JP2008215953A - Human body detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a human body detection device capable of detecting a human body surely. <P>SOLUTION: This human body detection device is characterized by including an ultrasonic transmitting element 1 for transmitting an ultrasonic wave toward a detection object, an ultrasonic array sensor 2 formed by arraying a plurality of ultrasonic receiving elements 5 for receiving the ultrasonic wave transmitted from the ultrasonic transmitting element and reflected by the detection object, a thermopile 3 for detecting an infrared ray radiated from the detection object, a height calculation means 6 for calculating the height of the detection object based on an output signal from the ultrasonic array sensor 2, and a determination means 7 for determining whether the detection object is a human body or not based on each output signal from the ultrasonic array sensor 2 and the thermopile 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a human body detection device that automatically detects a human body that falls within a predetermined detection range.

  Various techniques for detecting a human body have been developed for accident prevention and crime prevention. As one of them, a human body detection technique combining an ultrasonic sensor and a pyroelectric infrared sensor is known. For example, Patent Document 1 discloses a human detection device that combines a pyroelectric infrared sensor and an ultrasonic sensor in order to detect the presence / absence of a person before and after a construction vehicle. This human detection device detects infrared rays of a specific wavelength emitted by a person using a pyroelectric infrared sensor and outputs a detection result, and also detects ultrasonic waves reflected from the person using an ultrasonic sensor and outputs a detection result. . By performing the logical operation of both outputs, the disadvantages of both the pyroelectric infrared sensor and the ultrasonic sensor are compensated to prevent the occurrence of false alarms.

Further, Patent Document 2 discloses a security sensor that monitors intrusion of a human body by a change in infrared energy and a change in reflected waves of ultrasonic waves. This security sensor is configured to determine that a human body has entered when a change in infrared energy in the detection area (detected by a pyroelectric infrared sensor) and a change in reflected ultrasonic waves are detected at the same time.
JP-A-8-218310 JP 2001-118160 A

  The pyroelectric infrared sensors used in Patent Documents 1 and 2 detect changes in infrared energy in the detection area. Therefore, when a person once enters the detection area and then stops still, it is detected after that. There is a problem that results are not output. Another problem is that false alarms are unavoidable because the sensor operates even with infrared rays or sunlight that is emitted by small animals other than humans or high-temperature objects.

  Moreover, since the ultrasonic sensor used in Patent Documents 1 and 2 captures the presence or absence or change of an ultrasonic reflected wave, the ultrasonic reflector is a human body, a small animal, or other general equipment. Cannot be determined.

  Then, the subject of this invention is providing the human body detection apparatus which can detect a human body reliably.

  In order to solve the above-mentioned problems, the invention of claim 1 is directed to an ultrasonic transmission element that transmits ultrasonic waves toward a detection object, and an ultrasonic wave that is transmitted from the ultrasonic transmission elements and reflected by the detection object. An ultrasonic array sensor in which a plurality of ultrasonic receiving elements to receive are arranged, a thermopile for detecting infrared rays emitted from the detected object, and a height of the detected object based on an output signal of the ultrasonic array sensor And a determination means for determining whether or not the detected object is a human body based on the output signals of the ultrasonic array sensor and the thermopile.

  The ultrasonic array sensor instantaneously obtains a signal (distance image signal) related to the azimuth and distance of a plurality of locations on the surface of the detection object in front of it by receiving one ultrasonic wave. A rough shape can be detected. On the other hand, unlike a pyroelectric infrared sensor, a thermopile continuously detects infrared energy. In view of this, a human body detection apparatus in which an ultrasonic transmission element, an ultrasonic array sensor, and a thermopile are combined is configured. The thermopile is a non-contact type temperature detection sensor using infrared rays, and has features of zero power consumption, high speed detection (0.03 sec), and wide range temperature detection (-100 to 1000 ° C.). By using this thermopile, the presence of a human body in the detection area can be continuously detected not only at the moment of intrusion but also continuously thereafter. In addition, it is difficult for a thermopile alone to distinguish between a small animal that emits infrared rays and a human body, like a pyroelectric infrared sensor. However, the ultrasonic array sensor measures, for example, the height position of the head of a human body having a high ultrasonic reflection intensity, and adds this to the determination element, so that the distinction between the small animal and the human body becomes more reliable.

  The invention according to claim 2 is the signal output from the thermopile according to claim 1, wherein the determination means has a height of the detected object calculated by the height calculation means larger than a predetermined threshold value. When the intensity is greater than a predetermined threshold, the detected object is determined as a human body.

  By setting such a threshold value, it is possible to set the height (height) and temperature of the detection target to be detected, and to prevent the sensor from reacting to a small animal and issuing a false alarm.

  The invention of claim 3 is characterized in that, in the invention of claim 1, the ultrasonic transmission element, the ultrasonic array sensor, and the thermopile are arranged at the front and / or rear of the vehicle.

  Since the object to be detected can be continuously detected by the thermopile, the human body can be detected reliably, and a collision accident or an entrainment accident can be prevented.

  The invention of claim 4 is characterized in that, in the invention of claim 1, the ultrasonic wave transmitting element, the ultrasonic array sensor, and the thermopile are arranged above a region where a person passes.

  Since the object to be detected can be continuously detected by the thermopile, the presence / absence of a person is reliably detected, and the reliability in crime prevention applications is improved.

  The invention of claim 5 is characterized in that, in the invention of claim 1, the ultrasonic transmission element, the ultrasonic array sensor, and the thermopile are disposed above the bed in the hospital room.

  Since the object to be detected can be continuously detected by the thermopile, the presence / absence of the patient can be reliably detected, and a nurse call or the like can be taken quickly.

  According to the present invention, since the ultrasonic array sensor and the thermopile are combined, it can be accurately and continuously determined whether or not the detected object is a human body based on the output signals of both.

  Hereinafter, the best mode for carrying out the present invention will be described.

  FIG. 1 schematically shows a sensor unit S used in the human body detection apparatus of the present invention, wherein 1 is an ultrasonic transmission element, 2 is an ultrasonic array sensor, and 3 is a thermopile. The ultrasonic transmission element 1 is disposed at a position slightly off the center on the substrate 4 so as not to overlap the thermopile 3. Since the ultrasonic transmission element 1 and the thermopile 3 are miniaturized, they can be arranged adjacent to the substantial center on the substrate 4. Of course, you may arrange | position the ultrasonic transmission element 1 and the thermopile 3 in positions other than FIG. The ultrasonic array sensor 2 is composed of 16 ultrasonic receiving elements 5 arranged on a substrate 4 in 4 rows and 4 columns. This arrangement form is merely an example, and 16 or more ultrasonic receiving elements 5 may be arranged in 4 rows and 4 columns, or 3 or more and 16 ultrasonic receiving elements 5 may be arranged in 4 rows and 4 columns. You may arrange in the following. The thermopile 3 is disposed at the center on the substrate 4 and between the ultrasonic receiving elements 5. As the ultrasonic transmitting element 1, the thermopile 3, the substrate 4, and the ultrasonic receiving element 5, conventionally known elements can be appropriately used. The infrared ray emitted from the human body has a wavelength of 8 to 12 μm, and a filter for selecting and transmitting the infrared ray having this wavelength is attached to the thermopile 3. Usually, a filter that transmits a wavelength of 5 μm or more is preferably attached to the thermopile 3.

  FIG. 2 schematically shows an embodiment in which the sensor unit S described above is mounted on a tire roller 8 as a construction vehicle. 9 is a vehicle body, 10 is a front wheel roller, 11 is a rear wheel roller, 12 is a handle, and 13 is a driver's seat. The sensor units S are preferably installed at two positions on the left and right sides of the front surface and the rear surface of the vehicle body 9. A range indicated by broken lines ahead and behind the tire roller 8 is a human body detection area by the sensor unit S. As shown in FIG. 3, a height calculation unit 6 and a human body determination unit 7 are connected to the sensor unit S. That is, the output signal of the ultrasonic array sensor 2 includes information regarding the distance and direction to the location where the ultrasonic waves of the detected object are reflected, and based on this information, the height calculating means 6 detects the detected object. Calculate the height. The human body determination means 7 detects the detected object when the height value of the detected object calculated by the height calculating means 6 is greater than a predetermined threshold and the intensity of the output signal of the thermopile 3 is greater than the predetermined threshold. Is determined to be a human body.

  In the tire roller 8 of FIG. 2, when the person 15 enters the detection area of the sensor unit S, the ultrasonic wave transmitted from the ultrasonic transmission element 1 of the sensor unit S is reflected on the person 15, and the reflected wave is an ultrasonic wave. Received by the array sensor 2. Based on the output signal of the ultrasonic array sensor 2, the height calculation means 6 calculates the head position of the person 15 with high ultrasonic reflection intensity in the detection area, and calculates the height h of the person 15. . On the other hand, the thermopile 3 detects the infrared rays radiated from the person 15 and outputs an output voltage proportional to the amount of infrared rays received. The human body determination means 7 determines that the person 15 is a human body because the height value of the person 15 calculated by the height calculation means 6 is greater than a predetermined threshold value and the intensity of the output signal of the thermopile 3 is greater than the predetermined threshold value. judge. Based on the determination result, safety measures such as automatically forcibly stopping the tire roller 8 are taken. In addition to automatically forcibly stopping the tire roller 8, the driver may manually stop the tire roller 8 by issuing an alarm with a warning light and / or a horn based on the determination result.

  In a conventional human body detection device combining a pyroelectric infrared sensor and an ultrasonic sensor, since the pyroelectric infrared sensor detects only a change in infrared energy, the detection area is detected after the person 15 once enters the detection area. If it stays inside, subsequent human body detection becomes impossible. Further, it is not possible to detect the person 15 who remains in the detection area before the human body detection device is started. On the other hand, in the human body detection device of the present invention, since the thermopile 3 always detects infrared energy, a person who has once entered the detection area or continuously in the detection area before the start of the human body detection device. Anyone staying in can also be detected.

  In addition, in a conventional human body detection device that combines a pyroelectric infrared sensor and an ultrasonic sensor, since the receiving element of the ultrasonic sensor is fixedly arranged as one, the height of the detected object cannot be calculated. . For this reason, it is impossible to distinguish between human bodies, small animals or other objects in the detection area. On the other hand, in the human body detection device of the present invention, the detected object is detected based on the receiving element array pitch of the ultrasonic array sensor, the distance between the ultrasonic array sensor and the detected object, and the phase difference according to the direction of the reflected wave. It is possible to calculate a distance image or height. Therefore, it is possible to distinguish a human body from small animals and other objects by making one condition for determining the human body that the height value of the detected object is larger than a predetermined threshold value.

  Next, an embodiment in which the sensor unit S of the human body detection device of the present invention is installed on the ceiling 16 in a building is schematically shown in FIG. A triangular or conical region indicated by a dashed line hatching is a detection area A of the human body detection device.

  The sensor unit S is connected to a height calculation means 6 and a human body determination means 7 as in FIG. The ultrasonic wave transmitted from the ultrasonic transmission element 1 is reflected by the person 15, and the reflected wave is received by the ultrasonic array sensor 2. Since the output signal of the ultrasonic array sensor 2 includes information on the reflected location and orientation of the object to be detected, the height calculation means 6 is based on the output signal of the ultrasonic array sensor 2 in the detection area. The head position of the person 15 with high ultrasonic reflection intensity is calculated, and the vertical distance D1 between the ultrasonic array sensor 2 and the head of the person 15 is calculated. The distance from the ceiling 16 to the ultrasonic wave receiving / transmitting surface of the sensor unit S, that is, the mounting height D2 of the sensor unit S is known, and the height calculation means 6 adds the distance D1 and the distance D2 so A vertical distance D3 to the top of 15 is calculated. The height calculating means 6 calculates the height (height L) of the person 15 by subtracting the distance D3 from the ceiling height H, assuming that the height H of the ceiling is known.

  On the other hand, the thermopile 3 detects the infrared rays radiated from the person 15 and outputs an output voltage proportional to the amount of infrared rays received. The human body determination means 7 determines that the person 15 is a human body because the height L of the person 15 calculated by the height calculation means 6 is larger than a predetermined threshold and the intensity of the output signal of the thermopile 3 is larger than the predetermined threshold. To do. Based on this determination result, a system such as automatically issuing an alarm or notifying a security company is adopted.

  Next, FIG. 5 schematically shows an embodiment in which the sensor unit S of the human body detection device of the present invention is installed on a ceiling in a sick room for monitoring a sick person. A region indicated by an alternate long and short dash line is a detection area B of the sensor unit S. The sensor unit S is connected to a height calculation means 6 and a human body determination means 7 as in FIG. When the patient 15a lies on the bed 18 in the detection area B, the ultrasonic wave transmitted from the ultrasonic transmission element 1 of the sensor unit S is reflected on the patient 15a, and the reflected wave is received by the ultrasonic array sensor 2. Is done. Then, based on the output signal of the ultrasonic array sensor 2, the height calculation means 6 calculates the head position of the patient 15a having high ultrasonic reflection intensity in the detection area, and the head of the patient 15a in the detection area. Calculate the height of.

  On the other hand, the thermopile 3 detects infrared rays emitted from the patient 15a and outputs a detection signal. The human body determination means 7 is configured so that the height value of the head of the patient 15a calculated by the height calculation means 6 is larger than a predetermined threshold value and the intensity of the output signal of the thermopile 3 is larger than the predetermined threshold value. Is determined to be on the bed 18. When the detection signal of the thermopile 3 is not output, it is considered that the patient 15a has gone out of the detection area B and a system such as sending an automatic nurse call is adopted.

  As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, by mounting the human body detection device of the present invention on a home entertainment robot, An operation such as detecting the person 15 existing near the robot and talking to the person from the robot becomes possible. At that time, it is possible to determine whether the person 15 existing near the robot is walking or stopped by using the ultrasonic array sensor 2 of the human body detection device. Further, by calculating the head position of the person 15 existing near the robot by the human body detection device, the height of the human body 15 can be calculated, and it is possible to estimate whether the person is an adult or a child. For this reason, between the robot and the person 15 by changing the talking direction and the contents of the talking to the situation according to whether the person 15 near the robot is walking, stopped, an adult, or a child. It is possible to improve the interaction.

It is a front view of the sensor part of the human body detection apparatus concerning the present invention. It is a side view of the tire roller carrying the human body detection device concerning the present invention. It is a figure which shows typically the structure of the human body detection apparatus which concerns on this invention. 1 is a side view of an embodiment in which a human body detection device according to the present invention is installed on a ceiling of a building. It is a side view of an embodiment in which the human body detection device according to the present invention is installed on the ceiling of a hospital room.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic transmitter 2 Ultrasonic array sensor 3 Thermopile 5 Ultrasonic receiver 6 Height detection means 7 Human body determination means A Detection area B Detection area

Claims (5)

An ultrasonic transmission element for transmitting ultrasonic waves toward the detection object;
An ultrasonic array sensor in which a plurality of ultrasonic receiving elements that receive ultrasonic waves transmitted from the ultrasonic transmitting elements and reflected by the detection target are arranged;
A thermopile that detects the infrared rays emitted from the detected object;
A height calculating means for calculating the height of the detected object based on an output signal of the ultrasonic array sensor;
Based on the output signals of the ultrasonic array sensor and the thermopile, determination means for determining whether the detected object is a human body,
A human body detection device comprising:   When the height of the detected object calculated by the height calculating means is larger than a predetermined threshold and the signal intensity output from the thermopile is larger than a predetermined threshold, the determining means The human body detection device according to claim 1, wherein a human body is determined as a human body.   The human body detection device according to claim 1, wherein the ultrasonic transmission element, an ultrasonic array sensor, and a thermopile are disposed in a front portion and / or a rear portion of a vehicle.   The human body detection apparatus according to claim 1, wherein the ultrasonic transmission element, the ultrasonic array sensor, and the thermopile are disposed above a region where a person passes.   The human body detection device according to claim 1, wherein the ultrasonic transmission element, an ultrasonic array sensor, and a thermopile are disposed above a bed in a hospital room.

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