type of cargo handling vehicle that includes a cab 4 that moves up and down along the mast 3 and a pair of left and right forks 8 that protrude rearward from the cab 4. In the cargo handling work by the picking lift 100, the cab 4 on which an operator is placed moves to a high place, and the load and unload of the load B are performed at the high place. For this reason, the cab 4 of the picking lift 100 is usually provided with a safety device including the belt 11 and the safety belt 12.

  As such a safety device, for example, one disclosed in Patent Document 1 is known. In this safety device, it is determined whether or not the hook provided at the tip of the safety belt is correctly connected to the safety bar provided in the cab, and an alarm is issued when it is determined that the hook is not connected. . As a result, forgetting to connect the hook and the safety bar is prevented, and the safety of the worker is ensured.

JP 2004-18212 A

  However, the conventional safety device described above does not detect the state that “the hook and the safety bar are connected, but the belt is not worn by the operator”, so it does not like being restrained by a safety belt. As a result, a worker trying to carry out cargo handling work without wearing a belt was discovered, and could not be directed to correctly attach the belt. For this reason, the conventional safety device cannot sufficiently prevent the operator from falling.

  The present invention has been made in view of the above circumstances, and the problem is that a safety device that can more reliably prevent an operator from falling from the cab of the picking lift, and the safety device. It is in providing a picking lift provided with.

In order to solve the above-mentioned problems, a safety device according to the present invention is a safety device for preventing an operator who has boarded a cab of a picking lift from falling from the cab, and has two different colors. A pattern storage storing a belt to be worn by an operator, an imaging means for an operator boarding a predetermined position of a driver's cab, and a comparison pattern corresponding to the belt stripe pattern And binarize the original image obtained by the imaging means, compare the binarized image obtained by the binarization with the comparison pattern stored in the pattern storage unit, and compare in the binarized image If there is a pattern that approximates the pattern, it is determined that the worker is wearing a belt, while if there is no pattern that approximates the comparison pattern in the binarized image, the operator does not wear the belt. Wearing judgment Comprising a tough, the mounting determination unit, characterized in that binarization, only the region to be reflected by the worker of the waist of the original image with a threshold set based on the luminance histogram of the original image And

In this configuration, when the worker who has boarded the predetermined position wears the belt, the comparison pattern is included in the binarized image obtained by binarizing the original image obtained by the imaging unit directed to the worker. On the other hand, an approximate pattern exists. On the other hand, when the operator does not wear the belt, there is no pattern approximated to the comparison pattern in the binarized image. Therefore, according to this configuration, it is possible to determine whether or not the operator is wearing the belt by determining whether or not there is a pattern that approximates the comparison pattern in the binarized image.
In addition, according to this configuration, since the original image becomes whitish or blackish due to the influence of ambient brightness, the pattern corresponding to the belt that should be present does not exist in the binarized image. Can be prevented.
Furthermore, according to this configuration, it is possible to determine not only whether or not the worker is wearing the belt but also whether or not the wearing position of the belt is correct, and further binarize the entire original image. Compared to the case, it is possible to reduce the processing load for determining whether or not there is a pattern approximate to the comparison pattern.

  The safety device wearing determination unit also compares the binarized image with an enlarged pattern obtained by enlarging the comparison pattern at a predetermined magnification and a reduced pattern obtained by reducing the comparison pattern at a predetermined magnification. If the binarized image has a pattern that approximates at least one of the comparison pattern, the enlargement pattern, and the reduction pattern, it is determined that the operator is wearing the belt, while the comparison pattern is included in the binarized image. If there is no pattern approximate to either the enlarged pattern or the reduced pattern, it is preferable to determine that the operator is not wearing the belt.

  According to this configuration, even if the distance between the belt worn by the worker and the imaging means changes, it is possible to correctly determine whether or not the worker is wearing the belt.

  The striped pattern of the belt in the safety device can be formed by, for example, a D ring stopper, and in this case, the striped pattern is a vertical striped pattern.

  By using a D-ring stopper that has been conventionally used as an accessory of the belt, a striped pattern can be easily attached to an existing belt.

  A picking lift according to the present invention includes the above-described safety device and at least a vehicle control unit that controls the raising and lowering of the driver's cab. It is configured to determine whether or not the belt is attached, and to notify the vehicle control unit of the result of the determination, the vehicle control unit, when the determination result by the mounting determination unit is not mounted, It is characterized by prohibiting the raising and lowering of the cab.

  ADVANTAGE OF THE INVENTION According to this invention, the safety device which can prevent more reliably that an operator falls from the cab of a picking lift, and a picking lift provided with this safety device can be provided.

It is a side view of the picking lift provided with the safety device concerning the present invention. It is a control block diagram of the picking lift provided with the safety device concerning the present invention. It is an example of the original image imaged with the safety device which concerns on this invention. It is a figure which shows the mounting | wearing determination procedure by the safety device which concerns on this invention. It is the binarized image obtained with the safety device according to the present invention, wherein (B) is an example of the binarized image when the threshold is suitably set, and (A) and (C) are preferably the threshold. It is an example of the binarized image when it is not set. (A) is an example of the comparison pattern used with the safety device concerning the present invention, and (B) is a figure showing the comparison procedure of a comparison pattern and a binarized image. It is a side view of the picking lift provided with the conventional safety device.

  Embodiments of a safety device and a picking lift according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows a picking lift according to an embodiment of the present invention. As shown in FIG. 1, the picking lift 1 includes a vehicle main body 2 housing a traveling motor and the like, a mast 3 erected on the rear side of the vehicle main body 2, and a cab 4 that moves up and down along the mast 3. And a pair of left and right forks 8 protruding rearward from the cab 4. The cab 4 includes a floor frame 5, a front frame 6, a head guard 7, and an operation panel 9 provided on the front frame 6. In addition to a key switch for starting the picking lift 1, the operation panel 9 is provided with a handle and a lever for instructing the traveling of the picking lift 1 and the raising and lowering of the cab 4.

  The picking lift 1 also includes a belt 11, a safety belt 12, and a safety belt winding unit 13 that constitute the safety device 10. The belt 11 should be worn around the waist of an operator who is on the cab 4. As shown in FIG. 2, the belt 11 has a belt main body 11a whose surface is at least black or a dark color (low luminance color) close to the belt 11 and an end of the safety belt 12 that is detachably fastened. Metal fittings. The surface of the belt body 11a is provided with a striped pattern. In this embodiment, by attaching two D-ring stoppers 11b and 11c of white or light color (high luminance color) close to this to the belt body 11a, a vertical stripe pattern is formed on the surface of the belt body 11a. It is attached.

  The safety belt 12 has one end connected to the belt 11 and the other end attached to the safety belt winding unit 13. The safety belt winding unit 13 is fixed to the head guard 7 of the cab 4. From the safety belt winding unit 13, a portion from the end of the safety belt 12 to about 1 m is always drawn, and when a tension is applied, the remaining portion is drawn according to the tension.

  The picking lift 1 further includes a camera 14 (corresponding to “imaging means” of the present invention) constituting the safety device 10. As shown in FIG. 1, the camera 14 is provided below the operation panel 9. The camera 14 is a CCD camera that is capable of color imaging or gray scale imaging that is directed to an operator who has boarded a predetermined position of the cab 4. The camera 14 acquires an image P (hereinafter referred to as “original image”) as shown in FIG. 3 at a frequency of 30 images per second.

  FIG. 2 shows a control block diagram of the picking lift 1 including the safety device 10. As shown in the figure, the safety device 10 according to the present embodiment has a pattern storage made up of a wearing determination unit 15 made up of a microprocessor (MPU) and a nonvolatile memory in addition to the belt 11, the safety belt 12 and the camera 14 described above. A portion 16 is provided.

The pattern storage unit 16 stores a comparison pattern P _C corresponding to the stripe pattern of the belt 11 in advance. The wearing determination unit 15 binarizes the original image P obtained by the camera 14 and compares the binarized image P _BW obtained by binarization with the comparison pattern P _C stored in the pattern storage unit 16. . When there is a pattern that approximates the comparison pattern P _C in the binarized image P _BW , the mounting determination unit 15 determines that the operator is wearing the belt 11. On the other hand, when there is no pattern approximated to the comparison pattern P _C in the binarized image P _BW , the mounting determination unit 15 determines that the operator does not wear the belt 11.

  The vehicle control unit 20 includes a microprocessor. The microprocessor configuring the vehicle control unit 20 and the microprocessor configuring the mounting determination unit 15 may be the same. The vehicle control unit 20 controls the traveling system 21 and the hydraulic system 22 according to the instruction from the operator received by the operation panel 9 and the result of determination by the mounting determination unit 15.

  Specifically, the vehicle control unit 20 prohibits the operation of the traveling system 21 and the hydraulic system 22 when the result of the determination by the mounting determination unit 15 is “not mounted”. When the operation of the traveling system 21 is prohibited, the picking lift 1 does not travel even if the operator operates the operation panel 9. Further, when the operation of the hydraulic system 22 is prohibited, the cab 4 does not move up and down even when the operator operates the operation panel 9.

  On the other hand, if the result of the determination by the mounting determination unit 15 is “mounted”, the vehicle control unit 20 permits the operation of the traveling system 21 and the hydraulic system 22. As a result, the operator can move the picking lift 1 or move the cab 4 up and down by operating the operation panel 9.

  Next, the determination by the mounting determination unit 15 will be specifically described with reference to FIG. In this embodiment, it is assumed that the mounting determination unit 15 starts the determination in response to a request from the vehicle control unit 20, and when the determination ends, the mounting determination unit 15 notifies the vehicle control unit 20 of the result. In this embodiment, it is assumed that the camera 14 acquires the original image P at a frequency of 30 images per second.

When there is a request from the vehicle control unit 20, the mounting determination unit 15 binarizes the original image P1 _first obtained by the camera 14 to generate a binarized image P _BW1 , and the binarized image P _BW1. It determines whether the comparison pattern approximating the P _C pattern is present in the. When there is a pattern that approximates the comparison pattern P _C in the binarized image P _BW1 , the attachment determination unit 15 sets the determination result R ₁ to “present”. On the other hand, when there is no pattern approximated to the comparison pattern P _C in the binarized image P _BW1 , the attachment determination unit 15 sets the determination result R ₁ to “none”.

To reduce the processing load, the attachment check unit 15, the original image P ₁ of 1/30 second after the obtained original image P _2, and the original image based on the image P further obtained after 1/30 sec P ₂ For binary ₃ , binarization and determination are not performed, and binarization and determination are performed for the original image P ₄ obtained after 1/30 second of the original image P ₃ . That is, the wearing determination unit 15 determines whether or not there is a pattern approximated to the comparison pattern P _C in the binarized image P _{BW4 obtained by binarizing} the original image P ₄ , and determines the determination result R ₄ as “ “Yes” or “No”.

As described above, the mounting determination unit 15 obtains the original image P ₁ to the original image P obtained during a predetermined time (2 seconds in the present embodiment) after the request from the vehicle control unit 20 elapses. Two of ₆₀ are skipped and binarized to obtain determination results R ₁ , R ₄ ,..., R ₅₅ , R ₅₈ .

After obtaining the determination results R ₁ , R ₄ ,..., R ₅₅ , R ₅₈ , the mounting determination unit 15 determines whether the operator is wearing the belt 11 based on these. The mounting determination unit 15 according to the present embodiment determines that the determination result is mounted when all of the determination results R ₁ , R ₄ ,..., R ₅₅ , R ₅₈ are “present”, and otherwise. The determination result is “not installed”.

  Next, the binarization of the original image P will be described in more detail.

  The original image P acquired by the camera 14 becomes whitish or blackish under the influence of ambient brightness. For example, the original image P acquired outdoors tends to be whitish than that acquired indoors. In other words, the original image P acquired indoors tends to be darker than that acquired outdoors. Further, even indoors, the original image P acquired when the cab 4 is at a low position and the original image P acquired when the cab 4 is at a high position close to ceiling lighting, the latter is more whitish. Tend to be.

5A to 5C show a black original image P, a suitable original image P that is neither black nor white, and a binarized image P obtained by binarizing the whitish original image P using the same threshold value. _BW . In the binarized image P _BW in (B), there is a pattern corresponding to the belt 11 worn by the operator. On the other hand, in the binarized images P _BW of (A) and (C), there is no pattern corresponding to the belt 11 that should exist. For this reason, the determination using the binarized image P _BW as shown in (A) and (C) must be avoided.

Therefore, the wearing determination unit 15 of the present embodiment performs binarization using a threshold value set based on the luminance histogram of the original image P. When the luminance histogram of the original image P indicates “blackish”, the attachment determination unit 15 sets a lower threshold value. This prevents the binarized image P _{BW from} becoming an image as shown in FIG. On the other hand, if the histogram of the luminance of the original image P indicates “white”, the attachment determination unit 15 sets the threshold value higher. This prevents the binarized image P _{BW from} becoming an image as shown in FIG.

Also, the wearing determination unit 15 does not binarize the entire original image P, but binarizes only the region of the original image P where the operator's waist should be reflected. Thereby, it is possible to determine not only whether or not the worker is wearing the belt 11 but also whether or not the wearing position of the belt 11 is correct. Further, the two by a value limiting the area to be reduction, it is also possible to reduce the processing load of determining whether the pattern comparison pattern approximate to P _C in the binary image P _BW exists.

Next, referring to FIG. 6, it will be described in more detail compared with the comparison pattern P _C and the binary image P _BW.

When the binarized image P _BW is generated, the attachment determination unit 15 compares the region A ₀₀ of the binarized image P _BW with the comparison pattern P _C stored in advance in the pattern storage unit 16 in units of pixels. The attachment check unit 15 stores the number of matched pixels, or the ratio of the number of matched pixels to the total number of pixels in the area A ₀₀ in association with the area A _00.

Subsequently, the attachment check unit 15, a predetermined pixel (preferably, 1 pixel) in the X direction from the area A ₀₀ to an area A ₁₀ is shifted region and the comparison pattern P _C compared in pixels, regions results stored in association with the a _10.

Thereafter, the attachment determination unit 15 includes a region A ₂₀ that is a region shifted by a predetermined pixel in the X direction from the region A ₁₀ , a region A ₃₀ that is a region shifted by a predetermined pixel in the X direction from the region A ₂₀ ,. The comparison pattern P _C is sequentially compared in units of pixels. When the comparison between the area A _X0 and the comparison pattern P _C is completed, the attachment determination unit 15 compares the area A ₀₁ with the area A ₀₁ which is an area shifted from the area A ₀₀ by a predetermined pixel (preferably 1 pixel) in the Y direction. The pattern P _C is compared in pixel units. In this way, the attachment check unit 15 compares the total area of the binarized image P _BW and (regions A ₀₀ ~ region A _XY) and comparison pattern P _C.

As a result of comparing any region of the binarized image P _BW with the comparison pattern P _C , if the number or ratio of matched pixels exceeds a preset value, the attachment determination unit 15 sets the determination result R as “ Yes ". On the other hand, if the number or ratio of matched pixels does not exceed a preset value in comparison with any region, the attachment determination unit 15 sets the determination result to “none”.

Attachment check section 15, if the number or proportion of matching pixels are found region exceeding a preset value, may be omitted compared with the comparison pattern P _C and later regions.

  As mentioned above, although the Example of the safety device and picking lift which concern on this invention was described, this invention is not limited to the structure of an Example.

For example, in the above embodiment, the belt 11 is provided with a vertical stripe pattern by attaching two D ring stoppers 11b and 11c having a different color from the belt body 11a to the belt body 11a. It is not limited to this. The two colors constituting the striped pattern are not limited to white and black, and the striped pattern may be composed of any two colors having different luminances. It is not preferable to make the pattern other than the stripe pattern. In a short time compared with the comparison pattern P _C and the binary image P _BW, and because it becomes difficult to perform with high accuracy.

  Moreover, in the said Example, although the mounting determination part 15 decided to determine by the request | requirement from the vehicle control part 20, the timing which performs determination can be changed suitably. For example, the mounting determination unit 15 may perform determination at regular intervals during the cargo handling operation.

  Moreover, in the said Example, although the original image P acquired every 1/30 second was binarized by skipping two sheets, these can also be changed suitably.

In the above embodiment, the determination result R _1, R _4, · · ·, it is assumed that all of R _55, R ₅₈ is a determination of "attached" in the case of "Yes", the determination result R _1, When a part (for example, half) of R ₄ ,..., R ₅₅ , and R ₅₈ is “present”, “attachment” may be determined.

Further, attachment check section 15, after the comparison between the comparison pattern P _C and the binary image P _BW, further comparison pattern P _C becomes shrunk at a predetermined magnification reduction patterns P _C ', It is preferable to compare the enlarged pattern P _C ″ obtained by enlarging the comparison pattern P _C with a predetermined magnification and the binarized image P _BW . When the worker's boarding position deviates from the predetermined boarding position, the pattern of the belt 11 appearing in the binarized image P _BW increases or decreases depending on the amount of deviation. Even in such a case, an accurate determination can be made.

DESCRIPTION OF SYMBOLS 1 Picking lift 2 Vehicle main-body part 3 Mast 4 Driver's cab 5 Floor frame 6 Front frame 7 Head guard 8 Fork 9 Operation panel 10 Safety device 11 Belt 12 Safety belt 13 Safety belt winding part 14 Camera 15 Mounting judgment part 16 Pattern storage part 20 Vehicle Control Unit 21 Traveling System 22 Hydraulic System B Luggage

Claims (4)

A safety device for preventing an operator who has boarded the cab of the picking lift from falling from the cab,
A belt to be worn by the operator, with a stripe pattern of two colors having different luminances;
Imaging means directed to the operator boarded at a predetermined position of the cab;
A pattern storage unit storing a comparison pattern corresponding to the striped pattern of the belt;
The original image obtained by the imaging means is binarized, the binarized image obtained by the binarization is compared with the comparison pattern stored in the pattern storage unit, and the binarized image is included in the binarized image. If there is a pattern approximated to the comparison pattern, it is determined that the operator is wearing the belt, while if there is no pattern approximated to the comparison pattern in the binarized image, the operator A wearing determination unit for determining that the belt is not worn;
Equipped with a,
The wearing determination unit binarizes only an area in the original image where the waist of the worker is to be reflected, using a threshold value set based on a luminance histogram in the original image. Feature safety device. The mounting determination unit also compares the binarized image with an enlarged pattern obtained by enlarging the comparison pattern at a predetermined magnification and a reduced pattern obtained by reducing the comparison pattern at a predetermined magnification. If the binarized image includes a pattern that approximates at least one of the comparison pattern, the enlargement pattern, and the reduction pattern, the operator determines that the belt is worn, 2. The determination that the operator is not wearing the belt is made if there is no pattern approximate to any of the comparison pattern, the enlargement pattern, and the reduction pattern in the digitized image. Safety device as described in. The safety device according to claim 1 , wherein the striped pattern is a vertical striped pattern formed by a D ring stop . The safety device according to any one of claims 1 to 3,
A vehicle control unit that controls at least the raising and lowering of the cab;
With
The wearing determination unit of the safety device determines whether or not the worker is wearing the belt in response to a request from the vehicle control unit, and notifies the vehicle control unit of the result of the determination. Configured,
The vehicle control unit prohibits raising and lowering of the cab when the result of the determination by the mounting determination unit is not mounted.
Picking lift characterized by that.