JP2010055801A - Illumination system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable an illumination system to accurately light a lighting fixture eliminating wrong recognition of a person's existence, by changing detection accuracy between a state where the lighting fixture is lit and a state where it is not. <P>SOLUTION: The illumination system 1 is provided with a lighting fixture 2, an image sensor 3, and a control device 4 controlling the lighting fixture 2 through interpretation of image data by the image sensor 3. The control device 4 is to judge whether a person exists in an area where the lighting fixture 2 is installed on the basis of image variation amounts of the image data changing due to movements of a person, and is equipped with a setting part 42 for setting a threshold value of image variation amounts at which a person is judged to exist. With the lighting fixture 2 in a lit state, the threshold value is set smaller, so that detection accuracy is enhanced to enable to detect movements in more details. With the fixture 2 in an off state, the threshold value is set larger, so that detection accuracy is degraded to enable to detect large movements alone and little noise can be removed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lighting system for lighting a lighting fixture in accordance with image data output from an image sensor.

  2. Description of the Related Art Conventionally, a technique for determining whether or not a person exists using an image sensor including an image sensor that receives near infrared rays is known. As such a technique, as shown in FIG. 5, the difference image is calculated by comparing the reference image corresponding to the state where there is no person imaged in advance and the current captured image acquired from the image sensor, There is a method for determining the presence of a person when there is a certain difference between the two images. In addition, as shown in FIG. 6, there is a method of detecting a human motion by acquiring captured images continuous at predetermined time intervals from an image sensor and comparing the plurality of captured images in time series.

  As a system using human body detection technology as described above, the image sensor acquires image data of an area where a lighting fixture is installed, determines the presence of a person in the area, and turns on the lighting fixture according to the determination result There is an illumination system that changes control conditions (see, for example, Patent Document 1). As a control method in such a system, when it is determined that there is a person, the lighting apparatus in the off state is turned on, and when it is not determined that a person exists for a certain period of time during lighting of the lighting apparatus, the lighting apparatus is turned on. A method of turning off the light is conceivable.

In the system having the above control method, when a person is present in the area, the detailed operation of the person (for example, the person sitting at the desk and working) In order to detect (hand movement), it is necessary to increase the detection accuracy by reducing the threshold value of the image change amount determined to be a person. However, when the detection accuracy is increased as described above, when the controlled lighting fixture is turned off, it becomes easier to detect outside light, light from other lighting fixtures in the distance, and shadows caused by the light, The luminaire may be turned on unnecessarily due to the misrecognition that a person is present.
Japanese translation of PCT publication No. 2004-50196

  The present invention has been made in order to solve the above-described problem. By changing the detection accuracy between a state where the lighting fixture is turned on and a state where the lighting fixture is turned off, erroneous recognition of the presence of a person is achieved. An object of the present invention is to provide a lighting system capable of accurately lighting a lighting fixture by eliminating the above.

  In order to achieve the above object, the invention of claim 1 is directed to a lighting fixture, an image sensor for imaging an area where the lighting fixture is installed, and the lighting fixture by interpreting image data acquired by the image sensor. In the illumination system including a control unit that changes the lighting control condition for the image, whether the control unit includes a person in the area based on an image change amount that is changed by a human operation of the image data acquired by the image sensor. For this determination, the threshold value of the image change amount for determining that there is a person is set small when the lighting fixture is turned on, and the lighting fixture is turned off when the lighting fixture is turned off. It has a setting unit for setting a large threshold value.

  According to a second aspect of the present invention, in the first aspect of the present invention, the control unit performs skin color detection based on image data acquired by the image sensor at least in a state where the lighting fixture is lit, and the skin color is If detected, it is determined that a person is present in the area.

  According to the first aspect of the present invention, in the state in which the luminaire is turned on, the detection accuracy is improved by setting the threshold value of the image change amount that is determined to be present as a small person. It becomes possible to detect such detailed operations. Further, when the lighting fixture is turned off, the detection accuracy is lowered by setting the threshold value large, so that only a large operation can be detected, and fine noise can be removed. For this reason, it is no longer possible to detect external light, light from other distant luminaires, and shadows caused by the light, thereby eliminating false recognition of the presence of a person, and thus lighting the luminaires under desired lighting control conditions. It becomes possible.

  According to the invention of claim 2, since the skin color is detected at least in a state where the lighting fixture is lit, and it is determined that the person is present when the skin color is detected, the presence is recognized even when the person is stationary. it can. Further, when the lighting fixture is turned off, a floor surface, a wall, a document, or the like in the area where the lighting fixture is installed is not erroneously recognized as a person.

  An illumination system according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an electrical block configuration of a lighting system according to the present embodiment. The system 1 includes a lighting fixture 2, an image sensor 3 that captures an area where the lighting fixture 2 is installed (hereinafter referred to as an installation area), and image data acquired by the image sensor 3 to interpret the lighting fixture 2. And a control device (control unit) 4 for changing the lighting control condition for the. Here, the installation area is indoors such as an office, a school, or a factory.

  The luminaire 2 includes a plurality of light sources 21, an AC power supply 22 that supplies power to the light sources 21, and a lighting control circuit 23 that controls a current flowing through the light sources 21. Examples of the light source 21 include a fluorescent lamp, an incandescent lamp, and an LED. A plurality of light sources 21 may be connected to the lighting control circuit 23 as shown, or only one light source 21 may be connected. The lighting control circuit 23 is configured to adjust the duty ratio of the current flowing through the light source 21 in accordance with a PWM (Pulse Width Modulation) signal output from the control device 4.

  The image sensor 3 includes an image sensor 31 made of a CCD, a CMOS, or the like, and a lens 32 that determines the visual field range of the image sensor 31 and outputs color information of image data in a standard Yuv format. The image sensor 3 acquires the image data of the installation area at regular time intervals.

  The control device 4 includes a determination unit 41 that determines whether or not a person is present in the installation area based on an image change amount that is changed by a human action in the acquired image data, and an image change amount that is determined to be that a person exists. And a setting unit 42 for setting a threshold value. Further, the control device 4 stores the reference signal data used when the determination unit 41 calculates the image change amount, and the PWM signal to the lighting control circuit 23 according to the determination result by the determination unit 41. And a transmission unit 44 for transmission. The reference image data corresponds to a state where no person is present in the detection range of the image sensor 3, and is data obtained by capturing an installation area in a state where no person exists.

  The determination unit 41 performs image processing for taking a difference for each bit between the image data acquired by the image sensor 3 and the reference image data stored in the storage unit 43 and acquiring a difference area of the image as an image change amount. The determination unit 41 determines that there is a person when the difference area is equal to or larger than the threshold set in the setting unit 42, and determines that there is no person when the difference area is smaller than the threshold.

  When it is determined that there is a person, the determination unit 41 transmits a PWM signal from the transmission unit 44 to turn on the lighting device 2 when the lighting device 2 is turned off. At this time, after determining that a person is present, the determination unit 41 turns on the luminaire 2 until a preset lighting holding time elapses. When it is determined that there is a person, the determination unit 41 extends the time for lighting the lighting fixture 2 when the lighting fixture 2 is turned on. In addition, the determination unit 41 performs skin color detection based on the acquired image data in a state where the lighting fixture 2 is turned on. When the skin color is detected, the determination unit 41 determines that there is a person in the installation area, and performs the same as described above. The lighting time of the lighting fixture 2 is extended.

  The setting unit 42 sets the threshold value of the image change amount (difference area) to be small enough to detect a fine operation (for example, movement of a human hand) in a state where the lighting fixture 2 is lit. When is turned off, the threshold value is set large enough to detect a large motion (for example, walking of a person).

  Next, with reference to FIG. 2, the lighting aspect of the lighting fixture 2 controlled by the control apparatus 4 in the illumination system 1 of this embodiment is demonstrated. The lighting fixture 2 that is turned off starts to be turned on when the judgment unit 41 of the control device 4 judges that a person is present (operation detection). At this time, the lighting fixture 2 is provided with a lighting holding time of, for example, 3 minutes. When it is determined that there is a person (operation detection or skin color detection), the lighting fixture 2 that is lit is provided with a lighting holding time again, and when the lighting holding time has elapsed without being determined that a person exists Turns off.

  Next, an installation example of the light source 21 and the image sensor 3 of the lighting fixture will be described with reference to FIG. In this example, the light sources 21 are installed at a plurality of locations on the entire ceiling of the indoor 5, and the image sensor 3 is installed at one location with the lens facing downward in the approximate center of the ceiling of the indoor 5 so as to capture the entire interior 5. Has been. The light source 21 and the image sensor 3 are not limited to such an arrangement. For example, the image sensor 3 may be installed so as to image the vicinity of the entrance 51 of the indoor 5.

  The operation of the illumination system 1 configured as described above will be described. FIG. 4 shows a processing procedure of the determination unit 41 in the control device 4. Here, it is assumed that the determination unit 41 turns off the lighting fixture 2 (# 1). First, the determination unit 41 performs the above-described image processing for acquiring an image difference area (# 2). Next, the determination unit 41 determines whether there is a person in the installation area based on the difference area of the image (# 3). The determination here is to detect an operation, and the threshold value of the difference area is set large so that a large operation can be detected by the setting unit 42. When it is determined that the difference area is equal to or greater than the threshold and that there is a person (YES in # 3), the determination unit 41 turns on the lighting fixture 2 and starts counting operation of the lighting holding time (# 4). When it is determined that the difference area is smaller than the threshold value and no person exists (NO in # 3), the determination unit 41 performs image processing (# 1) again.

  After the processing of # 4, the determination unit 41 performs image processing in the same manner as in # 2 (# 5), and determines whether or not a person exists as in # 3 (# 6). Here, the threshold value of the difference area is set small so that a fine operation can be detected by the setting unit 42. When it is determined that the difference area is equal to or greater than the threshold value and there is a person (YES in # 6), the determination unit 41 resets the lighting holding time counting operation, and then restarts the lighting holding time counting operation to perform illumination. The lighting time of the appliance 2 is extended (# 7). When it is determined that the difference area is smaller than the threshold and no person exists (NO in # 6), the determination unit 41 performs skin color detection on the image data to determine whether a person exists (# 8). When the skin color is detected and it is determined that there is a person (YES in # 8), the determination unit 41 extends the lighting time of the lighting fixture 2 (# 7). When the skin color is not detected and it is determined that there is no person (NO in # 8), the determination unit 41 determines whether the counting operation of the lighting holding time is completed (# 9). When the counting operation of the lighting holding time is completed (YES in # 9), the determination unit 41 turns off the lighting fixture 2 (# 1), and when the counting operation is not completed (NO in # 9), Image processing (# 5) is performed again.

  As described above, according to the lighting system 1 according to the present embodiment, in the state where the lighting fixture 2 is lit, the detection accuracy is increased by setting the threshold value of the image change amount that is determined to be present as a small person. It becomes possible to detect fine movements such as the movement of a human hand. Further, when the lighting fixture 2 is turned off, the detection accuracy is lowered by setting the threshold value large, so that only a large operation can be detected, and fine noise can be removed. For this reason, it is no longer possible to detect external light, light from other distant luminaires, and shadows caused by the light, thereby eliminating false recognition of the presence of a person, and thus lighting the luminaire 2 under a desired lighting control condition. It becomes possible to make it.

  Further, skin color detection is performed at least in a state in which the lighting fixture 2 is lit, and when the skin color is detected, it is determined that a person exists, so that the presence can be recognized even when the person is stationary. In addition, when the lighting fixture 2 is turned off, a floor surface, a wall, a document, or the like in the area where the lighting fixture 2 is installed is not erroneously recognized as a person.

  In addition, this invention is not restricted to the structure of the said embodiment, A various deformation | transformation is possible in the range which does not change the meaning of invention. For example, in the above-described embodiment, the configuration in which one lighting fixture is provided for the control device 4 has been described. However, a configuration in which a plurality of lighting fixtures are provided for the control device 4 and the lighting fixtures are collectively controlled. It may be. In addition, the control device 4 may turn on the luminaire when it is determined that there is a person and turn off the luminaire when it is determined that there is no person.

The block diagram of the illumination system which concerns on one Embodiment of this invention. The figure which shows the lighting aspect of the lighting fixture of the said illumination system. The top view which shows the example of installation of the light source and image sensor of the said illumination system. The flowchart which shows the process sequence of the control apparatus in the said illumination system. The figure explaining an example of the technique which judges presence of a person using an image sensor. The figure explaining the other example of the said technique.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lighting system 2 Lighting fixture 3 Image sensor 4 Control apparatus (control part)
42 Setting section 5 Indoor (area)

Claims (2)

A lighting system comprising: a lighting fixture; an image sensor that captures an area in which the lighting fixture is installed; and a controller that interprets image data acquired by the image sensor and changes a lighting control condition for the lighting fixture. In
The control unit determines whether or not there is a person in the area based on an image change amount that changes due to a person's operation in the image data acquired by the image sensor. Illumination characterized by having a setting unit for setting a small threshold value for image change that determines that a person is present when the fixture is lit, and for setting the threshold value large when the luminaire is extinguished. system.   The control unit performs skin color detection based on image data acquired by the image sensor at least in a state where the lighting fixture is lit, and determines that there is a person in the area when the skin color is detected. The illumination system according to claim 1.