GB2197106A

GB2197106A - Monitoring and control system

Info

Publication number: GB2197106A
Application number: GB08725548A
Authority: GB
Inventors: Christopher Douglas
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-11-04
Filing date: 1987-10-30
Publication date: 1988-05-11
Also published as: GB8725548D0

Abstract

A monitoring and control system for electrical or electronic circuits, comprising a portable signal emitter which can emit signals to a receiver, carrying instructions for it to override the normal operation of an automatically controlled device. The emitter preferably emits ultrasonic signals, which optionally may act not only on the receiver but also carry signals already interpretable by the controlling device, coding or other signals to initiate different actions. Especially it can emit a signal which defeats a time delay circuit, for example in an automatic lighting system in a store, to keep it on while the user is in the area. The portable signal emitter can be secured to the user, for example to clothing by a clip, or be fixed temporarily in the monitored area so that it will not encumber the user while in the monitored area, and may incorporate a timer. <IMAGE>

Description

SPECIFICATION Monitoring and control system and device This invention relates to a monitoring and control system and device, especially for the monitoring and control of electrical and electronic circuits containing automatic controls for actuation and deactivation.

Systems are known which introduce a measure of control in the use of lighting and other powe'r-consuming equipment. Examples are occupancy-detecting devices activated by movement or sound, or simple "time-out" controls which will switch off a specified time after being activated, or devices which will switch off a circuit on receipt of a mainsborne or hard-wired signal from a controlling device.

Such systems have many advantages but there are occasions when, for practicai reasons, the automatic action needs to be overridden. One example is where a movement detector, set to switch off a circuit (especially a lighting circuit) several minutes after movement is last detected, is used in an application where legitimate occupancy takes place out of range or out of "sight" of the detector. The movement detector may be acceptable for normal use but on such an occasion will present a problem. Similarly, with a "time out" device or other control, there are situations where the automatic device requires to be over-ridden.

For example, if a conventional device is used to turn off a light in a storeroom automatically when the anticipated use has ceased, this can be quite satisfactory so long as the occupant continues to make the movements which are required to affect a movement-detecting sensor or the pre-set time delay for switching off is not exceeded. Premature switching off of a light can be very dangerous, however, if the legitimate occupant is not in a position which allows adequate access to the means for switching it on again.

There is a need, therefore, for devices or systems capable of overriding the automatic controller so as to maintain the controlled load circuit. Especially, there is a need for some means by which an automatic circuit can be over-ridden when necessary without reliance on the predetermined means or position of the controls to which it normally responds.

Thus according to the present invention there is provided a monitoring and control system for an electrical or electronic circuit, which comprises: (a) a portable signal emitter which is adapted to send out signals indicative of the requirement to override the operation of an automatically controlled device, and (b) a receiver adapted to accept signals from the portable signal emitter (a) and, in response to them, operate to override the normal operation of an automatically controlled device.

In use, the system may use more than one such portable signal emitter and/or receiver.

The portable signal emitter may use any of the conventional systems of signal emission known in the art, and known circuitry can be used to produce the signals required. Most conveniently, this may be a self-contained and suitably miniaturised electronic device in a lightweight container of convenient size for handling and carrying about by a user. Thus, the portable emitter may be for example an emitter of sound, light, radio waves, microwaves or combinations of these.

The portable signal emitter may emit any signal which can be received by the receiver but should not emit any signal or radiation which is troublesome or dangerous to people present. preferably it emits sound waves of ultrasonic frequency. One reason for this preference is that these are effective without being heard; another reason is the ability of sound waves to be reflected or diffused around obstacles, so enabling the sensor to detect them even when the emitter and sensor are not in direct "line of sight" with each other. Other radiation such as light (visible or infrared) tends to be less able to cope with obstructions and so be less useful in practice -- for example if the user is moving around a warehouse or storeroom area in which objects may partly screen him from the receiver.

The controlling device which is used to actuate the circuit to be controlled, in response to signals from the receiver, and the operative link between the controlling device and the receiver may also be any of those known in the art for this purpose. Especially, it may be one which is responsive to movement within a defined area.

The term "override" is used here to include any form of alteration of the normal routine operation of the automatic device, but especially any intervention in a way which prevents, delays or forestalls the normal automatic deactivation or "turn off" step of the circuit.

The invention provides not only the complete systems but also the components which contribute to making up such systems, and especially the portable signal emitter control unit.

An especially useful arrangement is that in which the portable emitter sends out a signal which is already interpreted by the controlling device or sensor as a "turn on," "activating" or "maintaining" instruction signal, as this will obviate the need to have a special receiver to interpret the signals from the portable emitter unit of this invention.

In some circumstances it may be desirable to introduce some form or level of coding into the emitted signal so that the receiver or receivers take appropriate action in response.

For example, it may be appropriate to send out a different signal to switch on a controlled load from that which is required to sustain a load which is already switched on. Additionally, the receiver may be configured to respond to signals in a different manner depending upon its existing state, for example "on/off" or switched over into some other operating mode.

The portable signal emitter may be made to emit a single signal intended solely to convey the instruction to the receiver that the circuit under its control is to be maintained in the operative state. This is the most simple form.

The signal may be continuous or intermittent, and to conserve power it is preferred that the signal should be intermittent but sent out regularly enough to defeat the time delay circuitry and avoid the deactivation of the controlled circuit until the portable signal emitter is deliberately turned off.

If desired, however, it may be made so that it can also emit other signals conveying control instructions to which the receiver can respond. Especially, it may advantageously include means by which the operator of the portable signal emitter can make it send out a signal to which the receiver responds and produces a signal indicative of the need to initiate the activation of a desired circuit. Similarly, it can include means by which the operator can make it send out a signal to which the sensor responds and produces a signal indicative of the need to initiate the deactivation of a desired circuit. One form can include means for sending out all three signals, as required.

When the format of using more than one signal is used, the portable emitter may be made so that the different signals may be emitted from it independently of each other and in any desired sequence, for example "switch on, ' "maintain" or "switch off." This facility is especially useful as a safeguard against the possibility that the switching circuit may be deactivated which the user is still present, as it can then enable the user to reactivate it and avoid being left in the dark in a storeroom if for some reason he cannot activate the "turn on state of the sensor by the means to which it is normally responsive.

If desired, the portable signal emitter unit may be adapted to activate one particular receiver or type of receiver and not another.

This can be the case when a variety of sensors may be present and interference between them and/or misinterpretation of instruction signals is to be avoided.

Furthermore, if desired, the portable emitter may be configured to respond itself to a signal so that it changes its state of activity. The signal for this purpose may be any of the conventional forms which can be transmitted to it and received by it (airborne sound, light, microwave, radio wave, etc.) but may if desired be derived from a device, for example a timer, within the portable signal emitter itself.

The system will usually have the receiver fixed to a wall or other support in or near the area to be monitored. The means for actuating the circuit to be controlled, in response to signals from the portable signal emitter unit, may be situated in any convenient position.

In use, the portable emitter can be carried by the user into the area monitored and controlled, so that -- when it is switched on -- it emits the instructing signal to the sensor. It may be adapted to be merely carried, and possibly laid down in a convenient position within sensing range of the sensor, or it may be adapted to be secured to the user (for example to his clothing by a clip or the like) or it may be adapted to fixed temporarily to a suitably situated holder in the monitored area (for example to be hung on a hook, or secured by a temporary adhesive or sucker device, or by a magnetic or mechanical clip) so that it will not encumber the user while in the monitored area. It may be convenient to adapt it so that it has more than one such mode of fixture, to increase its versatility.

The invention is especially applicable to the control of lighting circuits, but may if desired be used for the control of other circuits for example alarms, heating, ventilating, and the like.

The invention is illustrated but not limited by the following Examples.

Example An ultrasonic movement detector is located in a storage aisle of a warehouse or storeroom and connected into a control unit for a lighting circuit for the aisle. Anyone entering the aisle will activate the detector and so turn on the lighting. During stocktaking, for example, the occupant may make no appreciable or detectable movements for long periods which exceed the normal time for which the automatic controller of the movement detector holds the lighting circuit "on," with the result that the lights go out. Though a deliberate movement can turn them back on again, this may be difficult if the occupant cannot make that movement within range of the movement detector. The extinguishing of the lights, even only briefly, may also be dangerous if fragile or hazardous materials are in the aisle.

The occupant who wishes to work in the area takes in a portable signal emitter unit which sends out an ultrasonic signal, of a frequency to which the movement detector responds and interprets as movement. By carrying this emitter unit or putting it down in a position within range of the movement detector, the lights will be maintained "on" without interruption for as long as desired. When the occupant leaves, he can restore normal automatic operation of the lighting by simply taking the portable signal emitter away with him.

The portable emitter unit may send out a continuous signal, but when the movement detector incorporates a "time out" delay (which holds the lighting on for a pre-set time after movement is last detected) the portable emitter unit may send out signals which are continuous or intermittent and, so long as the signals are sent out at intervals which are less than the "turn off" or "time out" period of the automatic controller, the lighting will remain on.

In this particular situation, a special receiver for the signal is not required.

Example 2.

The lighting in an aisle of a warehouse or storeroom is controlled by a simple "time out" device, for example a mechanically or electronically operated time delay set to switch off automatically a given time after being switched on, which the user switches on as he enters.

The occupant who wishes to work in the area takes in a portable signal emitter unit which sends out an ultrasonic signal.

To provide an overriding control of the lighting, an ultrasonic receiver is fitted conveniently near to the aisle to monitor it, and this receiver unit is connected to a switching circuit which, on receipt of an ultrasonic signal as sent out by the emitter unit, is actuated to close the lighting circuit and by-pass the "time off" device.

By carrying this emitter unit or putting it down in a position within range of the receiver, the lights will be maintained "on" without interruption for as long as desired.

When the occupant leaves, he can restore normal automatic operation of the lighting by simply taking the portable emitter away with him.

The receiver unit may operate to by-pass the "time out" device indefinitely -- in which case a positive or cancellation device for the by-pass circuit is included -- or can be made self-cancelling by responding only to a continuous or repeated series of signals from the portable emitter.

Claims

1. A monitoring and control system for an electrical or electronic circuit, which comprises: (a) a portable signal emitter which is adapted to send out signals indicative of the requirement to override the operation of an automatically controlled device, and (b) a receiver adapted to accept signals from the portable signal signal emitter (a) and, in response to them, operate,to override the normal operation of an automatically controlled device.

2. A monitoring and control system as claimed in Claim 1 wherein one which is responsive to movement within a defined area.

3. A monitoring and control system as claimed in Claim 1 or Claim 2 wherein the portable signal emitter is self-contained and suitably miniaturised for handling and carrying about by a user.

4. A monitoring and control system as claimed in any one of Claims 1 to 3 wherein the portable signal emitter emits sound waves of ultrasonic frequency.

5. A monitoring and control system as claimed in any one of Claims 1 to 4 wherein the portable signal emitter sends out a signal which is already interpreted by the controlling device or sensor as a "turn on," -"activating" or "maintaining" instruction signal.

6. A monitoring and control system as claimed in any one of Claims 1 to 5 wherein coding is introduced into the emitted signal so that the receiver or receivers take appropriate action in response.

7. A monitoring and control system as claimed in any one of Claims 1 to- 6 wherein the receiver is configured to respond to signals in a different manner depending upon its existing state.

8. A monitoring and control system as claimed in any one of Claims 1 to 7 wherein the portable signal emitter is made so as to emit a single signal intended solely to convey the instruction to the receiver that the circuit under its control is to be maintained in the operative state.

9. A monitoring and control system as claimed in Claim 8 wherein the signal emitted by the portable signal emitter is intermittent but sent out regularly enough to defeat the time delay circuitry and avoid the deactivation of the controlled device or circuit until the portable signal emitter is deliberately turned off.

10. A monitoring and control system as claimed in any one of Claims 1 to 9 wherein the portable signal emitter includes means by which it can also emit other signals conveying control instructions to which the receiver can respond.

11. A monitoring and control system as claimed in any one of Claims 1 to 10 wherein the portable signal emitter includes means by which its operator can make it send out a signal to which the receiver responds and produces a signal indicative of the need to initiate the activation of a desired circuit.

12. A monitoring and control system as claimed in any one of Claims 1 to 11 wherein the portable signal emitter includes means by which its operator can make it send out a signal to which the sensor responds and produces a signal indicative of the need to initiate the deactivation of a desired circuit.

13. A monitoring and control system as claimed in any one of Claims 1 to 12 wherein the portable signal emitter is configured to respond itself to a signal so that it changes its state of activity.

14. A monitoring and control system as claimed in Claim 13 wherein the activity changing signal is derived from a device, for example a timer, within the portable signal emitter itself.

15. A monitoring and control system as claimed in any one of Claims 1 to 14 wherein the receiver is fixed to a wall or other support in or near the area to be monitored.

16. A monitoring and control system as claimed in any one of Claims 1 to 15 wherein the portable signal emitter is adapted to be secured to the user, for example to clothing by a clip or the like.

17. A monitoring and control system as claimed in any one of Claims 1 to 16 wherein the portable signal emitter is adapted to be fixed temporarily in the monitored area so that it will not encumber the user while in the monitored area.

18. A monitoring and control system as claimed in any one of Claims 1 to 17 applied to the control of lighting circuits,

19. A monitoring and control system substantially as described.

20. A portable signal emitter and/or a receiver device adapted for use in a monitoring and control system as claimed in any one of Claims 1 to 19.

21. A portable signal emitter and/or a receiver device adapted for use in a monitoring and control system substantially as described.