JPH11343009A - Safety device for self-advancing shelf - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety device for a self-advancing shelf to reduce the number of arranged projection means and receiving means for detecting an obstacle and reduce a cost. SOLUTION: A safety device for a self-advancing shelf is to prevent nipping of an obstacle 51 in a work passage 31 selectively formed between a plurality of moving shelves 25, 27, and 29, being movably arranged. Irregular reflection by a floor 45 being infrared rays 40 projected in the work passage 31 from obliquely upward by projectors 41 arranged at the moving shelves 25, 27, and 29 is received by a plurality of receivers 47 arranged at the moving shelves 25, 27, and 29 and this way detects the presence of the obstacle 51 in the work passage 31. The infrared rays 40 entering the work passage 31 are interrupted by the obstacle 51. When the shade 53 of the obstacle 51 is generated, a quantity of received light of some receivers 47 of a plurality of receivers 47 is remarkably reduced and this constitution detects entrance of the obstacle 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a self-propelled shelf.

[0002]

2. Description of the Related Art A conventional safety device for a self-propelled shelf is shown in FIG. 7 (JP-A-5-186017).
In this safety device, obstacles are detected by a plurality of infrared zone sensors 5 and 7 arranged at predetermined intervals in the longitudinal direction on the opposing surfaces of the movable shelves 1 and the fixed shelves 3, and safety when the movable shelves 3 are moved is provided. Is secured. Each of the infrared zone sensors 5 and 7 is composed of a light emitter for emitting infrared light and an infrared light receiver, and the reflected light of the infrared light emitted by the light emitter from an obstacle such as a human body is detected by the light receiver. Thus, the presence of an obstacle is detected.

In this safety device, as shown in FIG. 7, an infrared zone sensor 5 and an infrared zone sensor 7 disposed on opposing surfaces opposing each other alternately have respective detection areas 9 and 11 alternately. They are arranged adjacent to each other.

[0004]

However, in the above-mentioned conventional safety device, the reflected light from the obstacle such as the human body of the infrared rays emitted by the projectors of the infrared zone sensors 5 and 7 is detected by the light receiver. In order to reliably detect the presence of a human body, it is necessary to arrange the infrared zone sensors 5 and 7 at intervals equal to or smaller than the width of the human body. For this reason, many infrared zone sensors 5 and 7 are required, and there is a problem that the cost is high.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a self-propelled shelf safety device in which the number of light emitting means and light receiving means for detecting an obstacle can be reduced and cost can be reduced. And

[0006]

A technical means for achieving the above object is a work passage selectively formed between a plurality of movable shelves provided so as to be movable in an array direction by a predetermined driving means. A safety device for a self-propelled shelf that prevents an obstacle from being pinched in the moving shelf, wherein the safety device is installed at a predetermined position on each of the movable shelves and emits light for obstacle detection by an obstacle present in the work passage. A light projecting means for projecting light toward a floor surface in the work passage so that a shadow of light is generated, and a plurality of light projecting units installed on each of the movable shelves along the work passage, and light is projected from the light projecting means. Light receiving means for receiving the light reflected by the floor surface in the work passage, and determining means for determining the presence or absence of an obstacle in the work passage, based on a light reception result of the light receiving means, The judgment means judges that there is an obstacle And answers, characterized in that it comprises, and inhibiting means for inhibiting the movement of the moving rack closing the working channel by the driving means.

[0007] Preferably, the light projecting means projects the light toward the floor from substantially obliquely upward along a longitudinal direction in the work passage.

[0008] Preferably, light having a predetermined modulation applied between the light projecting means and each of the light receiving means is transmitted and received.

Further, preferably, the prohibition means prohibits the movement of the movable shelf, and then releases the prohibition in response to the determination means determining that there is no obstacle.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view showing an overall configuration of a mobile shelf facility to which a self-propelled shelf safety device according to an embodiment of the present invention is applied, and FIG. 2 is a side view thereof. It is. The movable shelf equipment includes two fixed shelves 21 and 23 installed opposite to each other at a predetermined interval, and both fixed shelves 21 and 3.
It is provided with a plurality of self-propelled movable shelves 25, 27 and 29 which are installed so as to be able to reciprocate between the five shelves.

A rail (not shown) is laid between the fixed shelves 21 and 23, and a plurality of movable shelves 25, 27 and 29 move along the rail. Each of the movable shelves 25, 27, and 29 is provided with a drive motor (drive means) 71 (see FIG. 4).
1 drives the wheels of the movable shelves 25, 27, 29, so that the movable shelves 25, 27, 29 reciprocate on rails.

The fixed shelves 21, 23 (here, fixed shelves 21) and the movable shelves 25, 27, 29 are provided on the right (or left) sides of the fixed shelves 21 and the movable shelves 25, 27, 29, respectively. ) Is provided to instruct the formation of the work passage 31 in (1). By operating each of the passage selection switches 33, the corresponding movable shelves 25, 27, and 29 are automatically moved. The work passage 31 is provided on the right (or left) of the fixed shelf 21 or each of the movable shelves 25, 27, 29 provided with the passage selection switch 33.
Is formed.

Further, one of the right and left fixed shelves 21 and 23
(Here, fixed shelf 21), and each movable shelf 25, 27,
A limit switch 35 is provided on the movable shelf 25 at a position where the limit switch 35 can be in contact with the adjacent movable shelves 25, 27, 29 or the fixed shelf 21, and the limit switch 35 is adjacent to the movable shelves 25, 27, 29. Alternatively, by contacting the fixed shelf 23, the fixed shelf 21 or the movable shelf 25, 27, 29 provided with the limit switch 35 and the adjacent movable shelf 25, 27, 29 or the fixed shelf 23 are provided. It is detected that the work passage 31 is closed.

In addition, one of the fixed shelves 21 and 23
(Here, fixed shelf 21), and each movable shelf 25, 27,
At the upper end of one end in the longitudinal direction of 29, a support member provided with a light projector (light emitting means) 41 for emitting an infrared ray (light for obstacle detection) 40 for detecting an obstacle on the lower surface of the tip end 43 is attached. The support member 43 supports the projector 41 so as to extend from the upper end of each of the movable shelves 25, 27, and 29 onto the work passage 31 formed on the right or left side (right side in FIG. 2).

The projector 41 supported in this manner is
As shown in FIG. 3, the infrared light 40 is projected obliquely from above and substantially along the entire length of the floor surface 45 in the work passage 31 along the longitudinal direction of the work passage 31 as shown in FIG. It is illuminated.

Correspondingly, one of the right and left fixed shelves 2
1 and 23 (here, fixed shelf 23), and each movable shelf 2
5, 27, or 29 on either side of the work passage 31 (FIG. 2)
A plurality of light receivers (light receiving means) for obstacle detection are provided at predetermined intervals in the longitudinal direction of each of the movable shelves 25, 27, 29 and the fixed shelf 23 at a portion facing the left work passage 31 side). 47 are provided. Each of the light receivers 47 is a light emitter 4
1 is arranged so as to receive irregularly reflected light (reflected light) irregularly reflected (reflected) on the floor surface 45 in the work passage 31 out of the infrared rays 40 emitted by the light source 1. As shown in FIG. 3, each light receiver 47 has a floor surface 45 in the work passage 31.
Are allocated respectively, and the infrared rays 40 irregularly reflected in each of the allocated areas 45a are assigned.
Are received by the corresponding light receivers 47. Such a light receiver 47 is configured by a photoelectric conversion element or the like.

Such a light projector 41 and a plurality of light receivers 47
In the present embodiment, the one of the two movable shelves 25, 27, 29 that are provided on the left and right opposite sides of the movable shelves 25, 27, 29 and are adjacent to each other across the work passage 31. Irregularly reflected light from the floor surface 45 of the infrared rays 40 emitted by the light projectors 41 provided on 25, 27, and 29 is received by the respective light receivers 47 provided on the other movable shelves 25, 27, and 29. ing.

Then, in a work passage 31 formed between the movable shelves 25, 27, 29 and the fixed shelves 21, 23,
As shown in FIG. 3, when an obstacle 51 such as a human body enters, the infrared light 40 emitted from the light projector 41 is blocked by the obstacle 51, and a shadow 53 of the infrared light 40 is generated on the floor surface 45 in the work passage 31. Thereby, the light receiving amount of the irregularly reflected light of the light receiver 47 including the region where the shadow 53 has occurred in the allocation region 45a is greatly reduced.

At this time, since the infrared rays 40 are projected obliquely from above the obstacle 51 along the longitudinal direction of the work passage 31, the shadow 53 of the infrared light 40 due to the obstacle 51 is removed from the work passage 31. 31 is widely distributed in the longitudinal direction of the obstacle 31, and is distributed in a region much wider than the width of the obstacle 51 in the longitudinal direction. Due to the influence of the shadow 53, the region is much wider than the width of the obstacle 51. The light receiving amount of the irregularly-reflected light of the light receiver 47 located at the position is greatly reduced. Therefore, the installation interval of the light receiver 47 is
Even if the width is set to be larger than the width of the obstacle 51 such as a human body, the obstacle 51 can be sufficiently detected.

In the present embodiment, the presence of the obstacle 51 is detected by the determination unit 61b, which will be described later, detecting the decrease in the amount of light received by the light receiver 47 by a predetermined method described later.

FIG. 4 is a block diagram showing an electrical configuration of each of the movable shelves 25, 27, and 29. In the present embodiment, a control unit 61 for controlling the movement of each of the moving shelves 25, 27, and 29 is provided in each of the moving shelves 25, 27, and 29.
The control units 61, 27, and 29 cooperate with each other to control the movement of each of the movable shelves 25, 27, and 29. However, centralized control that centrally controls the movement of each of the movable shelves 25, 27, and 29 The unit may be provided on any one of the movable shelves 25, 27, 29, or other fixed components such as the fixed shelves 21, 23. Further, in the present embodiment, the determination unit 61b is provided inside the control unit 61, but may be provided outside the control unit 61 for each individual light receiver 41.

The control section 61 is composed of an MPU or the like, and includes a projector control section 61a, a determination section (determination means) 61.
b, an interlock control section (prohibiting means) 61c and a movement control section 61d.

The floodlight controller 61a controls the lighting of each of the floodlights 41 provided on the other adjacent moving shelves 25, 27, and 29.
While the working path 31 is formed between the light source 5, 27, and 29, the infrared light 40 to which a predetermined modulation is applied is emitted from the light projector 41.

As an example, the light emitter 41 is controlled to emit light in a pulsed manner at a predetermined lighting cycle. As shown in FIG. 5, there are two types of long and short periods 63 and 65 in each lighting period of the light emitter 41 that is controlled to be pulsed, and the two types of lighting periods 63 and 65 are arranged in any order. Whether or not transmission is performed interwoven is determined according to a predetermined pulse pattern (pulse data) registered in advance in the projector control unit 61a.

In this embodiment, two types of long and short periods 63,
65, the longer period 63 is associated with 1 and the shorter period 65 is associated with 0 (zero), and the pulse pattern is, for example, “1001001”.
00 ... "is stored, and the light emitter 41 is intermittently lit so that two types of long and short lighting periods 63 and 65 are arranged at predetermined intervals in an arrangement corresponding to the pulse pattern. .

The projector control unit 61a outputs a pulse pattern to a determination unit 61b, which will be described later, and then outputs a predetermined clock signal for synchronization to the determination unit 61b, and synchronizes with the clock signal. The light projector 47 is intermittently turned on in accordance with the registered pulse pattern.

In response to this, while the work passage 31 is formed between the moving shelves 25, 27, and 29 adjacent to each other, the judging section 61b detects the infrared rays 40 received by each light receiver 47.
Monitoring the amount of irregularly reflected light received from the floor surface 45 of the
By reading the change in the amount of received light in synchronization with the clock signal, the received light pulse pattern is determined. Then, it is determined whether or not the obstacle 51 has entered the work passage 31 by determining whether or not the received light pulse pattern matches the pulse pattern sent from the projector control unit 61a. Lock control unit 6
1c. Here, if there is at least one of a plurality of pulse patterns read from the amounts of light received by the plurality of light receivers 47 that is different from the pulse pattern given from the projector control unit 61a, it is determined that an obstacle exists. It is supposed to be.

Here, this determination principle will be described in more detail.
In a state where the obstacle 51 does not exist in the work passage 31, the infrared rays 40 emitted from the light projector 41 reach the floor surface 45 without being interrupted by the obstacle 51, are irregularly reflected by the floor surface 45, and receive each light. The light received by the light detector 47 and the amount of light received by each light receiver 47 fluctuates in a pulse shape according to the predetermined modulation with the flickering of the light transmitter 41 according to the predetermined modulation.
However, a predetermined pulse pattern can be read from the change in the amount of received light, and the read received pulse pattern matches the pulse pattern sent from the projector control unit 61a.

On the other hand, the obstacle 51
In a state where the obstacle 51 exists, the infrared rays 40 are blocked by the obstacle 51, and a shadow 53 of the obstacle 51 is generated on the floor surface 45 in the work passage 31, and the influence of the shadow 53 causes any one of the plurality of light receivers 47. The amount of the irregularly reflected light from the floor surface 45 of the infrared light 40 received by the light receiver 47 is greatly reduced. For this reason, the light receiver 4 whose received light amount has decreased
The received light amount of the light receiving unit 7 is substantially unchanged, and the determination unit 6 is based on the received light amount of the light receiver 47 whose received light amount is reduced.
The light receiving pulse pattern read by 1b naturally does not coincide with the pulse pattern sent from the projector control unit 61a.

The interlock control section 61c includes a judgment section 6
During a period in which 1c determines that there is an obstacle, a movement control unit 61d, which will be described later, is instructed to prohibit movement of the moving shelves 25, 27, and 29 in a direction to close the work passage 31 (interlock is performed). The judgment unit 61
When c determines that there is no obstacle, the interlock is released.

The movement control unit 61d drives and controls the corresponding motor 71 based on the input signals from the passage selection switch 33 and the limit switch 35 while following the instructions given by the interlock control unit 61c.
5, 27 and 29 are controlled. In addition, the movement control unit 61 determines that the other moving shelves 25 and 2 are adjacent to each other.
It is determined whether or not the work passage 31 is formed between the light source control unit 61 and the light transmission control unit 61, the determination unit 61b, and the interlock control unit 6 described above.
1d.

FIG. 6 is a flowchart showing the interlock control of the moving shelf equipment of the self-propelled shelf safety device according to the present embodiment. In step S1, any of the moving shelves 2
When the work passage 31 is formed between the work shelves 5, 27, 29 and the fixed shelves 21, 23, the process proceeds to step S2, in which the control unit 61 of the movable shelves 25, 27, 29 facing the formed work passage 31 moves. The control unit 61d outputs a result of the determination that the work passage 31 has been formed to the projector control unit 61a, the determination unit 61b, and the interlock control unit 61d. Interlock control is started, and the projector control unit 61a determines the determination unit 61b. A pulse pattern is output.

In step S3, a flashing operation of the projector 47 according to a predetermined pulse pattern by the projector controller 61a is started, and a clock signal synchronized with a lighting cycle of the flashing operation is output from the projector 61a to the determination unit 61b. Then, the process proceeds to step S4, where the determination unit 61b determines
The light receiving pulse pattern is read from the fluctuation pattern of the light receiving amount of each light receiver 47 in synchronization with the input clock signal.

In step S5, each light receiving pulse pattern corresponding to each light receiver 47 read by the determination section 61b in step S4 is converted into the light projector control section 61 in step S2.
The determination unit 61b determines whether or not all the pulse patterns given from a coincide with each other, that is, whether or not the obstacle 51 exists in the work passage 31, and determines that there is an obstacle. In step S6, the interlock is applied by the interlock control unit 61c,
The movement of the work passages 5, 27, and 29 in the direction of closing the work passage 31 is prohibited, and the process returns to step S3. If it is determined that there is no obstacle, the process proceeds to step S7 and the interlock is applied. Has an interlock control unit 61
When the interlock is released by c and the interlock is not applied, the state is maintained as it is, and the process proceeds to step S8.

In step S8, the movement control section 61d determines whether or not the work passage 31 is closed. If it is determined that the work passage 31 is closed, the work passage 31 is closed in step S9. The output to the effect that the alarm has occurred is provided from the movement control unit 61d to the projector control unit 61a, the determination unit 61b, and the interlock control unit 61c.
Is stopped, and the interlock control of the movable shelves 25, 27, and 29 facing the work passage 31 is ended, while it is determined that the work passage 31 is not closed, the process proceeds to step S3. Returning, the interlock control is continued until the work passage 31 is closed.

Although omitted in the flowchart of FIG. 6 for the sake of convenience, during the period in which the interlock is released during the period in which the processing of steps S1 to S8 is performed, the input from the passage selection switch 33 is not applied. Based on this, the movement of the movable shelves 25, 27, 29 is appropriately performed.

As described above, according to the present embodiment, each light receiver 47 receives the irregularly reflected light from the floor surface 45 of the infrared light 40 emitted from the light projector 41 toward the floor surface 45 in the work passage 31. Therefore, the obstacle 5 in the work passage 31
1 to detect the presence of the
Also, even if the light receivers 47 are arranged at intervals wider than the width of the human body or the like, the obstacles 51 such as the human body can be reliably detected. Can be reduced, and the cost can be reduced.

Further, by receiving the irregularly reflected light of the infrared ray 40 from the floor surface 45 by each of the light receivers 47, the obstacle 51
Is detected, the obstacle 51 can be reliably detected without being affected by the height, posture, and the like of the human body serving as the obstacle 51.

Further, the light projector 41 is connected to each of the movable shelves 25 and 2.
7 and 29 and a support member 43 attached to the upper end of one end of the fixed shelf 21 in the longitudinal direction.
1 is supported obliquely upward and the infrared rays 40 are projected from the obliquely upward along the longitudinal direction of the work passage 31 toward the floor surface 45 in the work passage 31. If an obstacle 51 enters the obstacle, the obstacle 5
1 can produce a shadow 53 of the infrared ray 40 having a large area extending in the longitudinal direction of the work passage 31. Thereby, the installation interval of the light receivers 47 can be made longer to further reduce the number of the light receivers 47 to be installed, and the entire range in the work passage 31 can be covered by one light emitter 41, so that Cost reduction can be achieved.

Further, the light projector 47 is intermittently lit in a pulse shape according to a predetermined pulse pattern, thereby modulating the infrared light 40 emitted by the light projector 47 into a signal. Since the presence / absence of the obstacle 51 is determined by determining whether or not the reading has been performed correctly, the light is affected by light (disturbance light) other than the infrared light 40 emitted by the light projector 41. Therefore, the obstacle 51 can be reliably detected.

Further, the interlock is applied as the obstacle 51 enters the work passage 31, and the interlock state is maintained while the obstacle 51 exists in the work passage 31, so that the obstacle 51 is Since the interlock is released as the vehicle is evacuated from the work passage 31, the interlock control is automatically performed in real time as the obstacle 51 enters and retracts into the work passage 31. Thus, it is possible to reliably prevent the artificial obstacle 51 from being pinched by an operation error or the like.

In the present embodiment, each of the movable shelves 25, 2
A case where the light projector 41 is provided only at one end in the longitudinal direction of the light guides 7 and 29, but the length of each of the movable shelves 25, 27 and 29 is long, and one light transmitter 41 cannot cover the entire area in the work passage 31. In the same manner, a light projector 41 is provided at the other end in the longitudinal direction of each of the movable shelves 25, 27, and 29, or the light projecting section 4 is similarly provided at an intermediate portion of each of the movable shelves 25, 27, and 29.
1 may be provided, and a predetermined assigned area in the work passage 31 may be assigned to each of the light projectors 41.

[0043]

According to the first aspect of the present invention, the obstacle detecting light emitted by the light projecting means is blocked by an obstacle such as a human body entering the work passage, and the floor in the work passage is blocked. An obstacle is detected by the determination means detecting a decrease in the amount of light received by the light receiving means caused by the shadow of the light generated on the surface. The area of the shadow of the obstacle is generally larger than the area of the cross section of the obstacle, and the influence of the shadow formed by the obstacle covers a relatively wide area around the obstacle. Even if they are arranged at wide intervals, obstacles such as the human body can be reliably detected, thereby reducing the number of light-emitting elements and light-receiving elements to be installed and adjustment work, and reducing costs. Can be planned.

Further, the presence of an obstacle is detected by receiving the irregularly reflected light of the light for obstacle detection from the floor surface by the light receiving means, so that the height and posture of the human body as the obstacle are detected. Obstacles can be reliably detected without being affected by such factors.

According to the second aspect of the present invention, the light projecting means projects light for obstruction detection from obliquely upward to the floor in the work passage substantially along the longitudinal direction of the work passage. With this configuration, when an obstacle enters the work passage, the obstacle can cause a large area of the light shadow extending in the longitudinal direction of the work passage. Thereby, the installation interval of the light receiving means can be increased to further reduce the number of light receiving means to be installed, and a single light emitting means can cover a wide area in the work passage, and the installation of the light emitting means The number can be further reduced.

According to the third aspect of the present invention, since the light subjected to the predetermined modulation is projected and received between the light projecting means and each light receiving means, the light projecting means can emit the light. An obstacle can be reliably detected without being affected by light (disturbance light) other than the light for illuminating obstacle detection.

According to the fourth aspect of the present invention, the prohibiting means prohibits the driving means from moving the movable shelf closing the work passage in response to the judging means judging that there is an obstacle. Lock is applied) and the prohibition is released (interlock is released) in response to the detection means judging that there is no obstacle, so that when the obstacle enters the work passage, The interlock can be applied automatically, and the interlock can be automatically released as obstacles move away from the work path, enabling quick and reliable interlock and release. As a result, it is possible to reliably prevent an artificial obstacle from being pinched by an operation error or the like.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall configuration of a mobile shelf facility to which a self-propelled shelf safety device according to an embodiment of the present invention is applied.

FIG. 2 is a side view of the moving shelf equipment of FIG. 1;

FIG. 3 is a perspective view showing a state in which obstacle detection is performed in the mobile shelf facility of FIG. 1;

FIG. 4 is a block diagram showing an electrical configuration of each moving shelf provided in the moving shelf facility of FIG. 1;

FIG. 5 is a diagram showing a pulse pattern when a floodlight provided in the mobile shelf equipment of FIG. 1 is intermittently turned on.

FIG. 6 is a flowchart showing interlock control of the mobile shelf equipment of FIG. 1;

FIG. 7 is a plan view showing a configuration of a conventional self-propelled shelf safety device.

[Explanation of symbols]

 21, 23 Fixed shelf 25, 27, 29 Moving shelf 31 Work passage 33 Path selection switch 35 Limit switch 40 Infrared 41 Projector 45 Floor surface 47 Light receiver 51 Obstacle 53 Shadow 61 Control unit

Claims (4)

[Claims] 1. A self-propelled shelf safety device for preventing an obstacle from being pinched in a work passage selectively formed between a plurality of movable shelves provided movably in an array direction by a predetermined driving means. It is installed at a predetermined position on each of the movable shelves, and directs light for obstacle detection toward a floor surface in the work passage so that an obstacle present in the work passage creates a shadow of the light. A plurality of light projecting means, each of which is provided along the work path on each of the movable shelves, and wherein the light emitted from the light projecting means is reflected by the floor surface in the work path. Light receiving means for receiving the reflected light; determining means for determining the presence or absence of an obstacle in the work path based on a light receiving result of the light receiving means; and in response to the determining means determining that there is an obstacle, Closing the working passage by the driving means Safety device self-propelled shelf, characterized in that it comprises a prohibiting means for prohibiting the movement of the serial moving rack, the. 2. The self-propelled vehicle according to claim 1, wherein the light projecting unit projects the light toward the floor from substantially obliquely upward along a longitudinal direction in the work passage. Shelf safety device. 3. The self-propelled shelf according to claim 1, wherein light having a predetermined modulation is transmitted and received between the light emitting means and each of the light receiving means. apparatus. 4. The prohibition unit, after prohibiting movement of the movable shelf, canceling the prohibition in response to the determination unit determining that there is no obstacle. The self-propelled shelf safety device according to any one of the above.