AU1491500A - Proximity detection response by adjustment of transmitter power - Google Patents

Description

P/00/0011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

b too* Name of Applicant: Actual Inventor: Address for service in Australia: Invention Title: AUSTRALIAN ARROW PTY LTD Campbell Richard James CARTER SMITH BEADLE 2 Railway Parade Camberwell Victoria 3124 Australia Proximity Detection Response by Adjustment of Transmitter Power Details of Associated Provisional Application: PP8491 filed 5 February 1999 The following statement is a full description of this invention, including the best method of performing it known to us Field of the Invention This invention relates to proximity detection response with varying transmitter power and relates particularly to a system to detect the proximity of a device emitting a radio or other form of signal.

The invention will be described with particular reference to its use in association with a motor vehicle access control system. However, it will be understood that the invention is not limited to such use and may be used for a range of purposes including access control systems for buildings and rooms in buildings and in domestic premises, controlling operation of machinery or equipment, mobilising and immobilising machinery and equipment, or the like.

Background of the Invention Access control systems for buildings, motor vehicles and the like are well known. In one such system, an actuating module is carried by a user and a coded .eeeei radio signal is transmitted by the actuating module on actuation of a push-button. If the actuation module is within range of a receiver associated with an operating S module in the building or motor vehicle, certain functions are performed, such as unlocking of doors, activation of ignition systems or the like. However, such systems require manual actuation of an actuating switch or button, which may, in some circumstances, be undesirable or inconvenient.

20 Another known form of system for access control as applied to motor vehicles uses a low power radio beacon transmitter in an actuating module carried by a user. When the user is in relatively close proximity to the vehicle, the coded signal from the transmitter is able to be detected and validated by a receiver and controller in the vehicle. If the coded signal is validated, the vehicle doors may be unlocked and immobilised systems enabled. If the user carrying the actuating module moves out of range of the receiver, the valid code is no longer received and the operating module causes the doors to become locked and reactuates the immobilisation system. With such a radio beacon transmitter, it is found that at the edge of the range of the transmission, or when moving through dead spots in the receivable pattern around the vehicle, the system may frequently and undesirable alternate between locked and unlocked states.

DCC:TG:#33550.CAP 4 February 2000 One method of reducing spurious responses is to reduce the receiver range, which may cause inconvenience in that the driver must be immediately adjacent the receive antenna before the vehicle doors are unlocked. With this arrangement, antennae need to be located adjacent each access point, and this has undesirable consequences of increasing system complexity and cost. It is also undesirable that only the door containing or adjacent the receive antenna is unlocked on receipt by that antenna of a validated signal.

In another proposed system, the vehicle doors are unlocked only when a plurality of consecutive coded signals are received and validated, and the doors are locked only when no signal is received for a predetermined period of time.

However, such a system has the undesirable feature of a substantially increased S:system response time unless the period between transmissions is relatively short in which case the battery life in the activating device is substantially decreased.

ooooo S"It has also been proposed that, with a proximity detection system, the door locks of a vehicle remain locked until both a validated coded signal is received by the receiver in the operating module and a door handle is contacted or lifted as detected by a contact detector or a door handle switch. With this proposal, however, a switch or contact detector must be located at each access point of the ,*oo vehicle and integrated with the system thereby substantially increasing system 20 costs.

Systems where the transmitter is not a beacon but is activated by an energising unit, for example, a microwave unit that provides energy to operate the transmitter, with or without battery assistance, such as is used at building doors for access control, have similar deficiencies. From a given location on the edge of the range of the transmitter, the operation of the access control system is unreliable and may give rise to unwanted and undesirable toggling of door locks, alarm systems and the like.

Summary of the Invention It is therefore desirable to provide an improved proximity detection system that alleviates at least some of the disadvantages of known systems.

It is also desirable to provide a proximity detection system which improves DCC:TG:#33550.CAP 4 February 2000 the convenience associated with a user carrying an actuating module.

It is also desirable to provide an improved proximity detection system which maximises battery life in an actuating module but which, at the same time, is relatively economical to produce and install.

It is also desirable to provide an improved proximity detection system which may be used in a large range of access or control situations requiring proximity detection.

According to one aspect of the invention there is provided a proximity detection system for control of access or other function associated with a building, motor vehicle, machine, equipment or other structure comprising: i) an actuating module adapted to be carried by a user, said actuating module including a transmitter to transmit encoded signals at spaced intervals, said actuating module including means to vary the effective o oi radiated power of the transmitter; ii) receiver means adapted to receive said coded signals; iii) an operating module associated with said receiver means and including validating means to validate a received coded signal, the operating module being adapted to activate control of said access or activate other o functional control from first to second conditions when a predetermined 20 sequence of validated coded signals is received.

2In one preferred form of the invention, the transmitter is a radio transmitter which transmits a predetermined coded signal. The coded signal may be a fixed coded signal or it may incorporate an identification portion and a rolling or pseudorandom code portion. However, any form of coded signal known in the art may be used in the performance of this invention.

The effective radiated power of the transmitter may be varied between a first level which provides a relatively short range and a second level providing a greater, maximum range. In one embodiment, the effective radiated power of the transmitter is varied in sequence between the first level and the second level thereby providing a two step sequence of transmissions of low power and high power transmissions.

DCC:TG:#33550.CAP 4 February 2000 With this arrangement, the receiver means associated with the actuating module is able to detect the signal as long as the actuating module is within the range defined by the effective radiated power of the transmitter (and the maximum effective sensitivity of the receiver means and antenna assembly in the environment in which it is used). The signal from the receiver means is processed by control logic of the operating module that activates control of the access or other operational control associated with the building, motor vehicle or the like. When a full, predetermined sequence of validated coded signals is received, this indicates that the actuating module is relatively close to the receiver means as the lowest power transmission can be received thereby. Thus, the control logic causes the operating module to activate control of the access or other operational control to unlock doors, disable alarm systems, enable ignition systems and the like.

When no signal is present for a period greater than the time for a complete ool.oi S"sequence, this establishes that the transmitter is out of range so that no even a signal S 15 at the maximum effective radiated power can be received. The operating module accordingly reactivates the vehicle door locks, enables the alarm system and disables the ignition system, and the like.

""By monitoring the two level transmission, the operating module is able to accurately establish the location of the actuating module either within the low power transmitter range or outside the high powered transmitter range. Unwanted toggling of states by an actuating module located at the edge of the effective range is thereby avoided. Further, effective detection of the direction of movement of an operator carrying the actuating module may be achieved allowing more effective control.

In a modified embodiment, the variation in transmitter power may be used to vary the response of the operating module. Thus, in a sequence of more than two levels of effective radiated power of the transmitter, a sequential series of events can be triggered by the operating module as an operator carrying the actuating module approaches a vehicle, for example. Thus, the receipt and validation of a first transmitted signal at the maximum effective radiated power may result in the operating module causing vehicle lights to be energised. Subsequent receipt of DCC:TG:#33550.CAP 4 February 2000 further coded signals may result in the vehicle doors being unlocked and the alarm system being disabled. Thus, the receipt of two out of three sequential transmission enables access to the vehicle. The receipt of the third sequential transmission, indicating close proximity of the actuating module to the receiver means, may result in activation of interior lights, enabling ignition systems or other functional operations.

A similar, multi-step sequence may apply as the actuating module moves away from the operating module and receiver. Thus, when only two out of three signals of a sequence are received, the doors may be immediately locked and when no signals are received, all systems may be disabled and the alarm system enabled.

In a further application of a multi-power transmission system of the present invention, a plurality of receivers may be associated with an operating module in, for example, a building environment. Control logic processed by the operating module may cause functional operation of various access locks, lighting systems, disabling alarm systems or the like according to which receivers receive coded o signals and the sequence of signals received by those receivers. Thus, in a system associated with a building, receivers adjacent different access doors may give rise to S"operational control of relevant door locks as an actuating module carried by an operator moves towards and/or through the building. Still further, in a multi-zone system where the sensitivity of each receiver might otherwise be adjusted to give a large or short range response, the operating module may instead respond to a predetermined sequence of validated signals for controlled operation of door locks, lighting systems and the like. Where two out of four transmissions are received, one level of control is effected whereas reception of all four transmissions of a sequence will result in a second level of operational control.

In a further modification of the invention, a manual switch may be associated with the actuating module to enable the transmission of a second coded signal to be manually actuated. The receipt by the operating module receiver of a second coded signal may give rise to a different, predetermined control function for the motor vehicle, building, machine or the like. Alternatively a manual switch operation of the actuating module, instead of a periodic coded signal transmission, may give rise DCC:TG:#33550.CAP 4 February 2000 to a system response which varies in accordance with the apparent proximity as indicated by the number of sequential transmission received by the receiver means.

Thus, for example, if an alarm system is active in a vehicle, a push-button switching operating on the actuating module in the apparent far field will disarm the alarm, but not unlock the door. Operation of the push-button in the apparent near field would both disarm the alarm and unlock the door.

In order that the invention is more readily understood embodiments thereof will now be described with reference to the accompanying drawings.

Brief Description of the Drawings Fig 1 is a schematic block diagram of an actuating module and an operating module in accordance with one embodiment of the present invention; Fig 2 diagrammatically illustrates the operating zones around an operating module receiver located in a vehicle; ooooo Fig 3 indicates the effective radiated power of an actuating module in 15 accordance with one embodiment of the invention; S.Fig 4 indicates a received signal at one effective radiated power level; Fig 5 indicates a received signal at a second effective radiated power level; and Fig 6 indicates the effective radiated power of the actuating module in accordance with a further embodiment of the invention.

:"Description of Preferred Embodiments Referring to the drawings, one embodiment of a proximity detection system in accordance with the invention is illustrated. The illustrated system is particularly adapted for use with motor vehicles, and the system is designed to provide access control by means of controlling door locks through lock driver motors 9 (Fig 1).

The system may also be designed to enable and disable the vehicle ignition system, fuel pump control system, vehicle alarm system, or any other electrical system within the motor vehicle, including interior lights, exterior lights and the like.

The system of this embodiment incorporates an operating module 5 which is located within the vehicle and which includes a receiver 6 and a controller 7.

At least one actuating module 1 which is adapted to be carried by a user, DCC:TG:#33550.CAP 4 February 2000 such as a vehicle driver, includes a power source, such as battery 2, a control circuitry 3 and a radio transmitter section 4. The control circuitry generates a predetermined encoded signal at periodic intervals, the coded signals being transmitted by the radio transmitter section 4. As the control circuitry and transmitter circuitry is well known in the art, no further description of that circuitry will be required herein. The periodic intervals at which the encoded signal is transmitted need not be accurately time intervals thereby reducing the complexity and attendant cost of the control circuitry 3.

One feature of the control circuitry 3, however, is that the drive to the radio transmitter section 4 alternates so that the power is correspondingly varied, such as between high and low effective radiated power levels, such as is indicated in Fig 3.

Thus, the transmitted encoded signals are in a sequence of alternating high and low power levels which effectively governs the range of the transmitter between S"maximum range 31 and minimum range 32, as shown in Fig 2.

The operating module 5 incorporates a radio receiver 6 and a controller 7, both of which are known in the art and will not be described in greater detail. The signals received by the receiver 6 are fed to the controller 7, which may be a mini 7' controller as known in the art, for decoding, validating and determining a response in accordance with control logic, such as releasing a door latch 9 by energising it by means of driver 8.

S"Referring to Fig 2, if a user carrying the actuating module which is alternately transmitting high and low power signals, is located at position 14, the vehicle V is outside the maximum range circle 31 so that the receiver 6 will not pick up the signal transmitted at maximum power by the transmitter 4. Accordingly, the operating module will maintain the vehicle doors in the locked condition, the alarm system will be enables, electrical systems such as ignition and fuel pump systems will be disabled, and the controller 7 will be in a steady state awaiting reception by the receiver of a coded signal.

As the user carrying the actuating module moves to position 15, the receiver is located within the maximum range circle 31 although it is still outside the minimum range circle 32. However, the receiver 6 will receive a transmitted coded DCC:TG:#33550.CAP 4 February 2000 signal which is transmitted at the high effective radiated power level, and the controller 7 will be readied to check if a sequence of signals is received. However, the signal transmitted a t the low effective radiated power, having the effective minimum range circle of 32, will not be received. Accordingly, no change to the state of the vehicle systems will occur.

As the person carrying the actuating module 1 moves to the position 16, the vehicle and the operating module are within the minimum range circle 32 so that the receiver 6 will receive all signals transmitted by the transmitter 4. The signals will be demodulated, decoded and validated by the controller 7 and, as the sequence of high power and low power signals is received, the controller 7 actuates the door latch driver 8 to release the door locks 9 and enables other electrical systems as S'required.

If the user carrying the actuating module 1 moves from position 16 to position 15, the coded signal will still be received by the receiver 6 at maximum effective radiated power, and the controller 7 will recognise that the actuating S* module is still within maximum transmission power range. Accordingly, the doors will remain unlocked and no change of state will occur.

i However, should the actuating module 1 then be moved from position 15 to position 14, where no signal is received even at maximum effective radiated power, the non-receipt of a coded signal within a predetermined period, which is a period greater than the intervals between timed transmission, the controller 7 will recognise that the actuating module is no longer within effective range and will operate to lock the doors by actuating the door latch 9 and will enable any alarm and disable other electrical systems as required. It will then be necessary to move the actuating module 1 back to a near field position 16 to again cause the doors to be unlocked.

The reception of the transmitter signal at the maximum effective radiated power is illustrated in Fig 4, where there is no reception of the transmission at the minimum effective radiated power.

Fig 5 illustrates the signal reception when the actuating module 1 is in the near field position 16.

DCC:TG:#33550.CAP 4 February 2000 Referring to Fig 6, in this modification, the transmitter 4, the control circuitry 3 of the actuating module drives the radio transmitter section 4 in three steps so that the power is correspondingly varied between high, medium and low effective radiated power levels, as indicated in Fig 6. With this arrangement, the controller 7 may have control logic which progressively activates predetermined functional systems associated with the vehicle when the receiver 6 detects the coded signal which is transmitted at maximum effective radiated power, but does not detect the signal transmitter at the medium or lower power levels. However, the controller 7 may, on receipt of the maximum power transmission, activate a light in the vehicle or effect some other operation. As the actuating module 1 moves closer to the vehicle V, the receiver then receives the transmission at full power and that at medium power level. The controller, on receipt of these coded signals, may then :i activated, in accordance with control logic, other functional circuits of the vehicle, 0 such as unlocking doors, disabling an alarm, or the like. As the actuating module 1 15 moves within range of the receiver at low effective radiated power, and the receiver receives all three sequential signals, all systems of the vehicle are enabled. Thus, with the system of the present invention, it is possible to predetermine appropriate O' responses associated with movement of an actuating module transmitting a coded signal at varying power levels as the module moves towards and away from the 20 vehicle.

,•co In a modified form of the invention, a push-button 12 is associated with the control circuitry 3 on the actuating module 1. Actuation of the push-button switch 12 causes the control circuitry 3 to give rise either to a sequence of coded signal transmissions at varying transmission power or the transmission of a different coded signal at maximum transmission power.

With the push button giving rise to a sequence of coded signals, the timed interval transmission is replaced by the push-button initiated transmission, but all other features associated with the varying power transmission remain.

With the alternate operation of the push-button, to give rise to a different coded signal at maximum power, such actuation of the push-button overrides the functional aspects of the varying power transmission of coded signals and the DCC:TG:#33550.CAP 4 February 2000 11 reception of the different coded signal causes a predetermined response by the controller 7, such as immediate enabling of all electrical systems, disabling of alarm and unlocking of doors, even though the actuating module 1 may be at the maximum range only.

It will be appreciated that more than one push-button may be associated with the control circuitry 3 to give rise to different coded signals which will have different functional responses. Such push-button actuated systems are well known and, of themselves, do not form a part of this invention.

It will be appreciated that many levels of effective radiated power may be used in the performance of this invention. It will also be appreciated that the operating module may have more than one receiver associated with the controller 7.

Additionally, more than one actuating module 1 may be functionally associated with the operating module 5. It will also be understood that the embodiment of the invention may be utilised in association with a building security system, a security 15 system for watercraft, or any other structure. The system of the invention provides a mechanism to prevent unwanted toggling of states by an actuating module located at the edge of an effective transmission range. Further, the invention provides convenience and indiscrete actuation of door unlocking systems and alarm disabling systems while permitting convenient manual override. Further, the life of the 20 battery which powers the transmitter is extended as compared to equivalent systems as only some of the transmissions are made at full power.

DCC:TG:#33550.CAP 4 February 2000

Claims (19)

1. A proximity detection system for control of access or other function associated with a building, motor vehicle, machine, equipment or other structure comprising: i) an actuating module adapted to be carried by a user, said actuating module including a transmitter to transmit encoded signals at spaced intervals, said actuating module including means to vary the effective radiated power of the transmitter; ii) receiver means adapted to receive said coded signals; iii) an operating module associated with said receiver means and including validating means to validate a received coded signal, the operating module being adapted to activate control of said access or activate other functional control from first to second conditions when a predetermined sequence of validated coded signals is received. 15

2. A system according to claim 1 wherein the transmitter is a radio transmitter.

3. A system according to Claim 1 wherein the effective radiated power of the transmitter is varied between a first level providing a relatively short range and a second level providing a greater, maximum range. 20

4. A system according to any one of Claims 1 to 3 wherein said S predetermined sequence of validated coded signals comprises a single validated coded signal.

A system according to any one of Claims 1 to 3 wherein said predetermined sequence of validated coded signals comprises two or more sequential validated coded signals received with a predetermined period.

6. A system according to Claim 3 wherein the effective radiated power of the transmitter is changed between the first level and the second level on every alternate transmission.

7. A system according to Claim 3 wherein the effective radiated power of the transmitter is varied in sequence over a predetermined number of transmissions between the first level and the second level. DCC:TG:#33550.CAP 4 February 2000

8. A system according to Claim 7 wherein said operating module is adapted to activate predetermined control of access or other functional control in a sequence which is determined by the receipt of one or more validated coded signals of a sequence of signals within a predetermined period.

9. A system according to Claim 8 wherein said predetermined period is slightly greater than the transmission time for a full sequence of coded signals.

A system according to Claim 1 wherein said operating module is adapted to actuate control of said access or activate other operational control from the second to the first conditions when a predetermined sequence of validated coded signals is not received within a predetermined period.

11. A system according to Claim 9 wherein said predetermined period is greater than the interval between signal transmissions but less than the interval :..":between a predetermined number of signal transmissions.

12. A system according to Claim 10 wherein said predetermined period is slightly greater than the transmission time of a full sequence of coded signals.

13. A system according to any one of the preceding claims wherein said actuating module includes manual switch means to activate said transmitter to transmit a second coded signal at maximum effective radiated power, and said operating module is adapted to activate control of said access or activate other S 20 operational control from one condition to another in response to the receipt of a validated second coded signal.

14. A system according to Claim 1 wherein said operating module is associated with a plurality of receiver means each adapted to receive said coded signals, said operating module being adapted to activate control of said access or activate other operational control from one condition to another according to control logic in response to the receipt of predetermined sequences of validated coded signals by one or more receiver means.

A proximity detection system for control of access or other function associated with a building, motor vehicle, machine, equipment or other structure comprising: i) an actuating module adapted to be carried by a user, said actuating DCC:TG:#33550.CAP 4 February 2000 14 module including a transmitter to transmit coded signals in response to switch means, said actuating module including means to vary the effective radiated power of the transmitter; ii) receiver means adapted to receive said coded signals; iii) an operating module associated with said receiver means and including validating means to validate a received coded signal, the operating module being adapted to activate control of said access or active other operational control from first to second conditions when a predetermined sequence of validated coded signals is received.

16. A system accordingly to Claim 15 wherein the transmitter is a radio transmitter.

17. A system according to Claim 15 or Claim 16 wherein said transmitter transmits a predetermined number of sequential coded signals of varying effective radiated power in response to activation of said switch means. 15

18. A system according to Claim 15 or Claim 16 wherein said transmitter transmits sequential coded signals of varying effective radiated power for a predetermined period in response to activation of said switch means.

19. A system according to Claim 15 wherein said operating module is adapted to actuate control of said access or activate other operational control from the second to the first conditions when a further predetermined sequence of validated code signals is received after receipt of a first sequence of signals. A proximity detection system for control of access or other function associated with a building, motor vehicle, machine, equipment or other structure substantially as hereinbefore described with reference to the accompanying drawings. DATED: 4 February 2000 CARTER SMITH BEADLE Patent Attorneys for the Applicant: AUSTRALIAN ARROW PTY LTD DCC:TG:#33550.CAP 4 February 2000