JP5406683B2 - Lighting control device, lighting control system, and lighting control device - Google Patents

Description

  The present invention relates to a lighting control device that controls lighting of a lighting load that irradiates the region when a person is present in a preset region, a lighting control system that includes the lighting control device, and a lighting control that is used in the lighting control device. Relates to the device.

  Conventionally, various image sensors using a CCD camera or a CMOS camera have been developed and marketed. Human detection that detects the presence of a person in an imaging region using the image sensor has been applied and deployed in many fields.

  As an application example to illumination control, there is known an illumination control system that turns on an illumination load when it is detected that a person is present in an imaging region using a captured image captured by an image sensor. For example, the image sensor is installed on a ceiling surface (see FIG. 2B). The imaging area at this time is a vertically downward area from the ceiling surface.

  The illumination control system includes an image sensor, an image processing unit, and an illumination control unit. The image sensor includes an imaging unit and a conversion unit. The imaging unit is a camera to which a semiconductor imaging element such as a CCD or CMOS is applied. The conversion unit converts analog data output from the imaging unit into digital data, and transmits the converted digital data to the image processing unit as image data.

  The image processing unit uses a captured image at a certain point in time (a captured image in which no person is present in the imaging region) as a background image, and brightness for each pixel between the current captured image (hereinafter referred to as “current image”) and the background image. A difference image is generated by obtaining a difference between values (pixel value, density value). When the luminance values of all the pixels do not change between the current image and the background image, the luminance values of all the pixels of the difference image are “0”. On the other hand, if there is a pixel whose luminance value changes between the current image and the background image due to the presence of a person in the region, the luminance value of some pixels in the difference image does not become “0”. . The image processing unit detects the total number or the size of a continuous or adjacent set for pixels whose luminance value is not “0” in the difference image, and if these values exceed a preset threshold, It is determined that there is a person inside. At this time, a detection signal indicating that the presence of a person is detected is output from the image processing unit to the illumination control unit.

  The lighting control unit that has received the detection signal starts power supply necessary for lighting the lighting load, and performs dimming control on the lighting load so that the lighting load has a predetermined brightness.

  As described above, the lighting control system is a system that controls lighting of a lighting load in conjunction with the presence of a person in the area, and thus it is important to detect a person when the lighting load is turned off. However, when the illumination load is turned off, the area becomes relatively dark when there is little external light. That is, the analog data output from the imaging unit and the digital data converted by the conversion unit are very small. For this reason, the image sensor further includes an amplifying unit to acquire a brighter captured image. The amplifying unit amplifies the digital data to generate image data. At this time, the amplifying unit adjusts the amplification degree (amplification factor) appropriately by AGC (Auto Gain Control) so that the average value of the luminance values of all the pixels in the captured image created from the image data is kept constant. Signal amplification.

  Accordingly, when the illumination control system detects a person using an image sensor, the AGC of the amplifying unit can always create a captured image with appropriate brightness. Can be detected.

  By the way, the illumination control system which controls the brightness of an area | region using an image sensor apart from the said illumination control system is known (for example, refer patent document 1). In this lighting control system, first, a brightness target value is set in order to make the area the brightness desired by the user. The brightness target value is set as an average luminance value of all the pixels of the captured image in a state where external light into the imaging region is blocked. After the brightness target value is set, when outside light is incident on the imaging area, the area is brightened by the outside light, so that the average luminance value of the captured image is larger than the brightness target value. At this time, the lighting control unit that controls lighting of the lighting load performs dimming control on the lighting load so as to reduce the light output of the lighting load until the average luminance value of the captured image reaches the brightness target value, and the average luminance value is When the brightness target value is reached, the average brightness value can be maintained at the brightness target value.

  As described above, in the illumination control system, it is possible to control the light output of the illumination load while actively using outside light so that the imaging region has a brightness desired by the user.

JP 2009-238410 A

  However, the illumination control system that performs human detection using the image sensor (imaging unit and amplification unit) and the illumination control system that performs brightness control using the image sensor are configured separately. When it is desired to perform both the human detection and the brightness control, it is necessary to install each lighting control system. That is, it is necessary to attach both a configuration for performing human detection and a configuration for performing brightness control for one illumination load. For this reason, the shape of the lighting fixture is deformed, the mounting position of each component and the structure of the lighting fixture are restricted, and the system configuration becomes complicated.

  The present invention has been made in view of the above points, and an object of the present invention is an illumination control device capable of achieving both human detection and brightness control with a single imaging unit, and an illumination control system including the illumination control device. And it is providing the lighting control apparatus used for this illumination control apparatus.

  The invention of the illumination control device according to claim 1 is an illumination control device that controls lighting of an illumination load that illuminates the area when a person is present in a preset area, and a plurality of light receiving elements are arranged. An imaging unit that images the region using an imaging element, an amplification unit that amplifies the light reception values of the plurality of light receiving elements, respectively, and an adjustment unit that adjusts the amplification degree of the amplification unit; A detection unit that detects the presence / absence of a person in the region from the distribution of the plurality of output values; and a lighting control device that controls lighting of the lighting load; and the lighting control device determines whether the person in the region exists. A first mode to detect and a second mode to control the brightness of the region, and has a function of alternately switching between the first mode and the second mode, The average value of the output values in the first mode While adjusting the amplification degree to be a constant value, the amplification degree is fixed to a preset reference value in the second mode, and the lighting control device is controlled by the detection unit in the first mode. When the presence of a person in the area is detected, the lighting state of the lighting load is changed, while the average value of the output values of the amplification unit is included in a preset target range in the second mode. As described above, the lighting load is dimmed and controlled.

  According to a second aspect of the present invention, there is provided the lighting control device according to the first aspect, wherein in the second mode, no person is captured in the second mode in the captured image having the output value as the luminance value. The lighting load is dimmed and controlled so that an average value of luminance values included in the pixel range is included in the target range.

  The invention of a lighting control system according to a third aspect includes the lighting control device according to the first or second aspect and a lighting load that irradiates the region.

  The invention of the lighting control device according to claim 4 is used for the lighting control device according to claim 1 or 2.

  According to the first, third, and fourth aspects of the invention, the lighting state of the lighting load is changed when it is detected that a person is present in the area, and the amplification degree of the amplification unit is fixed to a preset reference value. By controlling the brightness of the area, both human detection and brightness control can be realized by a single imaging unit and amplification unit. Thereby, according to invention of Claim 1, simplification of an apparatus can be achieved.

  According to the second aspect of the present invention, when performing brightness control, only the luminance value of the pixel range in which a person is not imaged is used in the captured image, so that the pixel range having a large variation in luminance value can be removed. Therefore, the accuracy of brightness control can be increased.

It is a block diagram which shows the structure of the illumination control system which concerns on embodiment of this invention. It is the illumination control system which concerns on the same as the above, Comprising: (a) is the schematic which shows a use condition, (b) is a figure which shows a captured image. It is a figure explaining operation | movement of the amplification part of the illumination control system which concerns on the same as the above. It is a figure explaining operation | movement of the image process part of the illumination control system which concerns on the same as the above. It is a flowchart which shows operation | movement of the illumination control system which concerns on the same as the above. It is a flowchart which shows operation | movement of the normal control of the illumination control system which concerns on the same as the above. It is a flowchart which shows the operation | movement of the brightness control of the illumination control system which concerns on the same as the above. It is a figure explaining operation | movement of the lighting control apparatus of the illumination control system which concerns on the same as the above. It is a figure explaining operation | movement of the lighting control apparatus of the illumination control system which concerns on the same as the above. It is a figure explaining operation | movement of the illumination control system which concerns on the same as the above.

  The lighting control system 1 according to the embodiment of the present invention includes a lighting control device 2 and a lighting load 3 as shown in FIG. The illumination control system 1 is installed on the ceiling surface C as shown in FIG.

  The illumination load 3 is, for example, an LED (Light Emitting Diode) or a fluorescent lamp, and is turned on by power supply from an AC power source (not shown) and irradiates a preset region A. An AC power source includes a commercial power source with a voltage of 100V.

  As shown in FIG. 1, the illumination control device 2 includes an image sensor 4, an image processing unit 5, a storage unit 6, a light receiving unit (receiving unit) 7, and a lighting control device 8. The lighting control device 2 controls lighting of the lighting load 3 when the person B exists in the area A (see FIG. 2).

  The image sensor 4 includes an imaging unit 41, a conversion unit 42, an amplification unit 43, and an adjustment unit 44. The image sensor 4 creates approximately 30 captured images per second by the operation described below, and transmits image data of the captured images to the image processing unit 5 as needed.

  The imaging unit 41 is a camera that images a region A (see FIG. 2) using an imaging element (semiconductor camera element) in which a plurality of light receiving elements are arranged, such as a charge coupled device (CCD) or a CMOS. The light receiving value of each light receiving element is an electrical value that becomes a larger value as the amount of light increases, and is an analog value.

  The converter 42 converts the light reception value of each light receiving element from analog data to digital data. The digital data of the light reception value of each light receiving element is output from the conversion unit 42 to the amplification unit 43.

  The amplification unit 43 is, for example, an ISP (Image Signal Processor) or the like, and amplifies the light reception value converted into a digital value by the conversion unit 42. The output value is output from the amplification unit 43 to the image processing unit 5 as image data of the captured image.

  The adjustment unit 44 is configured by, for example, a computer, and adjusts the amplification degree G so that the average value of all output values of the amplification unit 43 becomes a constant value by AGC in a first mode described later. The amplification degree G refers to the ratio of the average value of all output values of the amplification unit 43 to the average value of all received light values. On the other hand, in the second mode described later, the amplifying unit 43 fixes the amplification degree G to a preset reference value.

  In the lighting control system 1 of the present embodiment, the lighting load 3 is controlled to be turned on in conjunction with human detection, so that human detection when the lighting load 3 is turned off is important. However, when the illumination load 3 is turned off, the area A becomes dark when there is little external light. That is, each light reception value from the imaging unit 41 is minute. Therefore, in the illumination control system 1 of the present embodiment, in the first mode, the adjustment unit 44 adjusts the amplification degree G using AGC, and the amplification unit 43 appropriately amplifies each received light value, The brightness of the captured image can be ensured. As a result, as described later, when the image processing unit 5 detects the person B (see FIG. 2A), the amplification unit 43 provides the image processing unit 5 with image data of a captured image with appropriate brightness. can do.

  FIG. 3 shows the relationship between the amplification degree G of the amplifier 43 and the brightness (average luminance value) D of the captured image. For example, assume that the current relationship is point X1 in FIG. When the brightness D of the captured image changes from D0 to D1 due to a change in external light (point X2 in FIG. 3), the amplification unit 43 gradually increases the amplification degree G from the current G1 by AGC. I will let you. Thereby, the brightness D of the captured image gradually approaches D0. The amplifying unit 43 stops increasing the amplification degree G when the brightness D0 is equal to the point X1 (point X3 in FIG. 3), and thereafter maintains the amplification degree G at G2.

  The image processing unit 5 illustrated in FIG. 1 acquires image data from the amplification unit 43 of the image sensor 4, and detects the presence / absence of a person B (see FIG. 2A) in the region A using the acquired image data. . As the image processing unit 5, a semiconductor device (for example, a DSP (Digital Signal Processor) or an advanced image processor) capable of advanced processing is used. The image sensor 4 corresponds to the detection unit of the present invention.

  The operation of the image processing unit 5 will be described with reference to FIG. Image data of a captured image at a certain point in time (captured image in which the person B does not exist in the area A) is stored in the storage unit 6 as image data of the background image P2 (see FIG. 4B). That is, the captured image in a state where the person B is not surely in the area A is always set as the background image P2. As the storage unit 6, for example, a volatile large-capacity memory such as DDRAM (Display Data RAM) is used.

  When the image data of the current image P1 (see FIG. 4A), which is the latest captured image, is transmitted from the image sensor 4 to the image processing unit 5, the image processing unit 5 sets the current image P1 and the background image P2. A difference in luminance value is obtained for each pixel between them to generate a difference image P3 (see FIG. 4C). When the luminance values of all the pixels do not change between the current image P1 and the background image P2, the luminance values of all the pixels of the difference image P3 are “0”. On the other hand, if there is a pixel whose luminance value changes between the current image P1 and the background image P2 due to the presence of the person B in the area A, the luminance values of some pixels in the difference image P3 are “ It will not be “0”. The image processing unit 5 detects the total number or the size of a continuous or adjacent set for pixels whose luminance value is not “0” in the difference image P3, and if these values exceed a preset threshold value. It is determined that the person B exists in the area A. At this time, a detection signal indicating the presence of the person B is output from the image processing unit 5 to the lighting control device 8.

  There are several other methods for setting the background image P2 by the image processing unit 5. As a general method, for example, there is a method in which the image processing unit 5 updates the latest captured image as the background image P2 in time series.

  The light receiving unit 7 illustrated in FIG. 1 receives an operation signal from a remote control device (hereinafter referred to as “remote control device”) 9. The operation signal includes operation information related to the operation content of the user to the remote control device 9. As the remote control device 9, an infrared remote control device that transmits an operation signal by infrared rays, a radio remote control device that transmits an operation signal by radio waves, or the like is preferably used.

  The lighting control device 8 includes a computer and a lighting circuit, and has a first mode for detecting the presence or absence of a person B in the area A, and a second mode for controlling the brightness of the area A. It has a function of alternately switching between the first mode and the second mode.

  When the lighting control device 8 receives the detection signal from the image processing unit 5 in the first mode, the lighting control device 8 starts supplying power necessary for lighting to the lighting load 3 or the lighting load 3 so as to have a predetermined brightness. Dimming control.

  Further, in the second mode, the lighting control device 8 acquires information on the luminance value of each pixel in the current image P1, and adjusts the lighting load 3 so that the average luminance value is included in a preset target range. Control. Here, the lighting control device 8 sets an average value of luminance values included in a pixel range in which a person is not captured in the current image P1 as an average luminance value. A pixel range in which a person is not imaged is a pixel range in which the luminance value is equal to or less than a predetermined value in the difference image P3 that is the difference between the current image P1 and the background image P2, that is, the luminance value is substantially “0”. Is a range of pixels.

  Furthermore, it is necessary for the lighting control device 8 to set a target range of brightness of the area A (see FIG. 2). For this reason, the lighting control device 8 has a normal control mode in which normal operation (human detection and brightness control) is performed, and a setting mode in which a target range of brightness in the region A (see FIG. 2) is set. . To set the target range, it is necessary to switch from the normal control mode to the setting mode. As a trigger signal for switching to the setting mode, a setting signal which is one of operation signals from the remote control device 9 is set. The target range is set in advance so that the average brightness value of the captured image becomes a median value when the brightness set in advance in the state where the external light is blocked in the region A is realized by the illumination load 3 irradiation. Yes.

  The light output of the lighting load 3 is adjusted and the desired brightness is determined when the remote control device 9 transmits a predetermined signal as one of the operation signals and the light receiving unit 7 receives the predetermined signal. This is performed by the control device 8.

  Next, operation | movement of the illumination control system 1 which concerns on this embodiment is demonstrated using FIG. First, power is supplied to the lighting control system 1 (S1 in FIG. 5). When the light receiving unit 7 receives the setting signal from the remote control device 9 (S2), the illumination control system 1 shifts to the setting mode (S3). After that, a state in which the external light to the region A is blocked is prepared (S4), and the lighting control device 8 has the region A in the above state based on the brightness information received from the remote control device 9 by the light receiving unit 7. Dimming control of the illumination load 3 is performed so that the brightness (brightness desired by the user) is obtained (S5). At this time, the average luminance value of the captured image is set as the target value D0, and the target value D0 is stored as the median value of the target range (S6). Thereafter, the setting mode is switched to the normal control mode (S7). On the other hand, when the light receiving unit 7 does not receive the setting signal from the remote control device 9 in step S2, the process shifts to the normal control mode (S7).

  Subsequently, the operation in the normal control mode in the illumination control system 1 of the present embodiment will be described with reference to FIGS. 6 and 7. In the normal control mode, the illumination control system 1 of the present embodiment repeats human detection (S11 in FIG. 6) and brightness control (S12) in a time division manner.

  As brightness control, as shown in FIG. 7, the lighting control device 8 acquires information on the luminance values of all the pixels in the captured image (S21 in FIG. 7). The average luminance value D obtained from the luminance value information of all the pixels acquired in step S21 is compared with the target value D0 (S22). If the luminance difference | D−D0 | is within σ% ((1−σ) D0 ≦ D ≦ (1 + σ) D0), the brightness control is terminated without performing any processing.

  On the other hand, when the luminance difference | D−D0 | is not less than σ% and D <D0 (S23), the lighting control device 8 increases the light output of the illumination load 3 by a predetermined amount (S24). After performing the process of step S24, step S22 is performed. When the luminance difference | D−D0 | is greater than or equal to σ% and D> D0 (S23), the light output of the illumination load 3 is decreased by a predetermined amount (S25). After performing the process of step S25, step S22 is performed. The processing from step S22 to step S25 is continued until the luminance difference | D−D0 | is within σ%, and when the luminance difference | D−D0 | is within σ%, the brightness control is terminated.

  As a result of the above operation, the average luminance value D can be adjusted to a target range that is substantially the same as the target value D0, so that the brightness of the area A is brought close to the desired brightness of the initial setting while including external light. be able to.

  For example, as shown in FIG. 8, the target value is set by storing the average brightness value D (D0) at the time when the brightness of the area A is set as the user's favorite brightness in an environment without external light. The In FIG. 8A, the user sets the light output of the lighting load 3 to 70% of the total lighting, and the average luminance value D at that time is set as the target value D0. After the target value D0 is set, the setting mode is switched to the normal control mode. Thereafter, when external light is incident as shown in FIG. 8B, the area A becomes brighter and the average luminance value D becomes D1 (D1 <D0). At this time, the lighting control device 8 lowers the average luminance value D by reducing the light output of the illumination load 3 so as to become the target value D0. The light output of the illumination load 3 is lowered until the average luminance value D reaches the target value D0, and when the average luminance value D reaches the target value D0, the light output of the illumination load 3 is stabilized. In the example of FIG. 8, the average luminance value D is set to the target value D0 by reducing the light output of the illumination load 3 from 70% of full lighting to 50% of full lighting. When the person B exists in the area A, the light output of the illumination load 3 is adjusted so that the average luminance value D of the pixels excluding the pixels determined to be detected by the person changes from D1 to the target value D0 (FIG. 8). (See (c)).

  From the above, as shown in FIG. 9, even when outside light is incident and the average luminance value D increases, the lighting control device 8 decreases the light output of the lighting load 3, thereby reducing the average luminance value. D goes down. That is, it moves from the point X11 to the point X10 as shown by the arrow in FIG.

  As described above, the illumination control system 1 of the present embodiment performs human detection (first mode) and brightness control (second mode) in a time-sharing manner. That is, brightness control is performed after human detection. In brightness control, the average brightness value of all the pixels excluding the pixels determined to be human detection is measured using the captured image processed by the human detection performed before and the pixel set of the extracted human B. Then, the value is compared with the target value. As a result, when it is higher than the target value, the light output of the illumination load 3 is reduced as correction processing, and when it is lower than the target value, the light output of the lighting load 3 is increased as correction processing. FIG. 10 shows an example in which the specified value δ is corrected for the average luminance value β. By executing correction every time human detection is performed, the final target value α is approached. At this time, when a certain allowable range is set as the target range with respect to the target value α, and the average luminance value β is included in the target range, the correction is terminated.

  As described above, according to the present embodiment, the lighting load 3 is turned on when it is detected that the person B exists in the area A, while the amplification degree of the amplifying unit 43 is fixed to a preset reference value. By detecting the brightness of the area A, both human detection and brightness control can be realized by the single image sensor 4 (the imaging unit 41 and the amplification unit 43). Thereby, according to this embodiment, simplification of the illumination control apparatus 2 can be achieved.

  Further, according to the present embodiment, when the lighting control device 8 performs brightness control, only the luminance value of the pixel range in which a person is not imaged in the current image P1 is used, and thus the luminance value varies greatly. Since the pixel range can be removed, the accuracy of brightness control can be increased.

  As a modification of the present embodiment, the lighting control device 8 uses the average value of the luminance values of all the pixels of the current image P1 as the average luminance value used when the lighting load 3 is dimmed and controlled in the second mode. Or an average value of luminance values in a pixel range (predetermined pixel range) in which almost no person exists may be used.

DESCRIPTION OF SYMBOLS 1 Illumination control system 2 Illumination control apparatus 3 Illumination load 4 Image sensor 41 Imaging part 43 Amplification part 5 Image processing part 8 Lighting control apparatus

Claims (4)

When a person is present in a preset area, an illumination control device that controls lighting of an illumination load that illuminates the area,
An imaging unit that images the region using an imaging element in which a plurality of light receiving elements are arranged;
An amplifying unit that amplifies the light reception values of the plurality of light receiving elements to obtain a plurality of output values;
An adjustment unit for adjusting the amplification degree of the amplification unit;
A detection unit for detecting the presence or absence of a person in the region from the distribution of the plurality of output values;
A lighting control device that controls lighting of the lighting load;
The lighting control device has a first mode for detecting the presence or absence of a person in the area, and a second mode for controlling the brightness of the area. The first mode and the second mode Has a function to switch between and
The adjustment unit adjusts the amplification degree so that an average value of the output values becomes a constant value in the first mode, and fixes the amplification degree to a preset reference value in the second mode. And
When the presence of a person in the area is detected by the detection unit in the first mode, the lighting control device changes the lighting state of the lighting load, while in the second mode, the lighting unit The lighting control device, wherein the lighting load is dimmed and controlled so that an average value of the output values is included in a preset target range.   In the second mode, the lighting control device is configured so that an average value of luminance values included in a pixel range in which a person is not captured among the captured images having the output value as a luminance value is included in the target range. The lighting control device according to claim 1, wherein dimming control is performed on the lighting load. The lighting control device according to claim 1 or 2,
An illumination control system comprising: an illumination load that irradiates the region.   The lighting control apparatus used for the illumination control apparatus of Claim 1 or 2.

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