Elevator anti-pinch method and system and automatic door anti-pinch method and system

Abstract

The invention discloses an elevator anti-pinch method and system and an automatic door anti-pinch method and system. The elevator anti-pinch method comprises the steps that in response to acquired preset elevator car door state information, an imaging device used for preventing pinch is started; the imaging device projects laser to a part of a slit area after being started and images the part of the slit area based on reflected light of the projected laser, and the slit area corresponds to a long and narrow part between the car door and the corridor elevator door; and on the basis of the imaging image, it is judged that shielding exists in the part of the slit area, and a car door opening signal is generated. According to the invention, the conventional depth camera is installed as an anti-pinch imaging device and only carries out imaging on a limited area before the automatic door is closed, so that the imaging device can focus on detection of a shielding object before the automatic door is closed, and efficient anti-pinch detection is realized at extremely low cost.

Description

Technical Field

[0001] The present disclosure relates to the field of machine vision, and in particular to an anti-pinch method and system for elevators, and an anti-pinch method and system for automatic doors. Background Art

[0002] The safety performance of modern automatic door systems, represented by box-type elevators, has been continuously improved. The anti-pinch function of automatic doors has evolved from the mechanical switch action mode of mechanical touch panels to a non-contact signal action mode of light curtains, and the performance of elevator light curtains has been improved through projected linear light curtains and matching ToF (time of flight) sensors.

[0003] However, due to safety considerations, in elevator applications, the gap between the car door and the corridor elevator door is usually very narrow (for example, less than 3cm), so the concentration of linear light is very high, which places extremely high performance requirements on the light source module that projects linear light, thereby greatly increasing the cost of elevator light curtain equipment. If linear light with a larger projection range is used, it will cause irregular reflections when the car door is closed, which will seriously interfere with the detection of whether there is an object in the gap when the car door is closed.

[0004] Therefore, a more stable and lower-cost elevator anti-pinch solution is needed. Summary of the invention

[0005] A technical problem to be solved by the present disclosure is to provide an elevator anti-pinch method and system, as well as an automatic door anti-pinch method and system. The present invention installs a conventional depth camera as an anti-pinch imaging device at a position closer to the lower part of the elevator and only turns on the device during the elevator closing process. By narrowing the field of view and the activation period, the imaging device can focus on detecting obstructions before the elevator is closed, thereby achieving efficient anti-pinch detection at a very low cost.

[0006] According to a first aspect of the present invention, a method for preventing elevator pinching is proposed, comprising: in response to obtaining predetermined car door status information, turning on an imaging device for preventing pinching; after the imaging device is turned on, projecting a laser onto a portion of a slit area, and imaging the portion of the slit area based on reflected light of the projected laser, wherein the slit area corresponds to a long and narrow portion between the car door and the corridor elevator door; and determining the presence of occlusion in the portion of the slit area based on the imaging image, generating a car door opening signal.

[0007] Optionally, the imaging device used for anti-pinch is a conventional depth measuring device with an aspect ratio of the projection area and the imaging area not exceeding 2:1.

[0008] Optionally, the method further includes: using a proximity sensor to acquire car door status information; and / or receiving car door status information acquired by a light curtain device.

[0009] Optionally, the predetermined car door status information includes at least one of the following: a car door start opening signal; a car door fully open signal; a car door start closing signal; and a car door closed to a specific stage signal.

[0010] Optionally, the portion of the slit area covered by the laser projection range of the imaging device corresponds to the portion before the car door is fully closed.

[0011] Optionally, the imaging device keeps the projection area and the imaging area unchanged during the startup process.

[0012] Optionally, the imaging device is installed above the car door.

[0013] Optionally, based on the imaging image, it is determined that there is an obstruction in the part of the slit area, and generating a car door opening signal includes: calculating the imaging part of the imaging image corresponding to the part of the slit area; and determining whether there is an obstruction in the part of the slit area based on the calculation result.

[0014] Optionally, the imaging device includes a light source module and a ToF sensor, wherein the light source module includes: a light-emitting device for generating a laser beam; and a diffuser arranged on a propagation light path of the light beam to convert the laser beam into a planar array light; and / or the ToF sensor is a direct time-of-flight sensor that generates a sensing signal representing the distance based on the reception time of the returned light.

[0015] According to a second aspect of the present invention, an elevator anti-pinch system is proposed, comprising: a car; a closing detection device for detecting whether the car door can be closed after the car door is opened; and an imaging device for anti-pinch, for executing the method described in the first aspect in response to obtaining predetermined automatic door status information.

[0016] Optionally, the closing detection device includes a light curtain device for generating the car door closing signal when it is determined that the car door is closed without obstruction, and the car door opening control authority of the imaging device for anti-pinch during the opening period is higher than the car door closing control authority of the closure detection device.

[0017] According to a third aspect of the present invention, an automatic door anti-pinch method is proposed, comprising: in response to obtaining predetermined automatic door status information, turning on an imaging device for anti-pinch; after being turned on, the imaging device projects a laser toward a portion of a long and narrow area, and images the portion of the long and narrow area based on reflected light of the projected laser, wherein the long and narrow area corresponds to a portion passed by the automatic door during opening and closing; and determining the presence of an obstruction on the portion of the long and narrow area based on the imaging image, generating an automatic door opening signal.

[0018] According to a fourth aspect of the present invention, an automatic door anti-pinch system is proposed, wherein the automatic door automatically opens or closes according to a control signal, and an imaging device for anti-pinch is provided, and the system includes: a device for executing the method described in the third aspect in response to obtaining predetermined automatic door status information.

[0019] Preferably, the system further comprises: a closing detection device for detecting whether the automatic door can be closed after the automatic door is opened.

[0020] The anti-pinch solution of the present invention uses a conventional depth camera that is cleverly set to accurately detect obstructions in high-interference and high-reflection scenes, overcoming the technical bias in the prior art that high-performance customized cameras are required to achieve accurate anti-pinch. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components in the exemplary embodiments of the present disclosure.

[0022] Figure 1A -C shows an example of the installation of an elevator light curtain device in the prior art and the relationship between the projection area, the imaging field of view and the elevator gap.

[0023] Figure 2A -B shows an example of the relationship between the position of the imaging device installed in the elevator anti-pinch method according to an embodiment of the present invention and its projection area, the imaging field of view and the elevator pinch.

[0024] Figure 3 A schematic flow chart of an elevator anti-pinch method according to an embodiment of the present invention is shown.

[0025] Figure 4A -C shows an example of the anti-pinch imaging device identifying an obstruction.

[0026] Figure 5 The imaging device is shown imaging the slit and the obstruction.

[0027] Figure 6 A schematic diagram of the operation of an elevator anti-pinch system according to an embodiment of the present invention is shown.

[0028] Figure 7 A schematic flow chart of an automatic door anti-pinch method according to an embodiment of the present invention is shown.

[0029] Fig. 8A -C shows several examples of realizing automatic door anti-pinch using the anti-pinch imaging device according to the present invention. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0031] The safety performance of modern elevator door systems is constantly improving. The anti-pinch function of the elevator door has evolved from a mechanical switch action mode of a mechanical touch panel to a non-contact signal action mode of a light curtain, and the performance of the elevator light curtain has been improved through a projected linear light curtain and a matching ToF (time of flight) sensor.

[0032] However, due to safety considerations, the gap between the car door and the corridor elevator door is usually very narrow (for example, required to be less than 3 cm). Figure 1A -C shows an example of the installation of the elevator light curtain device in the prior art and the relationship between the projection area, the imaging field of view and the elevator gap. For the convenience of description, the horizontal plane can be defined as the xy plane, where the direction parallel to the car door is the x direction, the direction perpendicular to the car door is the y direction, and the vertical direction of the elevator moving up and down is defined as the z direction. In order to cover the entire car door area as much as possible in space, Figure 1A The figure shows a schematic diagram of an elevator light curtain device installed above the elevator door projecting laser downward to form a "light curtain" between the elevator door and the corridor elevator door when both the elevator door and the corridor elevator door are open. The elevator light curtain device can be regarded as a depth camera that actively projects light and forms an image based on the reflected light of the projected light. Figure 1A As shown, the laser projected by the light source module of the elevator light curtain device has a predetermined divergence angle, and the "light curtain" formed thereby can cover most of the entry and exit area framed by the car door frame.

[0033] Figure 1B and Figure 1C It is a schematic diagram of the projection area and imaging field of view of the elevator light curtain relative to the gap from a bird's-eye view. Figure 1B and Figure 1C Can be seen as Figure 1A The cross-sectional view along the AA' direction in the figure is obtained. The height of the lower edge of the car door and the corridor elevator door is selected because both projection and imaging have divergence angles. The difficulty of the elevator light curtain is to keep the light beam and imaging area within a specific range at the position farthest from the elevator light curtain device. In addition, Figure 1B It shows the state when the car door and the corridor elevator door are closed. Figure 1CThe state when the car door and the corridor elevator door are both open is shown. The car door and the corridor elevator door shown in the figure are single-side opening doors, that is, the door retracts from the closed state on the left to the right to become open, and when closed, it changes from the retracted state on the right to the extended state toward the left.

[0034] It should be understood that for the sake of convenience, Figure 1B and Figure 1C The actual width of the gap is increased. In actual scenarios, for safety reasons, the gap between the car door and the corridor elevator door is much narrower than the relative width shown in the figure, for example, no more than 3 cm, while the width of the elevator door is usually 1.5 meters to 2 meters.

[0035] Figure 1B An example is shown in which the projection area and imaging field of the elevator light curtain roughly coincide with the elevator gap. Figure 1B The most theoretically preferred projection area and imaging field of view are shown. This is because limiting the projection area and imaging field of view within the gap range can avoid the influence of reflected light generated by the opening and closing of the car door on the imaging result to the greatest extent.

[0036] However, in actual application scenarios, the above projection area and imaging field of view are usually difficult to achieve. Figure 1A When installed on the top of the car door as shown, since the car door is usually about 2 meters high, a projection area of ​​1.5 meters long and 3 centimeters wide is still formed near the bottom of the car door 2 meters away. This places extremely high performance requirements on the projection concentration of the light source module, thereby greatly increasing the cost of the elevator light curtain equipment. Even if the light source module can maintain a high concentration in the early stage of use, the concentration of the linear light will deteriorate with the passage of use (for example, the width exceeds 10 cm after 3 months of use), resulting in frequent maintenance and replacement. Although the prior art can reduce the difficulty of forming linear light through point laser scanning, point laser diffusion splicing and other methods, the above scanning and diffusion splicing solutions will increase the complexity and cost of the system.

[0037] In addition, in conventional imaging devices, the imaging field of view is usually a rectangle with a close aspect ratio, for example, a rectangular field of view with an aspect ratio of 4:3 corresponding to 800x600 pixels. Therefore, it is also a huge challenge for conventional imaging devices to have an imaging area of ​​1.5 meters in length and 3 centimeters in width in a 2-meter shape.

[0038] to this end, Figure 1C A specially customized imaging sensor is used to achieve imaging of the slit area. Figure 1CAn example is shown in which the imaging field of view roughly coincides with the elevator gap, but the projection area is much larger than the elevator gap area. In this case, a ToF elevator light curtain device including a light source module and a ToF sensor can be used. In this case, the light source module can be a conventional light source module, such as a light source module that projects a planar array of light, as long as its projection range can include the gap between the car door and the corridor elevator door.

[0039] The ToF elevator light curtain device uses a special ToF sensor as an imaging sensor. The ToF sensor includes a customized strip-shaped imaging area for acquiring the return light from the gap and generating a sensing signal. Here, the imaging area is strip-shaped, which can refer to the fact that in its imaging area, the pixels in one direction are much larger than the pixels in another direction. In one embodiment, in the imaging area of ​​the ToF sensor, the ratio of pixel columns to pixel rows is greater than 10:1. In a preferred embodiment, the ratio of pixel columns to pixel rows in the imaging area of ​​the ToF sensor can even be greater than 50:1. Thus, the ToF sensor 320 can have a strip-shaped imaging field of view. When installing the ToF elevator light curtain, installation and debugging can be performed so that the field of view of the ToF sensor coincides with the gap area between the car door and the corridor elevator door. In this way, as long as the projected light can cover the gap area, only the return light in the gap area can be acquired.

[0040] exist Figure 1C In the example, the need for projecting highly concentrated linear light is eliminated by replacing the "light curtain" (i.e., the projection light coverage is like the curtain between the car door and the elevator door) with an "imaging curtain" (i.e., the imaging field of view is like the curtain between the car door and the elevator door in the corridor). Furthermore, since the imaging field of view stability of the ToF sensor is much higher than the projection concentration stability of the linear light (i.e., it is not easy to deteriorate with the increase of use time), the ToF sensor of this solution has lower maintenance and replacement requirements.

[0041] However, in Figure 1C In the implementation, a ToF sensor with a pixel column to pixel row ratio greater than 10:1 needs to be specially customized, resulting in a high cost for the imaging device. Furthermore, since the projection area of ​​a conventional light source module is much larger than the gap area, when people, animals or objects enter or exit the elevator, especially during the opening or closing of the car door, the ToF sensor will not be able to correctly image the gap area due to the large amount of reflections generated, and thus cannot recognize obstructions during the opening and closing of the car door.

[0042] In order to solve the above problems, contrary to the conventional thinking in the field of adopting more complex settings and more advanced imaging equipment, the inventors of the present invention abandoned the idea of ​​covering the entire car door area and instead adopted an extremely simple method to achieve highly accurate elevator anti-pinch.

[0043] In the elevator anti-pinch solution disclosed in the present invention, a special imaging device is provided which is turned on only after receiving a car door closing signal. The imaging device has a conventional narrow field of view and is preferably installed at a position closer to the bottom of the car. Figure 2A -B shows an example of the relationship between the position of the imaging device installed in the elevator anti-pinch method according to an embodiment of the present invention and its projection area, the imaging field of view and the elevator pinch.

[0044] Figure 2A The figure shows a schematic diagram of the anti-pinch imaging device of the present invention projecting laser downward to form a local "light curtain" between the car door and the corridor elevator door during the closing process of the car door and the corridor elevator door. Figure 2A As shown, the imaging device for preventing pinching is still preferably installed on the top of the car, but only a limited area is imaged.

[0045] Figure 2B It is a schematic diagram of the projection area and imaging field of the elevator light curtain relative to the gap from a bird's-eye view, and can also be seen as Figure 2A The cross-sectional view obtained along the AA' direction. Figure 1B and Figure 1C Different from the ones shown, Figure 2B The projection area and imaging area of ​​the imaging device shown are conventional rectangles with similar length and width, and do not completely cover the slit area, but only cover a part of the slit area. As shown in the figure, the car door and the elevator door move along the x direction during the closing process, and the imaging device is only turned on during the closing process, and only images the obstructions within the narrow field of view, thereby accurately determining the obstructions at the bottom of the car door when the car door is closed.

[0046] Figure 3 A schematic flow chart of an elevator anti-pinch method according to an embodiment of the present invention is shown. In step S310, in response to obtaining predetermined car door state information, an imaging device for anti-pinch is turned on. In step S320, the imaging device projects a laser on a portion of the slit area after being turned on, and images the portion of the slit area based on the reflected light of the projected laser. The slit area corresponds to the narrow and long portion between the car door and the corridor elevator door.

[0047] Here, the imaging device will be turned on when the predetermined car door status information is obtained. In one embodiment, the car door status information can be obtained by a proximity sensor. At this time, the proximity sensor can be installed in the imaging device for anti-pinch of the present invention, or can communicate with the imaging device. In another embodiment, the car door status information can be obtained by a conventional closing detection device (for example, a traditional light curtain device) equipped with the elevator. The imaging device for anti-pinch of the present invention can communicate with a conventional closing detection device, or as part of an overall light curtain device, obtain the car door status information.

[0048] In different embodiments, the imaging device for anti-pinch can be turned on under different car door status information. In one embodiment, the predetermined car door status information can be a car door start opening signal. As long as the car door starts to open, the imaging device for anti-pinch of the present invention starts to work. Since it takes a certain amount of time for the car door to open completely from the beginning, in another embodiment, the imaging device for anti-pinch of the present invention can also be turned on based on the car door fully open signal.

[0049] In one embodiment, the predetermined car door status information can be a car door start closing signal, or even a car door closing to a specific stage signal. At this time, due to the limited field of view of the imaging device for anti-pinch of the present invention, only obstructions located within the limited imaging area can be detected. The closing process of the car door itself will push the obstructions to move, and these obstructions are likely to be difficult to detect by conventional light curtains. When the obstruction is pushed to the side of the slit area close to the side before it is fully closed, the obstruction will be pushed into the field of view of the imaging device. Subsequently, in step S330, it can be determined based on the imaging image that there is an obstruction in the said part of the slit area, and a car door opening signal is generated.

[0050] Therefore, the present invention uses an active optical depth camera with a conventional imaging field of view and projection area as an anti-pinch imaging device. Through special settings of the opening time and installation position of the imaging device, the imaging device can accurately identify obstructions during the closing process of the car door, thereby solving the adverse effects of reflections caused by the movement of the car door on imaging in the prior art.

[0051] In order to facilitate the understanding of the principles of the invention, Figure 4A -C shows an example of an anti-pinch imaging device identifying an obstruction. Figure 4A -C, the upper part shows the imaging image of the anti-pinch imaging device, and the lower part shows the image captured by the additionally arranged visible light camera.

[0052] like Figure 4AAs shown in the visible light image at the bottom, the car door and the elevator door are in the process of closing from right to left. There is a vacuum cleaner in the car, but the cable of the vacuum cleaner is dragged outside, forming an obstruction across the slit. Note that the elevator door, car door and vacuum cleaner are all highly reflective objects that can easily cause misidentification by the depth camera. Since the imaging device for anti-pinch of the present invention only images a small area close to the right door frame, the cable as an obstruction has not yet entered the field of view of the imaging device. Figure 4A In the upper image, only the blue rectangle formed by the slit can be observed (this is because most of the light directed to the slit is not reflected back), as well as the large blue area caused by the moving car door and elevator door on the left and the door frame on the right.

[0053] As the car door and the elevator door continue to move to the left, the cable is pushed by the car door and the elevator door into the field of view of the imaging device and Figure 4B In the upper imaging image, a yellow-green line in the blue rectangular area is clearly formed. At this time, the imaging device can easily determine that there is an obstruction in the projected field of view of the slit area.

[0054] Further, as the car door and the elevator door continue to move to the left, as Figure 4C As shown in the lower part, the car door and the elevator door are about to close. Figure 4C In the upper image, a clear yellow-green line indicating the presence of an obstruction can still be observed. Similarly, the imaging device can easily determine that an obstruction exists in the projected field of view of the slit area.

[0055] When using Figure 4A -C When the imaging device is used as an anti-pinch device, there is no need to wait until the car door and the elevator door move to Figure 4C The degree shown, Figure 4B As shown, the yellow-green lines are not captured in the blue rectangular area, and it can be determined that there is an obstruction in the projected field of view of the slit area, thereby generating a car door opening signal. As a result, the car door and the elevator door begin to move to the right (i.e., from closed to open), and the personnel in the car can check and pull the vacuum cleaner cable back into the car. Subsequently, with the car door closed again, the imaging device can be turned on again. Since the obstruction has been removed, the car door and the elevator door can be closed smoothly.

[0056] In order to further analyze why the solution of the present invention can easily detect the obstruction, Figure 4B The upper image is shown enlarged. Figure 5 The imaging device is shown to image the slit and the obstruction. Figure 5 As shown in FIG. 1 , the blue rectangular area framed by the white dotted line corresponds to the slit area, and the yellow-green line across the blue area corresponds to the detected occlusion. Figure 4BThe visible light image at the bottom shows that the obstruction is in contact with the moving elevator door and car door. In other words, area 3 in the blue rectangle corresponds to the gap between the elevator door and car door. Area 2 corresponds to the gap that the elevator door and car door have not yet moved to. Area 1 corresponds to the reflection of the left door frame (compare Figure 4C As can be seen from the above, by placing the imaging device between the elevator door and the car door and close to the lower edge of the door, it is possible to ensure that the light projected by the imaging device is only reflected by the obstruction in the slit area, thereby forming Figure 5 Light reflections in dark areas shown.

[0057] Although it is possible to Figure 5 The entire image is calculated, but in a preferred embodiment, only the imaged portion of the image corresponding to the portion of the slit area can be calculated, and whether there is occlusion in the portion of the slit area can be determined based on the calculation result. In other words, only Figure 5 The image within the white frame is calculated to determine whether there is occlusion within the portion of the slit area, thereby greatly reducing the amount of calculation.

[0058] As shown above, the imaging device for anti-pinch can be a conventional depth camera that actively projects light. In one embodiment, the imaging device includes a light source module and a ToF sensor. The light source module may include: a light emitting device for generating a laser beam; and a diffuser arranged on the propagation light path of the light beam to convert the laser beam into a planar array light. In one embodiment, the ToF sensor can be a direct time-of-flight sensor that generates a sensing signal representing the distance based on the reception time of the return light.

[0059] like Figure 4A -C and Figure 5 As shown, the imaging device for anti-pinch is a conventional depth measuring device with an aspect ratio of the projection area and the imaging area not exceeding 2:1.

[0060] In one embodiment, the imaging device for anti-pinch is turned on during the process from the car door starting to open to the car door being completely closed. For example, as soon as the car door starts to open, the imaging device for anti-pinch of the present invention is turned on.

[0061] In one embodiment, the imaging device for anti-pinch is turned on during the process from the car door being fully opened to being fully closed. For example, the imaging device for anti-pinch of the present invention is turned on after the car door is fully opened.

[0062] In one embodiment, the imaging device for anti-pinch is turned on during the process from the beginning of the closing of the car door to the complete closing. For example, the imaging device is turned on as soon as the car door starts to close.

[0063] In another embodiment, the imaging device for preventing pinching can be turned on at a certain stage after the car door starts to close until it is completely closed. Figure 4A As shown, before the car door reaches a specific position, the obstruction in front cannot be pushed into the field of view of the imaging device. At this time, the imaging device can remain closed until the car door moves into the imaging field of view or opens near the imaging field of view.

[0064] like Figure 4A -C and Figure 5 As shown, in the process of the car door moving from right to left to close, the imaging device is arranged on the left door frame or near the left door frame, that is, above the car door, so that the part of the slit area covered by the laser projection range of the imaging device corresponds to the part before the car door is closed.

[0065] In the present invention, the imaging device for anti-pinch has a simple structure and setting, that is, the projection area and the imaging area are kept unchanged during the opening process (that is, the projection angle and the imaging area of ​​the imaging device remain unchanged during the opening process).

[0066] In a double door arrangement where the car door and the elevator door move from both sides to the middle to close, the imaging device may be fixedly mounted at a position near the middle of the upper portion of the car door.

[0067] In the case of a one-sided closing arrangement of the car door and the elevator door, the imaging device can be fixedly mounted on the upper part of the car door near the fully closed position. Thus, during the closing process, the imaging field of the imaging device is always the slit position of the part close to the edge of the car door or the elevator door.

[0068] In addition, although Figure 2A -B, the imaging device is preferably installed above the car door. However, in other embodiments, especially in elevator doors that open and close on one side, the imaging device can also be installed between the elevator door and the car door, and can even be installed at the bottom of the car door.

[0069] In one embodiment, the present invention can also be implemented as an elevator anti-pinch system. The system includes a closure detection device and an imaging device. The closure detection device can be a conventional device for detecting whether the car door can be closed after the car door is opened, such as an elevator light curtain, a mechanical detection device or other detection devices. The imaging device for anti-pinch as described above in the present invention is used to execute the anti-pinch method as described above in response to obtaining predetermined car door status information.

[0070] In one embodiment, the closure detection device and the imaging device can control the opening and closing of the elevator in different time periods. The closure detection device can generate the car door closing signal when it is determined that the car door is closed without obstruction. The car door opening control right of the imaging device for anti-pinch in the opening period is higher than the car door closing control right of the closure detection device.

[0071] Figure 6 The working schematic diagram of the elevator anti-pinch system according to an embodiment of the present invention is shown. As shown in the figure, the system 600 includes a conventional light curtain device 610 and an imaging device 620 for anti-pinch as described above in the present invention. The light curtain device 610 can be an infrared emitting device installed on one side of the car door and an infrared receiving device on the other side. As shown in the figure, the emitted infrared rays can form a "sparse light curtain". It is difficult for a sparse light curtain to detect small objects such as dog leashes and wires. Although the "partial light curtain" emitted by the imaging device 620 for anti-pinch as described above in the present invention can only cover a small part of the slit, small objects such as dog leashes and wires will be pushed into the local light curtain due to the closing of the car door, so it can accurately detect the above small objects and achieve anti-pinch.

[0072] Although an elevator anti-pinch method is described above in conjunction with the accompanying drawings, the present invention can also be implemented as an automatic door anti-pinch method. Figure 7 A schematic flow chart of an automatic door anti-pinch method according to an embodiment of the present invention is shown.

[0073] In step S710, in response to obtaining predetermined automatic door status information, an imaging device for anti-pinch is turned on. In step S720, after being turned on, the imaging device projects a laser toward a portion of the long and narrow area, and images the portion of the long and narrow area based on the reflected light of the projected laser, wherein the long and narrow area corresponds to the portion passed by the automatic door during the closing process. Here, projecting a laser toward a portion of the long and narrow area means that the imaging range of the imaging device does not cover the entire long and narrow area, but only a portion of the long and narrow area. Furthermore, the imaging range does not necessarily have to completely overlap with the portion of the long and narrow area (usually still a long and narrow area in shape), but can be as follows. Fig. 8A -C, the imaging range is a rectangle with a regular aspect ratio close to that of the conventional one, but covers a portion of the narrow and long area.

[0074] In step S730, it is determined in the imaging image that there is an obstruction on the portion of the narrow and long area, and an automatic door opening signal is generated.

[0075] Similarly, the present invention can also be implemented as an automatic door anti-pinch system. The automatic door anti-pinch system. The automatic door is automatically opened or closed according to a control signal. The system includes: an imaging device for anti-pinch, which is used to execute the anti-pinch method described above after receiving the automatic door closing signal. In one embodiment, the system also requires a conventional closing detection device, and therefore can also include a closing detection device for detecting whether the automatic door can be closed after the automatic door is opened.

[0076] Specifically, the anti-pinch solution of the present invention is applicable to various occasions where automatic doors are closed. In one embodiment, the anti-pinch solution of the automatic door of the present invention is applicable to anti-pinch scenarios of subway doors and train doors. In one embodiment, the anti-pinch solution of the automatic door of the present invention is applicable to anti-pinch scenarios of automatic doors of shopping malls or hotels. In another embodiment, the anti-pinch solution of the automatic door of the present invention is applicable to anti-pinch scenarios of automatic doors of injection molding machines.

[0077] For ease of understanding, Fig. 8A -C shows several examples of realizing automatic door anti-pinch using the anti-pinch imaging device according to the present invention.

[0078] Fig. 8A An example of an automatic door that opens on both sides is shown. The figure shows the state of the automatic door being fully opened. During the process of opening and closing, the automatic door will pass through the narrow and long area shown by the black straight line in the figure. In the present invention, the imaging device used for anti-pinch does not image the entire narrow and long area, but only images a part of the narrow and long area, especially the part before the automatic door is about to close. Since the area included in the imaging angle of view increases with the increase of distance, the imaging area corresponding to the imaging device in the figure (the overlapping area of ​​the imaging field of view and the laser projection area) is approximately a light cone. The imaging device can identify obstacles or obstructions that fall into the light cone area to generate an automatic door opening signal.

[0079] Figure 8B An example of an arc-shaped automatic door with double-sided opening is shown. The figure shows the state of the automatic door being fully opened. During the process of opening and closing, the automatic door will pass through the narrow and long area shown by the black arc in the figure. Since the automatic door is in an arc shape, the narrow and long area is also in an arc shape. Similarly, the imaging device can identify obstacles or shielding objects that fall into the light cone area to generate an automatic door opening signal.

[0080] Fig. 8A and Figure 8B The above elevator door examples are all examples of sliding doors. The imaging device for anti-pinch of the present invention can also be used in examples of automatic doors that open along the door axis, such as Figure 8CAs shown. The automatic door at this time may be an automatic door closing device, that is, the automatic door may be a door that is pushed open by a person but automatically closes. The narrow and long area may be the narrow and long area shown by the black arc in the figure that the outer side of the door passes through during the opening and closing process of the automatic door. At this time, the imaging device for anti-pinch can still image a part of the narrow and long area, especially the part before the automatic door is about to close. Similarly, the imaging device can identify obstacles or shielding objects that fall into the light cone area to generate an automatic door opening signal.

[0081] As described above in conjunction with the accompanying drawings, the automatic door anti-pinch method and system of the present invention, especially the elevator anti-pinch method and system, are described. The present invention uses a conventional depth camera that is cleverly set to accurately detect obstructions in high-interference and high-reflection scenes. This overcomes the technical bias in the prior art that high-performance customized cameras are required to cover the entire slit (narrow and long) area in order to achieve accurate anti-pinch.

[0082] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms used herein are selected to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An elevator anti-pinch method, comprising: In response to obtaining predetermined car door state information, turning on an imaging device for anti-pinch; The imaging device projects a laser onto a portion of the slit area after being turned on, and images the portion of the slit area based on reflected light of the projected laser, wherein the slit area corresponds to a narrow and long portion between the car door and the hall elevator door; as well as Based on the imaged image, it is determined that there is an obstruction in the portion of the slit area, and a car door opening signal is generated.

2. The method of claim 1, wherein: The imaging device used for anti-pinch is a conventional depth measuring device with an aspect ratio of a projection area and an imaging area not exceeding 2:

1.

3. The method of claim 1, further comprising: Use proximity sensors to obtain car door status information; and / or Receive the car door status information obtained by the light curtain device.

4. The method of claim 3, wherein: The predetermined car door status information includes at least one of the following: The car door starts to open the signal; Car door fully opened signal; The car door starts closing signal; and The car door closes to a specific stage signal.

5. The method of claim 1, wherein: The portion of the slit area covered by the laser projection range of the imaging device corresponds to the portion before the car door is fully closed.

6. The method of claim 1, wherein: The imaging device keeps the projection area and the imaging area unchanged during the start-up process.

7. The method according to claim 6, wherein: The imaging device is installed above the car door.

8. The method of claim 1, wherein: Determining based on the imaging image that there is an obstruction in the portion of the slit area, generating a car door opening signal comprises: calculating an imaged portion of the imaged image corresponding to the portion of the slit region; and It is determined whether there is occlusion in the portion of the slit area based on the calculation result.

9. The method of claim 1, wherein: The imaging device includes a light source module and a ToF sensor, wherein The light source module comprises: a light emitting device for generating a laser beam; and a diffuser, arranged on the propagation path of the light beam to convert the laser beam into a planar array light, and / or The ToF sensor is a direct time-of-flight sensor that generates a sensing signal representing a distance based on the reception time of returning light.

10. An elevator anti-pinch system, comprising: A closing detection device is used to detect whether the car door can be closed after the car door is opened; as well as An imaging device for anti-pinch is used to execute the method according to any one of claims 1 to 9 in response to obtaining predetermined car door status information.

11. The system of claim 10, wherein: The closing detection device includes a light curtain device for generating the car door closing signal when it is determined that the car door is closed without obstruction, and the car door opening control authority of the imaging device for anti-pinch during the opening period is higher than the car door closing control authority of the closing detection device.

12. An automatic door anti-pinch method, comprising: In response to obtaining predetermined automatic door state information, turning on an imaging device for anti-pinch; The imaging device projects a laser toward a portion of the narrow and long area after being turned on, and performs imaging toward the portion of the narrow and long area based on reflected light of the projected laser, wherein the narrow and long area corresponds to a portion passed by the automatic door during opening and closing; as well as Based on the imaging image, it is determined that there is an obstruction on the portion of the narrow and long area, and an automatic door opening signal is generated.

13. An automatic door anti-pinch system, wherein the automatic door is automatically opened or closed according to a control signal, and the system comprises: The imaging device for anti-pinch is used to execute the method as claimed in claim 12 in response to obtaining predetermined automatic door status information.

14. The system of claim 13, further comprising: A closing detection device is used to detect whether the automatic door can be closed after the automatic door is opened.

Images