JP2013008461A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device that detects existence of a human and controls the illuminance around the human to a desired illuminance.SOLUTION: A lighting device has a light source 21 which is installed on a ceiling 11 and lights the whole or a part of an indoor such as an office as a lighting range, and a sensor 30 which is mounted integrally with the light source and detects the position of a human in a range overlapped with the lighting range. The sensor 30 has a human determining portion 33 for detecting the movement of the human and a position determining portion 34 for detecting the position of the human. The lighting device has an illuminance calculator 36 for calculating the measured illuminance of a target area 92 corresponding to a predefined range containing the position of the human 51 on the basis of information supplied from the sensor 30. The lighting device controls the optical output of the light source 21 so that the measured illuminance calculated by the illuminance calculator 36 approaches the target illuminance stored in a target illuminance setting unit 35, and lights the lighting range so that the illuminance of a work plane around the human is kept to the target illuminance.

Description

  The present invention relates to an illuminating device that detects the presence of a person and illuminance, and controls the light output of a light source based on the detection.

  2. Description of the Related Art Conventionally, there has been provided an illuminating device that detects the presence or absence of a person and illuminance, and controls the light output of a light source based on the detection (see, for example, Patent Document 1).

  The illumination device described in Patent Literature 1 divides a detection range into a plurality of areas in advance, and detects the presence / absence of a person and illuminance for each area. When this lighting device detects the presence of a person in an area, it controls the light output of the light source based on the illuminance of the area, and maintains the illuminance of the area where the presence of the person is detected at a preset target illuminance. To do. In the lighting device described in Patent Document 1, a TV camera (image sensor) is used as a sensor for detecting the presence or absence of a person and detecting illuminance.

  Such an illuminating device is used, for example, in an office to maintain the illuminance on a work surface around a person (in the office, a desk top surface) at a target illuminance.

JP 2002-289377 A

  The illumination device described in Patent Literature 1 divides a detection range into a plurality of areas in advance, and when the presence of a person is detected in a certain area, the entire area is detected regardless of the position of the person in the area. Keep the illuminance at the target illuminance. The target range for maintaining the illuminance at the target illuminance includes other unnecessary ranges in the area in addition to the work surface around the person who originally needs to maintain the illuminance. The illuminance including the illuminance is maintained at the target illuminance. Therefore, even if the illuminance of the entire area is maintained at the target illuminance, the illuminance around the detected person may not be suitable for work.

  In order to solve the above problem, it is conceivable to specify a work surface within the detection range in advance and maintain the illuminance of the work surface in the area where the presence of a person is detected at the target illuminance. However, in that case, manual work by a person is required to specify the work surface within the detection range at the time of construction of the lighting device or the like.

  The present invention has been made in view of the above reasons, and is intended to maintain only the illuminance within a limited range around the detected person at the target illuminance, and to perform a manual operation to specify the work surface An object of the present invention is to provide an illuminating device that can make the illuminance around a person suitable for work.

  The illuminating device of the present invention includes a light source, a human sensor that detects the presence / absence of a person in the detection range and the position of at least one person, and a position in the detection range. An illuminance sensor that detects the illuminance of the light, an illuminance calculation unit that generates a dimming signal based on the position of the person given by the human sensor and the illuminance at each position given by the illuminance sensor, and dimming from the illuminance calculation unit A dimming control unit that receives the signal and controls the light output of the light source, and the illuminance calculation unit sets a range defined around the person based on the position of the person as a target area, The illuminance obtained from the illuminance sensor is used to calculate the measured illuminance for the target area, and a dimming signal that instructs the measured illuminance to approach the preset target illuminance is given to the dimming controller. To.

  In this illuminating device, the human sensor includes an image sensor that images the detection range, detects the presence / absence of the person in the detection range and the position of the person based on the image captured by the image sensor, It is desirable to detect the illuminance at each position within the detection range based on the gray value of each pixel obtained from the image.

  In this lighting device, when the human sensor detects a plurality of people, the illuminance calculation unit obtains an average illuminance for each target area set for each of the plurality of people, and measures a minimum value in the average illuminance. More desirable is illuminance.

  In this lighting device, the illuminance calculation unit obtains an average illuminance for each target area set for each of the plurality of people when the human sensor detects a plurality of people, and calculates the average value of the average illuminance as the measured illuminance. It is more desirable to do.

  In this lighting device, the illuminance calculation unit may estimate the direction of the person based on a person's range in the detection range given from the human sensor, and set the target area so as not to include the back of the person. More desirable.

  According to the configuration of the present invention, only the illuminance within a range limited to the detected person's surroundings is a target to be maintained at the target illuminance, and the illuminance around the person without performing the manual operation to identify the work surface There is an advantage that the target illuminance can be achieved.

It is a block diagram which shows this embodiment. It is a figure which shows the example of installation same as the above. It is a figure which shows the range which an image sensor same as the above images. It is a figure which shows acquisition of the difference image of an image same as the above. It is a figure which shows an example of a human motion in the visual field range of a sensor same as the above. It is a figure which shows the reference | standard range for setting the target illumination intensity same as the above. It is a figure which shows the other example of a human motion in the visual field range of a sensor same as the above. It is a figure which shows the other example of a human motion in the visual field range of a sensor same as the above. It is a figure which shows the target illumination intensity same as the above, the light output of a light source, and the change of measurement illumination intensity. It is a figure which shows the change of a target area same as the above.

  Hereinafter, as an example of the lighting device, as illustrated in FIG. 2, a lighting fixture 1 including a sensor 30 integrally with the fixture body 22 will be described. The luminaire 1 according to the present embodiment is installed on a ceiling 11 in a room such as an office, and the whole or a part of the room is used as a lighting range, and the movement of a person and the position of a person in a range overlapping the lighting range are detected by a sensor 30. .

  The lighting fixture 1 controls the light output of the light source 21 so that the illuminance around the person detected by the sensor 30 approaches the preset target illuminance. Thereby, the luminaire 1 brings the illuminance of the work surface around the person (for example, the desk surface in the office) close to the target illuminance and makes the work surface suitable for work.

  As shown in FIG. 1, the sensor 30 includes an image sensor 31 including an area-type imaging device and an imaging optical system (not shown), and has a visual field range 32 (see FIG. 2) defined by the imaging optical system. Take an image. As the image sensor, a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS), or the like is used. The image sensor 31 according to the present embodiment generates a grayscale image in the visual field range 32. Therefore, the illuminance can be obtained using the gray value for each pixel of the captured image. As shown in FIG. 2, the sensor 30 is installed so that the center of the visual field is directed downward from the ceiling 11 and the visual field range 32 overlaps the illumination range of the lighting fixture 1. The sensor 30 captures an image of about 30 frames per second. FIG. 3 is a view of the visual field range 32 captured by the sensor 30 installed on the ceiling 11 as viewed from the ceiling 11, and shows a case where a person 51 and a desk 61 are located in the visual field range 32 of the image sensor 31. .

  The sensor 30 includes a person determination unit 33 that detects the movement of a person and a position determination unit 34 that detects the position of the person based on the captured image. That is, the sensor 30 of the present embodiment detects the presence / absence of a person and the position of the person as a human sensor having the visual field range 32 as a detection range.

  The person determination unit 33 and the position determination unit 34 are realized by a storage unit including a volatile memory such as a DDRAM and a non-volatile memory such as an EEPROM, and a control unit including a DSP (Digital Signal Processor) and an advanced image processor. . The storage unit stores a program necessary for the operation of the sensor 30 and image data such as a background image, which will be described later, and is used to temporarily store a calculated value or the like. A control part performs the process which implement | achieves the function which detects the function of detecting a person's movement, and the position of a person according to the program memorize | stored in the memory | storage part. Note that the person determination unit 33 and the position determination unit 34 may share a storage unit and a control unit, and may include a storage unit and a control unit, respectively.

  The luminaire 1 includes a target illuminance setting unit 35 that stores the target illuminance, an illuminance calculation unit 36 that calculates the illuminance around the detected person as measurement illuminance based on information provided from the sensor 30, and an illuminance calculation unit. And a dimming control unit 41 that controls the light output of the light source 21 according to an instruction from 36. The illuminance calculation unit 36 generates a dimming signal so that the measured illuminance approaches the target illuminance of the target illuminance setting unit 35, and the dimming control unit 41 that receives the dimming signal from the illuminance calculation unit 36 outputs the light output of the light source 21. To control.

  The target illuminance setting unit 35 is realized by the storage unit described above. The illuminance calculation unit 36 is realized by the storage unit and the control unit described above. The target illuminance setting unit 35 and the illuminance calculation unit 36 may be configured by a storage unit and a control unit that are provided separately from the person determination unit 33 and the position determination unit 34.

  The luminaire 1 has two operations: a setting mode for acquiring a background image used when detecting a person and setting a target illuminance, and a normal operation mode for detecting a person and controlling the light output of the light source 21. It has a mode.

  In the normal operation mode, the sensor 30 according to the present embodiment detects a person when the person determination unit 33 regards a change in the visual field range 32 of the sensor 30 as an intruder (person).

  The person determination unit 33 uses the background image stored in the storage unit when detecting a person. As the background image, a captured image captured in a state where no person is located in the visual field range 32 of the sensor 30 is used. The person determination unit 33 detects a person based on a difference image between a captured image captured by the image sensor 31 and a background image.

  For each image, taking FIG. 4 as an example, the coordinates of the pixel at the upper left corner are (0, 0), the right direction is the x direction, and the downward direction is the y direction. In the following, the coordinates of each pixel are represented in the form (x, y). For example, coordinates (0, 0) to (639, 479) are assigned to each pixel of an image of horizontal 640 pixels × vertical 480 pixels. In the captured image, the background image, and the difference image, the same coordinates (x, y) are assigned to the pixels at the same position.

  The difference image is obtained by calculating a difference in gray value for each pixel at the same position in the captured image and the background image. The pixel value of the pixel of the difference image that has the same coordinates as the pixel that does not change substantially between the two images is ideally zero. On the other hand, the pixel value of the pixel of the difference image having the same coordinates as the pixel that has changed due to the invasion of a person between the two images becomes larger than a preset threshold value.

  The person determination unit 33 may use one captured image as a background image at all times or may update the background image.

  When one captured image is always used as a background image, a captured image captured in a setting mode in which no person is reliably present in the visual field range 32 of the sensor 30 is used as a background image. The captured image is picked up by a person visually confirming that no person is present in the visual field range 32 of the sensor 30, or is picked up in a time zone in which it is guaranteed that no person is present in the visual field range 32 of the sensor 30. And so on.

  On the other hand, when updating the background image, for example, two captured images sampled at a constant time interval are compared to generate a difference image. If the sum of the pixel values of the pixels of the difference image does not exceed a preset reference value, it is determined that there is no change between the frames in which the two captured images are captured (that is, no person has entered). When the determination that there is no change between frames is made continuously a plurality of times, it is considered that there is no person in the field of view range 32 of the sensor 30, and a newer captured image is updated as a background image of the two captured images. To do. The sampling period is appropriately set, for example, a few seconds.

  When one captured image is always used as a background image, processing for updating the background image in the normal operation mode is not necessary, and the processing load on the person determination unit 33 is reduced. However, when a change other than the entry of a person occurs in the visual field range 32 of the sensor 30 (for example, when the desk is moved), the change may be detected as a person intrusion. On the other hand, when updating a background image, even if a change other than the intrusion of a person such as moving a desk occurs, the change is made into a background, so the possibility of false detection of a person other than a person is reduced. . Therefore, it is desirable that the background image is updated in a timely manner.

  In the normal operation mode, the person determination unit 33 is a difference image between the background image 71 (see FIG. 4A) acquired by the above-described processing and the captured image 72 (see FIG. 4B) captured by the sensor 30. 73 is generated (see FIG. 4C). As shown in FIG. 4A, the background image 71 includes a first object 81 and a second object 82, and as shown in FIG. 1 includes a first object 81, a second object 82, and a third object 83. In this case, the pixel value of the pixel of the difference image 73 that is the same coordinate as the pixel of the third object 83 in the captured image 72 is larger than the threshold value.

  Therefore, the person determination unit 33 detects that a person has entered the visual field range 32 of the sensor 30 when the size of a connected component of pixels having a pixel value larger than the threshold value is greater than or equal to a reference value in the difference image 73. . The connected component means a set of pixels having a pixel value larger than a threshold and connected by 4 connections (or 8 connections). Further, in addition to the size of the connected component, whether or not the sum of the pixel values of the pixels of the connected component is equal to or greater than a preset reference value may be added to the condition for detecting human intrusion.

  Next, processing for determining the position of a person in the normal operation mode will be described.

  The position determination unit 34 is provided with a difference image from the person determination unit 33 for each preset processing frame such as an interval of several seconds. As described above, the intrusion of the person into the visual field range 32 of the sensor 30 appears as a connected component of pixels having a pixel value equal to or greater than the threshold value in the difference image. The position determination unit 34 calculates and stores the position coordinates (x, y) of the representative point of the connected component as the position of the connected component in the difference image. As representative points of the connected component, for example, the center of gravity of the connected component, the intersection of diagonal lines of the circumscribed rectangle of the connected component, each vertex of the circumscribed rectangle of the connected component, or the like is used. As the center of gravity of the connected component, the average of the coordinates of each pixel constituting the connected component is used.

  As shown in FIG. 5, it is assumed that the position coordinates of the person 51 at the time when the start of the intrusion into the visual field range 32 of the sensor 30 is detected is (x0, y0). Then, changes in the position coordinates of the person 51 when moving to the desk 61 are detected as (x1, y1) to (xn-1, yn-1), and the position coordinates of the person 51 when sitting on the desk 61 are detected. Is detected as (xn, yn). The movement distance of the person 51 between the adjacent processing frames (the distance between (xm, ym) − (xm−1, ym−1), where m is a certain time point of the processing frame)) It is large when you are facing, and it becomes small after you are seated. Therefore, when this predetermined distance elapses while the moving distance (that is, the rate of change of the position) is smaller than the predetermined value, it is determined that the person 51 is stationary, and the person 51 in the processing frame The position coordinates (x, y) are stored. As a result, the position determination unit 34 can acquire the position coordinates of a stationary person.

  Hereinafter, calculation of the target illuminance and the measured illuminance will be described.

  The target illuminance is acquired from the captured image in a state where the light output of the light source 21 is controlled in advance so that the illuminance required by the user is obtained in an environment where no external light is incident in the setting mode (preferably at night). The luminaire 1 stores the target illuminance obtained from the gray value of the captured image in the target illuminance setting unit 35. For example, as shown in FIG. 6, a central portion that is a pixel range defined in advance in the visual field range 32 of the sensor 30 is set as a reference range 91, and an average value of gray values of pixels in the reference range 91 is set as the target illuminance. Used. By setting the reference range 91 at the center portion of the visual field range 32 of the sensor 30, the target illuminance is calculated from a certain range immediately below the sensor 30.

  Next, calculation of the measured illuminance in the illuminance calculator 36 will be described.

  In the normal operation mode, the illuminance calculation unit 36 is given the position coordinates of the person from the position determination unit 34 for each processing frame of the position determination unit 34. As shown in FIG. 7, the illuminance calculation unit 36 sets a range defined around the person 51 as the target area 92 based on the position coordinates of the person 51 given from the position determination unit 34. The target area 92 is limited as much as possible to the area where the person 51 works. When the position coordinate of the person 51 is the center of gravity of the connected component, the target area 92 is set to a small area (for example, a square of 1 m square) centered on the center of gravity. .

  The illuminance calculation unit 36 calculates the average gray value of the target area 92 in the captured image as the measured illuminance, and gives a dimming signal that instructs the measured illuminance to approach the target illuminance. The dimming control unit 41 to which the dimming signal is given from the illuminance calculation unit 36 controls the light output of the light source 21. Thereby, the illuminance of the target area 92 (around the person 51) is maintained at the target illuminance.

  FIG. 9 shows an example of the control of the light output of the light source 21 that brings the measured illuminance closer to the target illuminance. The luminaire 1 increases the light output (curve C in FIG. 9) of the light source 21 so that the measured illuminance (curve A in FIG. 9) approaches the target illuminance (straight line B in FIG. 9). In the present embodiment, as shown in FIG. 9, the light output of the light source 21 is controlled so that the measured illuminance gradually changes toward the target illuminance as time passes.

  By the way, the number of position coordinates of a person changes according to the number of persons existing in the visual field range 32 of the sensor 30. As shown in FIG. 8, when there are a plurality of persons 51, the number of position coordinates given to the illuminance calculation unit 36 is also plural. In this case, the illuminance calculating unit 36 sets a range defined around the person 51 as the target area 92 based on the position coordinates of each person 51, and calculates an average gray value for each target area 92 in the captured image. To do. The illuminance calculation unit 36 sets the minimum value among the average gray values as the measured illuminance. Thereby, the lighting fixture 1 can control the light output of the light source 21 on the basis of the target area 92 with the least illuminance, and can maintain the illuminance of all the target areas 92 at the target illuminance.

  In addition, an average gray value for each target area 92 in the captured image may be calculated, and the average value of the average gray values may be used as the measurement illuminance. Thereby, the lighting fixture 1 can reduce power consumption more than said case, and can make the illumination intensity of all the target areas 92 as close to target illumination intensity as possible.

  In addition, as shown in FIG. 10A, the target area 92 includes the entire periphery of the person 51, and includes not only the front of the person 51 (the direction in which the work surface such as the desk 61 exists) but also the person 51. The rear side (the direction without the work surface such as the desk 61) is also included. Therefore, in order to bring the illuminance of the work surface closer to the target illuminance with higher accuracy, the target area 92 is set so that the rear side of the person 51 is the deletion range 93 and does not include the deletion range 93, as shown in FIG. It is desirable.

  Therefore, the illuminance calculation unit 36 estimates the direction of the person 51 (that is, the front-rear direction) based on the range of the person 51 occupying the visual field range 32 from the captured image. In the contrast area 92 of the difference image, many pixels having a pixel value larger than the threshold value appear due to the movement of the hand or the like in front of the person 51, but have a pixel value larger than the threshold value because there is almost no movement behind the person 51. Take advantage of the fact that pixels rarely appear. That is, the amount of pixels having a pixel value larger than the threshold value in a certain time is compared, and the larger one is regarded as the front, and the front-rear direction is estimated.

  The illuminance calculation unit 36 manages the frequency of change for each pixel in the target area 92 based on the information given from the person determination unit 33. The movement of the person 51 is mainly performed in front of the person 51, and the pixels behind the person 51 hardly change. Therefore, in the target area 92, the frequency of the change in the pixels behind the person 51 is relatively smaller than the pixels in the front of the person 51. Therefore, in the front-rear direction of the person 51 in the target area 92, the person with the lower frequency of change is regarded as the rear of the person 51, and this portion is excluded from the target area 92 as the deletion range 93. As the change of the pixel, for example, in the target area 92 of the difference image, a pixel having a pixel value larger than a preset threshold is located by the person 51 or the hand of the person 51 is moving due to work or the like. And so on.

  Thereby, the lighting fixture 1 excludes the deletion range 93 located behind the person 51 who does not need to maintain the target illuminance from the target area 92, and more specifically specifies the work range of the person 51 who needs to maintain the target illuminance. can do. Thereby, the illuminance of the work surface around the person 51 can be made closer to the target illuminance with higher accuracy.

  In addition, the same effect as described above can be expected even if pixels of a predetermined ratio with a small change frequency are removed from the target area 92 among all the pixels in the target area 92 regardless of the above processing. The predetermined ratio may be, for example, 30% of pixels from the least frequent change.

  In the present embodiment, the control of the light output of the single light source 21 has been described. However, the technique of the present invention can also be applied to a plurality of light sources 21. In setting the target illuminance, the reference range 91 is not limited to the central portion of the field-of-view range 32 of the sensor 30, and a position and a range may be set as appropriate. In addition, it is desirable that the start instruction such as the control of the light output of the light source 21 and the setting of the target illuminance can be appropriately performed using means such as a remote controller.

  In the present embodiment, the lighting apparatus has been described by exemplifying the lighting fixture 1 that integrally includes the light source 21 and the sensor 30. However, the lighting apparatus may be configured to include the light source 21 and the sensor 30 as separate bodies. Good.

21 Light Source 31 Image Sensor 36 Illuminance Calculation Unit 41 Dimming Control Unit 51 Person 92 Target Area

Claims (5)

  A light source, a human sensor for detecting the presence or absence of a person in the detection range and the position of at least one person and a illuminance at each position in the detection range as a detection range that overlaps the range illuminated by the light source An illuminance sensor, an illuminance calculation unit that generates a dimming signal based on the position of the person given from the human sensor and the illuminance at each position given from the illuminance sensor, and the adjustment from the illuminance calculation unit A dimming control unit that receives a light signal and controls the light output of the light source, and the illuminance calculation unit sets a range defined around the person as a reference with respect to the position of the person as a target area, Before calculating the measured illuminance for the target area using the illuminance obtained from the illuminance sensor in the target area, and instructing the measured illuminance to approach the preset target illuminance Lighting device a dimming signal, characterized in providing the dimming control unit.   The human sensor includes an image sensor that images the detection range, and detects the presence and position of a person in the detection range based on an image captured by the image sensor. The illumination device according to claim 1, comprising the image sensor, and detecting illuminance at each position in the detection range based on a gray value of each pixel obtained from the image.   When the human sensor detects a plurality of people, the illuminance calculation unit obtains an average illuminance for each target area set for each of the plurality of people, and calculates a minimum value among the average illuminances. The illumination device according to claim 1, wherein the illumination intensity is measured illuminance.   The illuminance calculation unit obtains an average illuminance for each of the target areas set for each of the plurality of people when the human sensor detects a plurality of people, and calculates the average value of the average illuminance as the measured illuminance. The lighting device according to claim 1, wherein the lighting device is a lighting device. The illuminance calculation unit estimates the direction of the person based on a range of the person in the detection range given from the human sensor, and sets the target area so as not to include the back of the person. The lighting device according to claim 1.

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