CONTROLLING THE SYSTEM.

Technical field

The disclosure herein generally relates to a system and a method for discouraging an animal from entering an area, a controller for the system, and a method for controlling the system.

Background An animal, for example a pet, may enter an area which is undesirable for them to enter, examples of which include but not limited to bedrooms, sofas, food preparation areas, garden beds, and other inside areas or outside areas. Problems that may arise from the animal entering an area may include:

• Dirtying particular areas of that are preferably kept clean, for example a bedroom or another area of a home or other building;

• Damaging furnishings or other items within the home or other building, for example a sofa;

• Going to the toilet in an area at which going to the toilet is intolerable, for example in a lounge room or garden bed;

· Walking on food preparation areas or other behaviours incompatible with good hygiene practice;

• Sleeping in areas which are undesirable, for example a baby's cot;

• Rummaging through bins or food storage; and

• Entering an area that may be unsafe for the pet. The pet entering an area used by an infant and/or small children may present significant health and safety issues. For example, children may be mauled, or babies may be smothered.

Many pet owners who experience such pet behaviours consider these behaviours as "annoying" or "extremely annoying". Many pet owners may have difficulty improving their pet's behaviour, because they may be unable to watch their pets all the time, and may be unaware when their pet enters specific areas. Summary

Disclosed herein is a system for discouraging an animal from entering an area. The system comprises a first unit for attachment to the animal and a second unit for placement within the area. One of the first unit and the second unit comprises a sonic generator arranged to generate a sonic signal. The other of the first unit and the second unit comprises a sonic signal receiver for receiving the sonic signal. The system comprises a sonic alarm generator. The system comprises a processor arranged to generate time of flight information indicative of a time for the sonic signal to travel from the sonic generator to the sonic signal receiver. The processor is arranged to determine a distance between the first unit and the second unit using the time of flight information. The processor is arranged to confirm that the distance is one of equal to and less than a predetermined distance, and subsequently cause the sonic alarm generator to generate a sonic alarm.

In the context of this document, "sonic" means relating to sound waves. The sonic alarm may be audible by a human or may be ultrasonic. In an embodiment, the processor comprises a time of flight information module arranged to generate the time of flight information.

In an embodiment, the processor comprises a distance determination module arranged to determine the distance between the first unit and the second unit using the time of flight information. In an embodiment, the processor has an alarm controller that is arranged to confirm that the distance is one of equal to and less than a predetermined distance, and subsequently cause the sonic alarm generator to generate a sonic alarm.

In an embodiment, the second unit comprises a substantially conical sonic distributer arranged to distribute the sonic signal around the second unit, which has the sonic generator. In an embodiment, the sonic generator is disposed adjacent an apex of the substantially conical sonic distributor. The sonic generator may be arranged and/or orientated to emit the sonic signal towards the substantially conical sonic distributor for a side surface of the substantially conical sonic distributor to reflect the sonic signal outwardly. The side surface of the substantially conical sonic distributor may be for reflecting the sonic signal radially outward. In an embodiment, in use the apex of the substantially conical sonic distributor points one of upwardly and downwardly.

In an embodiment, the side surface is convex adjacent the apex.

In an embodiment, the sonic signal is an ultrasonic signal. The sonic generator may comprise an ultrasonic generator for generating the ultrasonic signal.

In an embodiment, the sonic alarm comprises an ultrasonic alarm and the sonic alarm generator comprises the ultrasonic generator. Alternatively or additionally, the sonic alarm generator comprises a human audible alarm.

In an embodiment, the ultrasonic alarm is audible by the animal. An embodiment has a plurality of sonic alarm modes and wherein the sonic alarm generator comprises a human audible alarm generator, and in one of the plurality of sonic alarm modes the sonic alarm is the ultrasonic alarm and in another of the plurality of sonic modes the sonic alarm further comprises a human audible alarm generated by the human audible alarm generator.

In an embodiment, the sonic alarm generator comprises a human audible alarm generator and the sonic alarm comprises a human audible alarm generated by the human audible alarm generator.

In an embodiment, the first unit comprises a first unit radio and the second unit comprises a second unit radio for radio communications with the first unit radio.

An embodiment has a plurality of distance determination modes, wherein in one of the plurality of distance determination modes the processor is arranged to:

-generate the time of flight information indicative of the time for the sonic signal to travel from the sonic generator to the sonic signal receiver; and

-determine the distance between the first unit and the second unit using the time of flight information;

and in another of the plurality of distance determination modes, the processor is arranged to determine the distance between the first unit and the second unit using a Received Signal

Strength Indicator (RSSI) for a radio communication between the first unit radio and the second unit radio.

In an embodiment, the first unit is arranged for the first unit radio to send a request signal to the second unit requesting sonic signal transmission time information indicative of the start time of transmission of the sonic signal, receive the sonic signal transmission time information, and further arranged to start powering the sonic signal receiver substantially at the transmission time of the sonic signal indicated by the sonic signal transmission time information.

In an embodiment, the first unit is arranged to stop powering the sonic signal receiver substantially when the sonic signal is received. In an embodiment, the first unit is arranged for the first unit radio to send to the second unit radio sonic signal received time information indicative of the time that the sonic signal was received by the first unit.

In an embodiment, the processor is arranged to generate the time of flight information using the sonic signal received time information. In an embodiment, the first unit is an animal attachable unit arranged for attachment to the animal.

In an embodiment, the animal attachable unit comprises a tag. In an embodiment, the second unit comprises the processor.

In an embodiment, the second unit comprises a user interface for at least one of configuring and monitoring.

In an embodiment, the second unit has a wireless communications unit arranged to wirelessly communicate with a personal computational device and the system is configurable using the personal computational device.

In an embodiment, the second unit comprises memory for storing alarm information indicative of at least one time that the sonic alarm was generated, or alarm information derived using a plurality of times that the sonic alarm was generated and further arranged to communicate via the wireless communications unit at least part of the alarm information to the personal computational device for processing by an application thereon.

Disclosed herein is a system comprising a plurality of second units, each of the plurality of second units being in accordance with the above disclosure. One of the plurality of second units is arranged to wirelessly receive from each of the others of the plurality of second units alarm information indicative of at least one time that a respective sonic alarm was generated or alarm information derived using a plurality of times that respective sonic alarms were generated and subsequently wirelessly transmit the alarm information received from each of the other of the plurality of second units and alarm information generated by the one of the plurality of second units to a personal computing device for processing by an application thereon.

In an embodiment, each of the plurality of systems are arranged to cooperate such that the sonic signals generated by the plurality of systems do not overlap. Disclosed herein is a method for discouraging an animal from entering an area. The method comprises the step of attaching a first unit to the animal. The method comprises the step of placing a second unit within the area. The method comprises the step of causing one of the first unit and the second unit to produce a sonic signal. The method comprises the step of receiving the sonic signal at the other one of the first unit and the second unit and generating time of flight information indicative of a time for the sonic signal to travel between the first unit to the second unit. The method comprises the step of determining a distance between the first unit and the second unit using the time of flight information. The method comprises the step of confirming that the distance is one of equal to and less than a predetermined distance, and subsequently produce a sonic alarm. An embodiment comprises the step of distributing the sonic signal around the one of the first unit and the second unit that generated the sonic signal using a substantially conical sonic distributor.

An embodiment comprises the step on emitting the sonic signal towards the apex of the substantially conical sonic distributor whereby a side surface of the substantially conical sonic distributor reflects the sonic signal outwardly. An embodiment comprises the step of positioning the one of the first unit and the second unit such that the apex points one of upwardly and downwardly.

In an embodiment, the side surface is convex adjacent the apex.

In an embodiment, the sonic signal is an ultrasonic signal.

In an embodiment, the sonic alarm comprises an ultrasonic alarm. In an embodiment, the ultrasonic alarm is audible by the animal.

An embodiment comprises a plurality a sonic alarm modes, and in one of the plurality of sonic alarm modes the sonic alarm is the ultrasonic alarm and in another of the plurality of sonic modes the sonic alarm further comprises a human audible alarm.

In an embodiment, the sonic alarm comprises a human audible alarm. An embodiment comprises a plurality of distance determination modes, wherein one of the plurality of distance determination modes comprises the steps of:

-generating the time of flight information indicative of the time for the sonic signal to travel between the first unit and the second unit; and

- determining a distance between the first unit and the second unit using the time of flight information;

and another of the plurality of distance determination modes comprises the step of determining the distance between the first unit and the second unit using a Received Signal Strength Indicator (RSSI) for a radio communication between the first unit and the second unit. An embodiment comprises the first unit sending a request signal to the second unit requesting sonic signal transmission time information indicative of the start time of transmission of the sonic signal, the first unit receiving the sonic signal transmission time information, and starting to power a sonic signal receiver of the first unit substantially at the transmission time of the sonic signal indicated by the signal transmission time information. An embodiment comprises the step of stopping power to the sonic signal receiver substantially when the sonic signal is received.

An embodiment comprises the first unit sending to the second unit sonic signal received time information indicative of the time that the sonic signal was received.

An embodiment comprises the step of generating the time of flight information using the sonic signal received time information.

An embodiment comprises at least one of configuring and monitoring using a user interface of the second unit.

An embodiment comprises the step of wirelessly communicating with a personal computational device and setting the predetermined distance using the personal computational device. An embodiment comprises the step of wirelessly communicating at least part of alarm

information to the personal computational device for processing thereby.

Disclosed herein is a controller for a system for discouraging an animal from entering an area, the controller comprising a personal computational device having an application operable by a user to cause the personal computational device to wirelessly send instructions to the system and receive alarm information indicative of at least one time that a sonic alarm was generated or alarm information derived using a plurality of times that the sonic alarm was generated for review by a user.

Disclosed herein is a method for controlling a system for discouraging an animal from entering an area, the method comprising a user interacting with an application on a computation device to cause the personal computational device to:

wirelessly send instructions to the system; and

receive and subsequently display alarm information indicative of at least one time that a sonic alarm was generated or alarm information derived using a plurality of times that the sonic alarm was generated. Disclosed herein is non-transitory processor readable tangible media including program instructions which when executed by a processor causes the processor to perform a method disclosed above.

Disclosed herein is a computer program for instructing a processor, which when executed by the processor causes the processor to perform a method disclosed above. Any of the various features of each of the above disclosures, and of the various features of the embodiments described below, can be combined as suitable and desired.

Brief description of the figures

Embodiments will now be described by way of example only with reference to the

accompanying figures in which: Figure 1 shows an embodiment of a system for discouraging an animal from entering an area.

Figure 2 shows an exploded view of the first unit of figure 1.

Figure 3 shows an exploded view of the second unit of figure 1

Figure 4 shows an example electronic architecture of the second unit.

Figure 5 shows an example electronic architecture of the first unit.

Figure 6 shows a plurality of systems of figure 1 on a property. Figures 7 to 16 show example screen shots of an example application on a personal communication device in communication with the system of figure 1.

Description of embodiments

Figure 1 shows an embodiment of a system for discouraging an animal, for example a domestic animal in the form of a pet, from entering an area, the system being generally indicated by the numeral 10. The system 10 has a first unit 12 in the form of a tag for attachment to the animal, for example by attaching the first unit 12 to an animal's collar and then placing the collar around the animal. Figure 2 shows an exploded view of the first unit 12 of figure 1. The system 10 has a second unit 14 for placement within the area. Figure 3 shows an exploded view of the second unit 14 of figure 1. One of the first unit 12 and the second unit 14 - in this but not all embodiments the second unit 14 - has a sonic generator 16 comprising an ultrasonic transducer to generate the sonic signal which in this embodiment is an ultrasonic signal. The other of the first unit 12 and the second unit 14 - in this but not all embodiments the first unit 12 - has a sonic signal receiver 18 for receiving the sonic signal. The sonic receiver is housed within a tag casing 30 and is located behind a mesh portion 32 of the casing. The system 10 has a sonic alarm generator that in this embodiment comprises the ultrasonic transducer 16 and an audio transducer or speaker The system 10 has a processor 40 on a second unit circuit board 22. The processor 40 has a time of flight information module 103 arranged to generate time of flight information indicative of a time for the sonic signal to travel from the sonic generator 16 to the sonic signal receiver 18. The processor 40 has a distance determination module 105 arranged to determine a distance between the first unit 12 and the second unit 14 using the time of flight information. The processor 40 has an alarm controller 107 that is arranged to confirm that the distance is one of equal to and less than a predetermined distance, and subsequently cause the sonic alarm generator to generate a sonic alarm. In the illustrated embodiment, the sonic alarm generator includes the ultrasonic transducer and the sonic alarm includes an ultrasonic alarm audible by the animal but not a human. The ultrasonic alarm (and ultrasonic signal) may be in the range of 20 kHz - 50 kHz, which is generally considered to be audible by domestic animals including but not limited to dogs and cats but not humans, however the actual range may vary in view of individual variations in hearing range.

The ultrasonic alarm may provide a stimulus that only a domestic animal can hear, and may provide a level of irritation that may discourage domestic animals from entering and/or loitering in the area. The alarm also may provide a consistent feedback to pets that when coupled with a training regime may be effective in improving that animal's compliance with its exclusion from the area. In an alternative embodiment, the system only has a human audible alarm generator for generating a human audible alarm. An animal may still be deterred by the human audible alarm.

The system 10 has a plurality of sonic alarm modes. In one of the plurality of sonic alarm modes the sonic alarm is the ultrasonic alarm as described above (a "silent" mode in view of the inability of humans to hear ultrasound). In another of the plurality of sonic modes the sonic alarm further comprises a human audible alarm generated by a human audible alarm generator mounted on a second unit circuit board 22 of the second unit 14. The human audible alarm provides a warning when the animal enters the area, allowing the animal's owner to remove the pet before injury or damage is done. The silent mode may be selected, for example, during the night so that people may not have their sleep disturb. The system 10 is configured for a user to schedule switching from one of the plurality of sonic alarm modes to another one of the plurality of sonic alarm modes. The user may interact with the personal computing device to schedule the switching. The second unit 14 has a substantially conical sonic distributer 24 arranged to distribute the sonic signal when received thereby around the second unit 14. The sonic generator 16 is disposed adjacent an apex 26 of the substantially conical sonic distributor. The sonic generator 16 is arranged and/or orientated to emit the sonic signal towards the substantially conical sonic distributor 24, wherein a side surface 28 of the substantially conical sonic distributor 24 reflects the sonic signal outwardly. In use, the base 44 of the second unit 14 is placed on a flat surface, for example a floor, such that the apex 26 of the substantially conical sonic distributor 24 points upwardly. When so disposed, the sonic generator is above the apex and the sonic signal so reflected extends across the area. In an alternative embodiment, the conical sonic distributor 24 is inverted and the sonic generator is below the apex 26. The applicant has found that the sonic signal is better distributed when the side surface 28 is convex adjacent the apex 26.

The first unit 12 comprises a first unit radio 34 attached to the first unit circuit board 36. The second unit 14 comprises a second unit radio 38 attached to the second unit circuit board 22 for radio communications with the first unit radio. The first and second unit radios are, in this but not necessarily in all embodiments, digital radios.

The system has a plurality of distance determination modes. In one of the plurality of distance determination modes, the time of flight information module 103 of the processor 40 is arranged to generate the time of flight information indicative of the time for the sonic signal to travel from the sonic generator 16 to the sonic signal receiver 18, and determine the distance between the first unit 12 and the second unit 14 using the time of flight information. This one of the plurality of distance determination modes may have a ranging accuracy of 1 - 10 cm, for example, and may be generally operated when there is a line of site between the first unit 12 and the second unit 14, and may be operated when the user wishes to set accurate area perimeters and where the possibility of an object obscuring the range detection is not an issue. In another of the plurality of distance determination modes, the distance determination module 105 of processor 40 is arranged to determine the distance between the first unit 12 and the second unit 14 using a Received Signal Strength Indicator (RSSI) for a radio communication between the first unit radio 34 and the second unit radio 22. This other one of the plurality of distance determination modes may have a ranging accuracy of 1-5 m, however it may operate over a wider range of, for example, up to 5 meters. This other mode may be operated where range accuracy is less important but it is critical to detect animals even when objects are in the way. For example, this other mode may be used for keeping a cat away from a child's cot in a room cluttered with furniture causing intolerably short lines of sight.

The system 10 may operate by default in the one of the plurality of distance determination modes. The other distance determination modes may be selected, however, by operating a user interface 42 comprising buttons and lights, for example, at the top of the second unit 14. The user interface may be used to set other parameters, for example the predetermined distance and the volume. Alternatively, a personal computing device having an Application ("App") and in communication with the system 10 - as described below - may be used to select a distance determination mode and other modes. The second unit 14 may communicate with the personal computing device via Bluetooth 4.0 LE (BLE), for example, or any other suitable protocol. The App will automatically connect to a registered second unit 14 that has the highest BLE RSSI. When connected, the user may use an App to register devices, modify system settings, request statistics or page devices.

The predetermined distance may be set using range increment or decrement buttons or via the App. Pressing the range increment button may increase the predetermined distance by, for example, 0.5m from 0.5m to a maximum of 3m. Pressing the decrement button may decrease the predetermined distance by, for example, 0.5m from 3m to a minimum of 0.5m. Generally any suitable increments (for example lm increments) and any suitable method of selecting the predetermined distance may be used. When setting the predetermined distance using the buttons on a second unit 14, the predetermined distance is changed to the same value for all first units associated with the second unit 14.

The predetermined distance for each first unit may also be individually settable using the external App. When in normal mode, the App may allow the range to be set in 0. lm steps between 0m to 3m. No audio feedback may be provided when setting range within the App, rather the app will directly display the value of the set range.

The system 10 is arranged to conserve power. Without suitable power conservation, the system may not be practical because the first unit 12 may quickly drain the relatively small on board battery. The first unit radio is configured to send a request signal to the second unit 14 requesting sonic signal transmission time information indicative of the start time of transmission of the sonic signal, and receive the sonic signal transmission time information. The first unit radio is also arranged to start powering the sonic signal receiver substantially at the transmission time of the sonic signal indicated by the sonic signal transmission time information. The first unit 12 is arranged to stop powering the sonic signal receiver substantially after the sonic signal is received. The first unit 12 is arranged for the first unit radio 34 to send to the second unit radio 38 sonic signal received time information indicative of the time that the sonic signal was received. The time of flight information module 103 of the processor 40 is arranged to generate the time of flight information using the sonic signal received time information. The illustrated system 10, but not all embodiments, implement this power saving method as follows:

The first unit 12 periodically contacts the second unit 14 using the digital radios and requests information on when the second unit 14 is intending to start an Ultrasonic

"ping";

The second unit 14 periodically transmit an ultrasonic "ping"" at its scheduled time TO; The first unit 12 activates its ultrasonic receiver at the scheduled time (TO) and commence listening for the arrival of the "ping";

The first unit 12 measures the time Tl at which the ultrasonic "ping" arrives at the first unit 12 after TO;

The second unit 14 communicates with the first unit 12 via the digital radios and request the time delay of the arrival of the "ping" (T3 = Tl - TO); • The second unit 14 may uses the time delay T3 to determine the distance between the first unit 12 from the second unit 14 (since the time delay is proportional to the distance travelled by the Ping in accordance with the speed of sound); and

• The second unit 14 uses the calculated distance to determine whether the first unit 12 is within the predetermined range. When the first unit 12 is within the predetermined range the second unit 14 will sound an alarm.

To reduce the probability of false triggering due to environmental noise, the first unit 12 generally but not necessarily implements filtering and time based thresholds. The second unit 14 may also be required to confirm the range of a first unit 12 multiple times before triggering an alarm.

The second unit 14 has a wireless communications unit arranged to wirelessly communicate with a personal computational device 44 in the form of a smart phone or tablet computer. The system is configurable by a user operating an application ("App") on the personal computational device.

The second unit 14 has memory on the circuit board 22. The memory is for, amongst other things, storing alarm information indicative of at least one time that the sonic alarm was generated or alarm information derived using a plurality of times that the sonic alarm was generated, including but not limited to the number of times the alarm was generated, the average number of times the alarm was generated per day, or generally any suitable statistic. The second unit 14 is arranged to communicate via the wireless communications unit at least part of the alarm information to the personal computational device 44 for processing by the application thereon. For example, the personal computation device may present a human interpretable representation of the alarm information in the form of characters and/or graphics. Consequently, the owner of the animal is provided with what is generally, but not necessarily, useful information and statistics on their pet's behaviour. This may allow the pet's owner to quantify where their pet has been to gauge behavioural changes.

A plurality of second units 50, 52, 54 may be used on a property, for example a house, as shown in figure 6. The first unit 12 may be operable with respect to each of the plurality of systems 50, 52, 54. One of the plurality of second units 50, 52, 54 may be arranged to wirelessly receive from each of the others of the plurality of second units 52, 54 alarm information indicative of at least one time that a respective sonic alarm was generated or information derived using a plurality of times that the respective sonic alarms were generated. The second unit 50 subsequently wirelessly transmits the alarm information received from each of the other of the plurality of systems and alarm information generated by the one of the plurality of systems to a personal computing device for processing by an application thereon.

For the plurality of second units 50, 52, 54 to be used on a property, it may be necessary for each second unit of the plurality of second units 50, 52, 54 to "ping" at different times. Accordingly, second units may periodically identify and communicate with each other via radio to synchronise and space their "pings" within precise time slots.

Since the second unit pings are also typically synchronised in specific time slots, the first unit 12 may receive from the second unit 50 information on the timing of the pings for each of the plurality of second units 52, 54 to which it is networked. In this way the first unit 12 is able to determine the timing of each second unit by contacting only one second unit 50 rather than all, reducing the number of radio transactions and saving power.

The frequency of first unit 12 communications may be at a rate sufficient to ensure system response times are met and to correct clock drift that can result in range measurement errors.

In the event that a second unit is outside the networks range (i.e. the range of other second units), its Ping timing will be unknown. In this case the first unit 12 may contact this second unit directly to determine its respective Ping schedule. Since the Ping timing for such second units is uncoordinated, it may overlap with the pings of other second units. In this case the first unit 12 will only listen for the Ping of the second unit that is closer, as determined by the second unit which has the highest RSSI. Each first unit 12 and second unit 50, 52, 54, 14 maybe loaded during manufacture with a unique identifier. Each device may use the identifier during radio communications to address each radio packet. To ensure the robustness of the radio communication, radio packets may be addressed and protected by a 16-bit Cyclic Redundancy Check (CRC). Radio communications may be asynchronous, may be initiated by any device and in the case of addressed messages may require a reply acknowledgement to confirm delivery.

To reduce the prospect of radio message collisions, each first unit and second unit 14, 50, 52, 54 may implement a "listen before" speak algorithm that inhibits interrupting current transmissions.

Further, first unit and second unit transactions may implement message retries with a degree of timing randomisation. This will facilitate the successful passing of a message in the event that a collision occurs. In the event that the user wishes to access a second unit other than the second unit 50 connected via Bluetooth Low Energy (BLE), then the BLE connected second unit 50 will provide remote access to the second unit being accessed via digital radio. This will allow the user to seamlessly download statistics, configure, or page any registered second unit 50, 52, 54 without needing to be within the limited BLE range of that second unit.

Similarly, first units may be registered to other second units 52, 54(other than the one connected via BLE) and paged, using a radio network running between second units.

The App may be used to page a registered first or second unit in order to identify it. During paging the second unit will rapidly flash its power LED green for a period of 5 seconds. During paging the first unit 12 will rapidly flash its green LED for a period of 5 seconds.

The system 10 maintains statistics in relation to the number of transgression for each pet (i.e. each first unit 12) with respect to each location (i.e. second units). Statistics may be maintained, for example, for each day for a 28-day period. These statistics may be stored within each second unit, access via the radio network and BLE and presented to the user via the App. The system 10 maintains a log of the time and date of each transgression (when the alarm is generated) and duration for each pet (i.e. first unit 12) with respect to each location (i.e. second unit). The logs may be maintained for a period of 28-days. The logs may be stored within each second unit, accessible via the radio network and BLE and presented to the user via the App.

In order to a first unit 12 to be detected by a second unit, it may first be necessary to associate the first unit 12 with the second unit. This may be achieved by placing the first unit 12 in close proximity to the second unit and pressing a key on the second unit or by associating the first unit 12 to the second unit using the App.

If a first unit 12 is assigned to a second unit, then the first unit 12 will generally appear within the App as assigned to the second unit. In order to stop a first unit 12 being detected by a second unit, it may be necessary to de- associate the first unit 12 with the second unit. This may be achieved by placing the first unit 12 in close proximity to the second unit and pressing another key on the second unit, or by dissociating the first unit 12 using the App.

Architecture Details The electronic architecture of the second unit 14 will now be described with reference to figure 4. The second unit 14 incorporates, in this embodiment, a processor 101 in the form of a

Microcontroller Unit (MCU), that runs embedded software. The embedded software defines a plurality of processor modules, for example the time of flight information module 103, the distance determination module 105, and the alarm controller 107. In alternative embodiments, the modules may be implemented purely in hardware and may take the form of either analogue or digital circuitry. The MCU may be a low cost single chip microcontroller comprising memory in the form of integrated RAM and Flash, and having a reset/watchdog supervisor. The MCU may be in-circuit programmable. The MCU may be programmed via a third party Joint Test Action Group (JTAG) or vendor specific In System Programming (ISP) programmer connected via a header located on the main Printed Circuit Board (PCB). The programming header may be accessible with the enclosures open. The MCU incorporates a real time clock, which may be used for generating alarm time information and scheduling, for example. In alternative embodiments the real time clock may be external of the MCU. The second unit 14 has an un-licensed sub-GHz Radio Frequency (RF) transceiver ("radio"). The radio is be used for bidirectional communication between the first unit 12 and the second unit 14 and also between a plurality of second units.

The second unit 14 has an ultrasonic transmitter that emits an omnidirectional ultrasonic "ping". The "ping" may be used by the first unit 12 to measure the distance of the second unit 14 to the first unit 12.

The transducer may also be capable of generating a loud ultrasonic tone that can be heard by cats and dogs, for example, but that is inaudible to humans.

The second unit 14 has externally visible power/status Light Emitting Diode (LED) and an alarm LED. The Power/Status LED is, in this but not all embodiments, a tri-colour indicator (i.e. green, orange, red) that may be used to indicate when the device is off, on and the status of the battery and charging. This indicator may also be used to identify the first unit 12 during paging. The Alarm LED may be a red LED that will flash when a first unit 12 is within the set proximity.

The second unit 14 may provide various buttons for setting and controlling the system 10. This may include a power, learn, erase, volume up, volume down, range increment and range decrement soft keys.

The second unit 14 may provide a reset circuit that may reset the MCU when the power key is held for more than a few seconds. The reset circuit may be hardware based and may reset the MCU either by removing power or toggling the MCUs external reset line. The reset circuit is intended to be used to recover from a software crash, since there may be no other means by which power supplied from the internal battery can be disconnected.

The second unit 14 may incorporate an audio transducer that may be used to provide feedback to the user when pressing buttons on the user interface.

The audio transducer may also be capable of generating a loud tone for warning the user when a first unit 12 is within a set proximity.

The second unit 14 may be powered from an internal, non-replaceable, rechargeable Lilon battery. The second unit 14 may incorporate a charging circuit that manages battery charging. The

Charger may accept power from an external Direct Current (DC) plug pack connected via a DC jack. The Charger may be able to detect when the battery is flat or fully charged and may manage battery charge termination. The battery charger may protect the battery against short circuit, and over-temperature events. The charger may also include a power supply for generating voltage rails required by internal circuitry.

The electronic architecture of the first unit 12 (the "tag") will now be described with reference to figure 5. The first unit 12 may incorporate a Microcontroller Unit (MCU), which may run embedded software that implements the functions of the first unit 12. The MCU may be a low cost single chip microcontroller with integrated random Access Memory (RAM), Flash and reset/watchdog supervisor.

The MCU may be in-circuit programmable. The MCU may be programmed via a third party JTAG or vendor specific ISP programmer connected via a header located on the main PCB. The programming header may only be accessible with the enclosures open.

The first unit 12 may incorporate an un-licensed sub-GHz RF transceiver. The radio may be used to establish a communication link between the second unit 14 and first unit 12.

The first unit 12 may incorporate an ultrasonic receiver capable of receiving an ultrasonic "ping" emitted by the second unit 14. The "ping" may be used by the first unit 12 to determine the distance of the second unit 14 to the first unit 12. The first unit 12 may incorporate an externally visible green power LED that may flash to indicate when the first unit 12 is active. This indicator may also be used to identify the first unit 12 during paging.

The first unit 12 may be powered from a compact replaceable, non-rechargeable, battery in the form of, for example, a Lithium coin cell.

The first unit 12 may incorporate a power supply circuit for generating voltage rails required by internal circuitry.

The personal communication device application.

Separate Apps maybe support Android and iOS operating systems, or generally any suitable operating system. The App may provide a facility for registering a new second unit 14. The registration process may involve pressing the learn button on the second unit 14 to be registered.

Figures 7 to 16 show example screen shots of an application on a personal communication device in communication with the system of figure 1.

Figure 7 shows a home screen where the user can enter different screens for managing setting for the first units (pets), the second units (sentinels), view statistics (Stats), review logs (Log) and configure zones.

Figure 8 shows a first unit or pet selection window for configuring a first unit 12 associated with a pet. Further first units may be added. Figure 9 shows a window for the first unit associated with the pet "Lassie". Figure 10 shows a window for selecting a colour in relation to a pet. The colour is used to personalise the pet's icon, and also to highlight information and log entries associated with that pet for the purposes of identifying items within the App that relate to that pet.

Figure 11 shows a second unit selection window for configuration each of a plurality of second units on a premises. Each second unit is associated with an icon and name for its location, for example "pantry".

Figure 12 shows a configuration window for the second unit at a selected located, the location being "pantry".

Figure 13 shows statistics of transgressions for the first unit associated with a selected pet "Lassie" for each of the second units on the premises. Figure 14 shows a window of a log for all transgressions for all the first units.

Figure 15 shows a window that enables configuration of the response of a second unit to a selected first tag.

Figure 16 shows a window that enables the configuration of the response of a second unit to all first tags.

When first added, a second unit may be given a default name (e.g second unit 1) and default settings.

The App may provide a facility for viewing which second units have been registered in the system. The App may provide a facility for paging a second unit.

The App may provide a facility for naming a second unit, changing its icon, and specifying its location.

The App may provide a facility for deregistering a second unit.

The App may allow the modification of the following settings, which relate to the second unit: · Setting of the volume level of the audible alarm volume from silent to maximum

• Enabling/disabling and Setting of a single daily schedule (i.e. start and stop time) when the audible alarm will be silence (e.g. during sleeping times).

• Enabling/disabling of the ultrasonic alarm audible only to pets.

• Selection of modes. The App may provide a facility for registering a new first unit. The registration process may involve placing the first unit next to a second unit (within 0.5m, say) and pressing the learn button on the second unit.

The App may provide instruction during the registration process.

When first added, a first unit may be given a default name (e.g. first unit 1) and default settings. The App may provide a facility for viewing which first units have been registered in the system. The App may provide a facility for paging a first unit. The App may provide a facility for naming a first unit, changing its icon, replacing the icon with a photo of the associated pet, specifying the date of birth, bread and other details of the pet.

The App may provide a facility for deregistering a first unit.

The app may have the ability to associate registered first units with registered second units so that the second units detect the proximity of the associated first units.

The App may allow the modification of the following settings which relate to a zone:

• Enabling/disabling of the first unit proximity detection with respect to a specific second unit.

• When first unit proximity detection is enabled and the second unit is in infant mode, the first unit detection range may be set with a resolution of lm.

The App may display statistics of the number of detected transgressions for each day over, for example, a 28-day period. The types of statistics available may, for example, include:

• the number of transgression of any specific first unit/pet with respect to any or all second units.

· the number of transgression at any specific second unit with respect to any or all first units/pets.

The App may provide a scrollable log which includes the following information with respect to a transgression:

• the transgression time and date

· the pet/first unit which transgressed

• the second unit that represents the area of the transgression

• the duration of the transgression event

The App may provide a facility for viewing the status of the network connection between second units. It may also provide network statistics such as a quality of service. The App may provide a warning when a registered second unit is unreachable via the network.

Digital Radio Communications The radio communication between second units and between a first unit 12 and a second unit 14 may operate over a 433MHz license free digital radio band. The communications range between the first unit 12 and second unit 14 is generally but not necessarily greater than 10m.

Now that embodiments have been described, it will be appreciated that some embodiments may have at least one of the following advantages:

• Animals may be excluded from an area without cruel treatment;

• Pets and humans may be discriminated;

• Little or no obstruction and/or inconvenient may be experienced;

• A very narrow or specific set of behaviours may be targeted;

· Effectiveness.

Variations and/or modifications may be made to the embodiments described without departing from the spirit or ambit of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Prior art, if any, described herein is not to be taken as an admission that the prior art forms part of the common general knowledge in any jurisdiction.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word

"comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, that is to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.