JP7009691B2 - Crane work area safety confirmation device - Google Patents

Description

The present invention relates to a device for preventing a worker from being pinched or colliding with a handling object or a peripheral object in a crane working area.

Conventionally, as a crane work area safety confirmation device, a device that captures the area around the crane with a camera from above the crane, sets a dangerous area with the recognition unit that recognizes the operator's helmet, and displays it on the monitor to confirm safety has been proposed. (See, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2010-241548

By the way, in the technique disclosed in Patent Document 1, since the helmet of the worker is recognized by using the camera, depending on the working environment of the crane, the sunlight becomes ambient light and the target helmet is selected from the recognition range. It was sometimes very difficult to cut out, and if the background was bright, the object would be buried in the background. Furthermore, there are items to be handled and stored items in the area around the crane, and in order to ensure safety, it was necessary to confirm that there was a sufficient distance between these items and the worker, but the worker. It was also difficult to distinguish between the item and the item.

In view of the problems of the conventional crane work area safety confirmation device, the present invention implements measures against ambient light with a simple equipment configuration, and reliably extracts workers without being affected by the working environment of the crane. By doing so, the purpose is to provide a device that can confirm the safety of the crane work area.

In order to achieve the above object, the crane work area safety confirmation device of the present invention includes a camera that images the work area of the crane, an infrared floodlight provided near the camera, and retroreflective attachment attached to the helmet of the worker. It is equipped with a mark made of wood and an arithmetic device that captures and processes images taken by the camera, and transmits the worker's coordinates obtained by the arithmetic device to the crane controller to ensure the safety of the operator in the crane work area. The feature is that it is secured.

In this case, the arithmetic unit that captures and processes the image controls ON / OFF of the infrared light source, captures the image of the camera in synchronization with it, takes the difference between ON and OFF, and attaches it to the helmet. It is possible to eliminate the influence of ambient light by utilizing the property of the mark made of the retroreflective material returning to the light source direction of the incident light.

Further, a range sensor for recognizing the work area of the crane is provided, and the coordinates and size of the object in the work area are measured by the range sensor and transmitted to the crane controller, and the crane controller is used as the coordinates of the object. It is possible to compare the coordinates of the workers and confirm whether or not the distance between the two is greater than or equal to the specified distance to determine whether or not the crane can be operated.
Here, the "range sensor" (Laser Range Scanner or 3D Scanner) refers to a scanning type laser rangefinder capable of outputting physical shape data of space.

Further, when the worker is in the moving direction of the crane, the crane controller can prevent the crane controller from accepting the crane operation instruction even when the distance is more than a predetermined distance.

According to the crane work area safety confirmation device of the present invention, the crane work area is implemented by taking measures against ambient light with a simple equipment configuration and reliably extracting workers without being affected by the work environment of the crane. You can check the safety of the crane.

It is a side view (installation drawing of a camera and a range sensor) which shows an embodiment of the overhead crane to which the crane work area safety confirmation device which concerns on this invention apply. It is a block diagram of the control device of the crane work area safety confirmation device. An example of a mark made of a retroreflective material attached to a worker's helmet is shown, (a-1) is a plan view, (a-2) is a side view, and (b-1) is a plan view of another example. (B-2) is the same side view. It is a time chart showing the ON / OFF of the infrared projector and the shooting timing of the camera. An image taken by a camera is shown, (a) is an example of an image taken when the infrared projector is OFF, (b) is an example of an image taken when the infrared projector is ON, and (c) is an example of an image taken from the image of (a) to (b). An image example in which the difference between the images is taken is shown. It is explanatory drawing which shows an example of the push button switch arrangement of a radio handset. It is an explanatory view of a range sensor and a stepping motor, (a) is a plan view which shows the attached state, and (b) is a side view which shook the range sensor by a stepping motor. It is an image diagram of the principle of measuring the distance from the range sensor to the object at each angle, (a) is a front view, and (b) is a plan view. It is explanatory drawing which showed the coordinates of a helmet and the apex of the section of a handling object. It is explanatory drawing of the measurement principle of a range sensor, (a) is a plan view, (b) is a plan view, (c) is a side view. It is explanatory drawing of the principle of calibration. In the explanatory diagram of the principle of calibration, (a) is an image at the time of calibration of a shape detection personal computer, (b) is an image at the time of calibration of a human detection personal computer, and (c) is an image after calibration correction.

Hereinafter, embodiments of the crane work area safety confirmation device of the present invention will be described with reference to the drawings.

1 to 2 show an embodiment of an overhead crane to which the crane work area safety confirmation device according to the present invention is applied.

FIG. 1 is a schematic configuration diagram in which the crane work area safety confirmation device according to the present invention is applied to an overhead crane. Working. In order to confirm the safety of this state, the camera 21 installed in the club 02 of the crane 01 is monitoring. Further, a range sensor 23 is attached to the club 02 in order to measure the shape of the object to be handled 09.

FIG. 2 shows a control configuration of the crane work area safety confirmation device. The camera 21 and the infrared projector 22 are connected to a human detection personal computer 26 as an arithmetic unit. When the crane controller 30 instructs the human detection personal computer 26 to detect the worker 13 in the crane work area, the human detection personal computer 26 turns on / off the infrared projector 22 and takes a picture of the camera 21 in synchronization with it. conduct.

Here, the crane work area safety confirmation device can be applied to a general-purpose overhead crane, and the overhead crane 01 is equipped with a general-purpose overhead crane, for example, a traveling laser for grasping the traveling position of the overhead crane 01. Equipment such as a distance meter 27, a traversing laser distance meter 28 for grasping a traversing position, a hoisting inverter 31, a hoisting motor 32, a traversing inverter 33, a traversing motor 34, a traveling inverter 35, and a traveling motor 36 is provided. There is.

FIG. 5A is an image example when the infrared projector 22 is OFF, and FIG. 5B is an image example when the infrared projector 22 is ON. The human detection personal computer 26 divides the image of the mark 12 made of the regressive reflective material attached to the helmet 11 into ON / OFF and captures the image from the camera 21 to take the difference between the image at ON and the image at OFF. As a result, an image example in which the mark as shown in FIG. 5C is extracted can be obtained.
Here, the rereflective reflective material uses a conventionally known glass bead or the like to constantly reflect light in the incident direction with respect to light incident from all directions. Specifically, the incident light is used as a light source. A material having the property of reflecting toward can be used.

Hereinafter, the crane work area safety confirmation device according to the present invention will be described based on the operation of the overhead crane 01.
In the overhead crane 01, the club 02 operates in the direction of the arrow in the drawing, and the overhead crane 01 provided with traveling wheels 06 in the direction perpendicular to the traverse travels on the traveling rail 07 and moves to a target position.

When the movement to the target position is completed, the hoisting device 03 is operated to pay out the wire rope 04 and wind down the hook 05. The worker 13 performs the slinging work of the handling object 09, and attaches the slinging wire 14 to the hook 05.

The human detection personal computer 26 determines that the movement of the crane 01 to the target position has been completed because there is no operation signal for traversing and traveling for a predetermined time, and at that time, preferably, the hook 05 is unwound. Before, the worker 13 around the hook 05 is detected. The infrared projector 22 is turned ON / OFF, and the camera 21 is photographed in synchronization with the ON / OFF of the infrared projector 22 to record an image.
FIG. 4 shows a time chart of the operation.
Here, the infrared projector 22 uses light that is not visible light so as not to give stress to the operator 13 by turning the light on and off.

The image of the mark 12 made of the retroreflective material of the helmet 11 captured by the human detection personal computer 26 is shown in FIG. 5A when the infrared projector 22 is OFF, and FIG. 5 (a) when the infrared projector 22 is ON. As shown in b). This is based on the fact that the mark 12 made of a retroreflective material uses a material having a characteristic that the incident light is reflected toward the light source, and returns to the infrared projector 22 side installed near the camera 21. Is.

The human detection personal computer 26 takes the difference between FIGS. 5 (a) and 5 (b) of the captured image, and obtains an image as shown in FIG. 5 (c).
As the recognition method of the obtained image, a method of registering a cross pattern in advance and performing pattern matching or a method of obtaining by machine learning can be used.
Here, as for the shape of the mark 12 made of the retroreflective material attached to the helmet, the shape (cross or elliptical pattern) as shown in FIG. 3 is easy to attach to the helmet, and the shape recognition is also easy.

When the human detection personal computer 26 detects the mark 12 made of the retroreflective material, it sends the coordinates of the position to the crane controller 30.

The shape recognition personal computer 29 as an arithmetic unit determines that the crane has completed the movement to the target position, that is, the crane 01 has completed the movement to the target position, because there is no operation signal for traversing and traveling for a predetermined time. At that time, preferably, the object around the hook 05 is detected before the unwinding operation of the hook 05 is performed. The shape of the object to be handled 09 is obtained by using the range sensor 23.
Here, the range finder 23 is also called a Laser Range Scanner or a 3D Scanner, and refers to a scanning type laser rangefinder capable of outputting physical shape data of space, and refers to "light detection and distance measurement" or "distance measurement". "LIDAR" (abbreviation for Light Detection and Ranging or Laser Imaging Detection and Ranging), also known as "laser image detection and distance measurement". One of the remote sensing technologies using light, which measures scattered light for laser irradiation that emits in a pulse shape. A device for analyzing the distance to an object at a long distance and the shape and properties of the object.) For example, "UTM-30LX-EW" manufactured by Hokuyo Denki Co., Ltd. can be preferably used.
The range sensor 23 measures the time required to emit light in a semicircle and return the reflected light, and measures the distance from the range sensor to the target at each angle.
Then, as shown in FIG. 7, the range sensor 23 can change the scanning angle by using the stepping motor 24 controlled by the motor controller 25.
FIG. 8A is an image diagram of which scans light in the semicircular direction and measures the distance from the object to be handled 09. However, since this alone captures only a part of the handling object 09, the range sensor 23 is rotated in the direction perpendicular to the semicircular direction to measure the distance. FIG. 8B is a view from above of the handling object 09 when the operation is performed. In this way, an object higher than the floor surface, such as the handling object 09, is measured and its coordinates are obtained.
Measurement is performed on an object having all heights in the field of view of the range sensor 23, and the coordinates thereof are calculated.

The shape recognition personal computer 29 sends the calculated coordinates of the object and the positions of the vertices of the sections of the object to the crane controller 30 to create a three-dimensional map of the crane work area.

Here, to explain the measurement principle by the range sensor 23, as shown in FIG. 10, the light 80 projected directly below the range sensor 23 outputs the distance H as the measurement result. Similarly, the height of the point P of the handling object 09, which is displaced by X mm in the X-axis direction and Y mm in the Y-axis direction from directly below the range sensor 23, is defined as Z mm.
At the same time that the range sensor 23 performs a semicircular scan, the range sensor 23 is rotated in a direction perpendicular to the semicircular direction using a stepping motor 24 to measure the distance L from the object to be handled 09. At this time, let θ be the angle with the object to be handled 09 when the light 81 projected from the range sensor 23 is scanned in the semicircular direction, and let φ be the angle when rotated in the direction perpendicular to the semicircular direction. , The length of each position can be expressed by the following formula.
X = L × tanθ / (1 + (tanθ) ² + (tanφ) ² ) ^1/2
Y = L × tanφ / (1 + (tanθ) ² + (tanφ) ² ) ^1/2
Z = H- (L ^2- (X ² + Y ² ))
By continuously changing the above angles θ and φ, an object below the range sensor 23, for example, the handling object 09 can be grasped as three-dimensional, whereby the object existing in the working area of the crane can be grasped. You can know the position and size.

FIG. 9 shows a diagram showing the coordinates of the helmet and the vertices of the section of the handling object 09.
The crane controller 30 uses the coordinates of the helmet 11 and the position of the apex of the intercept of the handling object 09 sent from the human detection personal computer 26 and the shape recognition personal computer 29 to the coordinates of the helmet (Xh, Yh) and the intercept of the handling object 09. Find the difference between the apex coordinates (X1, Y1) to (X4, Y4), and confirm that the distance between the worker 13 and the handling object 09 is at least the specified value, for example, 1.5 m or more, and then perform the hoisting operation. Make a decision to give permission.

The operator 13 presses the "up" push button using the wireless device slave unit 38 as shown in FIG. 6, which transmits an operation signal to the wireless device master unit 37 in a state of being separated from the handling object 09 by a specified value or more. Wind up the handling item 09. In this case, if the crane controller 30 determines that the distance is not greater than or equal to the specified value, the push button instruction for hoisting is not accepted.

After winding up, the worker 13 presses any of the push buttons "east", "west", "south", and "north" in the desired movement direction to instruct the movement. The crane controller 30 does not accept the movement instruction when the operator 13 is present in the direction instructed to move, that is, on the extension line of the movement direction.

According to this crane work area safety confirmation device, the crane work is carried out by implementing measures against ambient light with a simple equipment configuration and reliably extracting the worker 13 without being affected by the work environment of the overhead crane 01. You can check the safety of the area.

By the way, the camera 21 and the range sensor 23 are installed so as to look at the same area, but for example, when the distance to the handling object 09 is about 10 m, the viewing range changes significantly due to the difference in angle. become. Therefore, if necessary, the accuracy of the crane work area safety confirmation device can be improved by calibrating the operation of aligning the fields of view with each other at the stage when the camera 21 and the range sensor 23 device are installed. can.

FIG. 11 is a layout diagram when calibration is performed, but the standard recognition object 08 is installed at the center of the schematic field of view of the camera 21 and the range sensor 23. For the standard recognition object 08, a rectangular parallelepiped whose plane shape is a regular quadrangle is used.

FIG. 12A shows an image in which the standard recognition object 08 is captured by the range sensor 23. FIG. 12B shows an image in which the standard recognition object 08 is captured by the camera 21.

In the image 08a in which the standard recognition object 08 is recognized by the range sensor 23 shown in FIG. 12A, the center coordinates are deviated by (x1, y1) and the angles are deviated by θ1 and θ2. Therefore, as shown in FIG. 12 (c), the shape recognition personal computer 29 gives the offset values of the coordinates and the angle so that the image 08a comes to the center of the screen. Further, since the size of the standard recognition object 08 is known, the correction multiplier of the distance count value is determined so that the result of measuring the size matches the size of the object.

The image 08b in which the standard recognition object 08 is recognized by the camera 21 shown in FIG. 12B is generally distorted as in the case of being photographed by the camera. Therefore, the human detection personal computer 26 converts the captured image 08b of the camera 21 into a square using, for example, an affine transformation, gives offset values of coordinates and angles, and gives a distance count value, as in the shape recognition personal computer 29. Determine the correction multiplier for.
Here, the "affine transformation" refers to a transformation method that combines translation and linear transformation (enlargement, reduction, rotation, etc.).

By this calibration work, the coordinates and scales seen by the shape recognition personal computer 29 and the human detection personal computer 26 can be matched and the recognition results of both can be shared.

The crane work area safety confirmation device of the present invention has been described above based on the embodiment thereof, but the present invention is not limited to the configuration described in the above embodiment and is appropriately used as long as it does not deviate from the gist thereof. The configuration can be changed.

The crane work area safety confirmation device of the present invention has a simple equipment configuration, implements measures against ambient light, and reliably extracts workers without being affected by the work environment of the crane, thereby ensuring the safety of the crane work area. Therefore, it can be suitably used for an overhead crane, and can also be used, for example, for a construction machine using a crane.

01 Crane (overhead crane)
02 Club 03 Hoisting device 04 Wire rope 05 Hook 06 Travel wheel 07 Travel rail 08 Standard recognition target 09 Handling item 11 Helmet 12 Mark made of retroreflective material 13 Worker 14 Sling wire 21 Camera 22 Infrared floodlight 23 Range sensor 24 Stepping motor 25 Motor controller 26 Computing device (human detection personal computer)
27 Traveling laser rangefinder 28 Traverse laser rangefinder 29 Arithmetic logic unit (shape recognition personal computer)
30 Crane controller 31 Hoisting inverter 32 Hoisting motor 33 Traverse inverter 34 Traverse motor 35 Traveling inverter 36 Traveling motor 37 Radio master unit 38 Radio slave unit 80 Light projected from the range sensor 81 Light projected from the range sensor 81 Light

Claims (3)

A camera that captures the work area of a crane, an infrared floodlight installed near the camera, a mark consisting of a retroreflective material attached to the worker's helmet, and a computing device that captures and processes images taken by the camera. And, the coordinates of the worker obtained by the calculation device are transmitted to the crane controller to ensure the safety of the worker in the work area of the crane, and the measurement for recognizing the work area of the crane. A range sensor is provided, the coordinates and size of the object in the work area are measured by the range sensor and transmitted to the crane controller, and the crane controller compares the coordinates of the object with the coordinates of the worker, and the distance between the two is specified. It is a crane work area safety confirmation device that checks whether the crane is operable or not by checking whether it is more than the distance away from the camera, and calibrates the camera and the range sensor to match each other's fields of view. This is a crane work area safety confirmation device that is characterized by the fact that the camera and the range sensor are installed so that they can see the same area . The arithmetic unit that captures and processes the image controls ON / OFF of the infrared light source, captures the image of the camera in synchronization with it, takes the difference between ON and OFF, and retroreflects attached to the helmet. The crane work area safety confirmation device according to claim 1, wherein the influence of ambient light is eliminated by utilizing the characteristic that the incident light of the mark made of a material returns to the light source direction. Claim 1 is characterized in that when the worker is in the moving direction of the crane, the crane controller does not accept the crane operation instruction even when the distance is more than a specified distance. Or the crane work area safety confirmation device according to 2 .

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