Object detection device and object detection system for elevator entrances and exits

Abstract

The objective is to obtain an elevator entrance object detection device and system that can accurately detect objects at elevator entrances without using any additional equipment other than cameras. [Solution] The system includes an acquisition unit 21 that acquires images taken by a camera 19 installed to photograph the landing threshold 11 and car threshold 15a of the entrance of the elevator 1 when the doors are open; a difference detection unit 23a that detects the difference in brightness between the brightness of a comparison image taken by the camera 19 and the brightness of a reference image when there are no objects on the landing threshold 11 and car threshold 15a of the entrance of the elevator 1; and a determination unit 24 that determines that an object is present at the entrance of the elevator 1 if the brightness difference is greater than or equal to a threshold.

Description

Technical Field

[0001] The present disclosure relates to an object detection device and an object detection system for an elevator entrance and exit for preventing the sandwiching of an object at an elevator door.

Background Art

[0002] Normally, an elevator is equipped with a sensor for detecting a person or the like at the elevator entrance and exit. However, this sensor can only detect an object of a certain size or more. For example, a string-like object such as a pet leash or a power cord cannot be detected by this sensor.

[0003] In the object detection device for an elevator entrance and exit described in Patent Document 1, light from a light-emitting device attached below the threshold of the door is captured by a camera that includes the threshold surface within the field of view across the width of the entrance and exit, and an area brightened by the light of the light-emitting device is extracted by image processing means. By checking for changes such as segmentation and / or partial omission in the bright area, a string-like object at the elevator entrance and exit is detected.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In order to realize an object detection device for an elevator entrance and exit as described in Patent Document 1, in addition to a camera, it was necessary to provide a light-emitting device as an additional device.

[0006] This disclosure was made to solve the problems described above, and aims to provide an elevator entrance object detection device and object detection system that can accurately detect objects at the elevator entrance without using any additional equipment other than a camera. [Means for solving the problem]

[0007] The elevator entrance object detection device according to this disclosure includes: an acquisition unit that acquires images taken by a camera installed to photograph the landing threshold and car threshold of the elevator entrance when the doors are open; a difference detection unit that detects the difference in brightness between the brightness of a comparison image taken by the camera and the brightness of a reference image when there are no objects on the landing threshold and car threshold of the elevator entrance; and a determination unit that determines that an object is present at the elevator entrance if the brightness difference is greater than or equal to a threshold. The difference detection unit generates a difference image that shows a difference in brightness, and even in areas with a difference in brightness, it detects the difference in brightness by displaying different brightness colors depending on the magnitude of the brightness difference in each area. Furthermore, an object detection device according to another embodiment sets a detection interval in the common section of the comparison image and the reference image and detects the brightness difference in the detection interval. In yet another embodiment, an object detection device updates the reference image based on the first image taken when the door is opened.

[0008] The elevator entrance object detection system according to this disclosure comprises: a camera installed to photograph the landing threshold and car threshold of the elevator entrance when the doors are open; an acquisition unit that acquires the image captured by the camera; a difference detection unit that detects the difference in brightness between the brightness of a comparison image captured by the camera and the brightness of a reference image when there are no objects on the landing threshold and car threshold of the elevator entrance; and a determination unit that determines that an object is present at the elevator entrance if the brightness difference is greater than or equal to a threshold. The difference detection unit generates a difference image that shows a difference in brightness, and even in areas with a difference in brightness, it detects the difference in brightness by displaying different brightness colors depending on the magnitude of the brightness difference in each area. ru. [Effects of the Invention]

[0009] According to the elevator entrance object detection device and object detection system described herein, it is possible to accurately detect objects at the elevator entrance without using any additional equipment other than a camera. [Brief explanation of the drawing]

[0010] [Figure 1] This diagram shows a building equipped with an elevator according to Embodiment 1. [Figure 2] This diagram shows the configuration of the entrance / exit of the basket as seen from inside the basket in Embodiment 1. [Figure 3] This is a diagram illustrating the configuration of an object detection system using an object detection device at the entrance / exit of an elevator in Embodiment 1. [Figure 4] This is an example of an image stored in the memory unit in Embodiment 1. [Figure 5] This diagram shows the hardware configuration of the object detection device at the elevator entrance / exit in Embodiment 1. [Figure 6] This is a flowchart showing the operation of the object detection system in Embodiment 1. [Figure 7] This is a diagram illustrating the configuration of an object detection system using an object detection device at the entrance / exit of an elevator in Embodiment 2. [Figure 8] This is an example of an image stored in the memory unit in Embodiment 2. [Figure 9] This is an example of an image stored in the memory unit in Embodiment 3. [Modes for carrying out the invention]

[0011] Embodiment 1. The configuration of the building 3 in which the elevator 1 is installed in Embodiment 1 will now be described. Figure 1 is a diagram showing the building 3 in which the elevator 1 is installed in Embodiment 1. In Figure 1, the building 3 comprises the elevator 1, a hoistway 2 for the car 7 to move vertically, a machine room 4 located above the hoistway 2, and landings 9 on each floor located opposite the hoistway 2. The machine room 4 is equipped with a hoisting machine 6 and a control panel 16 for controlling the elevator 1. The main rope 5 is wound around the hoisting machine 6, and the car 7 and counterweight 8 are connected by the main rope 5, and the elevator 1 is driven while balancing the car 7 and counterweight 8.

[0012] Furthermore, landing doors 10 are provided at the entrances and exits of each landing 9, and the landing doors 10 open and close along the landing sills 11 provided at the landings 9. In addition, a car door device 12 is provided at the entrance and exit of the elevator car 7. The car door device 12 comprises a car door 13 and a drive mechanism 14 provided above the car door 13 for opening and closing the car door 13. The car door 13 opens and closes along the car sill 15a provided below the car door device 12. Furthermore, when the elevator car 7 has arrived at the landing 9, the landing doors 10 and the car door 13 are connected by a coupling mechanism (not shown) according to a command from a door opening / closing control unit 25 (described later), and slide open and closed in conjunction with the operation of the drive mechanism 14.

[0013] The entrance and exit of car 7 will be described in detail. Figure 2 is a diagram showing the configuration of the entrance and exit of car 7 as seen from inside car 7 in Embodiment 1. In Figure 2, the front of the paper is the interior of car 7, and the back of the paper shows landing 9. Note that the ceiling of car 7 and the wall on the right side of car 7 are omitted from the illustration for explanatory purposes. Figure 2 also shows car 7 arriving at landing 9, with landing door 10 and car door 13 in the process of opening.

[0014] As shown in FIG. 2, at the entrance and exit of the car 7, a car door 13 and a car sill 15a are provided. The car door 13 is provided so as to face the landing door 10, and the car sill 15a is provided so as to face the landing sill 11. There is a gap 17 between the car sill 15a and the landing sill 11, and the hoistway 2 can be seen when looking down at the gap 17 from above.

[0015] Also, as shown in FIG. 2, inside the car 7, a car inner frame 18 is provided so as to surround the entrance and exit of the car 7. The car inner frame 18 is composed of an upper frame 18a provided at the upper part of the entrance and exit of the car 7 and vertical frames 18b provided on the left and right of the entrance and exit of the car 7. Further, a photographing device 19 is provided on the upper frame 18a.

[0016] The photographing device 19 is, for example, a camera. The photographing device 19 takes pictures at a predetermined cycle, for example, when the landing door 10 and the car door 13 are in the door-open state. Alternatively, the photographing device 19 may take pictures after detecting that a person or an object has boarded or alighted when the landing door 10 and the car door 13 are in the door-open state. The photographing device 19 is installed so as to be able to photograph an object that may be sandwiched by the landing door 10 and the car door 13 at the entrance and exit of the landing 9 and the entrance and exit of the car 7, that is, the entrance and exit of the elevator 1. Since the landing sill 11 and the car sill 15a exist at the entrance and exit of the elevator 1, specifically, the photographing device 19 is installed so as to be able to photograph the landing sill 11 and the car sill 15a. In addition to the installation location where the above-described members can be photographed, it is desirable that the photographing device 19 be installed at a location where unnecessary passenger photography can be avoided. For example, in the case of a double-opening car door 13 having a pair of panels as shown in FIG. 2, it is provided at a position that is the center of the frontage width at the entrance and exit of the car 7. Also, in the case of a single-opening car door 13 having one panel, it is provided at a position that is either the left or right end of the frontage width at the entrance and exit of the car 7.

[0017] Next, the object detection device 20a at the entrance and exit of the elevator 1 will be described. FIG. 3 is a configuration diagram of an object detection system 30a using the object detection device 20a at the entrance and exit of the elevator 1 in the first embodiment. The object detection system 30a includes a photographing device 19 and an object detection device 20a. The object detection device 20a includes an acquisition unit 21, a storage unit 22, a difference detection unit 23a, and a determination unit 24. Note that the functions of the acquisition unit 21, the storage unit 22, the difference detection unit 23a, the determination unit 24, and the door opening / closing control unit 25 that can communicate with the determination unit 24 may be realized by the control panel 16 or the drive machine 14, or may be configured separately from these.

[0018] The acquisition unit 21 acquires an image photographed by the photographing device 19.

[0019] The storage unit 22 stores the image acquired by the acquisition unit 21 as a reference image or a comparison image.

[0020] The reference image is an image obtained by photographing the entrance and exit of the elevator 1 when there is no object on the landing sill 11 and the car sill 15a at the entrance and exit of the elevator 1. For example, the reference image is the first image photographed by the photographing device 19 when the car 7 arrives at the landing 9 and the door is open. Also, when a reference image is already stored in the storage unit 22, the reference image stored in the storage unit 22 may be updated based on the first image photographed by the photographing device 19 when the door is open. Further, the reference image may be an image photographed at the landing 9 on each floor before the elevator 1 starts operating, for example, during installation work or maintenance work. Also, the reference image may be photographed by another photographing device other than the photographing device 19.

[0021] A comparison image is an image of the same area as the reference image, and is an image taken by the imaging device 19 after the reference image was taken. For example, the comparison image is the most recently taken image among multiple images taken by the imaging device 19 after the elevator car 7 arrives at landing 9, the doors open, and the reference image is taken. Although the comparison image is an image of the same area as the reference image, it does not need to be an image of the exact same area as the reference image; it is sufficient if an area that can be compared with the reference image for object detection at the entrance / exit of the elevator 1 is captured. Furthermore, it is not necessary to use the most recently captured image as the comparison image. For example, an average image obtained by averaging multiple images taken under different conditions such as exposure time may be used as the comparison image.

[0022] Figure 4 shows an example of an image stored in the memory unit 22 in Embodiment 1. Figure 4(a) is a reference image, Figure 4(b) is a comparison image, Figure 4(c) is a difference image, and Figure 4(d) is a waveform image showing the brightness difference.

[0023] Figure 4(a) is a reference image taken by the camera 19 when there are no objects on the landing sill 11 and car sill 15a at the entrance of elevator 1. This reference image shows the car sill 15a, the landing sill 11, and the gap 17 between the car sill 15a and the landing sill 11, with parts of the surrounding components, such as the car floor 7a, car door 13, landing floor 9a, and landing door 10, visible. Looking at the reference image, the car sill 15a, landing sill 11, car door 13, and landing door 10 are white, while the car floor 7a and landing floor 9a are gray. The hoistway 2 is visible in the gap 17, but because the hoistway 2 is dark, it appears as a black area.

[0024] Figure 4(b) is a comparative image of the entrance and exit of elevator 1, taken by the camera 19. In addition to the components shown in the reference image in Figure 4(a), this comparative image also shows a string-like object 26a. Object 26a is visible across the car floor 7a, car sill 15a, gap 17, landing sill 11, and landing floor 9a. Furthermore, looking at the comparative image, object 26a is a gray color with a brightness close to black, which is a color with a brightness that is darker than the car floor 7a and landing floor 9a, but brighter than the gap 17.

[0025] The difference detection unit 23a detects the luminance difference, which is the difference between the luminance of the comparison image and the luminance of the reference image. Specifically, it generates a difference image, which is an image showing the luminance difference, and detects the luminance difference.

[0026] Figure 4(c) is a difference image, showing the difference in brightness between the reference image shown in Figure 4(a) and the comparison image shown in Figure 4(b). In the difference image, areas with a small difference in brightness are displayed in a color close to white, and areas with a large difference in brightness are displayed in a color close to black. In other words, areas with a small difference in brightness are displayed in a bright color, and areas with a large difference in brightness are displayed in a dark color.

[0027] In Figure 4(c), the region 50, where object 26a is not visible in the comparison image, is displayed in white, indicating that this region has no brightness difference or a very small brightness difference.

[0028] On the other hand, in Figure 4(c), regions 27, 28, and 29, which are areas in the comparison image where object 26a is visible, are shown in gray or black, indicating that these regions have a difference in brightness.

[0029] Furthermore, even in areas with brightness differences, the brightness difference between the reference image and the comparison image differs depending on the area, so different areas are displayed with different brightness colors. Area 27, where the cage sill 15a or landing sill 11 is located, is displayed in black; area 29, where the gap 17 between the cage sill 15a and the landing sill 11 is located, is displayed in a light gray; and area 28, where the cage floor 7a or landing floor 9a is located, is displayed in a gray with a brightness between area 29 and area 27. In other words, area 29 is the brightest area, area 27 is the darkest area, and area 28 is displayed as an area with brightness between area 29 and area 28. Therefore, it can be said that area 29 is the area with the smallest brightness difference, area 27 is the area with the largest brightness difference, and area 28 is an area with brightness between area 29 and area 28.

[0030] Ideally, the difference detection unit 23a should detect brightness differences for all pixels in the difference image, but this requires considerable processing power. Therefore, it may also set a detection interval within the difference image and detect brightness differences within that interval. In other words, the difference detection unit 23a may set a detection interval in a common section of the comparison image and the reference image and detect brightness differences within that interval. The AA interval shown in Figure 4(c) is a detection interval that includes region 50 and region 27 where the elevator car sill 15a or landing sill 11 is provided. The following describes the case where the AA interval is set as the detection interval.

[0031] Figure 4(d) is an image showing the luminance difference in the AA section shown in Figure 4(c) as a waveform. This waveform image shows the luminance difference for each pixel (horizontal pixel) in the AA section, and the position of each pixel in the AA section corresponds to the position of the point plotted on the horizontal axis.

[0032] As can be seen in Figure 4(d), there are areas where the brightness difference is 0 and areas where the brightness difference is a positive value. Here, the areas where the brightness difference is 0 correspond to the location of region 50 in Figure 4(c), and the areas where the brightness difference is a positive value correspond to the location of region 27 in Figure 4(c). Therefore, by generating a waveform image like that in Figure 4(d), the difference detection unit 23a can easily detect the presence of a brightness difference in the detection interval.

[0033] In this way, the difference detection unit 23a can detect the brightness difference between the reference image and the comparison image by generating a difference image like the one shown in Figure 4(c) from the reference image shown in Figure 4(a) and the comparison image shown in Figure 4(b). Alternatively, a waveform image like the one shown in Figure 4(d) may be generated as a difference image that shows the brightness difference in the detection interval, and the brightness difference may be detected by this waveform image.

[0034] The determination unit 24 determines whether the brightness difference detected by the difference detection unit 23a is greater than or equal to a threshold. If it is greater than or equal to the threshold, the determination unit 24 determines that an object is present at the entrance of elevator 1 and transmits detection information indicating the presence of an object at the entrance of elevator 1 to the door opening / closing control unit 25. If it is less than the threshold, the determination unit 24 determines that no object is present at the entrance of elevator 1 and does not transmit detection information to the door opening / closing control unit 25. In this case, the door closes as usual.

[0035] The door opening / closing control unit 25 controls the opening and closing of the landing door 10 and the car door 13. The door opening / closing control unit 25 is provided separately from the object detection device 20a and the object detection system 30a, and when it receives detection information from the determination unit 24, it controls the landing door 10 and the car door 13 so as not to close the doors. Specifically, the door opening / closing control unit 25 controls the door to stop the closing operation if the door is in the process of closing, and controls the door to maintain the open state without issuing a door closing command if the door is in the open state.

[0036] Here, the hardware configuration of the object detection device 20a at the entrance / exit of elevator 1 in Embodiment 1 will be described. Figure 5 is a diagram showing the hardware configuration of the object detection device 20a at the entrance / exit of elevator 1 in Embodiment 1. The object detection device 20a at the entrance / exit of elevator 1 is implemented by a computer, such as a personal computer or a microcontroller.

[0037] The object detection device 20a at the entrance / exit of elevator 1 comprises a processor 41, memory 42, interface 43, and secondary storage device 44, all connected to each other via a bus 40.

[0038] The processor 41 is, for example, a CPU (Central Processing Unit). The processor 41 reads the operation program stored in the secondary storage device 44 into the memory 42 and executes it, thereby realizing each function of the object detection device 20a at the entrance and exit of the elevator 1.

[0039] Memory 42 is a main memory device, for example, composed of RAM (Random Access Memory). Memory 42 stores programs read by the processor 41 from the secondary memory device 44. Memory 42 also functions as work memory when the processor 41 executes programs.

[0040] Interface 43 is an I / O (Input / Output) interface such as a serial port, USB (Universal Serial Bus) port, or network interface. Input from the imaging device 19 is received through interface 43.

[0041] The secondary storage device 44 is, for example, flash memory, an HDD (Hard Disk Drive), or an SSD (Solid State Drive). The secondary storage device 44 stores various information necessary for the operation of the object detection device 20a at the entrance / exit of the elevator 1, as well as programs executed by the processor 41.

[0042] Next, the operation of the object detection system 30a using the object detection device 20a at the entrance / exit of elevator 1 will be described. Figure 6 is a flowchart showing the operation of the object detection system 30a in Embodiment 1. This flowchart shows the flow from when the car 7 arrives at landing 9, when the doors open, until when they close. In this flow, the reference image is assumed to be the first image taken by the camera 19 after the car 7 arrives at landing 9 and the doors are open.

[0043] In step S1, when the elevator car 7 stops at the landing 9, in step S2, the door opening / closing control unit 25 starts opening the landing door 10 and the elevator car door 13. The landing door 10 and the elevator car door 13 are connected by a coupling mechanism (not shown) and slide open in conjunction with the operation of the drive unit 14. In step S3, when the doors are open, in step S4, the camera 19 first takes a reference image as shown in Figure 4(a). The acquisition unit 21 acquires the reference image, and the storage unit 22 stores the reference image acquired by the acquisition unit 21. If the storage unit 22 has already stored a reference image, the storage unit 22 updates the reference image stored in the storage unit 22 based on the image first taken by the camera 19 when the doors are open.

[0044] In step S5, the imaging device 19 takes comparison images as shown in Figure 4(b) at predetermined intervals. The acquisition unit 21 acquires the comparison images, and the storage unit 22 stores the comparison images acquired by the acquisition unit 21.

[0045] In step S6, the difference detection unit 23a detects the luminance difference in step S7 by generating a difference image as shown in Figure 4(c) in order to detect the luminance difference, which is the difference between the luminance of the comparison image and the luminance of the reference image. Alternatively, in steps S6 and S7, the difference detection unit 23a may be configured to generate a waveform image showing the luminance difference from the difference image as shown in Figure 4(d) and detect the luminance difference.

[0046] In step S8, the determination unit 24 determines whether the brightness difference detected by the difference detection unit 23a is greater than or equal to a threshold.

[0047] If the luminance difference detected by the difference detection unit 23a is greater than or equal to a threshold, the determination unit 24 determines that an object is present at the entrance / exit of elevator 1 and proceeds to step S9. If the luminance difference detected by the difference detection unit 23a is less than a threshold, the determination unit 24 determines that no object is present at the entrance / exit of elevator 1 and proceeds to step S10.

[0048] In step S9, the determination unit 24 transmits detection information to the door opening / closing control unit 25 indicating that an object is present at the entrance / exit of elevator 1. Upon receiving the detection information, the door opening / closing control unit 25 controls the landing door 10 and the car door 13 to prevent them from closing.

[0049] After the door is controlled not to close in step S9, the processes in steps S5 to S8 are repeated. Then, in step S8, the processes in steps S5 to S8 are repeated until the determination unit 24 determines that the brightness difference detected by the difference detection unit 23a is less than the threshold and that there is no object at the entrance of elevator 1.

[0050] In step S10, the door opening / closing control unit 25 starts closing the landing door 10 and the car door 13. Then, in step S11, if the doors are fully closed, the process ends. Also, in step S11, if the doors are not fully closed, i.e., the door closing operation is in progress, the process returns to step S5 to detect whether or not an object is present at the entrance / exit of the elevator 1, and the process from step S5 to step S8 is repeated. In this way, the acquisition unit 21 acquires images captured by the camera 19 even during the door closing operation, the difference detection unit 23a detects the brightness difference between the brightness of the comparison image captured by the camera 19 during the door closing operation and the brightness of the reference image, and the determination unit 24 determines that an object is present at the entrance / exit of the elevator 1 if the brightness difference is greater than or equal to a threshold. With this configuration, it is possible to detect an object at the entrance / exit of the elevator 1 even during the door closing operation. Note that a process may be added to ignore the brightness difference caused by the door being captured during closing.

[0051] As described above, the object detection device 20a at the entrance of elevator 1 includes: an acquisition unit 21 that acquires images taken by a camera 19 installed to photograph the landing threshold 11 and car threshold 15a at the entrance of elevator 1 when the doors are open; a difference detection unit 23a that detects the difference in brightness between the brightness of a comparison image taken by the camera 19 and the brightness of a reference image when there are no objects on the landing threshold 11 and car threshold 15a at the entrance of elevator 1; and a determination unit 24 that determines that an object is present at the entrance of elevator 1 if the brightness difference is greater than or equal to a threshold. In this way, the object detection device 20a at the entrance of elevator 1 can accurately detect objects at the entrance of elevator 1 without using any additional equipment other than a camera. Furthermore, because it is configured to detect the brightness difference between a reference image and a comparison image, it can accurately detect even objects that are too small to be detected by sensors normally installed in elevator 1 to detect people at the entrance of elevator 1.

[0052] Furthermore, the difference detection unit 23a can reduce the processing burden when detecting brightness differences by pre-setting a detection interval in a common section of the comparison image and the reference image and detecting the brightness difference in the detection interval.

[0053] Furthermore, while the difference detection unit 23a previously detected the luminance difference by generating a difference image, which is an image showing the luminance difference, the difference detection unit 23a only needs to be able to detect the luminance difference. For example, it may output the luminance of each image without generating a difference image and detect the luminance difference by calculating the difference in luminance.

[0054] Alternatively, the difference image may be generated as a waveform image showing only the brightness difference within the detection interval, which is the AA interval. In this case, the processing burden when generating the difference image can be reduced.

[0055] Furthermore, in step S4 of the operation of the object detection system 30a, a reference image is first captured when the door is opened, and this reference image is stored in the memory unit 22. If a reference image is already stored in the memory unit 22, the reference image stored in the memory unit 22 is updated based on the image first captured when the door is opened. With these configurations, a reference image that reflects environmental changes and aging changes of materials can be set, so that the difference detection unit 23a can accurately detect the brightness difference between the comparison image and the reference image. Environmental changes refer to changes in the brightness of the reference image due to the weather or the lighting conditions inside the landing 9 or car 7. Aging changes of materials refer to changes in materials such as scratches or dents appearing on materials that are visible in the reference image.

[0056] Furthermore, as shown in step S11 of the operation of the object detection system 30a, the acquisition unit 21 acquires images captured by the camera 19 even during the door closing operation, the difference detection unit 23a detects the brightness difference between the brightness of the comparison image captured by the camera 19 during the door closing operation and the brightness of the reference image, and the determination unit 24 determines that an object is present at the entrance of the elevator 1 if the brightness difference is greater than or equal to a threshold. This configuration makes it possible to detect an object at the entrance of the elevator 1 even during the door closing operation.

[0057] Furthermore, the location where the imaging device 19 is installed is not limited, as long as it can be installed in a place where it can photograph whether or not an object is present at the entrance / exit of elevator 1.

[0058] Furthermore, the detection interval set by the difference detection unit 23a within the difference image is not limited to a linear interval as shown in Figure 4(c), but may be set as an area with a certain area. In this case, the generated difference image may be represented as a three-dimensional waveform image rather than a two-dimensional waveform image as shown in Figure 4(d).

[0059] Furthermore, when detection information is received from the determination unit 24, in addition to controlling the elevator so as not to close the doors, a warning device installed inside the elevator may also be configured to warn that an object has been detected.

[0060] Embodiment 2. Figure 7 is a diagram showing the configuration of the object detection system 30b using the object detection device 20b at the entrance / exit of elevator 1 in Embodiment 2. As shown in Figure 7, in Embodiment 2, the object detection device 20b and the object detection system 30b at the entrance / exit of elevator 1 differ from the object detection device 20a at the entrance / exit of elevator 1 in Embodiment 1 in that the difference detection unit 23b sets two detection intervals.

[0061] Figure 8 shows examples of images stored in the memory unit 22 in Embodiment 2. Figure 8(a) is a reference image, Figure 8(b) is a comparison image, Figure 8(c) is a difference image, and Figures 8(d) and (e) are waveform images showing the brightness difference. Note that Figure 8(a) is the same figure as Figure 4(a).

[0062] Figure 8(b) shows a string-like, black object 26b in addition to the components shown in the reference image in Figure 8(a). Object 26b is visible across the elevator car floor 7a, elevator car sill 15a, gap 17, landing sill 11, and landing floor 9a. Furthermore, in the comparison image, object 26b and gap 17 appear as black objects of the same brightness.

[0063] In Figure 8(c), region 70, where object 26b is not visible in the comparison image, is displayed in white. Furthermore, region 60, where object 26b is visible in the comparison image and where a gap 17 with the same brightness as object 26b (black) is present, is also displayed in white. Thus, since regions 70 and 60 are displayed in white, it can be seen that these regions have no brightness difference, or the brightness difference is very small.

[0064] Furthermore, in Figure 8(c), among the areas where object 26b is visible in the comparison image, the area 61 where the white landing sill 11 or car sill 15a is located is displayed in black, indicating that there is a difference in brightness in that area.

[0065] In this embodiment, the difference detection unit 23b sets two detection intervals: a BB interval which spans both region 70 and region 60, and a CC interval which spans both region 70 and region 61, and performs detection for both detection intervals. The waveform image in Figure 8(d) is a waveform image showing the brightness difference in the BB interval, and the waveform image in Figure 8(e) is a waveform image showing the brightness difference in the CC interval. In the waveform image in Figure 8(d), no brightness difference is detected at the positions corresponding to region 70 and region 60, but in the waveform image in Figure 8(e), although no brightness difference is detected at the position corresponding to region 70, a brightness difference is detected at the position corresponding to region 61. Therefore, the difference detection unit 23b can detect a brightness difference in the CC interval, even though no brightness difference was detected in the BB interval.

[0066] As described above, the difference detection unit 23b in Embodiment 2 is configured to set two detection intervals. These detection intervals are set at the locations where the gap 17, which is black, and the landing sill 11 or car sill 15a, which is white, are provided. In this way, the difference detection unit 23b detects the difference in brightness by comparing the brightness of two or more detection intervals, which have different brightness levels in the reference image, with the brightness of the region in the comparison image corresponding to each detection interval. This makes it possible to detect the difference in brightness even if the object at the entrance of the elevator 1 has the same brightness color as one of the members set in the detection interval.

[0067] Embodiment 3. Embodiment 3 differs from Embodiments 1 and 2 in that the cage sill 15c is composed of two colors.

[0068] Figure 9 shows an example of an image stored in the memory unit 22 in Embodiment 3. Figure 9(a) is a reference image, Figure 9(b) is a comparison image, Figure 9(c) is a difference image, and Figure 9(d) is a waveform image showing the brightness difference in the DD section.

[0069] The reference image shown in Figure 9(a) shows the elevator car sill 15c, with parts of the surrounding components, the elevator car floor 7a and elevator car door 13, visible. Note that the landing sill 11, gap 17, landing floor 9a, and landing door 10, which are the same components as those shown in the reference image in Figure 4(a) in Embodiment 1, are omitted from the illustration. The elevator car sill 15c is composed of two colors, white and black, and has a diagonal stripe design with alternating white and black stripes. Similarly, some components are omitted from the illustrations in Figures 9(b) and 9(c).

[0070] The comparison image shown in Figure 9(b) includes, in addition to the components shown in the reference image in Figure 8(a), a string-like, black object 26c. Object 26c is visible across the cage floor 7a, the cage sill 15c, and the gap 17. Furthermore, the comparison image shows that object 26c is depicted as black with the same brightness as the black area of ​​the cage sill 15c.

[0071] In Figure 9(c), region 90, which is the area in the comparison image where object 26c is not visible, is displayed in white. Also, in the comparison image where object 26c is visible, region 80, which corresponds to the black area of ​​the black cage sill 15c with the same brightness as object 26c, is also displayed in white. Thus, since regions 90 and 80 are displayed in white, it can be seen that these regions have no brightness difference or a very small brightness difference.

[0072] Furthermore, in Figure 9(c), in the comparison image, region 81, which corresponds to the white region of the cage sill 15c, is displayed in black, indicating that it is a region with a difference in brightness.

[0073] In this embodiment 3, the difference detection unit 23a sets the detection interval to a DD interval, which is the region spanning region 90, region 80, and region 81. In the waveform image of Figure 9(d), no brightness difference is detected at the positions corresponding to region 90 and region 80, but a brightness difference is detected at the position corresponding to region 81. Therefore, the difference detection unit 23a can detect a brightness difference in the DD interval.

[0074] Although an example was given in which the car sill 15c is made of two colors, the landing sill 11 may also be made of two colors, or both the car sill 15c and the landing sill 11 may be made of two colors. However, in a building with one elevator 1, there is only one car sill 15c and one landing sill 11 for each floor, so if only the car sill 15c is made of two colors, the number of components that need to be changed will be reduced.

[0075] Thus, at least one of the landing thresholds 11 and car thresholds 15c that constitute the entrance and exit of elevator 1 is composed of two or more colors, and the difference detection unit 23a sets the detection interval to include areas of two or more colors in the landing threshold 11 or car threshold 15c, so that even if an object at the entrance and exit of elevator 1 is the same brightness color as one of the two colors of the landing threshold 11 or car threshold 15c set in the detection interval, a brightness difference can be detected.

[0076] In the example given, the cage sill 15c is composed of two-color diagonal stripes, but it can be made with three or more colors, and the design is not limited to stripes; it can also be a striped pattern, mosaic pattern, or other designs. In this way, the more colors that make up the cage sill 15c, the lower the possibility of detection failure and the higher the detection accuracy. Also, the more complex the design pattern, the lower the possibility of detection failure and the higher the detection accuracy.

[0077] The configurations shown in the embodiments described above are examples of the content of this disclosure. The embodiments can be combined with other known technologies. Some parts of the configurations of the embodiments can be omitted or modified without departing from the gist of this disclosure.

[0078] The various aspects of this disclosure are summarized below as an appendix. (Note 1) An acquisition unit that acquires images captured by a camera that is installed to photograph the landing threshold and car threshold of the elevator entrance when the doors are open, A difference detection unit detects the difference in brightness between the brightness of a comparison image captured by the aforementioned imaging device and the brightness of a reference image when there are no objects on the elevator entrance threshold and the elevator car threshold. A determination unit determines that an object is present at the elevator entrance if the brightness difference is greater than or equal to a threshold, An object detection device for elevator entrances and exits equipped with [the specified feature]. (Note 2) The difference detection unit sets a detection interval in the common section of the comparison image and the reference image, and detects the brightness difference in the detection interval. An object detection device for an elevator entrance / exit as described in claim 1. (Note 3) The difference detection unit detects the difference in brightness by comparing the brightness of two or more detection intervals in the reference image, where the brightness of each detection interval is different from that of the corresponding region in the comparison image. An object detection device for an elevator entrance / exit according to claim 2. (Note 4) At least one of the landing threshold and the car threshold of the elevator entrance is composed of two or more colors. The difference detection unit sets the detection interval to include the two or more colored areas on the landing threshold or the elevator car threshold. An object detection device for an elevator entrance / exit according to claim 2. (Note 5) The difference detection unit generates a difference image, which is an image showing the difference in brightness, and detects the difference in brightness. An object detection device for an elevator entrance / exit according to claim 1 or 2. (Note 6) The difference detection unit generates a waveform image as a difference image, which is an image showing the brightness difference in the detection interval. An object detection device for an elevator entrance / exit according to claim 2. (Note 7) The acquisition unit includes a storage unit that stores the images acquired by the acquisition unit, The storage unit updates the reference image stored in the storage unit based on the image first captured by the camera when the door is opened. An object detection device for an elevator entrance / exit according to any one of claims 1 to 6. (Note 8) The acquisition unit acquires the image captured by the camera during the door closing operation. The difference detection unit detects the difference in brightness between the brightness of the comparison image captured by the camera during the door closing operation and the brightness of the reference image. The determination unit determines that an object is present at the elevator entrance if the brightness difference is greater than or equal to a threshold. An object detection device for an elevator entrance / exit according to any one of claims 1 to 6. (Note 9) A camera is installed to photograph the landing threshold and car threshold of the elevator entrance when the doors are open, The aforementioned imaging device includes an acquisition unit that acquires an image captured by the imaging device, A difference detection unit detects the difference in brightness between the brightness of a comparison image captured by the aforementioned imaging device and the brightness of a reference image when there are no objects on the elevator entrance threshold and the elevator car threshold. A determination unit determines that an object is present at the elevator entrance if the brightness difference is greater than or equal to a threshold, An object detection system for elevator entrances and exits equipped with [the specified feature]. [Explanation of Symbols]

[0079] 1 Elevator, 2 Hoistway, 3 Building, 4 Machine Room, 5 Main Rope, 6 Hoisting Machine, 7 Cage, 7a Cage Floor, 8 Counterweight, 9 Landing, 9a Landing Floor, 10 Landing Door, 11 Landing Threshold, 12 Cage Door Device, 13 Cage Door, 14 Drive Machine, 15a, 15c Cage Threshold, 16 Control Panel, 17 Gap, 18 Cage Interior Frame, 18a Upper Frame, 18b Vertical Frame, 19 Photographing Device, 20a, 20b Object Detection Device, 21 Acquisition Unit, 22 Storage Unit, 23a, 23b Difference Detection Unit, 24 Judgment Unit, 25 Door Opening / Closing Control Unit, 26a, 26b, 26c Object, 27, 28, 29, 50, 60, 61, 70, 80, 81, 90 Area, 30a, 30b Object detection system, 40 Bus, 41 Processor, 42 Memory, 43 Interface, 44 Secondary storage device

Claims

1. An acquisition unit that acquires images captured by a camera that is installed to photograph the landing threshold and car threshold of the elevator entrance when the doors are open, A difference detection unit detects the difference in brightness between the brightness of a comparison image captured by the aforementioned imaging device and the brightness of a reference image when there are no objects on the elevator entrance threshold and the elevator car threshold. A determination unit determines that an object is present at the elevator entrance if the brightness difference is greater than or equal to a threshold, Equipped with, The difference detection unit generates a difference image of the image showing the brightness difference, in which even in the region where there is a brightness difference, the brightness of the region is displayed in a different color depending on the magnitude of the brightness difference, and detects the brightness difference. Object detection device at elevator entrance / exit.

2. An acquisition unit that acquires images captured by a camera that is installed to be able to photograph the landing threshold and car threshold of the elevator entrance when the doors are open, A difference detection unit detects the difference in brightness between the brightness of a comparison image captured by the aforementioned imaging device and the brightness of a reference image when there are no objects on the elevator entrance threshold and the elevator car threshold. A determination unit determines that an object is present at the elevator entrance if the brightness difference is greater than or equal to a threshold, Equipped with, The difference detection unit sets a detection interval in the common section of the comparison image and the reference image, and detects the brightness difference in the detection interval. Object detection device at elevator entrance / exit.

3. The difference detection unit detects the brightness difference by comparing the brightness of two or more detection intervals in the reference image that have different brightness levels with the brightness of the corresponding region in the comparison image for each detection interval. An object detection device for an elevator entrance / exit according to claim 2.

4. At least one of the landing threshold and the car threshold of the elevator entrance is composed of two or more colors. The difference detection unit sets the detection interval to include the two or more colored areas on the landing threshold or the elevator car threshold. An object detection device for an elevator entrance / exit according to claim 2.

5. The difference detection unit generates a waveform image as a difference image, which is an image showing the brightness difference in the detection interval. An object detection device for an elevator entrance / exit according to claim 2.

6. An acquisition unit that acquires images captured by a camera that is installed to be able to photograph the landing threshold and car threshold of the elevator entrance when the doors are open, A difference detection unit detects the difference in brightness between the brightness of a comparison image captured by the aforementioned imaging device and the brightness of a reference image when there are no objects on the elevator entrance threshold and the elevator car threshold. A determination unit determines that an object is present at the elevator entrance if the brightness difference is greater than or equal to a threshold, The system includes a storage unit that stores the image acquired by the acquisition unit, The storage unit updates the reference image stored in the storage unit based on the image first captured by the camera when the door is opened. Object detection device at elevator entrance / exit.

7. The acquisition unit acquires the image captured by the camera during the door closing operation. The difference detection unit detects the difference in brightness between the brightness of the comparison image captured by the camera during the door closing operation and the brightness of the reference image. The determination unit determines that an object is present at the elevator entrance if the brightness difference is greater than or equal to a threshold. An object detection device for an elevator entrance / exit according to any one of claims 1 to 5.

8. A camera is installed to photograph the landing threshold and car threshold of the elevator entrance when the doors are open, The aforementioned imaging device includes an acquisition unit that acquires an image captured by the imaging device, A difference detection unit detects the difference in brightness between the brightness of a comparison image captured by the aforementioned imaging device and the brightness of a reference image when there are no objects on the elevator entrance threshold and the elevator car threshold. A determination unit determines that an object is present at the elevator entrance if the brightness difference is greater than or equal to a threshold, Equipped with, The difference detection unit generates a difference image of the image showing the brightness difference, in which even in the region where there is a brightness difference, the brightness of the region is displayed in a different color depending on the magnitude of the brightness difference, and detects the brightness difference. Object detection system for elevator entrances and exits.

9. A photographic device installed to photograph the landing threshold and car threshold of the elevator entrance when the doors are open, An acquisition unit that acquires images captured by a camera that is installed to photograph the landing threshold and car threshold of the elevator entrance when the doors are open, A difference detection unit detects the difference in brightness between the brightness of a comparison image captured by the aforementioned imaging device and the brightness of a reference image when there are no objects on the elevator entrance threshold and the elevator car threshold. A determination unit determines that an object is present at the elevator entrance if the brightness difference is greater than or equal to a threshold, Equipped with, The difference detection unit sets a detection interval in the common section of the comparison image and the reference image, and detects the brightness difference in the detection interval. Object detection system for elevator entrances and exits.

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