FIELD

[01 ] The invention is a system and method for actuating a locking member when an alarm is detected, for example to actuate a door on hearing a fire alarm.

BACKGROUND

[02] It is known that fire doors must not be held open in the event of a fire. It is also desirable that exit doors might also be opened automatically to allow occupants to exit a building without delay.

[03] Existing systems that listen for audible alarms are not very selective, so they mistake sustained loud noises as being the alarm. Vacuum cleaners, loud machinery or music can actuate these types of detector. Tone decoders could potentially be set to select for specific frequencies but this is problematical due to the large variation in fire alarm tones and patterns. This approach won't work with alarms that have varying frequencies.

[04] The purpose of the invention is to address the problems with existing systems and to provide a system which reliably actuates a door on hearing a fire alarm.

SUMMARY

[05] According to the present invention there is provided an apparatus and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

[06] According to a first aspect of the invention, there is provided an alarm detector comprising a housing; a locking mechanism located within the housing, the locking mechanism comprising a locking arm which is moveable between a locking position and an unlocking position; a microphone for detecting a sound signal, the microphone being located on the housing; and a processor located within the housing wherein movement of the locking arm between an unlocking position and a locking position is user operated and movement of locking arm between a locking position and an unlocking position is automatically operated by the detector and wherein the processor is configured to receive at least one sample which is derived from a sound signal detected by the microphone; compare the at least one received sample with a reference pattern using fuzzy logic to determine whether an alarm is sounding and if the processor determines that an alarm is sounding, release the locking mechanism so that the locking arm moves from automatically from its locking position to its unlocking position.

[07] According to a second aspect of the invention, there is provided a method of actuating a locking mechanism on detecting an alarm, wherein the locking mechanism comprises a locking arm which is moveable between a locking position and an unlocking position and movement of the locking arm between an unlocking position and a locking position is user operated; the method comprising detecting a sound signal; analysing the sound signal to produce at least one sample; comparing the at least one sample with a reference pattern using fuzzy logic to determine whether an alarm is sounding; if it is determined that an alarm is sounding, releasing a locking mechanism so that the locking arm automatically moves from its locking position to its unlocking position.

[08] The following features apply to both aspects.

[09] The method may further comprise learning the reference pattern for example, the processor may be further configured to learn the reference pattern. Alternatively, the reference pattern may be a preset reference pattern which encompasses all continuous alarm patterns so that the detector will respond without learning a specific alarm.

[10] The reference pattern may comprise a series of reference frequencies with each reference frequency being the frequency of the maximal sound level for each of a plurality of samples of a sound signal. For example, when learning the alarm, the system may record the frequency of the loudest sound in each sample, so that it has a series of reference frequencies that the alarm produces. For example, if the alarm is of the 2-tone variety, the samples will have the same number of samples of the two frequencies, if the alarm has a varying tone pattern, the frequencies recorded will be spread between an upper frequency and a lower frequency. When a sound is compared with this pattern, it is not possible to guarantee a precise match to these reference points because they may be sampled at different points in the alarm sequence. This issue may be addressed as follows.

[1 1 ] When the reference pattern comprises a series of reference frequencies, there is preferably a plurality of samples to compare. Thus, a plurality of samples may be generated from the received sound signal, e.g. by taking samples at regular intervals, e.g. every 4 seconds. The processor may be configured to wait until it has received a plurality of samples before comparing the received sample and the reference pattern. The processor may be configured to determine whether the number of received samples is greater than a sample preset threshold before carrying out the compare step, e.g. the sample preset threshold may be 50% of the number of frequencies within the reference pattern.

[12] Furthermore, the processor may be configured to compare a frequency of each of the received samples with each of the series of reference frequencies and to determine whether an alarm is sounding by determining whether a match between the compared frequencies is greater than a match preset threshold. The determination of a match above a match preset threshold may be termed fuzzy logic. This fuzzy logic may aliow for each point (or frequency of the received sample) to be checked against the whole of the reference pattern, deciding how close each is to every reference point, in the reference pattern. The closer the detected (received) frequency is to a reference point in the reference pattern, the higher the score. Summing up these scores allows the Fuzzy Logic to determine how closely the incoming sample matches the reference sample, if the sum total is higher than the match preset threshold, the determination that the alarm is sounding may be made.

[13] The alarm detector may further comprise a fast Fourier transform (FFT) component which determines the frequency of a maximal sound within a sound signal detected by the microphone and the at least one sample is the determined frequency. If the alarm is sounding, this determined frequency will be the alarm and if the alarm is not sounding, this determined frequency is just the loudest ambient sound. This determined frequency may then be compared with each of series of reference frequencies as set out above.

[14] The system may determine whether the sound signal detected by the microphone has a loudness which is greater than a loudness preset threshold. This is because the microphone is sampling ambient noise and an alarm is likely to be present only when there is a persistent loud signal. The loudness preset threshold may be different for different environments and may be set at a specific value (e.g. 20dB) above the ambient noise level for each environment. The processor may make the determination. The processor may be configured to receive the at least one sample after this determination has been made and thus further analysis such as the FFT will only be done once a loud persistent sound is detecting. The subsequent analysis such as the FFT may use a lot of power whereas the determining step is likely to be relatively low power. However, determining whether or not there is a loud persistent noise may be omitted if power consumption is not an issue.

[15] The processor may be configured to determine whether the alarm is continuing to sound and to prevent user activation of the locking mechanism until the alarm is determined to have ceased. Determining whether the alarm is continuing to sound may comprise collecting a sound signal with the microphone and determining whether the sound level is below the loudness preset threshold. When the alarm is determined to no longer be sounding, the processor may reinitiate the locking mechanism to allow a user to move the locking arm from the unlocking position to the locking position.

[16] The locking mechanism may further comprise a locking plate having an aperture which receives and engages with the locking arm in the locking position. In the locking position, the locking arm may extend from the housing and in the unlocking position, the locking arm is substantially located within the housing.

[17] The alarm may be a fire alarm. Alternatively, the alarm may be a door bell or other similar alarm. The alarm is preferably of the continuous type, be that single tone, multi tone, or swooping tone. Any pattern is acceptable so long as the sound doesn't stop.

[18] For example for a fire alarm, the housing may be configured to be mounted to a door in use wherein when the locking arm is in the locking position, the door is held open (e.g. at 65 degrees) and when the locking arm is in the unlocking position, the door is closable. The door may be a fire door or an exit door. Typically fire doors and exit doors are weighted or otherwise controlled to close unless they are being held open.

[19] The alarm detector may further comprise a battery to power the alarm detector and the processor may be configured to determine whether the battery voltage is below a battery preset threshold and if the processor determines that the battery voltage is below a battery preset threshold, release the locking mechanism so that the locking arm moves from its locking position to its unlocking position. The locking mechanism may be reinitiated only once the battery voltage is determined to be above the battery preset threshold.

[20] The alarm detector may further comprise a user indicator to indicate when the alarm is sounding. The user indicator may be audible, e.g. an alarm, or may be visual, e.g. a display (e.g. LCD) with a message or a light, e.g. a flashing LED.

[21 ] Although a few preferred embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.

[22] For example, apart from fire door and exit door operation, the invention could also be used to trigger any other output to operate a device or warning system such as lights or vibrating systems to assist the hard or hearing or the deaf. It could also trigger fire extinguishers or contact a remote monitoring station.

[23] It is also possible to teach the device to detect any other audible patterns, such as door bell, a baby's cry or the noise of a chain saw. Any pattern of sound can be detected as long as that sound is louder than the ambient noise levels, provided that pattern produces broadly the same frequency spectrum with the same spread of frequencies over the time of the sample. The invention can sample continuously if there are no restrictions on power consumption. In this case, the samples can be long, and the invention can then detect discontinuous audio patterns. BRIEF DESCRIPTION OF DRAWINGS

[24] For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example only, to the accompanying diagrammatic drawings in which:

[25] Figures 1 a and 1 b are perspective views of a system according to the invention mounted on a door with Figure 1 a showing a unlocked state and Figure 1 b showing a locked state;

[26] Figure 1 c is a perspective view of a foot plate for use in the system of Figure 1 a;

[27] Figured 1 d is a plan view of an alternative foot plate;

[28] Figures 2a and 2b are front views of the system of Figure 1 a with the battery and LCD covers closed and open respectively;

[29] Figures 2c and 2d are front views showing the battery compartment removed and inserted respectively;

[30] Figure 3a is a schematic block diagram of the components of the system;

[31 ] Figures 3b and 3c are more detailed flowcharts for the method implemented by the system shown in Figure 3a;

[32] Figures 4a and 4b are schematic diagrams of components of the system;

[33] Figures 5a is a view of the display part of the system;

[34] Figures 5b to 5j are screen shots of the display each showing information when selecting and editing in different modes such as status, fault, log, date and time; [35] Figures 6a to 6k are screen shots of the display each showing information when selecting and editing in different modes such as night closing, opening, sounder and test;

[36] Figures 7a to 7h are screen shots of the display each showing information when selecting and editing in different modes such as learn, battery and restore.

DESCRIPTION OF EMBODIMENTS

[37] As explained in more detail below, the example embodiment of the device which may be known as "shuttle" is an intelligent acoustically triggered fire safety device designed to close fire doors quickly and effectively during an emergency. Shuttle has been designed to react only to the acoustic signature of the learnt alarm sound and will discard all other sounds. With flexible setting of times and dates and an intuitive setup menu, the Shuttle is easy to use for total peace of mind.

[38] Figures 1 a and 1 b show the device 10 comprises a housing 12 which is mounted to a lower part of a door 14. On an upper part of the housing there is a display 16 which is preferably an LCD, e.g. with a resolution of 144 x 168 or similar display and a display cover 18 to cover the controls for the device. The display and its associated controls are described in more detail below. On the opposite side of the upper part of the housing to the display, there is a battery cover 20 which is removable to allow access to the batteries as shown in more detail below.

[39] The device also comprises a foot actuator 24 which in this arrangement is centrally mounted although it will be appreciated that other arrangements are also possible. The foot actuator is moveable between a deactivated position (shown in Figure 1 a) and an activated position (shown in Figure 1 b). Activation of the foot actuator 24 causes a foot plunger 26 to move between an inactivated position in which it is substantially located within the housing of the device (shown in Figure 1 a) and an activated position (shown in Figure 1 b). In the activated position, the foot plunger 26 is received in an aperture in a foot plate (which may also be termed a floor plate or a locking plate) 22 which is fixed to the floor adjacent the door 14. Thus, when the actuator and hence the plunger is activated by a user by pressing down in the direction of the arrow shown in Figure 1 b on the foot actuator 24, the device locks the door. Thus, the foot actuator, foot plunger and foot plate form a locking mechanism with the foot plunger acting as a locking arm which is moveable between a locking position and an unlocking position. Activation of the foot plunger may only be triggered after all of the functions have been set, e.g. as described with reference to Figures 5a to 7c. The device can also return to the deactivated state and hence the door is unlocked as described below.

[40] Figure 1 c shows a large version of a foot plate 22 which comprises the aperture 23 which receives and engages with the foot plunger and a door stop 25, Figure 1 d shows a small version of a foot plate 22' which has an aperture 23' but no door stop. The small version is for use on a door where a door stop is already installed. To ensure the correct and continued operation of the device, the foot plate must always be installed regardless of the flooring surface and condition. Holes need to be drilled into the floor to receive corresponding fixings (e.g. rawl plugs and screws) through the foot plate. For example, for masonry floors a 6mm hole is recommended and for wooden floors a 3mm hole is recommended. Heavy fire doors weighing more than 100kg must always have the foot plate installed.

[41 ] The foot plate may be installed by positioning the door at an angle greater than 65 degrees and then placing the foot plate underneath the foot plunger as shown in Figure 1 a. If the small foot plate is being used, the point at which the door touches the door stop is the default position. To check alignment, the foot actuator is then gently pressed down to align the foot plunger with the aperture 23, 23' (which may alternatively be termed a recess) in the foot plate 22, 22',

[42] Figures 2a and 2b show further implementation details of the device which it will be appreciated may be optional or adapted as is well known to a skilled person. The battery cover 20 is securely closed by a security screw 28 which can be removed with a screw driver (or similar access cover tool) so that the cover can be slid open to access the battery holder 44 as shown in Figure 2b. After the batteries have been changed, the battery cover is replaced and securely fastened in place. Similarly, the display cover 18 is securely closed with a security screw 30 which can be removed with a screw driver so that the cover can be slid open to access the menu programming buttons 32 as shown in Figure 2b. Once the desired changes have been made, the display cover is replaced and securely fastened. A user also has basic control of the display 16 by using the enter button 38 which is accessible when the display cover is closed.

[43] Figures 2a and 2b also show the fixing locators 34 which are used to secure the device to the door. The device is fixed in position by aligning the locators 34 on the device which corresponding drilled holes on the door. In this arrangement, there are four locators and screws and screw washers are used to affix the device to the door but other arrangements can be used. Furthermore, in this arrangement, the display cover 18 and battery cover 20 must be removed to access the upper two fixing locations 34 to secure the device to a door and are then replaced.

[44] The device also comprises a microphone 36 together with a status indicator for the microphone. In this arrangement, the microphone is mounted to the body below the menu programming buttons 32 but it will be appreciated that another location could also be used. The device also comprises an access point 40 which could be a USB programmer slot and which, for example, allows manufacturer software updates to be entered in the device. The access point 40 is covered with a removable cover 42.

[45] Figures 2c and 2d illustrate how the battery holder 44 can be removed from the housing 12 by sliding the battery holder in the direction of the arrow in Figure 2c (in this arrangement, upwards). In this arrangement, two C/LR14 alkaline or lithium type batteries 46 are used but it will be appreciated that other suitable batteries may be used. Once the batteries are in place, the holder 44 is replaced and will click into place to confirm secure installation. Before replacing the cover, the display indicates a status message "setup required". This confirms correct battery installation, polarity and that the unit is correctly receiving power. If the display remains unlit, the unit is not receiving power and thus the battery polarity and installation needs to be checked,

[46] Figure 3a is a schematic drawing of the device which illustrates the various components some of which are internal as well as some decisions which are taken within the device. After all of the functions have been set and the foot plunger has been depressed, the door is locked in an open position. In this mode, the device samples the sound level approximately every 4 seconds, e.g. using the microphone 80. When a loud sound is heard, the sampling frequency increases and the system begins to count up or down, depending on whether the sound continues or not. As shown at decision S104, when enough samples of loud sounds have been heard, the unit considers that this is possibly an alarm. If the sound continues, it's compared to the learned alarm (e.g. at step S106) and when a sufficiently close match is found, a warning is provided to the user, e.g. an audible tone and flashing LED indicate that the door is about to close. The display and four High-Low audible warning tones will indicate that the door is about to close, i.e. to indicate that the device is to return to a deactivated state and unlock/open the door from the foot plate as shown in step S108.

[47] if the alarm persists, the system will continue to analyse the sounds and report what it's doing. When the alarm stops, the system will count down as long as the background noise isn't too loud. Once the count reaches zero, the system will re-arm itself in readiness for the foot to be latched down again. The log will show the sequence of events that have occurred.

[48] In addition to alerting the user to a closing door, the system issues warnings to the user.

For example, the system outputs an audible two tone signal Low-High every 30 seconds to draw attention and the LCD display remains turned on so that the user can see the STATUS which shows what requires attention. The LED may flash every 4 seconds at this time.

[49] Figures 3b and 3c expand on the steps shown in Figure 3a to show the operation of the device.

[50] At step S200, a microphone 80 collects a sound signal which includes all of the ambient sounds including a possible alarm sound. At step S202, the microphone signal is preferably amplified and filtered to remove high and low frequency noise, for example using the filter 84 and amplifier 82 shown in Figure 3a. The software (e.g. within the processor 94) automatically controls the amplifier gain, for example using the auto-gain component 86, so as to keep the values in the range of the analog to digital converter. The software keeps track of the gain for use in decisions about the noise threshold.

[51 ] As an example, when collecting the sound signal, the system takes 512 samples of the ambient sound at 50 KHz every 4 seconds on average (3-5second limits). Hereafter, 'sample' refers to one complete packet of 512 individual samples.

[52] The loudness of the sample is compared to the loudness preset threshold level at step S204 (or S100 in Figure 3a) by the processor 94. If the sample is louder than the loudness preset threshold, the loudness counter is incremented and the sampling frequency is increased to 3 samples per second as shown at step S208. Otherwise, the loudness counter is decremented as shown at step S206.

[53] Optionally a step of determining whether or not a preset level for the loudness counter has been reached can be implemented by the processor 94. If the counter reaches a preset level, it's determined that a loud persistent sound is being heard, and this may or may not be the alarm. The sound signal therefore needs further analysis. This step can be eliminated if power consumption is not an issue. It takes a lot of power to perform a Fast Fourier Transform, so this is only performed when a persistent loud sound is heard. This determining step itself takes very little power by comparison.

[54] When the loud sound is persistent, as shown at step S212, the sample is analyzed using a Fast Fourier Transform component 90 to determine the frequency and magnitude of the maximal sound. If the alarm is sounding, this frequency will be the alarm. If the alarm isn't sounding, this frequency will be the loudest ambient sound for this sample.

[55] As shown at step S214, the maximal frequency for this sample is now stored in a buffer (e.g. sample buffer 88 shown in Figure 3a) and the alarm counter is incremented by the processor 94. Samples continue to be accumulated as long as the sounds are above the loudness preset threshold. As shown in step S216 (and S104 in Figure 3a), a determination by the processor 94 as to whether enough samples have been collected is then made, i.e. a determination as to whether the number of samples is above a sample preset threshold is made. When enough samples have been taken to begin analysis of the sound pattern (e.g. 25 samples out of 50 totals), there is a determination as to whether the samples match the reference as shown in step S218 (and S106 in Figure 3a). This determination can be made by the processor 94 which uses Fuzzy logic to compare the membership of the samples with the reference samples (e.g. the 50 reference samples) learned when the alarm was installed. If the match is greater than the match preset threshold for agreement, then the alarm is deemed to have been detected.

[56] If the alarm has been detected, at step S220 (or S108 in Figure 3a) the system signals for the door to be released, e.g. using the processor 94, or any other appropriate action as desired.

[57] The alarm will continue the aforementioned processes, for example collecting a sound signal (step S222), optionally filtering and amplifying (step S224) until the noise level falls below the loudness preset threshold (step S226). When this happens, first the alarm counter is decremented, followed by the loudness counter (step S228) until they are both zero. When it is determined that the counters are both at zero (step S230), the alarm is determined to not be heard. The system is effectively reset, and the motor is signaled to allow the door to be held open again.

[58] Alongside the process shown in Figures 3a to 3c, the battery voltage is monitored every 60 seconds, and if this is below a battery preset threshold, the same action is taken as if the alarm had been heard so that the door is closed or other appropriate action to render the system safe. [59] A preset reference pattern can be used that encompasses all continuous alarm patterns so that the system will respond without learning a specific alarm.

[60] The system will normally be taught the sound of the alarm, e.g. using LEARN NEW ALARM mode described below and it will remember the sound of the alarm even if the battery is removed for prolonged periods of time. When learning a new alarm, a series of samples are taken without the alarm sounding so that the system can tell when the alarm sounds. When the alarm is sounded, 50 samples are takes at a frequency of 3 samples per second, and the frequency of the maximal sound is recorded for each sample. These become the centre values of the 50 membership functions used by the Fuzzy Logic system.

[61 ] Figures 4a and 4b are schematic drawings of some of the key components of the system which can be retrofitted to an existing door actuator to provide the functionality of the invention. Both Figure 4a and 4b show the part of the device which is under the display cover, i.e. the display 16 and the menu programming buttons 32. The display is operatively connected to and powered by a battery 146, 246. The battery also powers a lamp, e.g. an LED indicator 60, 160 which can be used to provide a visual indicator to a user, e.g. a warning of a fault or the status. The battery also powers a microphone 136, 236 which as explained above is used to collect sound data. Figures 4a and 4b illustrate alternative types of battery, lamps and microphones which are compatible with the system.

[62] As explained above, the display cover can be removed by unscrewing the security screw and sliding the display cover to reveal the menu programming buttons. Figure 5a shows the part of the device which is under the display cover and is thus revealed when it is removed. There are menu programming buttons which in this arrangement comprise five buttons 50, 52, 54 but it will be appreciated that other arrangements of buttons can be used. The display 16 is adjacent the menu programming buttons and the locator 34 is also visible to the other side of the buttons.

[63] The top and bottom programming buttons 50 are used to scroll between the different menu items which are explained in more detail below. The right and left programming buttons 52 are used to select items that are side by side on the display and to select delete function Y/N as explained in more detail below. The middle button 54 has the "enter" function and is used to either enter a sub-menu or to select an item for editing. In this arrangement, items which are selected are shown with brackets either side, e.g. <this>. The brackets will flash when the middle button selects them for editing. A user can only scroll between sections when the brackets are not flashing because flashing indicates that a user is in edit mode. Pressing the middle button again exits editing. As shown in Figure 1 a, the middle button is accessible when the display cover is closed, e.g. through an aperture in the display cover.

[64] The menu options can be viewed on the display and can be controlled using the menu programming buttons. As an example, the menu options include:

1 Status

2 Fault

3 Log

4 Date 5 Time

6 Night

7 Closing

8 Opening

9 Sounder

10 Test

1 1 Learn new alarm

12 Calibrate ambient level

13 Battery

14 Version

15 Restore

[65] The display will turn on automatically to inform the user when an event has occurred, for example as shown in Figure 5a, the message "foot armed" is shown to indicated to a user that they have armed the device by depressing the foot plunger. The display will remain on if the unit requires attention, during which time the sounder will beep and the status indicator will flash to alert the user. At all other times the display will be blank. This is normal and designed to save power. The display indicates whenever a button is pressed. The user can press the enter button on the cover to momentarily turn on the display if required.

[66] Figure 5b shows examples of status messages which may be displayed to the user during operation. A user can access these important messages by scrolling through the menu to the status function and pressing enter to edit. The status messages include:

Battery door open: The battery cover must be in place for the unit to function correctly.

Set up required: Date, time and learn set up required.

Idle foot up: The foot lever is in the up position

Active: The unit is now listening (monitoring) and is ready to detect a fire alarm.

Night closing The unit will remain inactive until the Night closing period ends.

Clear fault required: Scroll down to the Fault menu item and reset the fault to be able to proceed.

Replace battery: Replace battery

[67] If a fault shows on the STATUS screen, the nature of the fault can be seen along with the timestamp when it occurred. An example of this is shown in Figure 5c. The user can then scroll through the menu using the highlighted top and bottom buttons to the FAULT function and press enter (central highlighted button) to edit. The device is prevented from working while a fault is present. A user can delete the fault by scrolling to the left display shown in Figure 5d, selecting delete <Y> as shown in the right display of Figure 5d, using the highlighted left and right buttons, and pressing enter (central highlighted button).

[68] All significant events are logged, the last 50 of which are stored in a log. A user can scroll through the menu to access the log entries which are numbered in the title bar e.g. <LOG15> is the 15th most recent log entry. A user presses the enter button (central highlighted button) to gain access to the other log messages. The title will read <LOG15> when this mode is active as shown in Figure 5e. Using the up or down programming buttons (as highlighted to the right of the display) allows a user to scroll and press enter (central highlighted button) to confirm and go into edit mode. Using the left and right programming buttons (highlighted to the right of the display in Figure 5f) in this mode allows a user to delete entries. For example once the selection shown in Figure 5f has been made, pressing the enter button to confirm selection will delete the log entry and exit this mode.

[69] Figure 5g illustrates the display after a user has scrolled through the menu to the DATE function (using the highlighted top and bottom buttons to the right of the display), and pressed enter (central highlighted button) to edit. To set month, day and year, the user uses the up or down programming buttons to scroll, and presses enter to select as shown in Figure 5h. Once in edit mode, the user uses the same buttons to edit, and enter to confirm.

[70] Figure 5i illustrates the display after a user has scrolled through the menu to the TIME function (using the highlighted top and bottom buttons to the right of the display), and pressed enter (central highlighted button) to edit. As shown in Figure 5j, to select hours or minutes, the user uses the left and right programming buttons, and presses enter to select. Similarly, to edit hours or minutes, the user uses the up and down programming buttons to scroll, and presses enter to confirm.

[71 ] Figure 6a illustrates the display when a user has scrolled through the menu to the NIGHT function (using the highlighted top and bottom buttons to the right of the display), and pressed enter (central highlighted button) to edit. This mode allows a user to automatically close the door during the night. Using the left and right programming buttons allow a user to select Y as shown in Figure 6a and then press enter to select.

[72] Figure 6b illustrates the display when a user has scrolled through the menu to the GLOSING function (using the highlighted top and bottom buttons to the right of the display), and pressed enter (central highlighted button) to edit. This mode allows a user to define the time when the door must close overnight. As shown in Figure 6c, to select hours or minutes, the user uses the left and right programming buttons, and presses enter to select. Similarly, as shown in Figure 6d, to edit hours or minutes, the user uses the up and down programming buttons to scroll, and presses enter to confirm. Night closing must be set for "P " (i.e. 1 1 :30) between noon 12:00 and midnight 0:00.

[73] Figure 6e illustrates the display when a user has scrolled through the menu to the OPENING function, and pressed enter to edit. This mode allows a user to define the time when the door can be held open again. As shown in Figure 6f, to select hours or minutes, the user uses the left and right programming buttons, and presses enter to select. Similarly, to edit hours or minutes, the user uses the up and down programming buttons to scroll, and presses enter to confirm. Night opening must be set for "AM" the following day (i.e. 06:00) between midnight 0:00 and noon 12:00.

[74] Figure 6g illustrates the display when a user has scrolled through the menu to the SOUNDER function (using the highlighted top and bottom buttons to the right of the display), and pressed enter (central highlighted button) to edit. This mode allows a user to mute the sounder for night operation otherwise the device will always make an audible tone when the door closes during operation. The night silent function defines whether or not the sound is audible during night closing. A user selects night silent mode by using the left and right programming buttons to select <Y> as shown in Figure 6h and pressing enter to select.

[75] Figure 6i illustrates the display when a user has scrolled through the menu to the TEST function, and pressed enter to edit. This mode allows a user to define the time of day and day of the week when the self test is performed. The door will close automatically when the time is reached and the event is logged. As shown in Figure 6j, to select hours or minutes, the user uses the left and right programming buttons, and presses enter to select. Similarly, to edit hours or minutes, the user uses the up and down programming buttons to scroll, and presses enter to confirm. To select the day, the user uses the down programming button to scroll and presses enter to select. Once in edit mode as shown in Figure 6k, the user uses the up and down buttons to edit and then presses enter to confirm.

[76] Figure 7a illustrates the display when a user has scrolled through the menu to the LEARN function (using the highlighted top and bottom buttons to the right of the display), and pressed enter (central highlighted button) to learn. This function allows the device to learn the unique acoustic properties of the fire alarm as a reference to trigger the door release. Once the function is selected, this starts the alarm learning sequence which fakes place in two halves. Initially, in a first step, the Shuttle samples the background noise level, displaying for example 'Calib. No. 40' down counting to 'Caiib. No. 0' as if progresses. An alarm sequence may already be stored in the system and thus once the new alarm has been selected, the user may be presented with the display shown in Figure 7b which allows them to select whether or not to override an existing alarm. If overwriting the existing alarm is selected, the display shown in Figure 7c is presented to the user and the user selects enter (central highlighted button) if they wish to proceed. Alternatively, the up or down button can be pressed and any time to cancel.

[77] Once the calibration test completes, the device enters "waiting for alarm' mode. The device can be left in this state until the alarm is sounded, at which point it begins the learning process, displaying 'Sample No. 50' down to 'Sample No 0' when it reports 'Alarm Learnt' or 'No alarm heard'. Following setting, a self test may be automatically performed indicating that the foot actuator may be set. It is recommended that a test is performed with the device in place by sounding the fire alarm until the foot actuator is released and the door is closed.

[78] This feature aiiows multiple units to be installed in a variety of locations where they can be primed ready to learn the alarm at the same time. If the environment is noisy, the system will make sure that it sets an appropriate level above that for sensing the alarm, in other words the loudness preset threshold may be different for different environments and may be set at a specific value above the ambient noise level for the particular environment. The battery life might be compromised if the background noise level is significantly quieter when the alarm is learned compared to the levels normally in the area. The fire detection alarm must be sounded during at this point. Alarm Learnt showing in the display indicates the 'Learn process' has been successful. The device will typically perform a self test indicating "door closing" at this point, [79] Figure 7d illustrates the display when a user has scrolled through the menu to the CALIBRATE AMBIENT LEVEL function (using the highlighted top and bottom buttons to the right of the display), and pressed enter (central highlighted button) to learn. This function allows the device to calibrate an ambient level so that any persistent loud sound above the ambient level is treated as an alarm and triggers the door release. This mode should only be used as an interim solution when sounding the alarm is not possible. It is also not suitable for a noisy environment and it is recommended that the previous LEARN mode is used to be certain that the specific installed alarm can be detected and to avoid nuisance door releases.

[80] If an alarm is already stored, Figure 7e shows that the user is presented with a screen asking them to confirm whether or not to overwrite the stored alarm. A user uses the right and left buttons to select whether or not to overwrite the alarm and Figure 7f shows a user pressing enter (central highlighted button) to confirm the overwrite. If this is selected, the "calibrate ambient level" sequence is started. The device samples the background noise level, displaying for example 'Caiib. No. 40' down counting to 'Calib. No. 0' as it progresses. The calibrate ambient level sequence is complete when the calibration count reaches zero and for example 'Calib. No. 0' appears. Following setting, a self test may be automatically performed indicating door closing.

[81 ] Figure 7g illustrates the display when a user has scrolled through the menu to the BATTERY function, and pressed enter. This function shows the state of the battery. When the battery voltage begins to fall, the voltage is displayed. At all other times, the display shows OK as in Figure 7g. in the VERSION mode (not shown), the software version number is shown in the display and this should be sent by a user when corresponding with the manufacturer.

[82] Figure 7h illustrates the display when a user has scrolled through the menu to the RESTORE function, and pressed enter to edit. This mode allows a user to restore the device to the state it was in when it left the factory. Any of the settings which have been changed will be overwritten and the alarm sound will need to be learnt again. Using the left and right programming buttons allow a user to select Y as shown in the middle images and then press enter to select. In the final image, a user presses on enter to confirm the selection. Time, date and log settings will remain unchanged after restoring to factory defaults. Ail previously learnt sounds will be erased and must be reprogrammed after restoring.

[83] it will be appreciated for all the options described in relation to Figures 5a through to Figure 7h, the precise combination of buttons described above is merely illustrative and is not intended to be limiting. Similarly, the different modes are illustrative and the device may have more or fewer modes as required.

[84] Before installing the system or device of the present invention, it is recommended that the foilov/ing fire safety conditions are met. The fire door self closes and closes securely. There is an adequate clearance of at least 5mm for the fitting of the floor plate. The product, is included in a fire risk assessment (fire precautions regulations 1997). A suitable fire detection alarm is installed which meets the British standard for firm alarm installation. For example, BS5839-1 : 2013, (Clause 16.2), states: The sound pressure level of alarm signals should be generally, throughout ail accessible areas of the building, not less than 65dB(A). Where the sound pressure level of background noise is greater than 60dB(A), the sound pressure level of the fire alarm signal should be 5dB above the sound pressure level of the background noise.

[85] A summary of the set-up or quick start guide for installing a device is first to insert batteries, e.g. as shown in Figures 2a and 2b. The menu programming buttons can then be accessed as shown in Figure 5a and the menu can be used to set the date and then set the time. Optionally night closing and open/close times can be set as explained above. The device is then fixed to the door and the floor plate is fixed to the floor. The menu is then use to scroll through and select the LEARN function. A user presses the enter button and then selects Y using the left or right programming buttons. The enter button is then pressed to confirm the overwrite and a user waits until the calibration count reaches zero. The alarm can be sounded at any time after this to cause learning to begin. The next step is then to depress the foot actuator, e.g. by pressing the foot actuator downwards to arm the unit. The device is now listening (monitoring) and is ready to detect a fire alarm. At this point it is also essential to sound the alarm and test everything is functioning correctly and that the door is being released when the alarm sounds.

[86] Regular maintenance checks are recommended. For example, a weekly check to ensuring the device is holding and releasing the door is recommended by testing the fire alarm for 30 seconds. The door will release and close. For a monthly check, additionally the following actions should also be carried out: check to see the floor plate (if fitted) is securely attached, check screws for tightness, check unit is securely attached to door, check screws for tightness, dust microphone holes and wipe unit down with a moist cloth. Finally, for a yearly check, it is recommended to replace batteries. As explained above, the system will release the foot and show the general Fault "call Engineer" message if the battery voltage is too low to power the unit. The battery can be replaced without having to reset the time and date. The system will keep track of the time for up to 30 minutes with the batteries removed. After that period, the user will be required to re-enter the date and time. All other settings will be unchanged. Accessing the battery cover triggers the release of the foot. The unit cannot be armed while the cover is removed.

[87] As an example, the technical specifications may include a 3V voltage (x2 Type C 1 .5V ceils), a waveform sampling acoustic sensor, a "fail to safe" mode and visual and acoustic status alerts. Merely for guidance only, the dimensions may be 152mm high and 198 mm wide and 30.5 mm deep. The foot plunger may extend a further 40mm above the housing,

[88] At least some of the example embodiments described herein may be constructed, partially or wholly, using dedicated special-purpose hardware. Terms such as 'component', 'module' or 'unit' used herein may include, but are not limited to, a hardware device, such as circuitry in the form of discrete or integrated components, a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks or provides the associated functionality. In some embodiments, the described elements may be configured to reside on a tangible, persistent, addressable storage medium and may be configured to execute on one or more processors. These functional elements may in some embodiments include, by way of example, components, such as software components, object- oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Although the example embodiments have been described with reference to the components, modules and units discussed herein, such functional elements may be combined into fewer elements or separated into additional elements. Various combinations of optional features have been described herein, and it will be appreciated that described features may be combined in any suitable combination. In particular, the features of any one example embodiment may be combined with features of any other embodiment, as appropriate, except where such combinations are mutually exclusive. Throughout this specification, the term "comprising" or "comprises" means including the component(s) specified but not to the exclusion of the presence of others.

[89] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[90] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[91 ] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.