JPH09287913A - Apparatus for detecting position of object, method for detecting human body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a distance to an object in two dimensions by arranging distance- detecting means for detecting the distance in a noncontact manner disposed in a plurality of arrays so as to be detected in different directions by rotational scanning. SOLUTION: The apparatus is constituted of a distance sensor of pairs of infrared LEDs 1 for emitting electromagnetic waves, e.g. near infrared waves and photodiodes 2 for detecting reflected waves. A plurality of the pairs, for instance, four pairs are arranged in a longitudinal direction and loaded so as to detect light emitted in different directions. The apparatus is connected to a motor 4 and rotated right and left about a rotary shaft 3. The light projected from the infrared LED 1 and returning after being reflected at an object is detected by the photodiode 2. A distance to the object from the sensor is obtained on the basis of a time required for the lapse between a waveform when the light is projected and a waveform when the light is detected and the light velocity. When the measurement is repeated at the same time when the motor 4 rotates, a distance distribution in a horizontal direction at the emission angle of each infrared LED 1, that is, a two-dimensional distance distribution in four rows in the vertical direction and an arbitrary number of rows in the horizontal direction is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object position detecting device or a human body detecting method for detecting the position of an object in a measurement space.

[0002]

2. Description of the Related Art In recent years, in the fields of security, air conditioning, lighting, and the like, there is an increasing need for a human body detection device for detecting the number, positions, etc. of human bodies in a room without contact.

The most commonly used method for detecting a human body is to observe infrared rays emitted by a heated object such as a human body.

However, when a heat generating object such as a personal computer exists in the measurement space, there is a problem that it is erroneously detected as a human body.

In order to solve this problem, there is a method of observing infrared rays and at the same time observing the position information of an object existing in the measurement space using ultrasonic waves or the like, and comparing them to improve the accuracy of human body detection. Has been proposed.

[0006]

However, in detecting an object position by ultrasonic waves, there are problems such as the presence of a virtual image due to secondary reflection, and the shape of the horn having to be increased in order to sharpen the directivity. There is.

The present invention provides a device for detecting position information of an object, or a human body detection method with higher accuracy than position information and temperature information of an object.

[0008]

According to the present invention, a plurality of means for detecting the distance to an object in a non-contact manner are arranged in an array so that the distance detection directions are different, and the scanning is performed to rotate the object. It is an object position detection device that can detect the distance to 2D in two dimensions.

Further, according to the present invention, the difference between the object position information existing in the measurement space obtained by the object position detecting device for detecting the distance to the object in two dimensions and the background information measured in advance is calculated. Thus, the object position detecting device is characterized in that an object newly placed in the measurement space can be detected.

The present invention is also characterized in that an accurate object can be detected by combining neighboring pixels having a distance approximately equal to the distance of the pixel corresponding to the new object obtained from the result of the difference. It is an object position detecting device.

Further, according to the present invention, by comparing the position information regarding the object or the human body in the measurement space obtained by the object position detecting device with the information about the thermal object obtained by the two-dimensional thermal image detecting means, the human body is detected. A human body detection method characterized by being capable of detection.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows an outline of an object position detecting apparatus of the present invention. The distance sensor is composed of a pair of an infrared LED 1 that emits an electromagnetic wave (near infrared in this embodiment) and a photodiode 2 that receives a reflected wave thereof, and a plurality of pairs of the infrared LED and the photodiode (in the present embodiment, a plurality of pairs). 4 sets are arranged in the vertical direction), and the light emitting and receiving angles in the vertical direction are different from each other. Further, this detection unit is connected to a motor 4 as a rotation scanning unit so as to be able to rotate right and left around the rotation shaft 3.

As shown in the time chart of FIG. 2, this distance detecting means projects the AM-modulated light from the infrared LED 2 and receives the light reflected by the object and returned by the photodiode 3, The distance from the sensor to the object can be obtained based on the time and the speed of light between the waveform upon light projection and the waveform upon light reception. When the rotation of the motor 4 starts, the infrared LED emits light to the facing field of view and the photodiode 3
At, the reflected light from the object is received, and the distance is calculated from the time difference.

By repeating this measurement at the same time as the rotation of the motor 4, the distance distribution in the horizontal direction at the emission angle of each infrared LED, that is, four rows in the vertical direction and the two-dimensional distance distribution in which the horizontal direction has an arbitrary number of rows. Can be obtained.

In this embodiment, the light emitting portion and the light receiving portion are arranged in the horizontal direction and four pairs thereof are vertically overlapped, but of course the arrangement and the number of pairs are arbitrary. Further, the light emitting elements may be arranged so that the light emitting angles thereof are different in the horizontal direction, and the light emitting elements may be scanned in the vertical direction about the horizontal rotation axis.

(Second Embodiment) FIG. 3 shows the outline of the present invention. The object position detection device 31 is equipped with an array sensor in which several distance sensors (five in this case) that transmit and receive electromagnetic waves are vertically arranged, and by two-dimensionally rotating and scanning the array sensor. It is possible to obtain the distance image of. FIG. 4 is an example showing numerical values of the range image in the measurement space of FIG.

When the object 32 is placed in this measurement space (FIG. 5) and the same measurement is performed, the measurement result as shown in FIG. 6 is obtained. Subtracting the distance distribution data of FIG. 4 for each pixel from the distance distribution data of FIG. 6 yields the data shown in FIG.
By binarizing with an appropriate threshold value, it is possible to detect that a new object 32 has entered or carried in a place where the difference is large.

The object position detecting device may be one that scans a single distance sensor in both horizontal and vertical directions, or may be an array sensor in which a plurality of distance sensors are arranged two-dimensionally. .

(Embodiment 3) FIG. 8 shows an outline of a form in which the object detecting apparatus described in Embodiment 2 is applied to human body detection. First, when an image of the measurement space is measured in advance with only the chair 82 placed, the result is as shown in FIG. It can be seen that a chair exists there because the distance is extremely small only in the middle six pixel areas. Then the human body 83
FIG. 10 shows the result when the measurement is performed while the person is sitting on the chair 82. As shown in the first embodiment, the difference between FIG. 10 and FIG. 9 is obtained as shown in FIG. 11, which is binarized with an appropriate threshold value. At this time, since the difference between the distance A between the object position detecting device 81 and the backrest of the chair 82 and the distance B between the object position detecting device 81 and the human body 83 is small (see FIG. 8), the threshold value is set (in the present embodiment). Depending on the form, depending on −40), the binarization may result in an image as shown in gray in FIG. In FIG. 11, when the distance to the human body 83 and the distance to the chair 82 are almost the same, the presence of the human body 83 cannot be recognized there, and only the part of the human body 83 protruding from the chair 82 may be recognized as an image. It is shown that.
Therefore, in such a case, there is a problem that the accuracy of human body detection is lowered as a result.

To deal with this problem, consider the following processing. The distance of the pixel a2 in the distance image (FIG. 9) corresponding to the pixel determined to be a new object as a result of binarization (eg, a1 (-130) in FIG. 11 (distance value to the protruding portion 270 ) Is compared with the distance values 405, 280, 275, 280, 405 of the pixel (b2) in the vicinity of a2, and if the absolute value of the difference is less than or equal to a threshold value, the pixel is regarded as a human body. That is, 280,275,280 pixels are also regarded as the area of the new object. Further, the same processing is recursively performed on pixels (distance values 285, 280, 285) in the vicinity of the pixel b2 that is newly regarded as a human body, so that the human body image finally shown in gray in FIG. Was able to be detected.

(Embodiment 4) FIG. 13 shows another embodiment of the present invention. The human body detecting means 131 includes both an array sensor in which a plurality of distance sensors that transmit and receive electromagnetic waves are arranged in a one-dimensional array and an array sensor in which a plurality of infrared sensors that detect infrared rays are arranged in a one-dimensional array, and rotate each. By scanning, it is possible to obtain both a two-dimensional range image and a two-dimensional thermal image.

With respect to the measurement space shown in FIG. 13, a two-dimensional distance image processed by the object position detecting device described in the third embodiment is shown in FIG. 14, and a two-dimensional thermal image obtained by using an infrared sensor is shown as a human body temperature. The binarized level is shown in FIG. By making only the images appearing in both the range image and the thermal image the human body, for example, the personal computer 1 which has the heat of the human body but is not a newly introduced object 1
32 or a bag 133 that is a newly introduced object but does not have heat
It is possible to detect a human body with high accuracy without erroneously detecting the human body.

A specific human body detecting device of such a human body detecting method is, as shown in FIG. 16, an object position detecting device 161 in which several distance sensors for transmitting electromagnetic waves and receiving reflected waves are arranged one-dimensionally. And an infrared detecting device 162 equipped with an infrared sensor element having a one-dimensional array of infrared detecting portions as a two-dimensional thermal image detecting means. The detection device has a structure in which the facing direction of the detection device is continuously rotated, and the signals output from the object position detection device 161 and the infrared detection device 162 at the same time as the rotation are two-dimensional distance images by the signal processing device 163. Then, it is reconstructed into a two-dimensional thermal image and sent to the data processor 164. This measurement is usually performed at intervals of about 10 seconds to 1 minute. The data processing device 164 detects the human body from the sent data by the method described in the fourth embodiment. The result is displayed on the display device 166, and the data sent from the signal processing device 163 is stored in the storage device 165. Further, by transmitting the data stored in the storage device 165 to the communication system, it can be used in a TV audience rating measurement system, a monitoring system, or the like.

The two-dimensional thermal image detecting means of the present invention may be an infrared camera.

[0026]

As is apparent from the above description, according to the present invention of claim 1, distances are measured using electromagnetic waves, the distances are arranged in an array, and they can be rotated.
Distance data can be obtained accurately and at a wide angle.

The present invention according to claim 2 can easily recognize the new object by utilizing the difference.

According to the third aspect of the present invention, when the difference is used, even another object having almost no difference in distance can be accurately detected by using the shift.

Further, according to the present invention of claim 4, the human body can be easily detected by utilizing the thermal image.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of an object position detection device of a first embodiment according to the present invention.

FIG. 2 is a time chart of sensor signals according to the first embodiment.

FIG. 3 is a schematic diagram of a measurement space in detecting a distance distribution according to the second embodiment of the present invention.

4 is a diagram showing a distance distribution in the measurement space of FIG.

FIG. 5 is a schematic diagram of a measurement space in detecting a distance distribution according to the second embodiment of the present invention.

6 is a diagram showing a distance distribution in the measurement space of FIG.

7 is a diagram obtained by subtracting the distance value of FIG. 4 from FIG. 6 for each pixel.

FIG. 8 is a schematic diagram of a measurement space in human body detection according to a third embodiment of the present invention.

9] The measurement space of FIG. 8 (when there is no human body)
It is a figure which shows the distance distribution in.

10 is a diagram showing a distance distribution in the measurement space of FIG.

11 is a diagram obtained by subtracting the distance value of FIG. 9 from FIG. 10 for each pixel.

12 is a diagram showing a distance distribution in the measurement space of FIG.

FIG. 13 is a schematic diagram of a measurement space in human body detection according to a fourth embodiment of the present invention.

14 is a binary image of the distance distribution in the measurement space of FIG.

15 is a binary image of a two-dimensional thermal image in the measurement space of FIG.

FIG. 16 is a configuration diagram showing an outline of a human body detection device of another embodiment according to the invention.

[Explanation of symbols]

 1 Infrared LED 2 Photodiode 3 Rotating shaft 4 Motor 5 Rotating belt 6 Rotating table 31, 81, 161 Object position detecting device 32 Object 82 Chair 83, 133, 167 Human body 131 Human body detecting means 132 Personal computer 134 Bag 162 Infrared detecting device 163 Signal processing device 164 Data processing device 165 Storage device 166 Display device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuyuki Yoshiike 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A plurality of pairs of a light emitting element that transmits an electromagnetic wave and a light receiving element that receives a reflected wave for detecting a distance to an object are arranged in an array so that the distance detection directions are different from each other. An object position detecting device comprising: a distance detecting means; and a rotary scanning means for rotationally scanning the distance detecting means. 2. A difference means for calculating a difference between two-dimensional distance distribution data of an object in the background, which has been measured in advance, and currently detected two-dimensional distance distribution data,
The object position detecting apparatus according to claim 1, further comprising: a recognizing unit that recognizes an object that has newly entered or carried into the measurement space based on the output of the difference unit. 3. The existing range of the new object by combining the surrounding of the newly intruded or carried in new object recognized by the recognizing means with an object that is substantially at the same distance as the new object. The object position detecting device according to claim 2, wherein 4. A position of a thermal image in a thermal image obtained by a two-dimensional thermal image detecting means for detecting a two-dimensional thermal image, and an object position obtained by the object position detecting device according to claim 3. A human body detection method characterized by detecting a human body by collating with.