Patent Application
20230076532
The present application claims the benefit of priority to Great Britain Patent Application No. 2112567.9 filed Sep. 3, 2021, the contents of which is incorporated by reference in its entirety.
This invention relates to an anti-climb system.
Turnstiles are commonly used to control the movement of pedestrians and other traffic from one defined area into another. When they are motorised and they are sometimes referred to as “Speedgates”. These usually have sensing systems such as infra-red beams, optical systems or other systems for detecting passage. Typically, they will comprise one or more moving barriers which move to physically block or allow pedestrian movement.
Often a token identifying a user is presented to a reader mounted on or near to the barriers and or biometric sensors are used. The reader or sensors are most often on the enclosure housing the barrier mechanism, which will extend outwards from the barrier or barriers, pairs of enclosures forming a channel through which users must pass. The moving barriers open to allow movement through said channel and close to prevent it.
Depending on the application and associated risk of intrusion the moving barriers may be of varying height to manage the risk of an unauthorised person climbing over them.
The space immediately in front of the barriers (i.e. before a person passes through the barriers) is often monitored by an optical system associated with security and barrier movement safety, so that an unauthorised person approaching the barrier in a closed position can be detected and an alarm signalled. This alarm may be in the form of an audible, visual or other indication in the vicinity of the barrier or provided to a remote location such as a location where security staff may be monitoring the security cameras.
The height of the enclosure is generally selected to provide a convenient height to present an access token at. It provides the mounting location for bearings supporting moving barriers and therefore cannot be very low because the resulting forces when the barriers are pushed will become difficult to contain. Typically, for a higher security Speedgate, the enclosure is perhaps around half the height of the moving barriers. However, this can vary.
Speedgate systems are often provided in entrance lobbies of buildings, typically with high ceilings, and indeed most often, for cost, practical and aesthetic reasons, there is a significant open space above the moving barriers. There is therefore a risk that a person can climb undetected over the barrier, for example by climbing onto the Speedgate enclosure and walking along it if the barrier is low, or using it as climbing aid to step over a higher barrier.
Various means have been implemented in the past to detect such an occurrence, including the use of pressure and load sensors to detect the weight and movement of an attacker, latterly directed inferred beams and so on.
In practice, pressure sensors are expensive and in some circumstances locating them on the barrier structure does not always provide a good balance between detection and false alarms.
Infrared beams can be used across the top of these moving barriers themselves, and have to be provided at a height which is unlikely to be triggered by the heads of pedestrians walking normally. However, such a method has limitations, including the need to place corresponding optical transmitters and receivers so that appropriate detection can be achieved. In addition, for a number of multiple Speedgates the alarm generated tends to not be specific to the particular Speedgate where the intrusion has occurred.
Ideally, detection is unique to the particular enclosure or enclosures involved so that any alarm triggered would identify the location of the attack so that, for example, a camera can be triggered to record the event.
The present invention arose in an attempt to provide an improved system for detecting a climb attack on a turnstile.
According to the present invention there is provided Detection apparatus comprising a speedgate having a longitudinal direction parallel to the direction of passage of persons using the speedgate, and having a secure end and an insecure end; a Ranging Time-of-Flight (RTOF) sensor positioned at the secure end of the top surface of an enclosure of the speedgate to direct a single beam in a fixed direction towards the insecure end and angled upwards, and a processor arranged to register objects or persons crossing the beam at greater than a minimum distance from the sensor to detect a person who has climbed onto the speedgate enclosure at the insecure end.
Preferably the processor triggers an alarm if a person or object crosses the beam at a distance greater than or equal to said minimum or less than or equal to a maximum distance ranging from the ranging time-of-flight (RTOF) sensor.
A speedgate has a secure end and an insecure end. The insecure end is generally the end at which a person arrives (the entrance), and the secure end is generally the end from which they depart (the exit). The secure end will therefore be the end remote a doorway and leading to the inner areas of a building, access to which is controlled (ie secure). Thus the speedgate protects against unauthorised entry.
Thus the RTOF sensor is provided at or towards the secure side to direct an upwardly angled beam along the line of the speedgate towards its other end.
The RTOF sensor may alternatively be provided behind the front of the body in order to project upwardly angled beam along the length or at least part of the enclosure, or may be mounted a distance above the body.
A RTOF sensor can detect the distance an object which breaks the beam from it (ie by measuring the time-of-flight, phase change etc of light reflected from an object). Such sensors are commonly used in many environments. An alarm is triggered only after a certain minimum distance from the sensor then any false alarms such as the hand of an exiting user being placed upon the enclosure, or a bag being swung, can be ignored as the minimum range would generally be set such that the height of the beam at this minimum range above the enclosure is greater than the height at which a person may place a hand or a bag when in use.
A maximum value may also be set so that an object detected which could not be a person climbing on the enclosure is not detected because it was too far away.
By having a maximum value then this reduces the number of false alarms caused by, for example, a ceiling, light or fan fixture.
In a further aspect the invention provides a method of detecting whether a person is climbing upon a speedgate, comprising providing an apparatus as above, and generating an alarm if a person or object is registered at least a minimum distance from the RTOF sensor.
In a further aspect the invention provides a speedgate provided with an anti-climb detection apparatus as described above.
The invention may further provide detection apparatus comprising a body having a longitudinal direction; a ranging time-of-flight sensor (LIDAR) positioned to direct a beam generally along at least part of the body and angled upwards, and a processor arranged to register objects or persons crossing the beam at greater than a minimum distance from the sensor to detect climbing on the body.
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which;
Ranging Time-of-Flight (RTOF) sensors (otherwise known as LIDAR) are used for a number of purposes, typically distance measuring. Generally they are used in a reflective mode in which a transmitter, which may be a laser, transmits a modulated single beam of light which strikes a target. The beam can be a very narrow diameter (they can be regarded as single pixel devices), and these are not cameras as such, i.e. they are not used for imaging, simply for distance measuring. However in some embodiments an RTOF sensor may have a larger or conical field of view. Some devices for example have a field of view half angle of around 10 degrees and integrate the perceived distance over the field of view. Any RTOF sensor can be used in embodiments of the invention.
Some of the beam of light, after it strikes a target, returns to a receiver on the RTOF and the time taken for the optical journey is used as a measure of the distance travelled. Thus, referring to
In embodiments of the invention, the sensor is controlled by a processor (which may be part of the sensor itself or a separate unit connected to it) 3 within an enclosure of
This is used to set a minimum and, optionally, a maximum distance at which an object is detected, or at least at which a detected object is registered. This is shown as Zone 4 in
As shown, the Speedgate includes enclosures 10, 12 which generally define the passageways protected by the barrier, such as passageways 5 and 6, and comprise plinths or other bodies which may mount electric control circuitry. The top of these enclosures will have a certain width W as shown most clearly in the plan view of
An RTOF sensor is mounted on the top of the secure side of a Speedgate enclosure 12, as is shown most clearly in
As is shown in
In addition to simply detecting the attacker, further processing is utilised to only register or be concerned with a target if it is a minimum distance, say nominal distance D from the RTOF sensor 1. The attacker may also be ignored if they are beyond a certain maximum distance (shown by 4b in
This can significantly reduce false alarms in that any temporary accidental obstruction of the transmitted beam by someone legitimately walking through the passageway or lane and breaking the beam by virtue of putting their hand outside the lane, swinging a bag or other object and so on, is ignored because the hand, bag and so on would generally be at a relatively low height.
Thus, only an attacker actually climbing on the enclosure will be registered. This can be used to trigger an alarm locally at the Speedgate and/or an alarm signal can be sent to a remote location where it can be viewed by an observer, logged and so on. An alarm may be visual, audible, haptic and/or in the form of a signal sent to other local or remote apparatus. An alarm may be used to instigate operation of a monitoring camera.
The secure end of the barrier is shown by reference E1.
As the system is a reflective one it has the great advantage that a hard to site receiver is not required and any object illuminated at an irrelevant distance can be ignored because its distance is known. Thus, by providing the minimum and, optionally, maximum distances (ie a gated distance) it can be established with a high degree of accuracy that an attacker is trying to gain access by climbing on the apparatus.
The beam will be directed generally in the line of the enclosure, either along its longitudinal access or at such an angle that most of the beam between the front end E1 and rear end E2 of the enclosure is over the lateral extent of the enclosure.
If the transmitted beam is permanently blocked in such a way that an alarm is not caused then the sensor can be effectively disabled and, subject to the status of the Speedgate, an alarm may be actuated, either audible or visual as desired. A small delay or other processing may be built in to allow for momentary obstruction caused by legitimate reasons, e.g. card presentation.
RTOF sensors may be used on all of the enclosures if desired. Typically, they will be mounted at or towards the secure side E1 of the gate and facing towards the insecure side. By secure side is meant the protected area, or ‘IN’, or the side which a security token is required to pass to. Very often a token is not required to exit
In other embodiments, the sensor need not be mounted directly upon the enclosure or gate but may be mounted in such a position that the beam still extends in any angled upwards direction along and above the part to be protected. It may alternatively be mounted above the enclosure to still transmit a beam which is angled upwards, in which case it will preferably be mounted at a height which is above a height by which a user would normally put their hand or a bag in normal traverse through the passageway.
The sensor may be placed at any position along the enclosure, though desirably it is at or towards one end thereof.
Typically, the minimum distance 4a will be 50 cm and the maximum distance 4b, will be 150 cm but this can vary. It may depend on the length of the enclosure/pedestal and the mounting position of the sensor.
By tracking the signals detected by the RTOF sensor, direction of movement can be sensed. Thus, in some embodiment the direction of any movement can detect an object or person, to further discriminate against false alarms, can be sensed.
In some embodiments one or more timers may be used so that, for example. a benign momentary obstruction by the hand of someone exiting from the secure side blocking the beam at short range does not cause an alarm. A timer can also be associated with the ranged detection of a climber such that a benign object like a raised hand momentarily breaking the beam in the alarm detection range will not cause an alarm if this occurs within a certain time period.
Thus in some embodiments, detection of a climb attack and/or a malicious obstruction includes processing which can look not just at an instantaneous signal but also to look for a signatures in a sequence of signals over time (e.g. to detect movement and direction of movement) to further discriminate between a genuine climb attack, malicious obstruction of the sensor and other events which may or may or be non-alarm, i.e. benign, events.
The invention can be used to protect other types of arrangements or constructions from climbing attacks, such as walls, fences, or others, by placing an RTOF sensor at an appropriate position to angle its beam upwards.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2112567.9 | Sep 2021 | GB | national |
