JP2000338259A - Regression reflection type safety and normality- verifying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser-type safety device for simultaneously verifying that no humans and objects exist and at the same time that a device is normal. SOLUTION: The laser-type safety device divides the scanning region of a laser beam into a safety verification region 14 for verifying that no humans and objects exist, a normality verification region 13 for verifying that scanning by the laser beam covers the entire region of the safety verification region, and a non-verification region 12 where no safety verification and normality verification can be made. The safety verification region and the normality verification region are provided with reflection plates 15 and 16 where regression reflectors 17 and 18 are provided with a specific width, number, or installation interval. The width, number, or installation interval of the regression reflectors that are provided at the reflection plate of the safety verification region differ from those of the regression reflectors that are provided at the reflection plate of the normal verification region. When the pattern of an electrical signal coincides with a specific normal pattern, an operation permission signal is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates not only to confirming that a human body or an object or a part thereof does not exist in a security confirmation area (security confirmation), but also to allow the apparatus to normally scan the entire security confirmation area. The present invention relates to a retroreflective type safety and normality confirmation device that also confirms the normal operation (confirmation of normality).

[0002]

2. Description of the Related Art When starting operation of a machine, it is necessary to confirm whether a human body or an object exists within the operation range of the machine. Hereinafter, this confirmation is referred to as “safety confirmation”. When confirming safety, it is common for an operator to directly observe the operating range of the machine with his / her eyes. However, due to the physiological limitations of human vision, if the operating range of the machine is wide, or if there is a blind spot from the position of the worker, it is quite difficult for the worker to confirm safety. Work.

For this reason, in a conventional mechanical device, a mirror (mirror) is provided so that a worker can indirectly check a blind spot, a plurality of workers jointly check safety, The work standard at the start of operation was determined in detail to prevent the operator from making mistakes in safety confirmation. However, human actions always involve errors, and the above-mentioned countermeasures have a problem in certainty. Therefore, recently, a device for automatically confirming the safety within the operation range of the machine by a non-contact type sensing means has been developed.

A typical example of such a device is a light beam type (infrared ray type) safety device. However, this device cannot be applied to a device having a wide operating range of a machine because the distance that infrared rays can reach is at most several meters. Therefore, recently, a safety device using laser light, which easily reaches a distant place compared to ordinary light (infrared light), has been used.

There is a safety device using a laser beam called a diffuse reflection type. In this method, a laser beam emitted from a projector is applied to a mirror surface of a mirror, and the mirror surface is rotated to diffuse the laser beam into a predetermined scanning area using a scanning device. This device determines that no human body or object exists when the laser beam does not return, and confirms safety.

[0006]

The above-mentioned diffuse reflection type laser device is indispensable for ensuring the safety of workers. However, in this system, since the laser reflected light is directly received from the human body or object with low reflectivity, the energy of the reflected light reaching the light receiver is extremely weak, and the energy from the location where the projector and light receiver are installed is extremely low. 5
There is a problem that the scanning area can be set only up to a distance of about 10 to 10 m. In addition, since the energy is weak, even small optical noise or electromagnetic noise
There was a problem that an operation permission signal was output by mistake. Further, in the above-described device, a failure (for example, the emission of the laser beam is stopped due to the failure of the light emitting device. The entire scanning area cannot be scanned due to the failure of the scanning device. The device operates normally due to changes in the light environment (such as output of an enable signal) and changes in the light environment (such as changes in the intensity of disturbance light, changes in the intensity of light emitted from the projector, and changes in the light receiving sensitivity due to dirt on the optical system). (See Table 1). In such a case, there is a problem that the worker cannot be detected even though the worker exists in the scanning area.

[0007] In order to solve the above-mentioned problems, a method of taking measures against failures by multiplexing devices and performing self-diagnosis has been implemented. However, even if such a method is adopted, since the energy of the reflected light is still weak, it is impossible to extend the scanning area to a distant place, and the problem of noise still remains. Was. In addition, these countermeasures are intended for electrical failures of the emitter / receiver and the signal processing circuit, and have no effect on the failure of the scanning device or changes in the light environment. (See Table 1). In addition, multiplexing of projectors, scanning devices, half mirrors, lenses, etc.
There is a problem that it is not realistic because it causes a cost increase.

According to the present invention for achieving the above object, a laser light is reflected not by a diffuse reflection type which is a direct reflection from a human body or an object but by a recursive reflection type which will be described later. The aim was to develop a device that could extend the scanning area to a distant place in order to obtain an extraordinarily high reflected light. Hereinafter, this device is referred to as a “retroreflective laser device”. Further, according to the present invention, it is possible to confirm not only that a human body or an object does not exist in the safety confirmation area (safety confirmation), but also to confirm that the device is scanning the entire area of the safety confirmation area normally (normal confirmation). ) Is performed simultaneously, not only when a human body or object enters the safety confirmation area, but also when the light emission of the light emitter stops, the light receiver or the signal processing circuit is electrically damaged, the scanning device fails, the light environment The purpose of this study was to develop a device that can reliably stop the output of the operation permission signal even when a change occurs. Hereinafter, this device is referred to as a "retroreflective safety and normality check device".

[0009]

According to a first aspect of the present invention, there is provided a retroreflective laser apparatus which emits laser light, applies the laser light to a mirror surface, and rotates the mirror surface by a set angle. A scanning device that diffuses the laser light into a predetermined area by causing the laser light to diffuse into a predetermined area, a reflector provided with a recursive reflector, a light receiver that converts the laser light into an electric signal, and processes the electric signal generated by the light receiver. This device is provided with a signal processing circuit, and has a configuration of such a device as means for solving the above-mentioned conventional problems.

[0010] Further, claim 1 for solving the above-mentioned problem.
The described retroreflective type safety and normality confirmation device is to provide an unconfirmed area at both ends of the area scanned by the laser beam, a normal confirmation area inside the area, and a safety confirmation area inside the area. Retroreflectors are provided at a predetermined width, number, or installation interval on the reflector provided in the normal confirmation area, and the width, number, or installation interval of the retroreflectors provided on the reflector in the safety confirmation area, and the reflection of the normal confirmation area By making the width, the number, or the installation interval of the recursive reflectors provided on the plate different, the time width, frequency or time interval of the electric signal generated from the light receiving device at the time of scanning both areas is made different, Is a device for outputting an operation permission signal when the pattern coincides with a predetermined normal pattern. It is.

Further, in order to solve the above-mentioned problem, the safety and normality confirmation apparatus of the recursive reflection type according to claim 2 generates a timing signal corresponding to a scanning time of the normal confirmation area and the scanning time of the security confirmation area. A logical operation is performed on the electric signal generated by the light receiving device and the light receiving device to perform a comparison with a predetermined normal pattern, and when the pattern matches the normal pattern, an operation permission signal is output. The configuration of such a device is used as means for solving the above-mentioned conventional problems.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a retroreflective laser device according to the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a retroreflective laser device according to the present invention. This device comprises a projector 1 for emitting laser light, a scanning device 3 for applying laser light to a mirror surface 2 and rotating the mirror surface by a set angle to diffuse the laser light into a predetermined area, and a recursive reflector 4. A reflector 5 provided with a laser beam, a condenser device 8 for condensing the laser light using a half mirror 6 and a lens 7, a light receiver 9 for converting the laser light collected by the light collector into an electric signal, and a light receiver And a signal processing circuit 10 for processing an electric signal generated by the control circuit.
In addition, as the light collecting device, only one of the half mirror and the lens, or a light collecting device other than these may be used.

The retroreflector of FIG. 1 includes a retroreflective tape or a retroreflective plate. The retroreflective device is a device in which a retroreflector 4 is provided on a reflector 5 and the light reflected from the reflector is constantly checked by a light receiver 9. This device has the advantage that when the light emitter stops emitting light due to a failure, the output signal of the light receiver is turned off, and the operation of the machine can be stopped (see Table 2). On the other hand, in the diffuse reflection type device, when the emission of the laser beam is stopped due to the failure of the projector, it is not possible to detect the presence of the worker even though it is in the scanning area. There is a problem of output (see Table 2). Therefore, in order to ensure the safety of workers, the scanning method of the laser beam must be a retro-reflection type, not a diffuse reflection type.

Next, an embodiment of the retroreflective safety and normality checking device according to the present invention will be described with reference to the drawings. FIG. 2 is a layout diagram of a safety confirmation area, a normal confirmation area, and an unconfirmed area, a reflector, and a recursive reflector according to the present invention. In this device, an unconfirmed area 1 is provided at both ends of an area (corresponding to the above-described “scanning area”) 11 scanned by a laser beam.
2A and 12B are provided, inside of which are provided normal checking regions 13A and 13B for checking that scanning by the laser beam extends over the entire safety checking region.
Safety confirmation area 1 for confirming that all or part of a human body or an object does not exist between the areas 13A and 13B.
4 are provided. Here, the unconfirmed area is provided because when the scanning of the laser beam reaches both ends of the detection area, it is necessary to reduce the scanning speed and reverse the scanning direction. This is because confirmation cannot be performed.

In this apparatus, the reflector 15 provided in the safety confirmation area and the reflector 16A provided in the normal confirmation area are provided.
And 16B are provided with a retroreflector having a predetermined pattern (predetermined width, number, or installation interval). This is because, when scanning with the laser beam, the reflectance of the laser beam at the location where the retroreflector exists and at the location where the retroreflector does not exist is significantly different. This is for outputting an electric signal having a specific time width, frequency, or time interval to the light receiving device.

Further, in this device, the pattern (width, number or installation interval) of the recursive reflectors 17 provided on the reflector in the safety confirmation area and the recursive reflectors 18A and 18B provided on the reflector in the normal confirmation area are different. The patterns (width, number or installation interval) are different. This means that the pattern (time width, frequency or time interval) of the electric signal generated from the photodetector when scanning each area is different, so that the laser beam scans either the safety confirmation area or the normal confirmation area. This is so that it can be distinguished.
The patterns (width, number or installation interval) of 18A and 18B may be the same or different.

When the normal confirmation area is scanned with the laser beam under the above-described configuration, the apparatus is normal and all or a part of a human body or an object exists in the safety confirmation area or the normal confirmation area. If not, the photodetector has P in FIG.
An ON / OFF waveform having a predetermined time width as described above is generated at a predetermined frequency and a predetermined time interval. Also,
When scanning the safety confirmation area with laser light,
An ON / OFF waveform having a predetermined time width such as Q shown in (a) occurs at a predetermined frequency and a predetermined time interval. Hereinafter, these waveforms are referred to as “normal patterns”. If this normal pattern is generated from the light receiver, it is determined that both safety and normal have been confirmed, and an operation permission signal is output.

On the other hand, when the whole or a part of the human body or the object exists in the safety confirmation area or the normal confirmation area, the output signals P and Q become abnormal patterns (DC signal) as shown in FIG. ) And deviates from the normal pattern. In addition, when the light emission of the projector stops due to a failure, when the laser beam cannot scan the entire safety confirmation area due to the failure of the scanning device, or when the light environment changes (this includes changes in the intensity of disturbance light, The output signal also deviates from the normal pattern when the intensity of the light emitted from the light projector changes, the light receiving sensitivity changes due to contamination of the optical system, etc.), or when the reflection tape shifts or becomes dirty. Therefore, at this time, the generation of the operation permission signal is stopped.

As described above, in the retroreflective safety and normality checking device according to the first aspect, not only when all or a part of the human body or the object enters the safety checking area, but also when the light emission of the projector is stopped and scanning is performed. The output of the operation permission signal can be stopped even when a failure of the steering device or a change in the light environment occurs. This is a feature not found in diffuse-reflective laser devices (including those that take measures against failures by multiplexing or self-diagnosis) or retroreflective laser devices (see Table 1).

Next, a second embodiment of the retroreflective safety and normality checking device according to the present invention will be described with reference to the drawings. FIG. 4 is a block diagram of a signal processing circuit according to the present invention. This circuit includes a timing signal generator 19, bandpass filters 20A and 20B, AND gates 21A and 2
1B. In the figure, a timing signal generator 19 outputs timing signals P, which become ON signals when scanning a normal confirmation area, a safety confirmation area, and an unconfirmed area, respectively.
This is a circuit for generating Q and R. In this circuit,
In order to generate a synchronous ON signal when scanning each area, holes 23A are formed in the face plate 22 in a positional relationship as shown in FIG.
(Light is transmitted when scanning the normal confirmation area), 23B (light is transmitted when scanning the safety confirmation area), 23C (light is transmitted when scanning the unconfirmed area), and the emitter / receiver 24 of the photoelectric sensor.
A and 25A (generate pulse P), 24B and 25B
(Generate pulse Q), 24C and 25C (Generate pulse R).

With the above configuration, when the laser beam scans the normal confirmation area, the light emitted from the light emitter 24A of the photoelectric sensor passes through the hole 23A to turn on the output signal of the light receiver 25A. I do. When the laser beam scans the safety confirmation area, the light emitted from the light emitter 24B of the photoelectric sensor passes through the hole 23B and turns on the output signal of the light receiver 25B. Further, when the laser light scans the unconfirmed area, the light emitted from the light emitter 24C of the photoelectric sensor passes through the hole 23C and turns on the output signal of the light receiver 25C. As described above, a predetermined timing signal can be generated from the light receiver 25. However, the holes 23A to 23C are configured such that light passes only when scanning of each area is started, and a timing signal can be generated by using a signal generated in the light receiver at this time as a trigger signal.

Next, the bandpass filter 20A is configured to pass only electric signals (ie, normal patterns) in a frequency band generated when scanning the normal confirmation area, and not pass other electric signals. FIG. 6 is a configuration diagram of the bandpass filter according to the present invention. In this filter, a frequency to be passed by a series resonance circuit composed of a coil 26 and a capacitor 27 is selected, and an electric signal of this frequency is transmitted to a parallel resonance circuit composed of a coil 29 and a capacitor 30 via a transformer 28, and further passed by the frequency. Is selected. Thereby, the normality confirmation signal _SN can be generated using the circuit of FIG. However, in the circuit of FIG.
And the series resonance frequency of the capacitor 27 and the parallel resonance frequency of the coil 29 and the capacitor 30 must be the same frequency.

Similarly, the bandpass filter 20B is configured to pass only electric signals (ie, normal patterns) in a frequency band generated during scanning of the safety confirmation area and not pass other electric signals. The circuit for this is the same as in FIG. This makes it possible to produce a safety check signal S _s with a filter 20B.

The normal confirmation area,
Timing signals P, Q, and R corresponding to the scanning times of the safety confirmation area and the unconfirmed area can be generated (see FIG. 7). Further, it is possible to generate a normal verification signal S _N and safety check signal S _s. Here, when P, Q, and R are generated, the logical value is 1, and when they are not generated, the logical value is 0.
S _s = 1 when there is no human body or object in the safety confirmation area, and S when it exists
_{s =} 0, _{S N =} 1 when device is normal, if the the S _{N =} 0 when not normal, operation permission signal W of the machine becomes the following equation. W = P · _SN VQ · S _s VR (1) where W is a binary logical variable indicating machine permission, W = 1 means operation permission, and W = 0 means no permission. . "." Is a logical product, and "V" is a symbol meaning a logical sum.

The circuit shown in FIG. 4 must not output an operation permission signal by mistake when a failure occurs. For this purpose, the electrical signals in the circuit are assigned to the ON signal for safety and the OFF signal for danger and failure, and the light receivers 9 and 25, the AND gate 21,
The bandpass filter 20 must be configured so as not to erroneously output an ON signal when a failure occurs. Of these, the receiver and AN
As for the D gate, an element having such properties is already commercially available. As the failure mode of the bandpass filter 20, but _{P 1, P 2, P 3} , disconnection of portions of the P ₄ in FIG. 6 is considered, the output signal from the even-band filter Izure the occurrence of these failures are It does not occur. Therefore, the circuit of FIG. 4 can be configured to not output an operation permission signal by mistake when a failure occurs.

As described above, in the retroreflective safety and normality checking device according to the second aspect, not only when all or a part of a human body or an object enters the safety checking area, but also when the light emission of the projector is stopped and the light is received. Even when the electrical failure of the detector or signal processing circuit, the failure of the scanning device, or the change of the light environment,
The output of the operation permission signal can be stopped. This includes diffuse-reflective laser devices (including those that take measures against failures by multiplexing and self-diagnosis), retro-reflective laser devices,
This is a feature not found in the retroreflective safety and normality checking device according to claim 1 (see Table 1).

The device to which the present invention can be applied can be applied to almost all devices in which all or a part of a human body or an object enters the movable range of the machine. For example, in the case of the manufacturing industry, the running range of a stacker crane provided in an automatic warehouse, the running range of an automatic guided vehicle, the internal area of a production system having a large area such as FMS and CIM, industrial robots, large robots The present invention can be applied to a movable range of a press machine, a conveyor, and the like.

Further, in the case of the construction industry, the present invention can be applied to an internal region of a building automatic construction system and a movable range of a construction machine or a construction robot. Furthermore, in the case of port cargo handling, it can be applied to the range of travel such as gantry cranes and straddle carriers. The present device can also be applied to the entry of a human body or an object (such as an automobile) into a railroad crossing, detection of a fall of a human body from a platform, and the like.

[0029]

According to the present invention, the reflection method of the laser beam is not a diffuse reflection type which is a direct reflection from a human body or an object, but a reflection plate is provided with a recursive reflector, and the reflected light from the reflector is constantly checked. By using the recursive reflection type, it is possible to obtain reflected light that is orders of magnitude higher than that of a conventional device, and thus has the effect that the scanning area can be extended to a distant place. Further, according to the present invention, it is possible to confirm not only that a human body or an object does not exist in the safety confirmation area (safety confirmation), but also to confirm that the device is scanning the entire area of the safety confirmation area normally (normal confirmation). ) Is not only performed when a human body or object enters the safety confirmation area, but also when
There is an effect that the output of the operation permission signal can be reliably stopped even when an electrical failure of the light receiving device or the signal processing circuit, a failure of the scanning device, or a change in the light environment occurs.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a retroreflective laser device according to the present invention.

FIG. 2 is a layout diagram of a safety confirmation area, a normal confirmation area, and an unconfirmed area, a reflector, and a recursive reflector according to the present invention.

FIG. 3 is a diagram showing a difference between a normal pattern signal and an abnormal pattern signal in the present invention.

FIG. 4 is a block diagram of a signal processing circuit according to the present invention.

FIG. 5 is a configuration diagram of a mechanism for generating timing signals P, Q, and R in the present invention.

FIG. 6 is a configuration diagram of a bandpass filter according to the present invention.

FIG. 7 is a relationship diagram of a timing signal, a normal pattern signal, and an abnormal pattern signal in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Floodlight 2 Mirror surface 3 Scanning device 4 Retroreflector 5 Reflector 6 Half mirror 7 Lens 8 Condenser 9 Receiver 10 Signal processing circuit 11 Scanning area 12 Unconfirmed area 13 Normal confirmation area 14 Safety confirmation area 15 Reflector (safety) 16 Reflector (installed in normal check area) 17 Retroreflector (installed in safety check area) 18 Retroreflector (installed in normal check area) 19 Timing signal generator 20 Band filter 21 AND gate 22 Face plate 23 Hole provided on face plate 24 Projector of photoelectric sensor 25 Receiver of photoelectric sensor 26 Coil 27 Capacitor 28 Transformer 29 Coil 30 Capacitor

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[Procedure amendment]

[Submission date] September 14, 1999 (1999.9.1.
4)

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Fig. 7

[Correction method] Deleted

Continuation of front page (72) Inventor Taku Hirose 1-2-2 Kanumadai, Sagamihara-shi, Kanagawa F-term in Optron Co., Ltd. 5J084 AA01 AB01 AB07 BA03 BA11 BA32 BB02 BB21 BB28 CA26 DA01 DA09 EA07

Claims (2)

[Claims] 1. A projector which emits a laser beam, a scanning device for applying the laser beam to a mirror surface and diffusing the laser beam into a predetermined area by rotating the mirror surface by a set angle, and a recursive reflector. A regression-reflection type laser device equipped with a reflector, a photodetector that converts laser light into an electric signal, and a signal processing circuit that processes the electric signal generated by the photodetector. An unconfirmed area is provided inside the normal confirmation area, and a safety confirmation area is further provided inside the unconfirmed area.
The width, number, or installation interval of the retroreflectors provided on the reflectors in the safety confirmation area is different from the width, number, or installation interval of the retroreflectors provided on the reflectors in the normal confirmation area. In this way, the time width, frequency or time interval of the electric signal generated from the photodetector during scanning of both regions is made different, and if the pattern of the electric signal matches a predetermined normal pattern, the operation permission signal is output. A regression-reflection-type safety and normality check device characterized by output. 2. The apparatus according to claim 1, wherein a timing signal corresponding to scanning of the normal confirmation area, the safety confirmation area, and the unconfirmed area is generated, and a logical operation is performed on the timing signal and an electric signal generated by the light receiver. A regression-reflection-type safety and normality checking device characterized in that a comparison with a predetermined normal pattern is performed by performing the operation, and when the pattern matches the normal pattern, an operation permission signal is output.