Surroundings monitoring system

Abstract

To improve safety with a simple configuration.SOLUTION: A surroundings monitoring system 1 includes a retroreflective material 42 attached to a helmet 41 of a worker 40; and an optical sensor 25 attached to a forklift 20 to detect reflected light from the retroreflective material 42. At least one of an attachment position of the retroreflective material 42 to the helmet 41 and an attachment position of the optical sensor 25 to the forklift 20 is set so as to be detected when the worker 40 is in a first state and so as not to be detected when the worker 40 is in a second state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a surroundings monitoring system for ensuring safety around a forklift. [Background technology]

[0002] The technology described in Patent Document 1 ensures the safety of workers in the work area of work machines by using a camera to photograph a mark made of retroreflective material attached to the worker's helmet and determining the worker's position (coordinates) based on the image. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-127372 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional technology, a retroreflective material of sufficient size is required for the helmet in order to reliably detect the worker, and image processing and other processes for detecting the worker are cumbersome.

[0005] The present invention has been made in view of the above circumstances, and has as its object to improve safety with a simple configuration. [Means for solving the problem]

[0006] The present invention provides a surroundings monitoring system including a retroreflective material attached to a worker's helmet and a sensor attached to a forklift to detect light reflected from the retroreflective material, At least one of the attachment position of the retroreflective material on the helmet and the attachment position of the sensor on the forklift is set so that the worker is detected when in a first state, and is not detected when in a second state. [Effects of the Invention]

[0007] According to the present invention, safety can be improved with a simple configuration. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a surroundings monitoring system according to an embodiment; [Figure 2] 1 is a block diagram showing a schematic control configuration of a surroundings monitoring system according to an embodiment; [Figure 3] 1A and 1B are three-view diagrams of a helmet in setting example 1 according to an embodiment. [Figure 4] 1A and 1B are diagrams for explaining a detectable state and an undetectable state according to an embodiment; [Figure 5] 10A and 10B are three-view diagrams of a helmet in setting example 2 according to the embodiment. [Figure 6] FIG. 10 is a diagram illustrating a detectable state of a worker in setting example 2 according to the embodiment. [Figure 7] 10A and 10B are three-view diagrams of a helmet in setting example 3 according to the embodiment. [Figure 8] FIG. 10 is a diagram illustrating a detectable state of a worker in setting example 3 according to the embodiment. [Figure 9] 10A and 10B are three-view diagrams of a helmet in a case where setting example 1 and setting example 2 according to the embodiment are combined. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0010] [Configuration of the perimeter monitoring system] FIG. 1 is a diagram showing a surroundings monitoring system 1 according to this embodiment, and FIG. 2 is a block diagram showing a schematic control configuration of the surroundings monitoring system 1. As shown in FIG. As shown in these figures, the perimeter monitoring system 1 detects a worker (human) 40 around a forklift 20 in operation, and prevents contact between the forklift 20 and the worker 40 to ensure safety in the work area. Specifically, the perimeter monitoring system 1 includes a forklift 20 and a retroreflective material 42 attached to a helmet 41 worn by a worker 40. 1 and FIGS. 4, 6, and 8 described later, the terms "front, back, left, right, top, and bottom" refer to directions as seen from the perspective of the forklift 20 (or the driver riding on the forklift).

[0011] The forklift 20 performs various loading and unloading operations by holding loads or pallets with a pair of left and right forks 12 provided on the vehicle body 10. The forklift 20 of this embodiment is a manned vehicle in which a driver rides on the vehicle body 10 to drive and operate it. Specifically, the forklift 20 includes a vehicle body drive unit 21, a fork drive unit 22, an operation unit 23, a display unit 24, an optical sensor 25, a warning light 28, a speaker 29, a memory unit 26, and a controller 27.

[0012] The vehicle body drive unit 21 includes a travel motor and a steering motor (both not shown) that are drive sources for the vehicle body 10 of the forklift 20. The travel motor drives the drive wheels among the wheels. The steering motor rotates the steered wheels among the wheels (performs steering operation). Each motor is powered by a battery (not shown). Note that the drive sources are not limited to motors and may be an internal combustion engine or the like. The fork drive unit 22 is a drive source that operates the pair of forks 12 that protrude forward. The fork drive unit 22 of this embodiment includes a tilt cylinder, a lift cylinder, and a reach cylinder that tilt, lift, and move the pair of forks 12 forward and backward (extend and contract) relative to the vehicle body 11. These cylinders are piston cylinders that are driven by fluid pressure (e.g., hydraulic pressure).

[0013] The operation unit 23 is an operating means for the driver to perform various operations. The operation unit 23 includes, for example, a steering wheel, pedals, levers, various buttons, etc., and outputs operation signals to the controller 27 according to the operation content of these. The display unit 24 is, for example, a liquid crystal display, an organic electroluminescence display, or other display, and displays various information based on a display signal input from the controller 27. The display unit 24 may be a touch panel that also serves as part of the operation unit 23.

[0014] The optical sensor 25 is attached to the forklift 20, detects the retroreflective material 42 within a predetermined scan area (detection area) R, and outputs the detection result to the controller 27. The optical sensor 25 is an example of a sensor according to the present invention. The optical sensor 25 of this embodiment is an optical sensor such as a ToF (Time of Flight) sensor. However, the sensor type of the optical sensor 25 is not particularly limited as long as it can detect light reflected from the retroreflective material 42. The specific position and orientation of the optical sensor 25 will be described later.

[0015] The warning light 28 and the speaker 29 are an example of an alarm unit according to the present invention, and output an alarm or the like based on an alarm command from the controller 27 . The warning light 28 is arranged, for example, on the overhead guard 15, and emits light in a predetermined manner to give a visual warning to nearby workers 40 (people) and drivers. The speaker 29 outputs sound in a predetermined manner to give an auditory warning or the like to nearby workers 40 (people) and drivers.

[0016] The storage unit 26 is a memory configured by, for example, a RAM (Random Access Memory) or a ROM (Read Only Memory), and stores various programs and data, and also functions as a work area for the controller 27. The controller 27 is, for example, a microcomputer, and controls the operation of each part of the forklift 20 based on the programs stored in the storage unit 26 and the operation contents of the operation unit 23 .

[0017] [Operation of the perimeter monitoring system] Next, the operation of the surroundings monitoring system 1 when detecting the worker 40 around the forklift 20 will be described.

[0018] In the surroundings monitoring system 1, the controller 27 of the forklift 20 detects that the worker 40 is in a specific state (state related to position and posture) depending on the mounting position of the retroreflective material 42 on the helmet 41 and the mounting position of the optical sensor 25 on the forklift 20. In other words, at least one of the attachment position of the retroreflective material 42 on the helmet 41 and the attachment position of the optical sensor 25 on the forklift 20 is set so that the worker 40 is detected when the worker 40 is in a predetermined detectable state (first state), and is not detected when the worker 40 is in a non-detectable state (second state). A specific example of the retroreflective material 42 and the optical sensor 25 will be described below.

[0019] <Setting example 1> FIG. 3 is a three-view diagram of a helmet 41A in setting example 1, and FIG. 4 is a diagram for explaining a detectable state and an undetectable state. 3 and Figures 5 and 7 described later, "front, back, left, right, top and bottom" refer to directions as seen from the perspective of the helmet 41 (or the worker 40 wearing it). In these figures, the brim is shown on the front of the helmet 41 to make the orientation easier to understand, but the brim may or may not be located on a part other than the front.

[0020] As shown in FIG. 3, in setting example 1, retroreflective material 42 is attached to the top of a helmet 41A. As shown in FIG. 1, in setting example 1, the optical sensor 25 is attached to the forklift 20 at a position higher than the driving operation unit 16 (for example, above the overhead guard 15) and facing diagonally downward and rearward.

[0021] The coefficient of retroreflection of the retroreflector 42 decreases as the angle of incidence increases (see JIS Z 9117). In other words, when the retroreflector 42 is attached to a curved surface directly facing the optical sensor 25, the reflective brightness decreases toward the edge of the curved surface. This is equivalent to the area of the retroreflector 42 becoming smaller as seen from the optical sensor 25.

[0022] Therefore, in setting example 1, as shown in Figure 4(a), when worker 40 is lowered behind but relatively close to forklift 20 (on the left side in the figure), the optical sensor 25 detects that the retroreflective material 42 on the top of the helmet 41 has a portion with a predetermined brightness or higher over a predetermined range (area) or higher. Therefore, setting example 1 can suitably detect worker 40 who is lowered immediately behind forklift 20. Here, lowering one's posture includes, for example, bending, crouching, or squatting. On the other hand, even if the worker 40 lowers his / her posture behind the forklift 20, if the distance from the forklift 20 is greater than a predetermined distance, the incident angle from the optical sensor 25 to the retroreflective material 42 becomes large, and the optical sensor 25 cannot detect an area (area) with a brightness greater than a predetermined value. In other words, in this case, the worker 40 cannot be detected. 4(b), when the worker 40 is standing relatively close to the rear of the forklift 20, the angle of incidence from the optical sensor 25 to the retroreflective material 42 becomes large, and the worker 40 is not detected. The worker 40 in this state is relatively easy for the driver to recognize, and can be said to be in a relatively non-dangerous state. Therefore, by preventing the worker 40 in this state from being detected, unnecessary alarms can be avoided.

[0023] However, in setting example 1, it is sufficient to detect a state in which the worker 40 has lowered his / her posture behind the forklift 20. In other words, the detectable state (first state) in setting example 1 is a state in which the worker 40 has lowered his / her posture behind the forklift 20.

[0024] <Setting example 2> Fig. 5 is a three-view drawing of helmet 41B in setting example 2, and Fig. 6 is a diagram showing a detectable state of worker 40 in setting example 2. Fig. 9 is a three-view drawing of helmet 41D in a case where setting example 2 and setting example 1 are combined.

[0025] As shown in FIG. 5, in setting example 2, retroreflective material 42 is attached to the back of the head of a helmet 41B. 6, in setting example 2, the optical sensor 25 is attached to the upper part of the overhead guard 15 of the forklift 20, facing diagonally downward toward the rear, as in setting example 1. However, in setting example 2, the optical sensor 25 only needs to be attached facing toward the rear of the forklift 20, and there are no particular limitations on the height position, for example.

[0026] In the case of setting example 2, the detectable state (first state) is a state in which the operator 40 is behind the forklift 20 with his back to the forklift 20. That is, in the setting example 2, the operator 40 who is behind the forklift 20 and has his back to the forklift 20 can be suitably detected.

[0027] Note that setting example 2 can be used in combination with setting example 1. In this case, the retroreflective material 42 may be attached to the top and back of the head of the helmet 41D as shown in Fig. 9. The optical sensor 25 may be attached in the position (state) of the first setting example. This makes it possible to detect a worker 40 who is in a low posture behind the forklift 20 or who is behind the forklift 20 with his back to the forklift 20.

[0028] <Setting example 3> FIG. 7 is a three-view diagram of a helmet 41C in setting example 3, and FIG. 8 is a diagram showing a detectable state of a worker 40 in setting example 3.

[0029] As shown in FIG. 7, in setting example 3, retroreflective materials 42 are attached to the back and sides of the head of a helmet 41C. 8, in setting example 3, optical sensors 25 are attached to both the left and right sides of the rear of the forklift 20. Each optical sensor 25 is directed diagonally rearward to the side of the forklift 20, and the height position is not particularly limited.

[0030] In the case of setting example 3, the detectable state (first state) is a state in which the operator 40 is positioned behind and to the side of the driver's seat 17 of the forklift 20 and faces the rear of the forklift 20. That is, in setting example 3, it is possible to suitably detect a worker 40 who is behind and to the side of the driver's seat 17 of the forklift 20 and facing away from or to the side of the forklift 20. This makes it possible to detect workers 40 other than those passing by head-on, regardless of the direction of travel.

[0031] [Technical effect of this embodiment] As described above, according to this embodiment, at least one of the attachment position of the retroreflective material 42 on the helmet 41 and the attachment position of the optical sensor 25 on the forklift 20 is set so that it is detected when the worker 40 is in a predetermined detectable state (first state), and is not detected when the worker 40 is in a non-detectable state (second state). Therefore, by arranging the retroreflective material 42 and / or the optical sensor 25 in a predetermined position, it is possible to detect a worker 40 in a particular, more dangerous state simply by detecting the retroreflective material 42 with the optical sensor 25. In other words, safety can be improved with a simple configuration.

[0032] Furthermore, according to setting example 1 of this embodiment, the optical sensor 25 is mounted on the forklift 20 at a position higher than the driving operation unit 16, facing rearward, and the retroreflective material 42 is attached to the top of the helmet 41. This makes it possible to detect a worker 40 in a low posture behind the forklift 20.

[0033] Furthermore, according to the setting example 2 of this embodiment, the optical sensor 25 is attached to the forklift 20 facing toward the rear, and the retroreflective material 42 is attached to the back of the helmet 41. This allows the operator 40 behind the forklift 20 with his back to the forklift 20 to be detected appropriately.

[0034] Furthermore, according to setting example 3 of this embodiment, retroreflective materials 42 are attached to the back and sides of the head of the helmet. This makes it possible to suitably detect the operator 40 who is behind and to the side of the driver's seat 17 of the forklift 20 and facing away from or to the side of the forklift 20.

[0035] [others] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, the controller 27 of the forklift 20 may issue a warning using the warning light 28 or the speaker 29 when the optical sensor 25 detects the worker 40 in the detectable state (first state). This allows the driver of the forklift 20 and the worker 40, who may not recognize each other, to be notified of the possibility of contact. In this case, the warning mode is not limited to lighting the warning light 28 or outputting a sound from the speaker 29, as long as it can notify the surrounding area that the forklift 20 and the worker 40 are approaching.

[0036] The controller 27 may also issue an alarm when the forklift 20 is operated in reverse by the driver and the optical sensor 25 detects the operator 40 in the detectable state (first state). Here, the operation in reverse means that an input of the operation to move in reverse to the operating unit 23 is detected. This makes it possible to avoid a situation in which the forklift 20 that is stopped issues an alarm.

[0037] Furthermore, in counter-type forklifts, the driver often twists his or her upper body to the right side of the vehicle when reversing, which makes the left side a blind spot for the driver. Therefore, the detection area of the optical sensor may be configured to cover only the rear left side of the vehicle body.

[0038] Furthermore, in the above embodiment, a case has been described in which a driver rides on the forklift, but the forklift according to the present invention includes a forklift that can be operated manned by remote control or unmanned (automatic) operation.

[0039] In addition, the details shown in the above embodiment can be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0040] 1. Perimeter monitoring system 10. Body 15 Overhead Guard 16 Driving operation unit 17 Driver's seat 20 forklift 23 Control section 25 Optical Sensor (Sensor) 27 Controller 28 Warning light (alarm part) 29 Speaker (alarm unit) 40 workers 41, 41A, 41B, 41C, 41D helmets 42 Retroreflective material R detection area

Claims

1. A surroundings monitoring system including a retroreflective material attached to a helmet of a worker and a sensor attached to a forklift to detect light reflected from the retroreflective material, At least one of the attachment position of the retroreflective material on the helmet and the attachment position of the sensor on the forklift is set so that the worker is detected when the worker is in a first state and is not detected when the worker is in a second state. Perimeter monitoring system.

2. the first state is a state in which the worker is in a low position behind the forklift, The sensor is attached to the forklift at a position higher than a driving operation unit and facing rearward, The retroreflective material is attached to the top of the helmet. The perimeter monitoring system according to claim 1 .

3. The sensor is attached to the top of the overhead guard. The surroundings monitoring system according to claim 2 .

4. the first state is a state in which the worker is behind the forklift with his / her back to the forklift, The sensor is attached toward the rear of the forklift, The retroreflective material is attached to the rear of the helmet. The perimeter monitoring system according to claim 1 .

5. the first state is a state in which the operator is positioned rearward and to the side of the driver's seat of the forklift and facing the rear of the forklift, The retroreflective material is attached to the rear and sides of the helmet. The perimeter monitoring system according to claim 1 .

6. The forklift has an alarm unit that issues an alarm, the alarm unit issues an alarm when the forklift is operated in reverse and the sensor detects the operator in the first state. The perimeter monitoring system according to claim 5 .

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