JP2020187031A - Optical detector - Google Patents

Abstract

To realize an optical detector constructed in two stages, with two light projection means and two light receiving means arranged in rows one above another, with which one stage detection is possible without complicating the shape of pulse signal light emitted from a light projector.SOLUTION: An optical detector is configured with a light projector equipped with one or a plurality of light projection units, and a light receiver equipped with one or a plurality of light receiving units corresponding to the light projection units, the light projector and light receiver including a synchronizing signal input unit. The light projector accepts input of the PPS signal of a GNSS receiver module from the synchronizing signal input unit and takes it as a synchronizing signal, with each light projection unit projecting a signal at different timing. The light receiver accepts input of the PPS signal of a GNSS receiver module from the synchronizing signal input unit and takes it as a synchronizing signal, and takes a signal received at the same timing as each light projection unit which each light receiving unit corresponds to, as a received light signal, and outputs a detection signal when the received light signal of one of the light receiving units is discontinued for a duration longer than a first set time.SELECTED DRAWING: Figure 1

Description

The present invention relates to a light beam type detection device including a floodlight and a light receiver, and more particularly to a technique for realizing a highly reliable device that reliably detects the passage of a human being.

Conventionally, as a light beam type detection device of this type used for the purpose of detecting an intruder, a light projector having two light emitting parts and a light receiving part having two light receiving parts are used. There is a form in which they are installed facing each other with a warning section in between. A human being (intruder) passing through the caution section blocks the light beam emitted from the floodlight, and the receiver detects this state and outputs an intruder detection signal. The two light emitting parts and the two light receiving parts are arranged one above the other in a two-stage configuration, and when it is required to detect both the case where a human runs through the caution section and the case where the person crawls past. It is required to detect the blocking of the upper ray and the blocking of the lower ray independently in one stage.

In order to realize such a detection device, a method of alternately emitting pulse signal light from two light emitting units or a light receiving unit having two light receiving parts by emitting different pulse signal lights from two light emitting parts. (See, for example, Patent Document 1 and Patent Document 2), a method is adopted in which only the pulse signal light of the corresponding light projecting unit is received.

Further, the projector and the receiver are connected by a synchronous signal transmission line, and the pulsed light emitted by the two projectors on the projector side and the pulsed light received by the receiver having the two receivers on the receiver side. A method of receiving only the corresponding pulsed light by matching the timing with the above has also been used (see, for example, Patent Document 3).

Japanese Unexamined Patent Publication No. 2004-355170 Japanese Unexamined Patent Publication No. 09-297184 Japanese Unexamined Patent Publication No. 2004-186744

However, each of the above-mentioned conventional examples has the following problems.
In the method of alternately emitting pulse signal light from two light projecting units, when a plurality of light beam type detection devices are installed above and below, pulse signal light from a plurality of light emitting units is input to the light receiving unit. There is a problem that if synchronization is not performed between each floodlight, between each receiver, or between a floodlight and a receiver using a synchronization signal transmission line, interference may occur and a false report or a false report may occur.

In the method of emitting different pulse signal lights from the two light projecting units and identifying the pulse signal light on the receiver side, the type of pulse signal assigned in consideration of mutual interference with other adjacent ray-type detectors is used. When the number increases, it becomes necessary to increase the signal discrimination ability on the receiver side, and there is a problem that the circuit configuration becomes complicated accordingly.
Further, when a pulse code is used, there is a problem that it takes time to identify the code and the detection response speed becomes long.

The method of connecting the floodlight and the receiver with a synchronous signal transmission line has a problem that the labor and cost of burying the synchronous signal transmission line increase.

In order to solve the above problems, the light beam type detection device of the present invention has a floodlight having one or more light projectors and a light receiver having one or more light receivers corresponding to the light projectors. The floodlight and the receiver are equipped with a synchronous signal input unit, and an external GNSS receiving module that generates a PPS (Pulse Per Second) signal from a standard time acquired by a GNSS (Global Navigation Satellite System) signal is attached. Alternatively, the projector has a structure that can be built in, and the projector inputs the PPS signal of the GNSS receiving module from the synchronization signal input unit to obtain a synchronization signal, and each projection unit projects signals at different timings to the receiver. Is to input the PPS signal of the GNSS receiving module from the synchronization signal input unit and use it as a synchronization signal, and use a signal received by each light receiving unit at the same timing as the corresponding light projecting unit as a light receiving signal. It is characterized in that a detection signal is output when the received light signal of the unit is interrupted for a longer time than a preset first set time.

According to the present invention, it is possible to realize a ray-type detection device capable of detecting only one stage without making the pulse signal light emitted from the floodlight into a complicated form, and a plurality of light-ray detection devices can be provided one above the other. Even if it is installed, it does not interfere, and false alarms and false alarms can be reduced compared to conventional ray-type detectors.
Moreover, since it is not necessary to identify the code of the pulse signal, a short detection response speed can be set.
Further, the same signal processing can be performed regardless of whether only the pulse signal from one light emitting unit is input to the light receiving unit or the pulse signal is input from a plurality of light emitting units. There is no need to set complicated conditions for signal processing.
Further, since it is not necessary to connect the floodlight and the receiver with a synchronous signal transmission line, it is possible to suppress an increase in wiring work and wiring cost. In addition, the pulse signal light emitted from the floodlight is not complicated and simple, and can be realized with a simple circuit configuration, so that the current can be reduced. The low current makes it possible to drive the battery, and it does not require a line for transmitting synchronous signals, so it can be used as a portable type that can change the caution area.

It is a block diagram of the 1st Embodiment of the ray type detection apparatus of this invention. It is a time chart of the light projection timing and the light reception timing of the first embodiment of the ray type detection device of the present invention. It is a figure which showed the state which four light ray type detection devices were installed up and down in the 1st Embodiment. It is a figure which showed the state which four light ray type detection devices were installed up and down in the 1st Embodiment. In the first embodiment, eight light ray type detection devices are used, and a warning zone is set linearly. In the first embodiment, eight light ray type detection devices are used, and a warning zone is set linearly. It is a block diagram of the 2nd Embodiment of the ray type detection apparatus of this invention.

FIG. 1 is a block diagram of the first embodiment of the light ray type detection device of the present invention, and FIG. 2 is a time chart of the light projection timing and the light reception timing of the first embodiment of the light ray type detection device of the present invention. ..
The light ray type detection device is composed of a floodlight 100 and a receiver 200, and the GNSS module 300 is externally or built in the floodlight 100 and the receiver 200, and the synchronization signal input unit of the floodlight 100 and the receiver 200. A GNSS receiving module is connected to the synchronization signal input unit. The GNSS receiving module generates a PPS (Pulse Per Second) signal from a standard time acquired by a GNSS (Global Navigation Satellite System) signal, and uses the PPS signal as a synchronization signal in the synchronization signal input unit of the floodlight 100 and the receiver 200. It is input to the synchronization signal input section.

The floodlight 100 generates a pulse signal from the floodlight signal generation unit 104 at a light projection timing described later based on the synchronization signal input from the synchronization signal input unit 103, and emits a pulse signal light based on the pulse signal. A unit 101 and a light projecting unit 102 are provided, and a light projecting timing setting switch 105 for setting the timing of the pulse signal light of the light projecting unit 101 and the light projecting unit 102 is provided. The light projecting unit 101 and the light projecting unit 102 are composed of a light emitting element such as an infrared LED and an optical system such as a parabolic reflector, and efficiently emit pulse signal light toward a receiver.

The projection timing will be described with reference to FIG.
In the floodlight 100, the PPS signal input from the GNSS receiving module is 1 PPS, the flooding timings that can be set are eight types of timings A to H, the PPS signal is input every second, and the floodlight signal generator is PPS. The timings A to H, which have different timings, are measured based on the signal.

Using the PPS signal as a synchronization signal, the timing measurement of the floodlight pulse is started. Synchronized with the input of the PPS signal, the timing of the first projection pulse of timing A is set. The timing of the first projection pulse of timing B is after time T / 8 after the PPS signal is input, the timing of the first projection pulse of timing C is after that time T / 8, and so on. Measure the timing of the light projection pulse. The timings A to H are set to the period T, and the measurement is remeasured each time a PPS signal is input. From the input of the PPS signal to the input of the next PPS signal, the time is measured by the self-oscillation of the floodlight, and the projection timing of the period T is continuously measured. As shown in FIG. 2, the timings A to H are different timings.

The pulse signal of the timing set by the light projecting timing setting switch 105 is transmitted to the light projecting unit 101 and the light projecting unit 102, and the light projecting unit 101 and the light projecting unit 102 emit the pulse signal light. The pulse signal lights of the light projecting unit 101 and the light projecting unit 102 have different timings. For example, in setting 1, the light projecting unit 101 has timing A, the light projecting unit 102 has timing B, and in setting 2, the light projecting unit 101 has timing C. The light projecting unit 102 can be set to timing D, the setting 3 allows the light projecting unit 101 to set timing E, the light projecting unit 102 to set timing F, and the setting 4 allows the light projecting unit 101 to set timing G and the light projecting unit 102 to set timing H. Keep it.

In the light receiver 200, the light receiving unit 201 is in the vertical position corresponding to the light projecting unit 101, and the light receiving unit 202 is in the vertical position corresponding to the light projecting unit 102. Each light receiving unit is composed of the same optical system as the light projecting unit, a light receiving means composed of a photoelectric conversion element such as a phototransistor, and a signal amplification unit. Pulse signal light emitted from the floodlight enters the two light receiving units, and the photoelectrically converted electric signal is amplified by the signal amplification unit and input to the signal processing unit 204.

The light receiving timing setting switch 205 is set to the same timing as the light emitting timing of the corresponding light emitting unit, and the signal processing unit 204 sets the light receiving timing to be described later based on the synchronization signal input from the synchronization signal input unit 203. When the electric signal input from each light receiving unit is the same as the light emitting timing of the corresponding light emitting unit, the light receiving signal is used.

The light receiving timing will be described with reference to FIG.
In the light receiver 200, the PPS signal input from the GNSS receiving module is 1 PPS, the light receiving timing is 8 types of timings A to H which are the same as the light projection timing, the PPS signal is input every second, and the signal processing unit is PPS. Timings A to H with different timings are measured based on the signal.

Using the PPS signal as a synchronization signal, timing measurement of the received signal is started. Synchronized with the input of the PPS signal, the timing of the first received signal at timing A is set. The timing of the first received signal at timing B is time T / 8 after the PPS signal is input, the timing of the first received signal at timing C is after that time T / 8, and so on. Measure the timing of the signal. The timings A to H are set to the period T, and the measurement is remeasured each time a PPS signal is input. From the input of the PPS signal to the input of the next PPS signal, the time is measured by the self-oscillation of the light receiver, and the light receiving timing of the period T is continuously measured. As shown in FIG. 2, the timings A to H are different timings.

The light receiving timing setting switch 205 sets the light receiving timing corresponding to the floodlight 100. The light receiving timings of the light receiving unit 201 and the light receiving unit 202 are different. For example, in setting 1, the light receiving unit 201 has timing A and the light receiving unit 202 has timing B, and in setting 2, the light receiving unit 201 has timing C and the light receiving unit 202 has timing D. In setting 3, the light receiving unit 201 can be set to timing E, the light receiving unit 202 can be set to timing F, and in setting 4, the light receiving unit 201 can be set to timing G and the light receiving unit 202 can be set to timing H.

When the GNSS signal to the GNSS receiving module 300 is interrupted, the floodlight 100 and the receiver 200 are capable of holding the synchronization signal for a certain period of time by self-oscillation or self-oscillation of the GNSS module 300. By doing so, even if the GNSS signal is interrupted due to environmental changes such as external noise and weather, the operation of the light ray type detection device can be maintained for a certain period of time.

When the light receiving signal based on any of the light receiving parts is interrupted for a longer time than the preset first set time, and when the light receiving signal based on all the light receiving parts is interrupted for a longer time than the preset second set time. Sometimes a signal is sent to the output unit 206. When a signal is input from the signal processing unit 204, the output unit 206 outputs a signal that detects an object to the outside in the form of a relay contact signal or the like.

The light projecting unit 101 and the light projecting unit 102 of the floodlight are arranged vertically with a distance of about 20 cm. The pulse signal light emitted by the light projecting unit spreads in a conical shape, and when the distance between the light projector and the light receiver is 100 m, the pulse signal light has a wide area of 2 m to 3 m in diameter before reaching the light receiver. The two light receiving parts on the receiver side are also shaped to be separated in the vertical direction by about 20 cm in the same manner as the light projecting part. Therefore, the pulse signal light emitted from the floodlight enters the two light receiving units regardless of the upper or lower stage.

However, the light projecting pulse and the light receiving signal are synchronized with the PPS signal from the GNSS standard time, and the light projecting timing and the light receiving timing of the light projecting unit 101 and the light receiving unit 201, and the light emitting unit 102 and the light receiving unit 202 do not deviate from each other. Therefore, it becomes a highly reliable ray-type detection device without interference.

Further, the first set time is set to be longer than the second set time. By doing so, it is possible to reliably detect both the case where both the upper and lower tiers where humans run through are blocked quickly and the case where only one tier where humans crawl past is blocked slowly. It is a highly reliable ray detector that does not detect the passage of small objects that block only one step quickly. Further, if the first set time can be changed to, for example, 100 msec to 500 msec, and the second set time can be changed to, for example, 35 msec to 500 msec, it is optimal according to the conditions of the actual installation location. The detection signal output condition can be set.

FIG. 3 shows a state in which four light ray type detection devices are installed vertically in the first embodiment.
The floodlight 110 sets the light-emitting timing of the light-emitting unit 111 to timing A with the timing setting switch, and sets the light-emitting timing of the light-emitting unit 112 to timing B with the timing setting switch. Is set to timing A, and the light receiving timing of the light receiving unit 212 is set to timing B.

The floodlight 120 sets the light-emitting timing of the light-emitting unit 121 to timing C with the timing setting switch, and sets the light-emitting timing of the light-emitting unit 122 to timing D with the timing setting switch. Is set to the timing C, and the light receiving timing of the light receiving unit 222 is set to the timing D.

The floodlight 130 sets the light-emitting timing of the light-emitting unit 131 to timing E with the timing setting switch, and sets the light-emitting timing of the light-emitting unit 132 to timing F with the timing setting switch. Is set to timing E, and the light receiving timing of the light receiving unit 232 is set to timing F.

The floodlight 140 sets the light-emitting timing of the light-emitting unit 141 to timing G and the light-emitting timing of the light-emitting unit 142 to timing H with the timing setting switch, and the light-receiving unit 240 uses the timing setting switch to set the light-receiving timing of the light-receiving unit 241. Is set to the timing G, and the light receiving timing of the light receiving unit 242 is set to the timing H.

In the light beam type detection device, the projector and the receiver may be installed several hundred meters apart, and the pulse signal light from the projector that does not correspond to the receiver may be input. By setting different timings for each light emitting unit and light receiving unit, even if pulse signal light from a light emitting unit that does not correspond to each light receiving unit is input, a pulse signal from the corresponding light emitting unit is input. Only light can be identified as a received signal.

By installing a plurality of light beam type detection devices of the present invention in the vertical direction as shown in the installation state of FIG. 3, a long warning area can be realized in the vertical direction, and a detection signal is output if any one of them is shielded from light. It is possible to demonstrate highly reliable detection performance.

Further, although the GNSS receiving module 300 is built in each of the floodlights and receivers in FIG. 3, one GNSS receiving module 300 may be shared by a plurality of floodlights or a plurality of receivers as shown in FIG. By sharing the GNSS receiving module 300, the number of GNSS modules used can be reduced, and the cost and power consumption can be reduced.

Further, in FIGS. 3 and 4, four light beam detectors were installed above and below, with a floodlight on the left and a receiver on the right, but four more ray-type detectors were installed on the right and the receiver on the left. It is possible to install up to a total of 8 units above and below.

FIG. 5 is a diagram in which eight light ray type detection devices are used in the first embodiment and a warning zone is linearly set. FIG. 5 (1) is a side view, and FIG. 5 (2) is a top view.

In the floodlights 110 and 110', the light projection timings of the light projectors 111 and 111'are set to timing A and the light projection timings of the light projectors 112 and 112' are set to timing B by the timing setting switch, and the light receivers 210 and 210' Set the light receiving timing of the light receiving units 211 and 211'at the timing A and the light receiving timing of the light receiving unit 212 at the timing B with the timing setting switch.

The floodlights 120 and 120'set the light projection timing of the light projectors 121 and 121'to the timing C and the light projection timing of the light projectors 122 and 122' to the timing D by the timing setting switch, and the light receivers 220 and 220' Set the light receiving timing of the light receiving units 221 and 221'to the timing C and the light receiving timing of the light receiving units 222 and 222'to the timing D by the timing setting switch.

The floodlights 130 and 130'set the light throwing timing of the light projecting units 131 and 131'to the timing E and the light projecting timing of the light projecting units 132 and 132' to the timing F with the timing setting switch, and the light receivers 230 and 230' Uses the timing setting switch to set the light receiving timing of the light receiving units 231 and 231'to the timing E and the light receiving timing of the light receiving units 232 and 232' to the timing F.

The projectors 140 and 140'set the projection timing of the projectors 141 and 141'to the timing G and the projection timing of the projectors 142 and 142' to the timing H by the timing setting switch, and the receivers 240 and 240' Set the light receiving timing of the light receiving units 241 and 241'to the timing G and the light receiving timing of the light receiving units 242 and 242'to the timing H by the timing setting switch.

As in the case of FIG. 3, in the light beam type detection device, the projector and the receiver may be installed several hundred meters apart, and the pulse signal light from the projector that does not correspond to the receiver is input. However, by setting different timings for each light emitting unit and light receiving unit as shown in FIG. 5, even if pulse signal light from a light emitting unit that does not correspond to each light receiving unit is input, it can be handled. Only the pulse signal light from the light projecting unit can be identified as the received signal.

By linearly installing a plurality of light beam type detection devices of the present invention as shown in the installation state of FIG. 5, a long-distance warning area can be realized, and if any one of them is shielded from light, a detection signal is transmitted. It is possible to demonstrate highly reliable detection performance for output.

Further, although the GNSS receiving module 300 is built in each of the floodlights and receivers in FIG. 5, one GNSS receiving module 300 may be shared by a plurality of floodlights or a plurality of receivers as shown in FIG. By sharing the GNSS receiving module 300, the number of GNSS modules used can be reduced, and the cost and power consumption can be reduced.

Further, in the first embodiment, the pulse signal light emitted from the light projecting unit is a single-modulated signal, but a double-modulated pulse signal light in which the carrier wave is amplitude-modulated based on the pulse signal may be used. FIG. 7 is a block diagram of the light beam type detection device of the present invention using double-modulated pulse signal light instead of single-modulated pulse signal light emitted from the light projecting unit as the second embodiment. The frequency changeover switch 106 can be used to switch the frequency of the carrier wave to be projected, and the frequency changeover switch 207 can be used to switch the frequency of the carrier wave determined to be a received signal.

In the second embodiment, by using the double-modulated pulse signal light, the discrimination of the signal from noise due to disturbance light or the like is improved. Further, by changing the frequency of the pulse signal, it is possible to further prevent false alarms and false alarms due to interference between the plurality of detection devices. Further, not only the frequency of the carrier wave but also the frequency of the signal wave may be switched by the frequency changeover switch at the same time, and the frequency changeover switch of the carrier wave and the signal wave may be provided separately.

In the first embodiment and the second embodiment, two light emitting parts and two light receiving parts are used, but the number may be one or three or more, and the number is not limited. In addition, although the timing is set to 8 types, the number of types is not limited.

Further, the light ray type detection device of the present invention may be battery-powered, and the light ray type detection device and the battery may be attached to a tripod to be portable. By making it portable, it will be possible to install it in places that require temporary caution, such as event venues and campsites of mobile units of the Self-Defense Forces, and there will be a synchronization signal line between the floodlight and the receiver. Since it is unnecessary, it can be installed in a short time. Further, even when the portable type is used, a plurality of light ray type detection devices may be installed above and below.

In the first embodiment and the second embodiment described above, one output unit is used, but when the light receiving signal based on one of the light receiving units is interrupted for a longer time than the preset first set time. An output unit may be provided at each time when the light receiving signal based on all the light receiving units is interrupted for a longer time than the preset second set time, and as three output units of the output combined with each output. May be good.

Although the embodiments of the present invention have been described above, the above-described embodiments are presented as examples, and the scope of the invention is not limited to this, and can be implemented in various other embodiments. It is included in the scope of the invention described in the claims and the equivalent scope thereof.

100 ... Floodlight 101, 102 ... Floodlight 103 ... Synchronous signal input unit 104 ... Floodlight signal generator 105 ... Floodlight timing setting switch 200 ... Receiver 201, 202 ...・ ・ Light receiving unit 203 ・ ・ ・ Synchronous signal input unit 204 ・ ・ ・ Signal processing unit 205 ・ ・ ・ Light receiving timing setting switch 206 ・ ・ ・ Output unit 300 ・ ・ ・ GNSS receiving module

Claims (4)

In a light ray type detection device having a floodlight having one or more light projectors and a light receiver having one or more light receivers corresponding to the light projectors.
The floodlight and the receiver are provided with a synchronous signal input unit, and have a structure in which a GNSS receiver module that generates a PPS (Pulse Per Second) signal from a standard time acquired by a GNSS (Global Navigation Satellite System) signal can be externally or built-in. ,
The floodlight inputs the PPS signal of the GNSS receiving module from the synchronization signal input unit to obtain a synchronization signal, and each floodlight unit projects a pulse signal at different timings.
The receiver receives the PPS signal of the GNSS receiving module from the synchronization signal input unit as a synchronization signal, and receives a signal received by each light receiving unit at the same timing as the corresponding light projecting unit as a light receiving signal. A ray-type detection device that outputs a detection signal when a light-receiving signal based on the light-receiving unit is interrupted for a longer time than a preset first set time. The light beam type detection device according to claim 1, wherein the floodlight and the receiver hold a synchronization signal for a certain period of time by self-oscillation or self-oscillation of the GNSS module when the GNSS signal to the GNSS receiving module is interrupted. The light receiver outputs a detection signal even when the light receiving signals based on all the light receiving units are interrupted for a longer time than the preset second set time, and the first set time is the second set time. The light beam type detection device according to claim 1 or 2, which has the above length. The light beam type detection device according to any one of claims 1 to 3, which is attached to a tripod and is battery-powered and portable.

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