JP2999345B2 - Human body detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects the presence or absence of a human body in a predetermined detection space based on the outputs of a plurality of different types of detectors. The present invention relates to a human body detection device that can be used as a start switch for controlling opening and closing of a door.

[0002]

2. Description of the Related Art Conventionally, a detector (sensor) for detecting a human body
There are passive far-infrared sensors that use fluctuations in the radiated far-infrared light flux based on the temperature difference between the background and the human body, and active near-infrared sensors that project near-infrared rays to detect changes in the amount of reflected light from an object. Exists. However, the sensitivity of the sensor is changed due to a change in the ambient temperature, or the detection of a small animal near the sensor installation position is detected similarly to the human body. It was not suitable as a sensor.

[0003] Therefore, a human body detecting device combining the above-mentioned sensor with a microwave sensor or an ultrasonic sensor having different detecting means has been devised. Microwave sensors detect the human body using the Doppler effect of radio waves, while ultrasonic sensors detect the human body from the time it takes for the emitted ultrasonic pulse to reflect off the object and return. Both have completely different human body detection principles from the above-mentioned passive far-infrared sensor and active near-infrared sensor, and can compensate for each other's drawbacks and improve the detection accuracy of the human body.

A conventional human body detection device of this kind has a configuration as shown in FIG. 6 or FIG. The one in FIG.
For example, an output signal of a first detector (1) composed of a passive far-infrared sensor is amplified, waveform-shaped and rectified by a pre-processing circuit (not shown), and then output by a first comparison circuit (5). Are compared with the reference voltage (3) of
The output signal level of the first detector is equal to the first reference voltage (3)
If it is larger than the threshold value, a detection signal is output from the first comparison circuit (5). On the other hand, the output signal of the second detector (2) composed of, for example, a microwave sensor is similarly amplified, waveform-shaped and rectified by a pre-processing circuit (not shown), and then output by the second comparison circuit (6). The second reference voltage (4) is compared with a threshold value, and the output signal level of the second detector is equal to the second reference voltage.
Is higher than the reference voltage (4), a detection signal is output from the second comparison circuit (6). Then, in the logic synthesizing circuit (7) composed of an AND gate, the AND of each output of the two comparing circuits (5) and (6) is taken, and the detection signals are simultaneously output from the two comparing circuits (5) and (6). Only at the time, a human body detection signal of a predetermined time length is output from the logic synthesis circuit (7) via the timer circuit (8). FIG. 8 shows a detection range of the human body detection device when the passive far-infrared sensor is used as the first detector (1) and the microwave sensor is used as the second detector (2). Both detectors (1),
The detection range based on the output signal level in (2) is a portion surrounded by a dashed line in the figure, where the broken line position in the figure is the value of each of the reference voltages (3) and (4).

On the other hand, FIG. 7 shows a second detector (2).
Changes in the level of the output signal of the first comparator circuit (5)
Are different from those in FIG. 6 in that the threshold value is changed, and the other components are the same as those in FIG. 6, and therefore, the same components as those in FIG. Accordingly, the detection range based on the output signals of the two detectors (1) and (2) is such that the width in the left-right direction of the portion surrounded by the dashed line in FIG. 8 is the level of the output signal of the second detector (2). It will expand and contract according to the change.

[0006]

By the way, the output signal levels of the two detectors (1) and (2) depend not only on the detection of the human body but also on various factors. FIG. 9 shows a distribution state of a change caused by various factors of the output signal levels of the two detectors (1) and (2) in the human body detection device having the same configuration as that of FIG. ) Indicates a change range of both output signal levels due to human body detection, and similarly, (B) indicates a change range of small animals such as dogs and cats,
(C) shows a change range due to pyroelectric element noise of the passive far-infrared sensor, (D) shows a change range due to radio wave noise of the microwave sensor, and (B) to (D) show signals which must not be detected. It is.

However, as can be seen from a comparison between the detection range of the human body of the apparatus shown in FIG. 6 shown by a dashed line in FIG. Because there is a large deviation, when both output signal levels due to the human body detection are low as in the lower left part of the figure in the change range (A), the human body detection signal is output despite the presence of the human body. However, when applied to a security alarm device, for example, a so-called "unreported" causes a very serious inconvenience for the device.

On the other hand, if the pyroelectric element noise of the first detector (1) is large and the radio wave noise of the second detector (2) is large coincidentally, or if the first detector (1) If the radio noise of the second detector (2) becomes large while 1) is detecting a small animal at a high level due to the environmental conditions at that time, the two comparison circuits (5) , (6) output a detection signal, and the logic synthesis circuit (7) removes the AND, and the human body detection signal is erroneously output. Therefore, for example, when the present invention is applied to a security alarm device, it is a so-called “false alarm”, which causes a great deal of trouble to the neighborhood.

The device shown in FIG. 7 has the same problem as the device shown in FIG. 6 except that the so-called "unreported rate" and "false report rate" are slightly improved. Moreover, the distribution of changes due to various factors in the output signal levels of the two detectors (1) and (2) as shown in FIG. 9 is not uniform because the environmental conditions differ depending on the installation location of the device. If the detection range shown in FIG. 8 is constant, the above-mentioned drawbacks will become more prominent.

Accordingly, the present invention provides a human body detecting device capable of detecting only a human body with high accuracy regardless of a difference in environmental conditions depending on an installation location, a change in an output signal level of each detector due to various factors, and the like. This is a technical issue.

[0011]

According to the present invention, as a technical means for achieving the above object, a human body detecting device is constituted as follows. That is, a plurality of detectors having different human body detecting means, A / D converting means for converting an output signal of each of the detectors into a digital signal, and coordinates in which the levels of the respective digital signals are opposed to each other. A table in which "1" is set only in the coordinates of the area corresponding to the signal level distribution of each detector when only the human body is detected and "0" is set in the coordinates of the other areas as condition data. A condition data memory stored in advance, a condition comparing means for comparing and determining whether or not the level of each digital signal matches "1" in the table of the condition data memory; And a time-series comparison unit that outputs a human body detection signal only when it is determined that the result is continuously output the set number of times in the time-series condition data. There.

[0012]

The table of condition data has an area corresponding to the distribution of the signal level of each detector when only the human body corresponding to the installation location is detected at the coordinates where the levels of the output signals of the respective detectors are opposed to each other. Is a table in which “1” is set only for the coordinates of “1”, and almost no human body detection leakage occurs. In addition, for example, when the first detector including a passive far-infrared sensor detects a small animal at a high level and the radio noise of the second detector including a microwave sensor increases, Can be clearly distinguished.

Further, even if the pyroelectric element noise and the radio wave noise coincidentally increase simultaneously and the judgment result of the coincidence is output from the condition comparing means, it is determined that the coincidence is continued for a predetermined number of times set in the time series condition data. Since the human body detection signal is not output unless the determination result is obtained, the above-mentioned noise disappears instantaneously, so that erroneous detection can be reliably prevented and the human body can be detected with high accuracy.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a block configuration of one embodiment of the present invention. In this embodiment, a first detector (1) and a second detector (2) are each a passive remote controller similar to FIG. 6 and FIG. The case where an infrared sensor and a microwave sensor are used will be described below. The output signals of the two detectors (1) and (2) are amplified, waveform-shaped and rectified by individual pre-processing circuits (9) and (10), respectively, and then processed by a microcomputer (11). Is done.

In the microcomputer (11), the output signals of the two detectors (1) and (2) are switched by the switching means (S
The signal is alternately introduced into the A / D conversion unit (12) according to W), converted into a digital signal, and then input to the central processing unit (13). The central processing unit (13) processes output signals of the two detectors (1) and (2) input as digital signals in accordance with a program stored in a program memory (14). That is, the output signals of the two detectors (1) and (2) are compared with the data table of the condition data memory (15) to make a judgment, and the judgment result is stored in the time series condition data memory (16). And when it is determined that a human body is detected based on the comparison result, the timer (1)
For a predetermined time based on the timing of 7), the I / O port (1
8) A human body detection signal is output to an external device via the above.

FIG. 2 is a functional block diagram of the software configuration shown in FIG. 1. In FIG. 2, components equivalent to those in FIG. 1 are denoted by the same reference numerals. The pre-processing circuit (9) in FIG.
(10) is omitted and not shown in order to simplify the description and facilitate understanding. The function of this functional block diagram will be described with reference to the flowchart of FIG. First, as shown in FIG. 1, when the switching means (SW) is switched and connected to the first detector (1) side,
Of the detector (1) of the A / D converter (12) with respect to the analog signal pre-processed by the pre-processing circuit (9).
The conversion into a digital signal by the / D conversion means (12a) is started (step S1), and after the conversion is completed (step S2), when it is determined that the conversion is completed, the switching means (SW) is turned on. After switching to the second detector (2) (step S3), the N-bit digital signal data obtained by converting the output signal of the first detector (1) is stored in a predetermined area (M1) of the RAM. ) (Step S4).

Subsequently, the A / D converter (12b) of the A / D converter (12) converts the output signal of the second detector (2) to the analog signal preprocessed by the preprocessing circuit (10). Conversion to a digital signal is started (step S
5) Wait for this conversion to end (step S
6) When it is determined that the conversion is completed, the switching means (S
After W) is switched to the first detector (1) side (step S7), the data of the M-bit digital signal obtained by converting the output signal of the second detector (2) is stored in a predetermined RAM. The data is written to the area (M2) (step S8).

Next, the data written in M1 and M2 is searched by the condition comparing means (13a) from the condition data previously written in the condition data memory (15) (step S9). This condition data is a data table as shown in FIG. 4, and in this figure, both detectors (1),
The case where each of the output signal levels of (2) is converted into a 3-bit digital signal is shown. This data table includes the detectors (1) when detecting only the human body at coordinates where the levels of the digital signals are opposed to each other,
"1" is set only for the coordinates of the area corresponding to the signal level distribution of (2), and "0" is set for the coordinates of the other areas. The area of "1" surrounded by the thick line is This corresponds to the distribution (A) of both output signals by the human body detection shown in FIG. That is, a coordinate pattern for accurately detecting a human body at a place where the device should be installed is experimentally obtained in advance and the ROM
In a fixed manner or stored in a rewritable RAM.

Then, the condition comparing means (13a) determines whether or not the coordinates of the data table corresponding to both converted digital signals are "1" (step S1).
0), and the data of the determination result is input to the L-stage shift register (13b). That is, when the determination result is "1", the shift register (13b) is bit-shifted to the left to set the rightmost least significant bit to "1" (step S11), and when the determination result is "0", the shift register (13b) is shifted. The register (13b) is bit-shifted to the left, and the least significant bit at the right end is set to "0" (step S12), thereby forming L data strings.

The above-described processing is performed by a timer interrupt every measurement cycle, and when the data sequence stored in the shift register (13b) is L bits previously set and stored in the time series condition data memory (16) at each measurement interval. The series condition data is compared with the time series comparison means (13c) (step S13). Now, assuming that 5-bit data shown in FIG. 5 is set as the time series condition data, the condition comparing means (13
Only when the determination result of "1" is output five times consecutively from a), it is determined that the detection of the human body is truly detected. Therefore, at each measurement interval, the shift register (13b)
The time series comparison means (13) determines whether or not the data sequence of the time series and the time series condition data of the time series condition data memory (16) match.
In step c14), the human body detection signal is output via the timer means (17) if it is determined that they match (step S15), and if not, the detection output is turned off. Is maintained (step S1
6). Therefore, condition data is created based on experimentally collecting and arranging in advance the distribution state of a plurality of signals generated in each of the detectors (1) and (2) due to various factors according to the installation location. If the data is stored in the ROM, the RAM, or the EEPROM, the signal distribution generated at the installation location is compared with the signal distribution, so that the detection loss of the human body hardly occurs.

Further, even if the pyroelectric element noise and the radio wave noise accidentally increase at the same time and coincidence is determined from the condition comparing means (13a), the noise is continuously generated a predetermined number of times set in the time series condition data. Since the human body detection signal is not output unless the result of the determination is that there is a match, the above-described noise disappears instantaneously, so that erroneous detection can be reliably prevented and the human body can be detected with high accuracy.

In the above embodiment, the first detector (1)
As an example, a case in which a passive far-infrared sensor is combined with a microwave sensor as the second detector (2) has been described. However, the present invention is not limited to this. For example, an active near-infrared sensor may be replaced with a first detector. May be combined with a second detector using a microwave sensor. Further, the first detector may be a passive far-infrared sensor, and the second detector may be combined as an ultrasonic sensor, or The same effect as described above can be obtained by combining the detector as an active near-infrared sensor and the ultrasonic sensor as a second detector.

In addition, condition data and time-series condition data are represented by R
If a communication function is provided between a plurality of human body detection devices and the control panel by storing them in AM or EEPROM, the operation of rewriting condition data and time-series condition data from the control panel to various human body detection devices can be performed. To switch the detection accuracy. Further, when the present invention is applied to a security alarm device, the output data of each detector at the time of non-warning in the daytime is sent to the control panel, and this data is collected and analyzed so that the human body in the installation place as shown in FIG. Information for obtaining an optimum detection pattern can be used as information, and the detection accuracy may be switched based on this information.

Furthermore, if the types of detectors are expanded to two or more types and the condition data is changed from a two-dimensional array to an N-dimensional array, a human body can be detected with higher accuracy. Further, two types of condition data for the human body and for the small animal are provided, and the distribution of each signal of each detector is determined in a time series as to which of these conditions is close. It can be further reduced. And when applied to a security alarm,
When it is determined that no signal is output from any of the detectors for a long time during the non-alert state, it is determined that the corresponding detector has been intentionally disabled due to a defect, failure, masking, or the like. A self-newcomer function to detect can be added.

[0025]

As described above, according to the human body detecting device of the present invention, the human body detecting means converts the output signals of a plurality of detectors different from each other into digital signals, and compares the levels of the digital signals with each other. A table in which “1” is set only to the coordinates of the area corresponding to the signal level distribution of each detector when only the human body is detected at the coordinates obtained, and “0” is set to the coordinates of the other areas. Is stored in advance in the condition data memory as condition data, and the condition comparing means determines whether or not the level of each digital signal matches "1" in the table of the condition data memory. Since it is configured to output a human body detection signal only when it is determined that the result of determining that it has been matched is output continuously to the time series condition data for the set number of times, human body detection leaks Etc. does not occur. Also, even when the first detector composed of the passive far-infrared sensor detects a small animal at a high level, the level of the second detector composed of the microwave sensor does not reach the level in the case of human body detection, This small animal can be clearly distinguished to prevent erroneous detection.

Further, even if the pyroelectric element noise and the radio wave noise coincidentally increase at the same time and the result of the determination is obtained from the condition comparing means, it is determined that the noises are continuously matched by the predetermined number of times set in the time series condition data. Since the human body detection signal is not output unless the determination result is obtained, the above-mentioned noise disappears instantaneously, so that erroneous detection can be reliably prevented and only the human body can be detected with high accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a functional block diagram of the above.

FIG. 3 is a flowchart of the above.

FIG. 4 is an explanatory diagram of condition data according to the first embodiment;

FIG. 5 is an explanatory diagram of time-series condition data.

FIG. 6 is a block diagram of a conventional device.

FIG. 7 is a block diagram of another conventional device.

8 is an explanatory diagram of a detection range by both detectors in FIG.

FIG. 9 is a diagram illustrating distributions of output signals of the passive far-infrared sensor and the microwave sensor due to various factors.

[Explanation of symbols]

 1, 2 detector 12, 12a, 12b A / D conversion means 13a condition comparison means 13c time series comparison means 15 condition data memory 16 time series condition data memory

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G08B 13/00-15/02

Claims (1)

(57) [Claims] 1. A plurality of detectors having different human body detection means, A / D conversion means for converting an output signal of each detector into a digital signal, and a level of each of the digital signals. A table in which “1” is set only in the coordinates of the area corresponding to the signal level distribution of each detector when only the human body is detected at coordinates consisting of “0” and “0” is set in the coordinates of the other areas. A condition data memory pre-stored as condition data, a condition comparing means for comparing whether or not the level of each digital signal matches "1" in the table of the condition data memory; A time series comparison means for outputting a human body detection signal only when it is determined that the result determined to have been output is continuously output for the set number of times in the time series condition data. Body detection device.