GB2549782A

GB2549782A - Monitoring passage through motorised gates

Info

Publication number: GB2549782A
Application number: GB1607500.4A
Authority: GB
Inventors: Huff Derek
Original assignee: Integrated Design Ltd
Current assignee: Integrated Design Ltd
Priority date: 2016-04-29
Filing date: 2016-04-29
Publication date: 2017-11-01
Also published as: GB201607500D0

Abstract

An access control portal 20 comprising a barrier movable between positions in which it blocks and allows access, and at least one time of flight camera 24, 25 arranged to monitor persons entering or exiting the portal. The portal may comprise a barrier 22 pivotally mounted to a body 21, wherein the barrier sweeps through a zone 23 that extends beyond the body. The camera may monitor a zone swept by the barrier, or a zone 27 beyond the reach of the barrier, in order to ensure that the barrier opens safely. Upon detection of a person approaching, the barrier may be opened to allow free passage. There may be at least two time-of-flight cameras arranged to monitor opposing directions. The camera(s) may be used to sense the direction and/or number of people. The portal may comprise two housings facing one another to define a passage, each comprising a movable barrier and at least one TOF camera. The portal may be a passgate, which is a turnstile having thin supports such that the opened barrier extends 23a, 23b beyond the supports in the passage direction.

Description

Monitoring passage through motorised gates

This invention relates to the monitoring of the passage of people through motorised gates.

Motorised turnstiles or "speedgates" are a known method for controlling the movement in and out of a controlled or secured area. They generally have housings forming a passageway between them and one or more moveable, typically rotatable, transparent gates which can be operated to allow or block passage. They are often used in conjunction with card, ticket and/or biometric readers and an electronic control for authorising credentials. Often such products have optical systems and electronics in addition to a physical barrier in order to enhance the security by detecting "tailgaters", for example, by two or more people attempting to use only one credential. It is also possible to detect and ignore "false objects", such as bags or any accompanying items.

The optical system can also be used to reduce the risk of a barrier striking a person and causing possible injuries. Thus, if a person is detected walking through an open barrier then the barrier can be prevented from closing unexpectedly which might injure the person or cause a trip hazard.

The optical system can also be used as a means of triggering the opening of the barrier for 'free entry' or 'free egress' for example when a credential is not required and the barriers must open automatically. A typical optical system comprises one or more transmit and receive devices where light, usually in the infra-red spectrum, is sent from one or more transmitting devices to one or more receiving devices across the passageway, such that interruption of the light paths will be used to detect the person or object if present. This works well for preventing inadvertent opening or closing where the physical enclosure of the product extends beyond the extent of the possible movement of the barrier, ie when the optical system "guards" the space where the barrier may be moving, typically in an arcuate sweep. It is also able to detect a person and trigger the opening of the barrier in a free exit arrangement. This is shown in Figure 1.

Some of these types of systems (alternatively called "optical turnstiles) have small closed footprints. That is, they take up very little physical space when in the secure state. These are conventionally referred to as "passgates". In these, the arc swept by the physical barriers (glass panels, etc) extends beyond the physical extent (in the passage direction) of the enclosure (ie the defined passage), usually both in the forward and backward directions.

Sometimes larger speedgates have barriers or closing arms placed near to the end of the defined passage and thus it is difficult using conventional optical systems to detect a moving person in time to make the movement of the barrier safe and also to open the barrier in time to facilitate free egress.

Figure 1 shows schematically an optical turnstile having two housing, 1, 2, which are elongate and define a passageway 3 between them. Each has a barrier in the form of a glass panel 4, 5 respectively. As shown, the glass panels can rotate about a pivot 6, 7 respectively to support an arch 8, 9 respectively. They pivot to open one way to allow passageway in one direction and the other way to allow passage in another direction. The entire extent of the movement is, however, within the elongated extent of the housing 1, 2. These refer to a speedgate often.

Figure 2 shows another prior art system of speedgate (a 'passgate') where the housings la, lb do not extend significantly in the passage direction. Thus, the glass panels 4a, 5a sweep paths 8a, 9a which extend beyond the front and/or rear edges of the housings la, 2a in the access direction. This type of passgate is often used as a way of providing greater width access for wheelchairs, trolleys etc or where passage through a conventional turnstile may be problematic.

In the conventional speedgate type of system as shown in Figure 1, an optical receiver/transmit arrangement, which may comprise a plurality of receivers and transmitters spaced along the length, such as transmitter 10 and receiver 11, can cover the whole longitudinal range protected by the barriers 4, 5. With the passgate arrangement of Figure 2 this cannot be done.

There is therefore a problem related to safe movement of a glass panel's security barrier in a passgate type product having a small footprint. The glass panels have to move in spaces which cannot be guarded by the conventional beam type arrangement. It is also impractical to use conventional optical sensors to trigger free exit or entry. Movement detectors eg microwave and ultrasonic detectors are able to provide an advanced trigger but these devices are poor at discriminating between a person who is approaching the passageway and one who is walking away from it or at another angle or simply standing at a safe distance.

It is possible to arrange the barriers to move very slowly, but this can have a negative impact on throughput and security. Alternatively, conventional camera type technology can be used to monitor the space by simply viewing the space with a camera and electronically processing the images. However, suitable camera positions are limited, may be obscured and also for conventional cameras a small object close to the camera will appear as big as a larger object further away so it is not generally possible to judge horizontal distance or position easily.

The present invention arose in attempt to provide an improved method of monitoring an optical turnstile type system.

According to the present invention there is provided an access control portal comprising a barrier arranged to move from a position where it blocks access to at least one position where it allows access and at least one time of flight camera arranged to monitor persons entering or exiting the portal.

The time of flight camera is preferably mounted at a body to which a barrier is mounted (eg pivotally mounted).

The barrier preferably moves to an open position which is in front of, or behind, the extent of the enclosure in the access direction.

Preferably two bodies and barriers generally facing each other in a closed position are provided, to provide a defined passage, and comprising at least one time of flight camera at each body.

Time of flight cameras are used in fields such as gaming. A time of flight camera is a range imaging camera system that resolves distance based on the known speed of light, measuring the time of flight of a light signal between the camera of the subject of each point of the image. It therefore enables some three dimensional and positional information to be obtained and can determine whether a target, which light from the camera has been reflected off, is moving towards or away from the camera and to gain an idea of distance. With present cameras distance resolution of about 1cm is possible and this is more than adequate for arrangements of the present invention, in which essentially a user is detected as they are moving towards or away from an access control device and so the movement of the barrier can be made dependent upon whether the barrier is likely to strike a person or imped his or her passage.

In a further aspect, the invention provides a method of monitoring passage to an access controlled portal, comprising using one or more time of flight cameras to monitor the approach and/or exit of persons and using an output from the time of flight camera to control movement of a moveable barrier of the access control system. A time of flight camera generally uses LEDs or similar light emitters and modulates these at a very fast rate, such that the time of flight of a pulse from a LED to a subject and back again can be detected. In some versions, modulation speeds of up to 100MHz might be used.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which:

Figure 1 shows a previously proposed access portal;

Figure 2 shows an alternative previously proposed access portal; and

Figure 3 shows an access portal in accordance an embodiment of the present invention.

Figure 4 shows a speedgate application, and:

Figure 5 shows a passgate application.

Figure 3 shows, in plan view, a schematic view of an access control panel in which a passgate 20 is provided with a barrier 21 in the form of a glass barrier 22 which is pivotally mounted to the passgate housing 21. The passgate housing includes control electronics, a motor for moving the barrier, braking mechanisms and so on. This may also have a card reader, means for obtaining biometric information or other means and may also be IP enabled or otherwise able to connect remotely with external control and/or monitoring equipment.

As shown the barrier may sweep through an arcuate path 23, either in a forward direction in the entry direction E or in a back direction opposite to direction E, ie sweep zones 23a, 23b. The passgate is therefore used to control entry and exit to and from a controlled space.

Time of flight type cameras 24, 25 are mounted on the body 21 of the passgate and directed so that their field of view (illustrated by the respective quadrants 26, 27 is generally downwards onto the floor and forwardly (in the case of exit detector/camera 24) and onto the floor and generally backwards in the case of entry detector/time flight camera 25. It is assumed that the normal entry direction is in the direction E. These therefore cover the detection zones 23a, 23b which the glass barrier will rotate through. Most preferably, the detection zones extend radially beyond the sweep zones 23a, 23b and thus monitor these.

Thus, the time of flight cameras (exit and entry detectors 24, 25) can monitor movements in the entry and exit zones and can detect whether a person is moving into them or out of them. They can also detect whether the person (within the tolerances of the system) is within the area which will be swept by the barrier in either direction or is moving into or out of this area.

If the panel is set to open by an opening signal, which may be an electronic authorising means, then electronic control circuitry 20a (shown schematically within passgate 20) can access, using inputs from one or both of the time of flight cameras, whether there is a person or object likely to be struck by the panel on opening or closing and can therefore prevent, or limit the speed of such closure. Thus, collisions or other safety risk can be avoided or minimised.

Because the time of flight cameras can sense direction of travel of a target (person) it is possible to sense that a person is approaching to enter or exit but has not yet reached the entry or detection zones and therefore, if appropriate, to automatically open the barrier in an appropriate direction.

The invention is therefore particularly useful where the sweep zones 23a, 23b extend beyond the extent of the body 21 in the passage direction, ie ones in which conventional infra-red or other transmission/reception means protecting the space between two gate bodies cannot be used.

Figure 3 shows an embodiment which only one passgate and barrier is used. In many embodiments, a pair of these will be used next to each other with the barriers of each one facing generally towards each other in the close position to provide a defined passageway, as shown in Figure 2. In this case, exit and entry detectors incorporating time of flight of cameras may be used on both passgates.

More than one camera may be used on each passgate to monitor each detection zone, if it has been vertically spaced, for example.

Although two detectors (exit and entry) are shown in Figure 3, in some embodiments only one detector may be used, for perhaps monitoring the entry detection zone.

The camera or cameras may be used to sense the number of people passing in each direction. That is, it may detect if more than one person is attempting to pass, either next to each other or sequentially (perhaps within a defined time window), or if more than one person is attempting passage when credentials for only one person have been provided.

The camera or cameras may sense speed of approach, direction of approach or other parameters.

Figures 4 and 5 show how one or more time of flight cameras 24 may be used to enable free exit/entry. As a person P approaches a gate (either of the speedgate type (Figure 4) or the passgate type (Figure 5)), the time of flight camera detects this before the person reaches the region swept by the barrier. A signal from the time of flight camera can be used to cause the barrier or barriers 22 to move to an open position, enabling free entry/exit (e.g. the gate opens automatically upon detecting approach). This is especially useful for passgate type products having a small defined passage but also useful for speedgates, where if the system had to wait until conventional detectors sensed approach the barrier may not be able to open quickly or sufficiently to be safely out of the way when the person passes.

Claims

1. An access control portal comprising a barrier arranged to move from a position where it blocks access to at least one position where it allows access and at least one time of flight camera arranged to monitor persons entering or exiting the portal.

2. An access control portal as claimed in claim 1 wherein the time of flight camera is adapted to monitor a zone swept by the barrier when operating.

3. An access control portal as claimed in claim 1 and claim 2 comprising a body, and a barrier pivotally connected to the body, wherein the barrier sweeps a zone which extends beyond the extent of the body in the passage direction.

4. An access control portal as claimed in claim 3 wherein the time of flight camera is arranged to monitor a zone which extends beyond the swept zone.

5. An access control portal as claimed in any preceding claim wherein upon detection of an approaching person by the time of flight camera free entry or egress is enabled.

6. An access control portal as claimed in claim 5 wherein upon detecting an approaching person by the time of flight camera the barrier is opened to allow free passage in the direction of approach.

7. An access control portal as claimed in any preceding claim comprising at least two of flight of time cameras arranged to monitor entry or exit from the passageway in opposing directions.

8. An access control portal as claimed in any preceding claim wherein the/or each time of flight of camera is directed to have a field of view extending to the floor at a position beyond a swept zone of the barrier.

9. An access control portal as claimed in any preceding claim wherein a time of flight camera is used to sense direction.

10. An access control portal as claimed in any preceding claim wherein a time of flight camera is used to sense the numbers of people passing in either direction.

11. An access control portal as claimed in any preceding claim wherein a time of flight camera is used to sense approach to the portal and to trigger opening of the barrier dependent upon this.

12. An access control portal in the form of a passgate having a barrier, and comprising at least one time of flight camera for monitoring a space not swept by a barrier during an opening or closing operation, to allow safe opening and closing of the barrier.

13. An access control portal as claimed in any preceding claim comprising two housings and barriers, the barriers generally facing each other in a closed position, to provide a defined passageway, and at least one time of flight camera provided at each housing.

14. A method of monitoring passage through an access control portal, comprising at least one time of flight camera to monitor the approach and/or exits of persons and using an output from at least one time of flight camera to control movement of a moveable barrier.

15. Access control equipment substantially as hereinbefore described with reference to, and as illustrated by, any of Figures 3 to 5 of the accompanying drawings.

16. A method of controlling access substantially as hereinbefore described with reference to any of Figures 3 to 5.