JP2001248789A - Safety verification system for extensive area - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem in a conventional safely verification system which determines that there is no worker by mistake to make a machine start operating against the existance of a worker in an area when the worker enters the area without removing a key. SOLUTION: This safety verification system for a extensive area comprises, the extensive area (hereinafter called 'a safety ensuring area 1') where plural workers enter and leaves, one or two and more machines 2 installed in the safety ensuring area, a fixing guard 3 provided around the safety ensuring area, an opening portion 4 provided on a part of the fixing guard so as to allow workers to enter/leave the safety ensuring area, a monitoring device 5 installed in the opening portion for observing the workers to enter/leave the safety ensuring area, key boxes 6, 7 provided on the outside and inside of the safety ensuring area and corresponding to the number of the workers, keys 8 capable of being inserted in the key boxes and corresponding to the number of the workers, a reset device 9 provided on the outside of the safety ensuring area, a control device 10 giving the machine an operation instruction as an input with information from the monitoring device and the key boxes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention automatically performs safety confirmation in a vast area where a plurality of workers enter or exit,
The present invention relates to a safety confirmation system for a large area that gives an operation command to machines.

[0002]

2. Description of the Related Art In an industrial field, if a worker accidentally contacts a dangerous moving part of a machine, a serious disaster is often caused. For this reason, in an actual site, an area in which a dangerous movable portion of the machine operates is determined in advance, and a fixed guard is provided around this area to prevent contact between the operator and the machine. However, in systems where machines occupy a vast area, such as large-scale production systems, setup, trapping,
There are many tasks such as maintenance / inspection, repair, and cleaning that must be performed by an operator entering the area inside the fixed guard.

In the work described above, a key box is often provided as a safety measure when an operator enters a large area in the fixed guard. For example, there are the following measures using this switch. 1) An opening 4 is provided in a part of the fixed guard to allow a worker to enter or leave the area. 2) Provide an external keypox adjacent to the opening. 3) Provide an internal key box directly or adjacent to the machine. 4) When the key is inserted into the external key box, it is determined that the worker has not entered the area, and the automatic (high-speed) operation of the machine becomes possible. 5) When the operator performs work such as setup, troubleshooting, maintenance / inspection, and repair inside the area, the operator removes the key inserted into the external key box and enters the area. 6) When the operator enters the area and inserts the key into the internal key box, manual (low speed) operation of the machine becomes possible. 7) If no key is inserted into either the external key box or the internal key box, the machine does not perform either automatic operation or manual operation.

[0004]

According to the above-described measures, if a worker enters the area without removing the key, the operator erroneously reads “existence” even though the worker exists in the area. Has not been performed ", and the machine starts operating. Also, in this measure,
Since the number of keys is one, there is a problem that it cannot be applied to a large area where a plurality of workers enter or leave.

Further, in this measure, even if the number of keys is provided by the number of workers so as to be able to cope with entry or exit by a plurality of workers, two or more workers remove only one key. When entering the area together, or when one worker pulls out two or more keys and exits from the area, even if there are workers in the area, erroneously " There is a problem that it is determined that it does not exist, and the machine starts operating.

[0006]

SUMMARY OF THE INVENTION A safety confirmation system for a large area according to the present invention is intended to solve the above-mentioned problems, and the means of claim 1 is a large area in which a plurality of workers enter or leave. Area (hereinafter referred to as the "security area") and one or more machines installed in the security area,
A fixed guard provided around the safety securing area, an opening provided in a part of the fixed guard to allow a worker to enter or leave the safety securing area, and a guard provided in the worker securing area. A monitoring device installed at the opening to monitor entry or exit, key boxes for the number of workers provided outside and inside the security area, and a number of workers that can be inserted into the key box , A reset device provided outside the safety ensuring area, and a control device for giving an operation command to the machine by inputting information from the monitoring device and the key box.

According to a second aspect of the present invention, in the system according to the first aspect, the number of workers in the safety ensuring area confirmed by the control device based on the information from the monitoring device and the information from the key box. The number of keys in the security area confirmed by the control device is compared with each other, and based on the result, it is determined whether the system is in a normal state, a dangerous side error or a safe side error. In the case of a dangerous error, no operation command is given to the machine in any case, and in the case of a safety error, a restart operation is performed following the operation of the reset device. And a control device for giving an operation command to the machine only when the operation is performed.

In the system according to the first aspect of the present invention, the alarm area set outside the security area and the first guard installed at the boundary between the security area and the alarm area instead of the fixed guard. A human body detecting device, a second human body detecting device or a hanging curtain installed on the outer periphery or inside of the alarm area, and an alarm device for giving a warning to an operator based on information from the second human body detecting device, When the human body detection device detects a worker, the control device does not give an operation command to the machine, and when the second human body detection device detects the worker, a control device that gives an alert to the alarm device is provided. It is characterized by.

Further, the means of claim 4 is based on claims 1 and 2
In the described system, when the number of keys in the security area confirmed by the control device is zero, an automatic operation command is given to the machine, and when the number of keys in the security area is not zero, the key is input to the internal key box. Characterized in that it comprises a control device for giving a manual operation command only to the machine into which is inserted.
The system of the notation is characterized by including a programmable controller having different types of redundancy, and a control device including a fail-safe AND operation element and a self-diagnosis device.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a safety confirmation system for a vast area according to the present invention will be described below with reference to the drawings.
FIG. 1 shows a first embodiment of the present invention. This system includes a large area (hereinafter referred to as a security area) 1 in which a plurality of workers enter or exit, one or more machines 2 installed in the security area 1, and a safety area 1 , An opening 4 provided in a part of the fixed guard to allow the worker to enter or leave the safety securing area 1, and into the worker safety securing area 1. A monitoring device 5 installed in the opening 4 for monitoring the entry or exit of the vehicle, a key box 6 for the number of workers provided outside the safety securing area 1, and a work provided in the safety securing area 1. Key boxes 7 for the number of workers and keys 8 for the number of workers that can be inserted into the key boxes
A reset device 9 provided outside the safety ensuring area 1;
A control device 10 is provided for inputting information from the monitoring device 5 and the key box 7 to give an operation command to the machine.

In the figure, the number of workers is four, but other numbers may be used. Although a mat switch is used for the monitoring device 5 in the figure, other devices such as a light beam type safety device and an ultrasonic sensor may be used. further,
Although the reset device 9 is installed at two locations in the figure, the number and installation locations of the reset devices 9 are determined in consideration of the size of the security area, blind spots, and the like so that the entire area of the vast security area can be reliably confirmed.

Next, the operation based on the above-described configuration will be described.
0 compares the number of workers N _H in the security area 1 with the number of keys N _K in the security area 1 confirmed by the control device 10 based on the information from the key boxes 6 and 7. ,
Based on this string, it is determined whether the system is in a normal state, a dangerous side error or a safe side error,
When the system is normal, an operation command is given to the machine 2; in the case of a dangerous error, no cultivation command is given to the machine 2 in any case; And a control device 10 for giving an operation command to the machine only when the restart operation is performed.

The determination at this time is as follows. 1) Normal state (when N _H = N _K ) This is the state in which the worker and the key are entering or leaving the safety assurance area 1 while maintaining a one-to-one correspondence. It is. 2) Dangerous side error (when N _H > N _K ) This means that the worker enters the security area 1 without removing the key, or two or more workers remove only one key together This occurs, for example, when the vehicle enters the security area 1 or when one worker pulls out two or more keys to leave the security area 1. In this case, even though a worker is present in the safety ensuring area 1, the machine that should be stopped cannot be stopped because it is erroneously determined to be "not present". This is called a dangerous error. 3) the safe side error (in the case of N _H <N _K) This is, or exit from secure area within the 1 in the operator does not remove the key, together disconnect two or more operators are only one of the key This occurs, for example, when the operator leaves the security area 1 or when one worker removes two or more keys and enters the security area. In this case, even though no worker exists in the safety ensuring area, the machine is erroneously determined to be "present" and the machine remains stopped. This is called a safe error.

Among the above, what is a problem in preventing occupational accidents is a dangerous mistake. Therefore, in the present invention, a safety confirmation system for preventing a dangerous error is configured as follows. 1) For all workers "Remove key 8 from external key box 6" → "Step on mat switch which is monitoring device 5 in FIG. 1 within a certain time in order of α, β, γ" → "For a certain time" The key 8 is inserted into the internal key box 7 of the machine 2 that the operator wants to move, and the operator "pulls the key 8 from the internal key box 7". Only when the leaving action of "the operator steps on the mat switch in the order of [gamma], [beta], [alpha]" → "the operator inserts the key 8 into the corresponding external key box 6 within a certain period of time" is normally performed. Give a driving instruction. 2) The worker enters and leaves the safety ensuring area only at the opening 4 where the monitoring device 5 of FIG. 1 is installed. The width of the opening 4 can be controlled by two or more workers at the same time in the safety securing area 1.
The radiation that cannot enter (for example, within 50 cm) and only one person can ride (for example, a square of 40 cm)
A mat switch β is provided. 3) Even if the key of the external key box 6 is removed, a certain time
(For example, within 10 seconds) Do not give an operation command to the machine. 4) When the worker enters the safety securing area 1 with the power of the safety confirmation system turned off, it is determined that the worker does not exist even though the worker exists in the safety securing area 1. Causes dangerous mistakes. Therefore, even after the power supply of the machine 2 is shut off, the energization is continued so that only the safety confirmation system can continue monitoring.

Next, in the case of a safety error, it is necessary to operate the reset device in order to release the state where the machine 2 is stopped. However, if you leave this operation to ordinary workers,
The safety check system will no longer be effective. Thus, in the present invention, the resetting device 9 which can be opened only by the key operator having a specific tag (key) can be opened.
The safety confirmation system was configured so that resetting could not be performed unless a switch in this device was operated. This switch is installed, for example, at two places outside the opening 4 and the safety ensuring area 1 in FIG. 1, and switches are operated in the order of the reset device 9 outside → the reset device 9 of the opening 4 within a predetermined time. If not, it is not considered as a reset operation.

Next, the key box 7 in the security confirmation area 1
When the number _NH of the keys 8 for the key 8 is zero, an automatic operation command is given to the machine 2 and the number _NH of the keys 8 in the safety ensuring area 1 is given.
If is not zero, a control device 10 is provided which gives a manual operation command only to the machine 2 in which the key 8 is inserted into the internal key box 6. The determination at this time is as follows. 1) In the case of N _H = 0 In this case, it is considered that no worker exists in the safety ensuring area 1, and an automatic operation command is given to the machine 2. This allows the machine 2 to perform high-speed operation. 2) N _H ≠ 0 In this case, it is considered that a worker is present in the safety ensuring area 1 and a manual operation command is issued only to the machine 2 in which the key 8 is inserted into the internal key box 6. give. Thus, low-speed operation can be performed during work such as troubleshooting and maintenance / inspection.

In the above-described embodiment, since the safety control becomes extremely complicated, there is no other way but to use a programmable controller (hereinafter abbreviated as "PLC"). However, the conventional PLC has a problem in that an erroneous operation command is generated when a failure occurs because control of the storage device is not fail-safe. Further, even when a failure occurs in hardware other than the storage device or when a bug is included in the control program (software), an erroneous operation command is generated.

Therefore, in the present invention, multiplexing of PLCs having different types of software and hardware (heterogeneous redundancy).
This problem has been solved by developing a system that gives an operation command to the machine 2 when the operation results of these multiplexed PLCs all match.

That is, the safety confirmation system for a large area according to the present embodiment includes a control device 10 according to the above-described embodiment in which a heterogeneous redundant program map
The problem has been solved by adding a controller, a fail-safe AND product element and a self-diagnosis device.

Further, another embodiment will be described with reference to FIG. This system uses heterogeneous redundancy (different types of C
It means redundancy by PU. (Hereinafter referred to as “diversity structure”), three types of PLCs 11 to 13, a fail-safe AND operation element 14 and a self-diagnosis device I 5, and only when all the operation results of the PLCs 11 to 13 are the same. And a control device 10 for turning on an operation command which is a signal output of the AND operation element 14.

Since the three types of PLCs 11 to 13 have different hardware structures, the three types of PLCs 11 to 13 are different.
13 is very unlikely to cause a hardware failure at the same point at the same time. Further, since the software processed on each CPU is also different, it is extremely unlikely that an operation permission signal is erroneously output due to a software bug. Further, in a system using the PLCs 11 to 13, malfunction due to an abnormality in a memory causes a problem. However, in this system, each of the CPUs 11 to 13 has a multiplexed memory, and the self-diagnosis device 15 performs Also, at the time of operation, the identity of all memories is regularly checked. Also, since the AND operation element used in this system is fail-safe,
An ON signal is not erroneously output when a failure occurs.

As described above, in the present system, the PLC hardware, software and memory
Also, it is possible to realize a fail-safe system that does not erroneously output the operation permission signal even when the AND operation element fails. In conventional fail-safe measures, a method of multiplexing the same type of CPU is generally adopted, but this method requires that the processing method of the multiplexed hardware and software is the same. Therefore, there is a disadvantage that the probability of occurrence of simultaneous multiple failures is extremely high as compared with the heterogeneous redundancy system. Therefore, in a system in which the occurrence of a failure may immediately lead to a serious disaster, such as the work by the present system, the multiplexing of hardware and software must be based on a diversity structure.

In any of the above-described embodiments, since the periphery of the safety ensuring area 1 is surrounded by the fixed guard 3, it is not easy to visually recognize the operation status of the machine 2 and the occurrence status of trouble. There was a problem. In addition, there is a problem that in the event of an emergency such as an earthquake or fire, the evacuation can only be performed through the opening 4 of the fixed guard 3.

Therefore, the present embodiment provides a safety confirmation system for a vast security area which can comprehensively solve the above problems. In the first embodiment, the alarm area 16 set outside the security area 1 and the fixed guard 3
In place of the first human body detection device 17 installed at the boundary between the safety ensuring area 1 and the alarm area 16, and the second human body detection apparatus 18 or the banner 1 installed on the outer circumference or inside the alarm area 16
9, an alarm device 20 for giving a warning to the worker based on information from the second human body detecting device 18, and a first human body detecting device 17 which does not give a driving instruction to the worker, The control device 10 for giving an alarm command to the alarm device 20 when the worker 18 detects an operator is provided, and the configuration of such a system is a means for solving the above-mentioned conventional problems.

In the above-mentioned embodiment, the light beam type safety device is used for the first and second human body detecting devices 17 and 18, but other human body detecting devices may be used. In addition, although an acoustic buzzer is installed in the alarm device 20, a rotary patrol light or the like may be used instead. The purpose of the hanging curtain 19 is to allow the worker to come into contact with the warning area 16 when the worker enters the warning area 16 so that the worker can touch the warning area 16.
This is to prevent entry into the area. For that purpose, the dimensions and the installation position are determined so as to ensure contact with the human body.

The processing in this system is as follows. 1) When the worker enters the warning area In this case, the buzzer or the patrol light of the warning device 20 is activated, or the hanging curtain 19 comes into contact with the human body, and a warning is issued so that the worker does not enter the safety ensuring area 1. give. 2) Warming when the worker enters the safety securing area If the worker enters the safety securing area 1 in spite of the above warning, the machine 2 is immediately stopped.

The present invention can be applied to almost all machinery and equipment in which a human body or a part thereof enters the safety ensuring area 1. For example, in the case of the manufacturing industry, the traveling range of a stacker crane in an automatic warehouse, the traveling range of an automatic guided vehicle, the internal area of a production system having a vast area such as FMS and CIM, industrial robots, The present invention is also applicable to a movable range of a large press machine, a conveyor, and the like.

Further, in the case of the construction industry, the present invention can be applied to an internal area of an automatic building construction system and a movable range of a construction machine or a construction robot. Further, in the case of a port cargo handling business, the present invention can be applied to a traveling range such as a gantry crane or a straddle carrier.

[0029]

As described above, according to the present invention, key boxes for the number of workers are provided inside and outside the safety securing area, and the entry of the worker into the security securing area is performed through the opening of the fixed guard. Since the monitoring device for monitoring the leaving is provided, even if a plurality of workers enter or leave the safety ensuring area, the safety of the workers can be reliably ensured.

Further, according to the present invention, it is possible to determine whether the system is in a normal state, a dangerous side error or a safe side error based on information from the monitoring device and the key box. It can realize safe control of various machines.

Further, according to the present invention, since a programmable controller having heterogeneous redundancy and a control device including a fail-safe AND operation element and a self-diagnosis device are provided, hardware (including a storage device) failure Even if a disconnection, a disconnection, a bug in a control program (software), or the like occurs, an operation command is not output erroneously.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a safety confirmation system for a large area according to the present invention.

FIG. 2 is a configuration diagram of a heterogeneous redundant control device according to the present invention.

FIG. 3 is a configuration diagram of a system in which a fixed guard is replaced with a human body detection device in the system of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Safety ensuring area 2 Machine 3 Fixed guard 4 Opening 5 Monitoring device 6 External key box 7 Internal key box 8 Key 9 Reset device 10 Control device 11 PLC 12 PLC 13 PLC 14 Logical operation element 15 Self-diagnosis device 16 Alarm area 17 first human body detecting device 18 second human body detecting device 19 banner 20 alarm device

Continued on the front page (72) Inventor Ritsuo Sanpeira 3-20-5 Shin-Yokohama 3-chome, Kohoku-ku, Yokohama-shi, Kanagawa 7th floor, inside Pilz Japan K.K.

Claims (5)

[Claims] A large area (hereinafter, referred to as a "security area") in which a plurality of workers enter or leave, one or more machines installed in the security area, and a safety area. A fixed guard provided in the periphery, an opening provided in a part of the fixed guard to allow the worker to enter or leave the safety ensuring area, and a worker entering or leaving the safety securing area. A monitoring device installed in the opening for monitoring, a key box for the number of workers provided outside and inside the safety ensuring area, a key for the number of workers that can be inserted into the key box, A safety confirmation system for a large area, comprising: a reset device provided outside a safety ensuring region; and a control device for giving an operation command to a machine by inputting information from a monitoring device and a key box. 2. The system according to claim 1, wherein the number of workers in the safety ensuring area confirmed by the control device based on information from the monitoring device, and the safety confirmed by the control device based on information from the key box. The number of keys in the reserved area is compared, and based on the result, it is determined whether the system is normal, dangerous error, or safe error. In the case of a dangerous error, no operation command is given to the machine in any case, and in the case of a safe error, the machine must be restarted following the reset device operation. A safety confirmation system for a large area, comprising: a control device for giving an operation command to the vehicle. 3. The system according to claim 1, wherein an alarm area set outside the security area, a first human body detecting device installed at a boundary between the security area and the alarm area instead of the fixed guard, and an alarm. A second human body detection device or a hanging curtain installed on the outer periphery or inside of the area, an alarm device for giving a warning to the worker based on information from the second human body detection device, and a first human body detection device for the worker A control device that does not give an operation command to the machine when it is detected, and has a control device that gives an alert to the alarm device when the second human body detection device detects an operator. Safety confirmation system. 4. The system according to claim 1, wherein when the number of keys in the security area confirmed by the control device is zero, an automatic operation command is given to the machine, and the number of keys in the security area is controlled. A safety confirmation system for a large area, comprising a control device for giving a manual operation command only to a machine whose key is inserted into the internal key box when is not zero. 5. The system according to claim 1, further comprising a programmable controller having different types of redundancy, and a control device including a fail-safe AND operation element and a self-diagnosis device. Safety confirmation system for large areas.