JP6377797B1 - Elevator boarding detection system - Google Patents

Abstract

When detecting a user using an image taken by a camera, malfunction of the user detection is prevented depending on a shooting environment.
An elevator boarding detection system according to an embodiment includes a camera, a user detection unit, a door opening / closing control unit, a parameter acquisition unit, and a malfunction prevention unit. The parameter acquisition unit 23 acquires parameters relating to brightness adjustment from the camera 12. The malfunction prevention unit 24 determines the brightness of the captured image used for the user detection unit 22 based on the parameter obtained by the parameter acquisition unit 23, and the error of the user detection unit 22 is determined according to the determination result. Implement processing to prevent operation.
[Selection] Figure 1

Description

  Embodiments described herein relate generally to an elevator boarding detection system that detects a user who gets in a car.

  Normally, when the elevator car arrives at the landing and opens, the door is closed after a predetermined time. At that time, since the elevator user does not know when the car is closed, when the user gets on the car from the landing, the user may hit or get caught in the door.

  In order to prevent such a collision between the user and the door or getting caught in the door during such a ride, a technology that uses a camera to detect the user coming from the landing to the car and reflect it in the door opening / closing control There is.

Japanese Patent No. 597932 JP 2004-315186 A

  However, there are situations in which the user cannot be detected correctly from the captured image of the camera, for example, when the landing is extremely dark or bright. In such a case, the detection accuracy of the user by the camera is lowered, and the door may malfunction. For example, because the hall is too bright, the shadow of a person coming and going to the hall is reflected in the photographed image, erroneously detected as a user, and the door is opened to wait. On the other hand, if the platform is too dark to distinguish between the user and the floor, the door will be closed within a specified time even if a user who tries to get on the car approaches.

  The problem to be solved by the present invention is that, when detecting a user using an image captured by a camera, only when the user can be detected correctly by preventing malfunction of user detection by the shooting environment, It is an object of the present invention to provide an elevator boarding detection system capable of reflecting the movement of the user in the door opening / closing control.

An elevator boarding detection system according to an embodiment includes an imaging unit capable of shooting a predetermined range from the vicinity of a door of the car toward the landing when the car arrives at the landing, and the imaging unit. User detection means for detecting a user using an image taken by the user, control means for controlling the opening / closing operation of the door based on a detection result of the user detection means, and brightness adjustment from the imaging means Based on the parameter acquisition means for acquiring the parameters and the parameters adjusted by the parameter acquisition means at the time of shooting, the brightness of the shot image used for the user detection means is determined and used from the shot image ingredients and malfunction prevention means for performing the processing for preventing the malfunction of the user detecting unit when it is determined not to be correctly detect the person To.

FIG. 1 is a diagram illustrating a configuration of an elevator boarding detection system according to the first embodiment. FIG. 2 is a view showing an example of an image taken by the camera in the embodiment. FIG. 3 is a diagram showing a state in which the captured image is divided into blocks in the embodiment. FIG. 4 is a diagram for explaining a detection area in real space in the embodiment. FIG. 5 is a diagram for explaining a coordinate system in the real space in the embodiment. FIG. 6 is a flowchart showing a user detection process during full opening of the boarding detection system in the embodiment. FIG. 7 is a flowchart showing a user detection operation while the door is closed in the boarding detection system according to the embodiment. FIG. 8 is a diagram illustrating an example of a captured image when the hall in the embodiment is too dark. FIG. 9 is a diagram illustrating an example of a captured image when the hall is too bright in the embodiment. FIG. 10 is a flowchart showing a malfunction prevention process of the boarding detection system in the same embodiment. FIG. 11 is a diagram illustrating an example of a captured image when the hall in the second embodiment is partially too bright / too dark. FIG. 12 is a flowchart showing a malfunction prevention process of the boarding detection system in the same embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration of an elevator boarding detection system according to the first embodiment. Note that, here, a single car will be described as an example, but a plurality of cars have the same configuration.

  A camera 12 is installed above the entrance of the car 11. Specifically, the lens portion of the camera 12 is installed in the curtain plate 11a covering the upper part of the entrance / exit of the car 11, with the lens 15 facing the landing 15 side. The camera 12 is a small surveillance camera such as an in-vehicle camera, and has a wide-angle lens and can continuously shoot images of several frames (for example, 30 frames / second) per second. When the car 11 arrives at each floor and opens, the state of the landing 15 is photographed including the state near the car door 13 in the car 11.

  The photographing range at this time is adjusted to L1 + L2 (L1 >> L2). L <b> 1 is a shooting range on the landing side and is, for example, 3 m from the car door 13 toward the landing 15. L2 is an imaging range on the car side, and is, for example, 50 cm from the car door 13 toward the back of the car. L1 and L2 are ranges in the depth direction, and the range in the width direction (direction orthogonal to the depth direction) is at least larger than the lateral width of the car 11.

  In the landing 15 on each floor, a landing door 14 is installed at the arrival entrance of the car 11 so as to be freely opened and closed. The landing door 14 opens and closes by engaging with the car door 13 when the car 11 arrives. The power source (door motor) is on the car 11 side, and the landing door 14 simply opens and closes following the car door 13. In the following description, it is assumed that when the car door 13 is opened, the landing door 14 is also opened, and when the car door 13 is closed, the landing door 14 is also closed.

  Each image (video) taken by the camera 12 is analyzed and processed in real time by the image processing device 20. In FIG. 1, the image processing device 20 is taken out from the car 11 for convenience, but the image processing device 20 is actually housed in the curtain plate 11 a together with the camera 12.

  Here, the image processing apparatus 20 includes a storage unit 21 and a user detection unit 22. The storage unit 21 has a buffer area for sequentially storing images taken by the camera 12 and temporarily holding data necessary for processing by the user detection unit 22. The user detection unit 22 pays attention to the movement of a person / thing closest to the car door 13 among a plurality of time-sequential images taken by the camera 12 and determines whether there is a user who intends to get on the vehicle. Detect. If this user detection part 22 is divided functionally, it will be comprised by the motion detection part 22a, the position estimation part 22b, and the boarding intention estimation part 22c.

  The motion detector 22a detects the motion of a person / thing by comparing the brightness of each image in units of blocks. The “movement of a person / thing” here refers to the movement of a person on the hall 15 or a moving body such as a wheelchair.

  The position estimation unit 22b extracts the block closest to the car door 13 from the blocks with movement detected for each image by the motion detection unit 22a, and the center of the car door 13 in the block (center of the door front). To the coordinate position in the hall direction (Y coordinate shown in FIG. 5) is estimated as the user's position (foot position). The boarding intention estimation part 22c determines the presence or absence of the user's boarding intention based on the time-series change of the position estimated by the position estimation part 22b.

  Here, in addition to the above configuration, the image processing apparatus 20 according to the present embodiment further includes a parameter acquisition unit 23 and a malfunction prevention unit 24.

  The parameter acquisition unit 23 acquires parameters related to brightness adjustment from the camera 12. Specifically, “parameters related to brightness adjustment” are exposure time, gain, aperture amount, and the like, and these are automatically adjusted to optimum values according to the brightness at the time of shooting.

  The malfunction prevention unit 24 determines the brightness of the captured image used for the user detection unit 22 based on the parameter obtained by the parameter acquisition unit 23, and the error of the user detection unit 22 is determined according to the determination result. Implement processing to prevent operation. Specifically, the malfunction prevention unit 24 calculates an index value LU representing the brightness of the captured image using one or more of the exposure time, gain, and aperture amount obtained as parameters related to the brightness adjustment. When the index value LU is higher than the preset upper limit value THa or lower than the lower limit value THb, processing for preventing malfunction is performed.

Note that some or all of the functions (user detection unit 22, parameter acquisition unit 23, malfunction prevention unit 24) provided in the image processing device 20 may be provided in the camera 12, or provided in the car control device 30. That's fine.

  The car control device 30 is connected to an elevator control device (not shown), and transmits and receives various signals such as a hall call and a car call to and from this elevator control device. The “call hall” is a call signal registered by operating a hall call button (not shown) installed at the hall 15 on each floor, and includes information on the registered floor and the destination direction. The “car call” is a call signal registered by operating a destination call button (not shown) provided in the car room of the car 11, and includes information on the destination floor.

  In addition, the car control device 30 includes a door opening / closing control unit 31. The door opening / closing control unit 31 controls the door opening / closing of the car door 13 when the car 11 arrives at the landing 15. Specifically, the door opening / closing control unit 31 opens the car door 13 when the car 11 arrives at the landing 15 and closes the door after a predetermined time has elapsed. However, when the person detection unit 22 of the image processing device 20 detects a person who intends to get in the vehicle while the car door 13 is open, the door opening / closing control unit 31 prohibits the door closing operation of the car door 13. And keep the door open.

FIG. 2 is a diagram illustrating an example of an image captured by the camera 12. In the figure, E1 represents a position estimation area, and yn represents a Y coordinate where a user's foot position is detected. FIG. 3 is a diagram illustrating a state in which the captured image is divided in units of blocks. An original image divided into a grid of one side W _block is called a “block”.

  The camera 12 is installed above the entrance of the car 11. Therefore, when the car 11 is opened at the landing 15, the predetermined range (L1) on the landing side and the predetermined range (L2) in the car are photographed. Here, when the camera 12 is used, the detection range is expanded, and even a user at a location slightly away from the car 11 can be detected. However, on the other hand, there is a possibility that a person who has just passed through the hall 15 (person who does not get on the car 11) is erroneously detected and the car door 13 is opened.

  Therefore, in this system, as shown in FIG. 3, the image captured by the camera 12 is divided into blocks of a certain size, a block with movement of a person / thing is detected, and the intention of boarding is detected by following the block with movement. It is set as the structure which judges whether it is a certain user.

  In the example of FIG. 3, the vertical and horizontal lengths of the blocks are the same, but the vertical and horizontal lengths may be different. Further, the blocks may be uniform in size over the entire image, or may be non-uniform in size, for example, the length in the vertical direction (Y direction) is shortened toward the top of the image. Thus, the foot position estimated later can be obtained with a higher resolution or a uniform resolution in the real space (if it is divided uniformly on the image, the farther away from the car door 13 the sparser the resolution is in the real space). .

  FIG. 4 is a diagram for explaining a detection area in real space. FIG. 5 is a diagram for explaining a coordinate system in real space.

  In order to detect the movement of the user who intends to get on the board from the photographed image, first, a user detection area is set for each block. Specifically, as shown in FIG. 4, at least a position estimation area E1 and a boarding intention estimation area E2 are set as user detection areas.

  The position estimation area E1 is an area for estimating a part of the user's body coming from the landing 15 toward the car door 13, specifically the position of the user's feet. The boarding intention estimation area E2 is an area for estimating whether or not the user detected in the position estimation area E1 has a boarding intention. The boarding intention estimation area E2 is included in the position estimation area E1 and is an area for estimating the user's foot position. That is, in the boarding intention estimation area E2, the user's stepping position is estimated and the user's boarding intention is estimated.

  In the real space, the position estimation area E1 has a distance L3 from the center of the car door 13 toward the landing, and is set to 2 m, for example (L3 ≦ shooting range L1 on the landing side). The lateral width W1 of the position estimation area E1 is set to a distance equal to or greater than the lateral width W0 of the car door 13. The boarding intention estimation area E2 has a distance L4 from the center of the car door 13 toward the boarding direction, and is set to 1 m, for example (L4 ≦ L3). The lateral width W2 of the boarding intention estimation area E2 is set to be approximately the same distance as the lateral width W0 of the car door 13.

  The lateral width W2 of the boarding intention estimation area E2 may be the same as the lateral width of W0 or may be a little wider than the lateral width of W0. Further, the position estimation area E1 and the boarding intention estimation area E2 may be trapezoids excluding the blind spots on both sides of the three-sided frame installed on the landing side, instead of the rectangle as shown by the dotted line in the drawing in the real space.

  Further, the user detection area may be further divided and the proximity detection area E3 may be set in front of the car door 13.

  The proximity detection area E3 estimates the user's foot position, and the user has a willingness to get on regardless of whether the user's foot position is approaching the car door 13 from the landing 15 or not. It is an area to be considered. The proximity detection area E3 has a distance L5 from the center of the car door 13 toward the landing, and is set to 30 cm, for example (L5 ≦ L4). The lateral width of the proximity detection area E3 is set to be the same as the lateral width W2 of the boarding intention estimation area E2.

  The relationship between each user detection area (E1, E2, E3) and the door opening / closing control process by the car control device 30 is as follows.

  The position estimation area E1 is an area where even if a user is detected in the area, the result is not reflected in the door opening / closing control process by the car control device 30.

  The boarding intention estimation area E2 is an area in which, when a user is detected in the area and the user has a boarding intention, the result is reflected in the door opening / closing control process by the car control device 30. Specifically, processing such as extending the door opening time is executed by the car control device 30.

  The proximity detection area E3 is an area in which the user is detected in the area and the result is reflected in the door opening / closing control process by the car control device 30. Specifically, processing such as extending the door opening time is executed by the car control device 30.

  Here, as shown in FIG. 5, the camera 12 has a horizontal direction with respect to the car door 13 provided at the entrance of the car 11 in the X axis, and from the center of the car door 13 to the landing 15 (with respect to the car door 13). The vertical direction) is taken as the Y axis, and the height direction of the car 11 is taken as the Z axis. In each image taken by the camera 12, the position estimation area E1 and the boarding intention estimation area E2 shown in FIG. 4 are compared in block units, so that the direction from the center of the car door 13 to the landing 15, that is, Y The movement of the user's foot position that is moving in the axial direction is detected.

  Next, the operation of this system will be described in detail.

(User detection operation when fully open)
FIG. 6 is a flowchart showing user detection processing during full opening in this system.

  When the car 11 arrives at the landing 15 on an arbitrary floor (Yes in Step S11), the car control device 30 opens the car door 13 and waits for a user to get on the car 11 (Step S12).

  At this time, a predetermined range (L1) on the landing side and a predetermined range (L2) in the car are photographed at a predetermined frame rate (for example, 30 frames / second) by the camera 12 installed in the upper part of the entrance / exit of the car 11. The image processing apparatus 20 acquires images captured by the camera 12 in time series, and sequentially stores the images in the storage unit 21 (step S13), and executes the following user detection processing in real time. (Step S14).

  The user detection process is executed by a user detection unit 22 provided in the image processing apparatus 20. This user detection process is divided into a motion detection process (step S14a), a position estimation process (step S14b), and a boarding intention estimation process (step S14c) as follows.

(A) Motion Detection Processing This motion detection processing is executed by the motion detection unit 22a that is one of the components of the user detection unit 22.

  The motion detection unit 22a reads out each image held in the storage unit 21 one by one, and calculates an average luminance value for each block. At this time, the motion detection unit 22a holds an average luminance value for each block calculated when the first image is input as an initial value in a first buffer area (not shown) in the storage unit 21. And When the second and subsequent images are obtained, the motion detection unit 22a determines the average luminance value for each block of the current image and the average luminance value for each block of the previous image held in the first buffer area. And compare. As a result, when there is a block having a luminance difference equal to or larger than a preset value in the current image, the motion detection unit 22a determines the block as a block with motion.

  When the presence / absence of motion with respect to the current image is determined, the motion detection unit 22a holds the average luminance value for each block of the image in the first buffer area for comparison with the next image. Thereafter, in the same manner, the motion detection unit 22a repeatedly determines the presence / absence of motion while comparing the luminance value of each image taken by the camera 12 in block order in time series.

(B) Position Estimation Process This position estimation process is executed by the position estimation unit 22b that is one of the components of the user detection unit 22.

  The position estimation unit 22b checks a block with motion in the current image based on the detection result of the motion detection unit 22a. As a result, when there is a block with movement in the position estimation area E1 shown in FIG. 4, the user detection unit 22 extracts a block closest to the car door 13 from the blocks with movement.

  Here, as shown in FIG. 1, the camera 12 is installed at the upper part of the entrance / exit of the car 11 toward the landing 15. Therefore, when the user is heading toward the car door 13 from the landing 15, there is a possibility that the right or left foot portion of the user is reflected in the foreground of the photographed image, that is, in the block on the car door 13 side. Is expensive. Therefore, the position estimating unit 22b obtains the Y coordinate (the coordinate in the direction of the landing 15 from the center of the car door 13) of the block with the movement closest to the car door 13 as data of the user's foot position, It is held in a second buffer area (not shown).

  Thereafter, in the same manner, the position estimation unit 22b obtains the Y coordinate of the block with the movement closest to the car door 13 for each image as the data of the user's foot position, and the second unillustrated second data in the storage unit 21 is obtained. Keep it in the buffer area. Note that such a foot position estimation process is performed not only in the position estimation area E1 but also in the boarding intention estimation area E2.

(C) Boarding intention estimation process This boarding intention estimation process is performed by the boarding intention estimation part 22c which is one of the components of the said user detection part 22. FIG.

  The boarding intention estimation part 22c smoothes the data of the user's foot position of each image held in the second buffer area. As a smoothing method, for example, a generally known method such as an average value filter or a Kalman filter is used, and detailed description thereof is omitted here.

  When the data at the foot position is smoothed and there is data whose change amount is equal to or greater than a predetermined value, the boarding intention estimation unit 22c excludes the data as an outlier. The predetermined value is determined by the standard walking speed of the user and the frame rate of the captured image. Further, outliers may be found and excluded before the foot position data is smoothed.

  When the user walks from the landing 15 toward the car door 13, the Y coordinate value of the user's foot position gradually decreases with time. For example, in the case of a moving body such as a wheelchair, the data changes linearly as shown by the dotted line, but in the case of a user, the left and right feet are detected alternately, so the data change curved as shown by the solid line become. Further, when some noise enters the detection result, the amount of instantaneous change in the foot position increases. Such foot position data having a large change amount is excluded as an outlier.

  Here, the boarding intention estimation part 22c confirms the motion (data change) of the foot position in the boarding intention estimation area E2 shown in FIG. As a result, if the movement (data change) of the user's foot position toward the car door 13 in the Y-axis direction within the boarding intention estimation area E2 can be confirmed, the boarding intention estimation unit 22c It is determined that there is a willingness to get on.

  On the other hand, when the movement of the user's foot position toward the car door 13 in the Y-axis direction in the boarding intention estimation area E2 cannot be confirmed, the boarding intention estimation unit 22c does not make a boarding intention to the user. Judge. For example, when a person crosses the front of the car 11 in the X-axis direction, a foot position that does not change in time in the Y-axis direction in the boarding intention estimation area E2 is detected. In such a case, it is determined that there is no intention to board.

  In this way, the block with the movement closest to the car door 13 is regarded as the user's foot position, and the presence / absence of the user's intention to board is estimated by tracking the temporal change of the foot position in the Y-axis direction. be able to.

  When a user with a boarding intention is detected (Yes in step S15), a user detection signal is output from the image processing device 20 to the car control device 30. Upon receiving this user detection signal, the car control device 30 prohibits the door closing operation of the car door 13 and maintains the door open state (step S16).

  Specifically, when the car door 13 is fully opened, the car control device 30 starts the door opening time counting operation and closes the door when the predetermined time T (for example, 1 minute) is counted. During this time, when a user who has a boarding intention is detected and a user detection signal is sent, the car control device 30 stops the count operation and clears the count value. Thereby, the door open state of the car door 13 is maintained during the time T.

  If a user with a new intention to board is detected during this time, the count value is cleared again, and the car door 13 is kept open for the time T. However, if the user comes many times during the time T, a situation in which the car door 13 cannot be closed indefinitely continues. Therefore, an allowable time Tx (for example, 3 minutes) is provided, and this allowable time is set. It is preferable to forcibly close the car door 13 when Tx has elapsed.

  When the counting operation for the time T is completed (step S17), the car control device 30 closes the car door 13 and leaves the car 11 toward the destination floor (step S18).

  If the proximity detection area E3 shown in FIG. 4 is set, the boarding intention estimation unit 22c confirms the user's foot position in the proximity detection area E3, and the user's foot position is determined. Regardless of whether or not the car door 13 is approaching from the landing 15, it is assumed that there is a boarding intention and is processed.

  In this way, by analyzing an image obtained by capturing the landing 15 with the camera 12 installed at the upper part of the entrance of the car 11, for example, a user coming toward the car door 13 from a place slightly away from the car 11 is detected. Can be reflected in the door opening and closing operation.

  In particular, by watching the user's foot position in the captured image and following the temporal change in the foot position in the direction from the car door 13 toward the landing 15 (Y-axis direction), the vehicle passes, for example, near the car. It is possible to prevent erroneous detection of only a person, and to correctly detect only a user who intends to get on and reflect it in the door opening / closing operation. In this case, the door open state is maintained while a user who intends to get on is detected, so that when the user tries to get on the car 11, a door closing operation is started and the door is hit. Can avoid the situation.

(User detection when the door is closed)
In the flowchart of FIG. 6, the description has been made assuming that the car door 13 of the car 11 is open at the landing 15. However, even when the car door 13 is closed (in the middle of closing), the camera 12 The presence / absence of a user who intends to get on the vehicle is detected using the image taken by the above. When a user who intends to get on is detected, the door opening / closing control unit 31 of the car control device 30 interrupts the door closing operation of the car door 13 and performs the door opening operation again.

  FIG. 7 is a flowchart showing the user detection operation when the door is closed in this system.

  When a predetermined time has elapsed since the car door 13 of the car 11 is fully open, the door opening / closing control unit 31 starts a door closing operation (step S21). At this time, the photographing operation of the camera 12 is continuously performed. The image processing device 20 acquires images taken by the camera 12 in time series, and sequentially stores these images in the storage unit 21 (step S22), and executes user detection processing in real time (step S22). S23).

  The user detection process is executed by a user detection unit 22 provided in the image processing apparatus 20. This user detection processing is divided into motion detection processing (step S23a), position estimation processing (step S23b), and boarding intention estimation processing (step S23c). Since these processes are the same as steps S14a, S14b, and S14c in FIG. 6, detailed description thereof is omitted.

  Here, when a user who has a boarding intention is detected (Yes in step S <b> 24), a user detection signal is output from the image processing device 20 to the car control device 30. When receiving the user detection signal while the door is closed, the car control device 30 interrupts the door closing operation of the car door 13 and performs the door opening operation (reopening) again (step S25).

  Thereafter, the same processing as described above is repeated. However, if a user who intends to get on the vehicle is continuously detected while the door is closed, the reopening is repeated and the departure of the car 11 is delayed. Accordingly, even when a user who intends to get on is detected, it is preferable to close the door without reopening if the above-described allowable time Tx (for example, 3 minutes) has elapsed.

  If the proximity detection area E3 shown in FIG. 4 is set, the boarding intention estimation unit 22c confirms the user's foot position in the proximity detection area E3, and the user's foot position is the landing. Regardless of whether or not the car door 13 is approaching from 15, it is assumed that there is an intention to get on and processing is performed.

  In this manner, even when the door is closed, the presence or absence of a user who intends to get on is detected and can be reflected in the door opening / closing operation. Therefore, it is possible to avoid a situation where the user hits the door when trying to get on the car 11 in the middle of the door closing.

(User detection operation when fully closed or door open: Pulled-in detection)
When the car door 13 is in the fully closed state or when the car door 13 is open, the user detection area is set on the car 11 side. Although not shown, the user detection area on the car 11 side has a predetermined distance (L6) from the center of the car door 13 toward the car 15 and is set to 30 cm, for example (L6 ≦ ride). Shooting range L2 on the car 11 side). The lateral width is substantially the same as the lateral width W0 of the car door 13.

  The user detection area on the car 11 side is used as a “drawn detection area”, and when a user is detected in the area, the result is reflected in the door opening / closing control process by the car control device 30. Specifically, the car control device 30 prohibits the door opening operation of the car door 13, slows the door opening speed of the car door 13, notifies the user of a message prompting the user to leave the car door 13, etc. Processing is executed.

(Malfunction prevention processing)
In this system, since the user is detected using an image captured by the camera 12, the state of the captured image affects the detection accuracy of the user. For example, when the hall 15 is too dark as shown in FIG. 8 or when the hall 15 is too bright and people's shadows are reflected strongly as shown in FIG. Cannot be detected correctly and the possibility of malfunctioning increases. The same applies when the inside of the car 11 is too dark or too bright. Therefore, in this system, when the image captured by the camera 12 is too dark or too bright, the detection process (sensing) is temporarily stopped, the output of the detection result is prohibited, or the sensitivity of the detection process To prevent malfunction.

  FIG. 10 is a flowchart showing a malfunction prevention process in the present system. This malfunction prevention process is executed after the captured image is acquired in step S13 in the flowchart of FIG. 6, and is executed after the captured image is acquired in step S22 in the flowchart of FIG.

  First, as a premise, it is assumed that the camera 12 has a function capable of automatically adjusting one or more of exposure time, gain, and aperture as a function for photographing at a predetermined brightness. The automatic adjustment function may be implemented by a device outside the camera.

  Aperture: Generally called “aperture”. The larger the aperture value, the smaller the aperture. Here, the aperture is expressed as “aperture”, and the larger the value, the more light is taken in, that is, the image is brighter. For the sake of simplicity, it is assumed that when the aperture value is doubled, the amount of light taken in is doubled.

In general, the value of “aperture” is halved as the amount of light taken in every 1.4 times. Therefore, aperture value = 1 / aperture ² is used when actually obtaining the value. There is no unit for the opening amount (there is no diaphragm, but it is called F value for convenience). The value range is, for example, 1/4 to 1/64 (aperture is 2 to 8).

  ・ Exposure time: Also called shutter speed. The unit is seconds. The value range is, for example, 1/1000 to 1/30.

  ・ Gain: The value of how many times the input signal is multiplied. There is no unit (magnification). The value range is, for example, 1-30.

  Here, the brightness of the image photographed by the camera 12 is quantified. This is called “brightness index value”. As a principle of the camera, the luminance value of the captured image has the following proportional relationship.

Luminance value ∝ (physical) light quantity × aperture amount × exposure time × gain If the light quantity is regarded as brightness, the brightness index value is obtained by the following equation (1).
Brightness index value = luminance value / (aperture amount × exposure time × gain) (1)
The parameter acquisition unit 23 provided in the image processing apparatus 20 acquires a value to be automatically adjusted from the above-described exposure time, gain, and opening amount as a parameter relating to brightness adjustment from the camera 12 (step S31).

  The malfunction prevention unit 24 calculates an index value LU representing the brightness of the captured image used for the user detection unit 22 based on the parameter obtained by the parameter acquisition unit 23 (step S32). The “brightness of the photographed image” here means specifically the brightness of the photographing range indicated by L1 + L2 in FIG.

  Here, in the present embodiment, it is assumed that the camera 12 can automatically adjust the exposure time and gain, and the opening amount is fixed. Further, assuming that the luminance value of the above equation (1) is constant, the malfunction prevention unit 24 obtains the brightness index value LU as follows.

LU = 1 / (exposure time x gain)
The malfunction prevention unit 24 compares the brightness index value LU with preset upper limit value THa and lower limit value THb (step S33). THa> THb, for example, THa = 300, THb = 3.

  If LU> THa or LU <THb, that is, if the captured image is overall too bright / dark (Yes in step S33), the malfunction prevention unit 24 cannot correctly detect the user from the captured image. And specific processing for preventing malfunction of the user detection unit 22 is performed (step S34). Specifically, the malfunction prevention unit 24 performs any one of temporarily stopping the detection process of the user detection unit 22, prohibiting the output of the detection result, and reducing the sensitivity of the detection process.

  “Temporarily canceling detection processing” means not performing user detection (sensing). That is, the user detection process (steps S14 to S15 in FIG. 6 / steps S23 to S24 in FIG. 7) is not performed on the captured image. In this case, since the detection result is not reflected in the door opening / closing control, normal door opening / closing control is executed.

  “Forbid the output of detection results” means that even if user detection is performed, the detection results are invalid and are not output to the car control device 30. Also in this case, since the detection result is not reflected in the door opening / closing control, normal door opening / closing control is executed.

  “Decrease the sensitivity of detection processing” is to decrease the accuracy of user detection. Specifically, in the motion detection process described in step S14a of FIG. 6, by increasing the threshold value of the luminance difference when comparing the luminance value of each captured image that is temporally continuous in units of blocks, This is to lower the detection rate of blocks with motion.

  In the case of LU> THa or LU <THb, the sensitivity of the detection processing for the captured image may be decreased in stages according to the LU value at that time (the more the LU value is away from THa or THb, Decrease sensitivity to the captured image).

  As described above, according to the first embodiment, in the system that detects the user using the image captured by the camera 12, the malfunction of the user detection when the captured image is too bright or too dark is prevented. be able to. Thereby, only when the user can be detected correctly, the movement of the user can be reflected in the door opening / closing control.

(Modification)
As a modification of the first embodiment, the brightness index value LU may be calculated by the following method.

(1) When using average luminance value It is assumed that the exposure time and gain can be acquired from the camera 12. The malfunction prevention unit 24 obtains the average luminance value of the entire captured image or the area used for detection, and obtains the brightness index value LU as follows.

LU = average luminance value / (exposure time × gain)
(2) Method Using Three Exposure Times, Gain, and Aperture Value Assume that the exposure time, gain, and aperture amount can be acquired from the camera 12. The malfunction prevention unit 24 uses these values to determine the brightness index value LU as follows.

LU = 1 / (exposure time × gain × aperture)
(3) Combination of values to be used The malfunction prevention unit 24 obtains the brightness index value LU as follows by combining the exposure time, the gain, the aperture amount, and the average luminance.

When using exposure time, gain, aperture, and average brightness LU = average brightness / (exposure time x gain x aperture)
・ When using exposure time (gain and aperture are fixed)
LU = 1 / exposure time • When gain is used (exposure time and aperture are fixed)
LU = 1 / gain Even when the brightness index value LU is obtained by the method as described above, as in the first embodiment, malfunction of user detection when the captured image is too bright or too dark. Can be prevented.

(Second Embodiment)
Next, a second embodiment will be described.

  In the first embodiment, the malfunction prevention process is performed on the basis of the brightness of the entire captured image of the camera 12, but in the second embodiment, a portion of the captured image that is too bright or dark An excessive portion is detected, and a malfunction prevention process is performed on the portion.

  That is, as shown in FIG. 11, a bright place or a dark place may occur partially due to illumination light or natural light. As described with reference to FIG. 3, in this system, the image captured by the camera 12 is divided into blocks of a certain size, a block with movement of a person or an object is detected, and the block with the movement is followed, thereby It is configured to determine whether or not the user is a certain user. Therefore, the brightness index value LUi (i is the number of blocks) is calculated for each block, and malfunction prevention processing is performed on a portion that is higher than the upper limit value THa or lower than the lower limit value THb.

  A specific processing operation will be described below.

  FIG. 12 is a flowchart showing a malfunction prevention process in the second embodiment. This malfunction prevention process is executed after the captured image is acquired in step S13 in the flowchart of FIG. 6, and is executed after the captured image is acquired in step S22 in the flowchart of FIG.

  Similar to the first embodiment, the camera 12 has a function capable of automatically adjusting one or more of exposure time, gain, and aperture as a function for photographing at a predetermined brightness. Shall. The automatic adjustment function may be implemented by a device outside the camera.

  The parameter acquisition unit 23 provided in the image processing apparatus 20 acquires a value to be automatically adjusted from the above-described exposure time, gain, and opening amount as a parameter relating to brightness adjustment from the camera 12 (step S41).

  Here, in the second embodiment, the malfunction prevention unit 24 divides the photographed image used for the user detection unit 22 into blocks of a predetermined size (step S42), and performs the following processing for each block. Do. In addition, the process of step S43-S46 enclosed with the dotted line in a figure is performed by each block.

  That is, first, the malfunction prevention unit 24 obtains the luminance value of each block (step S43). In this case, for each block, a value obtained by averaging the luminance values of the pixels belonging to the block is obtained as the luminance value of the block.

  Next, the malfunction prevention unit 24 obtains the brightness index value LUi for each block as follows using the luminance value obtained for each block (step S44).

LUi = luminance value of block i / (exposure time × gain)
Note that the camera 12 can automatically adjust the exposure time and gain, and the opening amount is fixed. i is the number of blocks.

  The malfunction prevention unit 24 compares the brightness index value LUi for each block with the preset upper limit value THa and lower limit value THb (step S44). THa> THb, for example, THa = 300, THb = 3.

  If LUi> THa or LUi <THb, that is, if the portion corresponding to the block in the shooting range is too bright / dark (Yes in step S45), the malfunction prevention unit 24 determines that the user Is not correctly detected, and a specific process for preventing malfunction of the user detection unit 22 is performed (step S46). Specifically, the malfunction prevention unit 24 temporarily stops the detection process for the block of the user detection unit 22, prohibits the output of the detection result for the block, or lowers the sensitivity of the detection process for the block. Implement one of the following:

  “Temporarily canceling the detection processing for the block” means that user detection (sensing) is not performed on a portion that is too bright or too dark in the captured image. In other words, the user detection process (the process of steps S14 to S15 in FIG. 6 / the steps S23 to S25 of FIG. 7) is not performed for a part that is too bright or too dark in the captured image. In this case, if the user is detected in another part, the detection result is output to the car control device 30 and reflected in the door opening / closing control.

  “Prohibit output of detection results for the block” means that even if user detection is performed on a too bright or too dark portion of the captured image, the detection result is invalidated and not output to the car control device 30. is there. In this case, if the user is detected in another part of the captured image, the detection result is output to the car control device 30 and reflected in the door opening / closing control.

  “Decrease the sensitivity of detection processing for the block” means to decrease the accuracy of user detection. Specifically, in the motion detection process described in step S14a of FIG. 6, the threshold value of the luminance difference when comparing the luminance value of each captured image that is temporally continuous for each block is set only for the block as compared with the normal time. By increasing the value, the detection rate of a block with motion for a portion that is too bright or too dark is lowered.

  In the case of LUi> THa or LUi <THb, the sensitivity of the detection processing for the block may be decreased in stages according to the value of LUi at that time (the more the value of LUi is away from THa or THb, the more Reduce sensitivity to block).

  As described above, according to the second embodiment, it is possible to prevent malfunction of user detection for a too bright part or a too dark part in the shooting range in the hall 15 or the car 11, and use in other parts. Only when the person can be detected correctly, the movement of the user can be reflected in the door opening / closing control. Thereby, for example, when the hall 15 side is generally dark and the inside of the car 11 has appropriate brightness, the hall 15 is not sensed and the inside of the car 11 is sensed.

(Modification)
As a modification of the second embodiment, the brightness index value LUi in units of blocks may be calculated by the following method.

(1) Method using three of exposure time, gain, and opening amount Assume that the exposure time, gain, and opening amount can be acquired from the camera 12. The malfunction prevention unit 24 uses these values to determine the brightness index value LUi for each block as follows.

LUi = luminance value of block i / (exposure time × gain × aperture amount)
(2) Combination of values to be used The malfunction prevention unit 24 obtains the brightness index value LU as follows, based on the combination of the exposure time, the gain, and the aperture amount.

・ When using exposure time (gain and aperture are fixed)
LUi = luminance value of block i / exposure time When gain is used (exposure time and aperture are fixed)
LUi = luminance value / gain of block i Even when the brightness index value LUi in units of blocks is obtained by the method as described above, as in the first embodiment, when the captured image is partially too bright or dark It is possible to prevent a malfunction of user detection when it is too much.

  According to at least one embodiment described above, when a user is detected using an image captured by a camera, the user can be detected correctly by preventing malfunction of the user detection depending on the shooting environment. It is possible to provide an elevator boarding detection system that can reflect the movement of the user in the door opening / closing control.

  In addition, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 11 ... Ride car, 12 ... Camera, 13 ... Car door, 14 ... Landing door, 15 ... Landing place, 20 ... Image processing apparatus, 21 ... Memory | storage part, 22 ... User detection part, 22a ... Motion detection part, 22b ... Position Estimating unit, 22c ... Riding intention estimating unit, 23 ... Parameter acquiring unit, 24 ... Malfunction prevention unit, 30 ... Car control device, 31 ... Door opening / closing control unit, E1 ... User position estimation area, E2 ... Riding intention estimation area , E3 ... proximity detection area.

Claims (7)

An imaging means capable of photographing a predetermined range from the vicinity of the door of the car toward the landing when the car arrives at the landing;
User detection means for detecting a user using an image taken by the imaging means;
Control means for controlling the opening and closing operation of the door based on the detection result of the user detection means;
Parameter acquisition means for acquiring parameters relating to brightness adjustment from the imaging means;
Based on the parameter adjusted at the time of shooting obtained by the parameter acquisition unit, the brightness of the shot image used for the user detection unit is determined, and it is determined that the user cannot be correctly detected from the shot image. The elevator boarding detection system comprising: a malfunction prevention means for performing a process for preventing malfunction of the user detection means.   The elevator boarding detection system according to claim 1, wherein the parameters include at least one of an exposure time, a gain, and an opening amount. The malfunction prevention means is
An index value representing the brightness of the captured image is calculated using one or more of the exposure time, gain, and aperture, and the index value is higher than or set in advance. 3. The elevator boarding detection system according to claim 2, wherein a process for preventing malfunction of the user detection means is performed when the value is lower than the lower limit. The malfunction prevention means is
The photographed image is divided in units of blocks, and an index value representing brightness is calculated in units of blocks using one or more of the exposure time, gain, and aperture, and the index values are preset. The process for preventing malfunction of the user detecting means is performed on the block when it is higher than the upper limit value or lower than a preset lower limit value. Elevator boarding detection system. The malfunction prevention means is
The elevator boarding detection system according to claim 1, wherein the detection process is temporarily stopped as a process for preventing the user detection means from malfunctioning. The malfunction prevention means is
The elevator boarding detection system according to claim 1, wherein output of detection results to the control means is prohibited as processing for preventing malfunction of the user detection means. The malfunction prevention means is
The elevator boarding detection system according to claim 1, wherein the sensitivity of detection processing is lowered as processing for preventing malfunction of the user detection means.

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