WO2011014911A1

WO2011014911A1 - Alarm system for portable or moveable objects

Info

Publication number: WO2011014911A1
Application number: PCT/AU2010/000978
Authority: WO
Inventors: Steven Metlitzky; Damian Shelton
Original assignee: Dynamco Pty Ltd
Priority date: 2009-08-03
Filing date: 2010-08-03
Publication date: 2011-02-10

Abstract

A sensor (10) for a security or monitoring system is disclosed, which has a tilt sensor (11) interfaced with a processor (13). The processor (13) has memory (17) arranged to store data from the tilt sensor (11) including at-rest data. The processor (13) is arranged to poll the tilt sensor (11) and obtain new data from the tilt sensor (11), and compare polled new data with data in the memory (17), and issue a notification signal in the event that the new data and data stored in the memory do not compare within a predetermined variation. A vibration sensor (15) may also be included to wake-up the processor (13), thus conserving power when vibration from movement is below a threshold level.

Description

"Alarm System for Portable or Moveable Objects" Field of the Invention

This invention relates to security systems and alarm systems for monitoring portable or moveable objects. In particular this invention relates to the monitoring movement of portable items such as tool boxes, and also hatches and covers providing access to areas where a hazard may exist or where items may be at risk of theft.

Background Art

The following discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge as at the priority date of the application.

The protection of motor vehicles, buildings, and zones within buildings against unauthorised access using alarm and monitoring systems, is well known. Techniques used in such systems include the monitoring of circuits which are broken by the opening of doors or windows or access hatches, or by the braking of glass, passive infrared detectors which detect body heat, ultrasonic detectors that can detect intrusion causing variation of an ultrasonic sound field, and systems that monitor continuity of a light beam. One of the most difficult areas to protect or provide safety alarm features for are items with lids that tilt vertically such as toolboxes, truck or utility vehicle covers as well as water areas such as pool or spa covers that are a key issue for child safety. Historically, vibration type movement sensors or magnets and reed relays have been utilised, but these have been found to be prone to false alarms. Wired systems are also often unsuitable and impractical due to complexity and cost of installation, especially in water/wet areas where moisture may present a safety or reliability issue.

Throughout the specification unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Throughout the specification unless the context requires otherwise, the word "include" or variations such as "includes" or "including", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. It is an object of one form of the invention to provide a wireless tilt sensor for security or safety purposes that is highly efficient from a battery life perspective and highly reliable in terms of sensing real "tilt" movement as opposed to vibration, reducing or eliminating false alarms.

Disclosure of the Invention In accordance with one aspect of the invention there is provided a sensor for a security or monitoring system, said sensor including a tilt sensor interfaced with a processor, said processor being arranged to receive data from said tilt sensor and compare said data from previously received data and issue a notification signal in the event that said data do not compare within a predetermined variation. In accordance with one aspect of the invention there is provided a sensor for a security or monitoring system, said sensor including a tilt sensor interfaced with a processor, said processor having memory, said memory being arranged to store data from said tilt sensor including at-rest data, said processor being arranged to poll said tilt sensor and obtain new data from said tilt sensor, and compare polled new data from said tilt sensor with said data in said memory, and issue a notification signal in the event that the new data and said data do not compare within a predetermined variation.

Preferably said data includes data from previous data obtained from the tilt sensor that falls within said predetermined variation. In this manner, a range of readings may be used to determine a baseline for comparison with any new data.

Preferably said sensor includes a vibration sensor, to provide vibration data to said sensor.

Preferably said tilt sensor is arranged to provide tilt data in two horizontal dimensions.

With such an arrangement, correct horizontal orientation of the tilt sensor needs to be observed. This can be achieved by marking the housing with indicia to show which way is up in a correct installation. However it is most preferred for the tilt sensor to provide tilt data in three dimensions (x, y and z), so that installation orientation and orientation when arming the system is not important.

Preferably said tilt sensor is an accelerometer capable of providing acceleration data in three dimensions. Also in accordance with a preferred arrangement, said tilt sensor includes at least one gyroscopic sensor capable of providing rotational data.

Preferably for purposes of increased battery life, said processor is arranged to periodically poll said tilt sensor.

Preferably said processor is arranged to periodically poll said tilt sensor with a period of up to 20 seconds.

Preferably said period is in the range of 100ms to 3 seconds. Preferably said period is in the range of 1 to 3 seconds. Preferably said period is about 2 seconds.

Preferably said sensor is arranged to operate said processor in a mode to minimise power consumption, and arranged to "wake up" said processor out of said mode to poll said tilt sensor and perform data comparison and notification signalling (if any) before resuming said mode.

Preferably said sensor is arranged to use data from said vibration sensor to "wake up" said processor out of said mode to poll said tilt sensor and perform data comparison and notification signalling (if any) before resuming said mode.

Preferably said sensor includes a wireless transmitter to transmit notification signalling.

Preferably said sensor includes an RF transmitter to transmit notification signalling.

Preferably said sensor is capable of being placed in a learn mode, to learn spatial data from said tilt sensor.

Preferably said sensor is capable of being placed in a learn mode, to learn vibration patterns sensed as data from said vibration sensor.

Preferably said sensor is capable of being placed in a learn mode, to learn vibration patterns sensed as data from said accelerometer or gyroscope sensor. Preferably said sensor includes a wireless receiver to receive control data. Such control data may include placing said sensor in and out of a learn mode where expected normal and/or at-rest data can be determined from said tilt sensor and said vibration sensor, and threshold data from said vibration sensor. Preferably said sensor includes an RF receiver to receive control data.

In accordance with a second aspect of the present invention there is provided a security or monitoring system for the sensor as described above, where said system may have an armed state and an unarmed state, where in said armed state, said security or monitoring system is arranged to issue an alarm signal in the event of receiving a notification signal from said sensor. The alarm signal may be an audible warning or other signalling method, which may be observed by an owner or user of the alarm system.

Preferably said system includes a wireless receiver for receiving data from said sensor. Preferably said wireless receiver is connected to a control circuit which is arranged for selective arming and disarming of said security system, and is provided with an alarm output device to issue said alarm signal.

Preferably said wireless receiver is also arranged to receive control data from a hand held controller operated by a user of the system. In accordance with a third aspect of the present invention there is provided a security system for a portable or movable object, said security system including a housing including a sensor as hereinbefore described for fitting to said portable or movable object.

Preferably, said sensor includes a wireless transmitter to transmit said notification signal; said security system including a wireless receiver to receive said notification signal interfaced with a warning device to issue an alarm signal.

The wireless receiver may be housed in a vehicle alarm system, in which case the security system is provided as an add-on to a vehicle security system, and the vehicle security system will provide an alarm signal in the normal manner, including a siren or pulsed sounding of the vehicle horn, and flashing of turn signal lamps. In another arrangement, the wireless receiver may be housed in a further portable housing which is carried on the person, and issues the alarm signal, by a sounding device to notify the person carrying the device.

Preferably said wireless receiver is interfaced with a control circuit which is arranged for selective arming and disarming of said security system. In this arrangement, the notification signal will be received when the housing is moved, but it will not be acted on unless the security system is armed.

In another preferred arrangement, the housing may also be interfaced with a warning device to issue an alarm signal, locally. This arrangement would need to be included in a stand-alone application, where there was no signalling of the notification to another device which issued the alarm signal. However, whether the alarm signal was issued locally or at another device, this may act as a deterrent in the event of attempted theft or movement of an object to which the housing is fitted.

Preferably said housing includes a receiver which is interfaced to a hand held controller, to arm or disarm the sensor, and/or to cancel a notification.

In another preferred arrangement, where said security system is provided as an addon to a vehicle security system, said security system includes a further housing which includes said wireless receiver wherein said wireless receiver is connected to a control circuit which is arranged for selective arming and disarming of said security system, and is provided with an alarm output which is interfaced to the vehicle security system.

The sensor and security/monitoring system of the invention provides a more reliable method of sensing movement of an object, such as the lid or cover of something, and unwanted access thereto, be it for security or safety reasons. This invention achieves the function of monitoring the movement status of the object.

In a preferred form the sensor is a separate, stand-alone module that communicates wirelessly with the monitoring or security system, reducing installation time, complexity and cost.

The invention resides in the utilisation of an in-built at least two dimensional tilt sensor housed inside the sensor, that is monitored preferably by a small CPU (computer chip) typically co-located with the tilt sensor inside the sensor, to assess whether an object has been tilted or moved. This determination is achieved by software algorithms inside the wireless sensor's CPU that log and analyse the pattern of acceleration, values of orientation data or rate of orientation or acceleration data in each of the preferably 3 dimensions. This can be done either in real-time, by looking for a specific pattern and rate of pulses over time, or by logging this data and then matching these to typical, predetermined tilt (acceleration), orientation values or patterns to determine whether the sensor has indeed been tilted or rotated and by how much. This information can then be used by the sensor to reliably tell whether to send an alarm trigger (notification signal) preferably wirelessly to the associated siren/alarm module. While the 3D accelerometer is most commonly co-located with the CPU in the sensor module, the accelerometer may actually be contained in a separate module that communicates a signal to the main security system CPU and system logic via either a wired or wireless connection.

In real-time mode, the software looks both at the amplitude data and the rate of change in a given timeframe for each of the dimensions output by the accelerometer or gyroscope. In a log and compare mode, the system takes the analogue voltage pulses or digital data from the accelerometer or gyroscope, translates these into digital pulses if required and stores these in memory as a pattern of amplitude vs time or acceleration data vs time and then uses a software algorithm to compare the pattern we see with a set of stored patterns or parameters to determine whether it qualifies as effective "tilt" of the lid/top or or say rotation or opening of a door or not.

Brief Description of the Drawings

Four preferred embodiments of the invention will now be described with reference to the drawings in which: Figure 1 is a block schematic of a sensor for an alarm system for portable or moveable objects according to the first embodiment;

Figure 2 is a block schematic of a receiver unit in the alarm system for portable or moveable objects according to the first embodiment;

Figure 3 is a block schematic of a sensor for an alarm system for portable or moveable objects according to the second and fourth embodiments;

Figure 3a is a block schematic of an alternative sensor for an alarm system for portable or moveable objects according to the second and fourth embodiments; Figure 3b is a block schematic of a further alternative sensor for an alarm system for portable or moveable objects according to the second and fourth embodiments;

Figure 4 is a block schematic of a remote control unit for an alarm system for portable or moveable objects according to the second and third embodiments;

Figure 5 is a block schematic of a receiver unit in the alarm system for portable or moveable objects according to the second embodiment;

Figure 6 is a block schematic of a sensor for an alarm system for portable or moveable objects according to the third embodiment; Figure 6a is a block schematic of an alternative sensor for an alarm system for portable or moveable objects according to the third embodiment;

Figure 6b is a block schematic of a further alternative sensor for an alarm system for portable or moveable objects according to the third embodiment; and Figure 7 is a block schematic of a receiver unit in the alarm system for portable or moveable objects according to the fourth embodiment.

Best Mode(s) for Carrying Out the Invention

The embodiments are a security or monitoring system for remotely monitoring an object, and issuing an alarm if the object is moved. The object may be a tool box which is normally stored in a tradesman's vehicle, or a lid of such a tool box, a compartment cover or access hatch, such as an opening window accessing the tray of a utility vehicle, or any other opening door which covers an area where access should be controlled or monitored.

In figure 1 , a wireless sensor module of the first embodiment is indicated generally at 10 intended to be fitted to an object, is shown. The wireless sensor module 10 is contained in a housing (not shown). The wireless sensor module 10 has a tilt sensor in the form of an accelerometer 11 capable of sensing in three dimensions (in the x, y, and z axes). The accelerometer 11 , which is a Freescale unit, part no.

MMA7361 LR2, is interfaced with a processor in the form of a processor chip 13 or CPU that allows the processing of input signals from the accelerometer 11. The processor chip 13 includes necessary A-D conversion to convert signals received from the accelerometer 11. A skilled addressee will understand that other tilt sensors may be employed with equal effectiveness. In particular there are some tilt sensors which utilise an SPI bus, and such tilt sensors having a digital output, obviates the need for the processor chip 13 to include A-D conversion. The processor chip 13 is also connected to a vibration sensor 15, and receives data from the vibration sensor 15, or analysis and action as will be described hereunder. The vibration sensor 15 is a SignalQuest™ SQ-SEN-200 omnidirectional tilt and vibration sensor.The processor chip 13 is interfaced with memory 17 for storage of information, and is interfaced for transmission of information via the wireless module 19. The memory 17 is used for storage of parameters for the software that runs on the processor chip 13 as well as storage of typical parameters and patterns relevant to determining how often the processor chip 13 should check/poll the various sensors as well as historical data received from the sensors so that comparisons can be made in terms of the last x, y and z data from the accelerometer 11 so that intelligent comparisons and pattern checks can be made to determine whether the processor chip 13 should make a decision to trigger a notification signal.

The wireless module 19 is used to transmit information relevant to pairing the wireless sensor module 10 with the safety/security alarm indicated generally at 20 and shown in figure 2, as well as sending status information to the safety/security alarm 20 such as low battery warnings, and the notification signal.

Referring to figure 2, the receiver unit 20 of the alarm system for portable or moveable objects of the first embodiment is illustrated. The receiver unit 20 has the function of monitoring and receiving information from the wireless sensor module 10. The receiver unit 20 has a control circuit formed by a CPU 21 which controls operation of the receiver unit 20 in accordance with a program stored in memory 23 with which the receiver unit 20 is interfaced. The CPU 21 is interfaced with a wireless module 25 which receives data transmitted by the wireless sensor module 10. The CPU 21 is also interfaced with an alarm sounder 27 which sounds a siren sound on issuance of an alarm signal by the CPU 21. The CPU 21 will issue an alarm signal in response to the notification signal being received by the wireless module 25, when determined valid by the CPU 21. In addition, the alarm sounder 27 sounds specific tones to indicate armed successfully, disarmed successfully and low battery voltage in the wireless sensor module 10, or no signal from the wireless sensor module 10 when the system is armed and any other relevant status conditions which may be pertinent to the installation. The wireless transmissions between the wireless sensor module 10 and the safety '/security alarm 20 are paired, being like encoded or encrypted, so that there will be no interference between similar installations of the embodiment that may be co-located. For best utility, the accelerometer 11 in the wireless sensor module 10 must have as a minimum, the ability to provide information about the 2 primary horizontal Axes being x and y. For correct operation with only these two axes, correct orientation of the wireless sensor module 10 during installation is important to allow determination of a tilt event. A single dimension may be possible, but very precise installation would be required. The most preferred arrangement is as described in this embodiment, with the accelerometer 11 to include 3 dimensional capability so an x, y and (Vertical) z parameter are monitored, which then allows the processor chip 13 to determine tilt or change in acceleration values in all three dimensions making orientation of the wireless sensor module 10 a non issue. The processor chip 13 in the wireless sensor module 10 is asleep by default to lower average current consumption to a minimum and to extend battery life. It therefore wakes up on detection of a vibration by the vibration sensor 15, and polls or checks the data coming from the accelerometer 11 on a regular basis (typically around every 2 seconds), retrieves the x, y and z parametric data, stores this in the memory 17 and compares this recently stored data with historically stored data in the memory 17 to make an intelligent decision about whether a real-world "tilt" has occurred, to a magnitude that translates to a trigger event. If the magnitude is sufficient a notification signal will be issued by the processor chip 13, which is transmitted by the wireless module 19. Further processing occurs in the safety/security alarm 20, as described above, if the safety/security alarm 20 is armed. If unarmed, then there will be no action taken by the safety/security alarm 20.

The inclusion of vibration sensor 15 in the wireless sensor module 10 provides even lower current consumption by allowing the processor chip 13 to be completely asleep and only be woken up via an Interrupt on the processor chip 13 that is connected to the vibration sensor 15 at which time the processor chip 13 is woken up by this Interrupt signal, in turn wakes up the accelerometer 11 , retrieves the x, y & z parametric data, stores this in the memory 17 and then after the requisite delay (typically around 2 seconds) it then again retrieves the x, y and z data from the accelerometer 11 , stores this in memory 17 and does the comparisons and calculations to decide whether a trigger event has occurred or not. The vibration sensor 15 is also critical for operating the wireless sensor module 10 in a situation where motion or 'tilt' on a horizontal plane (around a vertical axis) is desired as a trigger. A real-world example of this would be monitoring a normal house door that swings in or out on a vertical axis. In this scenario, if the optional vibration sensor 15 was omitted, it would be possible for the processor chip 13 to wake up, take a reading of data from the accelerometer 11 and store this data in memory 17, then after its predetermined delay, for example 2 seconds, the processor chip 13 would wake up again and take a second reading from the accelerometer 11 , store this in memory 17 but because the actual motion or acceleration had now stopped in the case of the door having already been opened, the event would not cause a trigger. To compensate for this scenario, if the wireless sensor module 10 is desired to function as a sensory module for horizontally tilting objects, when the processor chip 13 is woken up by the vibration sensor 15, it commences a more rapid logging sequence of reading data from the accelerometer 11 and remains on and rapidly reads x, y and z parametric data from the accelerometer 11 , storing all these readings in the memory 17 so that it can accurately determine changes in the parameters to determine if the object had indeed been opened or closed i.e. moved or rotated in a vertical axis or a horizontal plane to allow for determination of whether to trigger. The receiver unit 20 is constantly 'awake' in terms of having its wireless module 25 ready to receive wireless transmission from paired devices including the wireless sensor module 10. When the wireless module 25 in the receiver unit 20 receives a transmission from the wireless module 19 in the wireless sensor module 10, the CPU 21 in conjunction with various parameters stored in memory 23 such as whether the receiver unit 20 is in an armed or disarmed state, to determine whether it should sound its alarm sounder 27 which provides loud, audible warning that a trigger event has occurred.

The wireless module 25 of the receiver unit 20 is also used to receive transmission signals from remote control transmitters, previously coded into the receiver unit 20 that allow the safety/security alarm 20 to be armed, disarmed or perform other functions including that of coding in other wireless sensor module 10 or remote control transmitters.

The first embodiment shown in figures 1 and 2 is intended to have the wireless sensor module 10 installed in a toolbox or truck lid or the like, while the receiver unit 20 may be carried by the user, left in the vehicle, or left in a convenient location such as a work space, in order to notify the user in the event of unauthorised tampering with the toolbox. The wireless sensor unit 10 monitors both local vibration and tilt events as described above, and issues a notification signal via the wireless transmitter 19 to the receiver unit 20. As described above, the receiver unit 20 is controlled by a remote control (not shown) to arm and disarm the system. The remote control acts only on the receiver unit 20, and not on the wireless sensor module 10. It will be understood that in an alternative arrangement, the receiver unit 20 could be fitted with a switch or pinpad entry system, to select between armed and disarmed states, and selecting the disarmed state would over-ride operation of the alarm sounder 27.

The second embodiment is shown in figures 3, 3a, 3b, 4, and 5, and comprises one of the wireless sensor modules 10 shown in figures 3, 3a, or 3b, a receiver unit 20 shown in figure 5, and a remote control unit 30 shown in figure 4. There are three versions of the wireless sensor module 10 shown in figures 3, 3a and 3b. The wireless sensor module 10 shown in figure 3 is the same as that of the first embodiment, with like parts being indicated by the same numbering. The wireless sensor module 10 shown in figure 3a is similar to that of the first embodiment, except that the accelerometer 11 is replaced by a three dimensional tilt sensor in the form of a combined accelerometer and gyroscope 31 in order to provide additional position data to the CPU 13. The wireless sensor module 10 shown in figure 3b is similar to that of the first embodiment, except that the accelerometer 11 is replaced by a three dimensional tilt sensor in the form of a gyroscope 33 in order to provide additional position data to the CPU 13. The additional position data provided by the combined accelerometer and gyroscope 31 in the version shown in figure 3a, and by the gyroscope 33 in the version shown in figure 3b, in addition to that provided by the accelerometer 11 , is better yaw data than can be provided by the accelerometer, alone. This provides an advantage in that the sensor 10 may be fitted to a door or other object that pivots about a horizontal axis. In respects other than those noted, operation of the wireless sensor modules 10 of the second embodiment is identical to that of the first embodiment.

The accelerometers used are the same as that of the first embodiment, while the gyroscope used is sourced from ST Micro Electronics, under part number LPR 5150 L.

The transmitter 30 of the second embodiment includes a CPU 35 controlling its operation, memory 37 to store coding information and other data pertinent to functioning of the CPU, and a wireless transmitter 39 to transmit to the wireless receiver 25 of the receiver unit 20. The transmitter 30 has a user operable switch so that the user can arm and disarm the alarm system of the embodiment.

The receiver module 20 of the second embodiment is identical to that of the first embodiment.

The third embodiment shown in figures 4, 6, 6a and 6b is a stand-alone version of an alarm system for portable or moveable objects. There are three versions of the wireless sensor module 10 shown in figures 6, 6a and 6b. The wireless sensor module 10 shown in figure 6 is similar to that of the first embodiment, with like parts being indicated by the same numbering. The wireless sensor module 10 shown in figure 6a is also similar to that of the first embodiment, except that the accelerometer 11 is replaced by a three dimensional tilt sensor in the form of a combined accelerometer and gyroscope 31 in order to provide additional position data to the CPU 13. The wireless sensor module 10 shown in figure 6b is similar to that of the first embodiment, except that the accelerometer 11 is replaced by a three dimensional tilt sensor in the form of a gyroscope 33 in order to provide additional position data to the CPU 13. The other difference between all versions of the wireless sensor module 10 of the third embodiment is that the wireless transmitter 19 has been replaced by a wireless receiver 41. The wireless receiver 41 receives signals from the remote control unit 30 as described in connection with the second embodiment, to arm and disarm the alarm system. In all versions (figures 6, 6a, and 6b), the CPU 13 of the wireless sensor module 10 carries additional programmed functionality as it controls the operation of the entire alarm system, with respect to arming and disarming of the system. In addition, the wireless module 10 also includes an alarm sounder 43 interfaced with the CPU 13, which sounds when an alarm notification is issued by the CPU 13.

The alarm system of the third embodiment is intended to have the wireless module of one of the versions in figures 6, 6a, and 6b installed on the object to be protected, while the remote control unit 30 is carried by the user. In an application where the object to be protected is a toolbox normally stored on the deck of a utility vehicle or truck, the user would disarm the wireless module 10, using the remote control unit 30, retrieve the required tools from the toolbox, and re-arm the wireless module 10, using the remote control unit 30. In the event that there was attempted unauthorised access to the toolbox, the CPU 13 would be awoken by vibration sensed by the vibration sensor 15, and if the tilt sensor and gyroscope 31 detected movement of the toolbox (or its lid) in the manner described with reference to the first embodiment, the CPU 13 will issue an alarm notification by causing the alarm sounder 43 to sound.

The fourth embodiment shown in figures 3, 3a, 3b and 7 is also an alarm system for portable or moveable objects, and uses one of the the wireless sensor modules 10 of figure 3, 3a, or 3b which is identical to that of the second embodiment. The alarm system of the fourth embodiment differs in that the wireless transmitter 19 of the wireless sensor module 10 (of figure 3, 3a, or 3b) transmits to a wireless receiver 47 contained in a wireless bridge 49. The wireless bridge 49 is installed in a vehicle (not shown) and provides an interface between the wireless sensor module 10 and a vehicle alarm system 51 which is installed in the vehicle. The wireless bridge 49 includes a CPU 53 controlling its operation, memory 55 to store coding information and other data pertinent to functioning of the CPU 53, and an output interface 57 including a wired plug, to which is connected a wire 59 to send an alarm trigger signal to the vehicle alarm system 51. In all respects the vehicle alarm system 51 is the same as any normal vehicle alarm system, and includes provision for easy interconnection with the wireless bridge 49. The vehicle alarm system 51 includes a CPU 61 controlling its operation, memory 63 to store coding information and other data pertinent to functioning of the CPU 61. A sounding device in the form of a siren 65 is provided to provide an audible alarm indication in the event the vehicle alarm system 51 is triggered, when in an armed condition. Such vehicle alarm systems 51 normally include inputs to connect to devices such as tamper switches or sensors for spotlights, and the wire 59 is connected to one of these inputs 67.

When the wireless receiver 47 receives a notification from the wireless sensor module 10, a negative going (negative trigger) signal is relayed via the wire 59 to the vehicle alarm system 51. The vehicle alarm system 51 includes all of the normal features, including a remote to arm and disarm the vehicle alarm system 51. When vehicle alarm system 51 is armed, any negative going signal on the wire 59 will cause vehicle alarm system 51 to trigger the siren 65, to alert the owner to tampering of the object to which the alarm system for portable or moveable objects is fitted. Having described the invention, it will be apparent to the skilled addressee that certain features may be modified without departing from the spirit and scope of the invention. For example, the transmitter unit in the wireless sensor module 10 of the first and second embodiments could be replaced by a transceiver unit. This would allow for additional functionality and tasks to be carried out by the CPU 13 in the wireless sensor module 10, such as the CPU 13 in the wireless sensor module 10 could control the arming and disarming of the alarm system for portable or moveable objects under command from the remote control unit 30, while the receiver module 20 would have its CPU relieved of that task.

In addition, while all of the embodiments include a vibration sensor 15 to wake-up the CPU 13, in alternate embodiments the vibration sensor may be omitted, and the CPU may be arranged to periodically poll the tilt sensor.

It should be appreciated that the scope of the invention is not limited to the particular embodiments described herein.

Claims

The Claims Defining the Invention are as Follows

1. A sensor for a security or monitoring system, said sensor including a tilt sensor interfaced with a processor, said processor being arranged to receive data from said tilt sensor and compare said data from previously received data and issue a notification signal in the event that said data do not compare within a predetermined variation.

2. A sensor for a security or monitoring system, said sensor including a tilt sensor interfaced with a processor, said processor having memory, said memory being arranged to store data from said tilt sensor including at-rest data, said processor being arranged to poll said tilt sensor and obtain new data from said tilt sensor, and compare polled new data from said tilt sensor with said data in said memory, and issue a notification signal in the event that the new data and said data do not compare within a predetermined variation.

3. A sensor as claimed in claim 1 or 2 wherein said data includes data from previous new data obtained that falls within said predetermined variation.

4. A sensor as claimed in any one of the preceding claims wherein said sensor includes a vibration sensor, to provide vibration data to said sensor.

5. A sensor as claimed in any one of the preceding claims wherein said tilt sensor provides tilt data in three dimensions.

6. A sensor as claimed in any one of claims 2 to 5 wherein sensor causes said processor to poll said tilt sensor with a period of up to 20 seconds.

7. A sensor as claimed in any one of claims 2 to 6 wherein said sensor is arranged to operate said processor in a mode to minimise power consumption, and arranged to "wake up" said processor out of said mode to poll said tilt sensor and perform data comparison and notification signalling (if any) before resuming said mode.

8. A sensor as claimed in any one of claims 2 to 6 wherein said sensor is arranged to use data from said vibration sensor to "wake up" said processor out of said mode to poll said tilt sensor and perform data comparison and notification signalling (if any) before resuming said mode.

9. A sensor as claimed in any one of the preceding claims wherein said sensor includes a wireless transmitter to transmit notification signalling.

10. A security or monitoring system for a sensor as claimed in any one of the preceding claims, where said system may have an armed state and an unarmed state, where in said armed state, said security or monitoring system is arranged to issue an alarm signal in the event of receiving a notification signal from said sensor.

11. A security or monitoring system as claimed in claim 10 wherein said system includes a wireless receiver for receiving data from said sensor.

12. A security or monitoring system as claimed in claim 11 wherein said wireless receiver is connected to a control circuit which is arranged for selective arming and disarming of said security system, and is provided with an alarm output device to issue said alarm signal.

13. A security or monitoring system as claimed in claim 11 or 12 wherein said wireless receiver is also arranged to receive control data from a hand held controller operated by a user of the system.

14. A security system for a portable or movable object, said security system including a housing including a sensor as claimed in any one of claims 1 to 9 for fitting to said portable or movable object.

15. A security system as claimed in claim 14 wherein said sensor includes a wireless transmitter to transmit said notification signal; said security system including a wireless receiver to receive said notification signal interfaced with a warning device to issue an alarm signal.

16. A security system as claimed in claim 15 wherein said wireless receiver is housed in a vehicle alarm system, said security system being provided as an add-on to a vehicle security system, and the vehicle security system providing an alarm signal in the normal manner, including a siren or pulsed sounding of the vehicle horn, and flashing of turn signal lamps.

17. A security system as claimed in claim 15 wherein the wireless receiver may be housed in a further portable housing which is carried on the person, and issues the alarm signal, by a sounding device to notify the person carrying the device.

18. A security system as claimed in claim 14, 15 or 17, wherein said wireless receiver is interfaced with a control circuit which is arranged for selective arming and disarming of said security system.

19. A security system as claimed in claim 14 wherein the housing may also be interfaced with a warning device to issue an alarm signal, locally.

20. A security system as claimed in claim 14 wherein said housing includes a receiver which is interfaced to a hand held controller, to arm or disarm the sensor, and/or to cancel a notification.

21. A security system as claimed in claim 15 wherein said security system is provided as an add-on to a vehicle security system, said security system includes a further housing which includes said wireless receiver wherein said wireless receiver is connected to a control circuit which is arranged for selective arming and disarming of said security system, and is provided with an alarm output which is interfaced to the vehicle security system.