GB2350921A

GB2350921A - Monitoring of use restricted parking areas

Info

Publication number: GB2350921A
Application number: GB0014109A
Authority: GB
Inventors: David Leslie Walker
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-06-10
Filing date: 2000-06-10
Publication date: 2000-12-13
Also published as: GB0014109D0; GB9913368D0

Abstract

Means for monitoring use restricted parking areas including a detector unit 10 for detecting changes in a magnetic field in the region of a parking area to be monitored. The detector unit may include a plurality of transducers 18,20 for detecting magnetic fields in planes at right angles to each other. Once a car has been detected different devices could be triggered for example a sign 12 could be lit or a barrier could be lowered, a signal could also be sent to a controller to warn of a driver parked in the restricted area. The device can be overridden by a driver properly entitled to use the space with a handheld radio transmitter. The system can be powered by solar panels or mains electricity.

Description

2350921 monitoring of use restricted parking areas The invention relates

to the monitoring of use restricted parking areas, such as those provided for the exclusive use of disabled drivers, and to deterring the use of such areas by drivers who are not properly entitled to use them.

In public car parks and in parking areas provided by supermarkets and shopping malls for example there are usually provided several parking spaces for the exclusive use of particular groups of vulnerable drivers, for example disabled drivers and mothers with children, but it is often found that at busy periods, whilst most able bodied drivers respect the disabled drivers reservations, and most people avoid the improper use of the mother and child reservations, some people choose to ignore the restrictions. When such a reserved space has been occupied by a vehicle, the 'disabled driver' or other designation is usually hidden from view, this making the enforcement of the restriction very difficult and encouraging those who choose to deliberately ignore it. A supermarket manager will in any case probably be unwilling, for their own personal safety, to instruct his staff to enter into heated arguments with people who deliberately ignore 'disabled driver only' and other designations; the invention has for its object to effectively deter such people by simply causing them embarrassment.

According to the invention, means for monitoring use restricted parking areas, and for deterring their use by drivers who are not properly entitled to use them, are constituted by a deterrent system including a detector unit for detecting changes in a magnetic field in the region of a parking area to be monitored, said detector unit including decoding electronics for detecting the presence or absence of a motor vehicle in response to detected changes in said magnetic field, and a radio transmitter. The arrangement may be such that it can be overridden by a driver properly entitled to use the space concerned, for example by the use of a hand held signal transmitter. The deterrent system may also include a radio link to alert someone charged with the duty of monitoring the use of the parking area concerned. The decoding electronics may include at least one transducer for detecting magnetic fields; preferably, a multiplicity of transducers will be provided so arranged as to detect magnetic fields in planes at right angles to each other. The remainder of the deterrent system may be constituted by a sign or notice, triggered by a radio receiver, to warn a motorist that he is parked in a use restricted space; it may also include a flashing light, an audible alarm, or both. In addition, means may be provided whereby the system can trigger into operation a physical barrier designed to detain an offending vehicle.

The detector unit for detecting changes in the magnetic field, and the illumination of the sign arrangement (together with the powering of any audible or visual warning and the triggering into action of any physical barrier, if any of these are provided), may be powered by a re-chargeable battery charged by a plurality of solar cells and, if such solar cells are provided, they may be mounted on the top surface of the sign arrangement. Alternatively, the detector unit may be powered solely by batteries or by mains electricity.

Throughout this specification, references to use restricted parking areas can mean either single vehicle parking areas or areas containing a group of use restricted parking spaces in a correspondingly larger area such that a single base unit of the deterrent system may be arranged to monitor a single parking space or individually monitor the status of a number of parking spaces such that the electronics can check, monitor and respond to individual movements in a multiplicity of parking spaces. For example, a single sign arrangement as described above may be located alongside an area containing, say, four separate disabled parking spaces. The parking spaces, besides being clearly marked out for the exclusive use of disabled drivers, will be provided with respective detector units for detecting changes in the magnetic fields in those particular spaces and those units will all be monitored by a single base unit, this being built into the sign arrangement referred to.

One way of carrying out the invention is described in detail below with reference to drawings in which:- Figure 1 is a view showing an installation embodying the invention in a public car park, Figure 2 is a view similar to Figure 1 but with a motor vehicle entering the parking space concerned, Figure 3 shows a shopping trolley being wheeled past the installation, Figure 4 is a perspective view of another part of the system, Figure Sa is a diagrammatic illustration of how a device monitoring changes of magnetic flux in only one plane might possibly be confused, Figure 5b, in conjunction with Figure 5a, shows how the confusion may be overcome, Figure 6 is a view illustrating a detector unit embodying the invention and designed to combat this possible confusion, and Figures 7 and 8 are illustrations of electronic circuits forming part of the apparatus which will presently be referred to.

Referring now to Figures 1 to 3 of the drawings, the installation there illustrated includes a detector unit, generally indicated 10, which is located on or just beneath the surface of the ground within the area which will be covered by a vehicle parked in a parking space to be monitored. The detector unit 10 contains at least one transducer, decoding electronics and a radio transmitter. The transducer is arranged to detect changes in magnetic flux as a vehicle occupies the parking bay concerned and can discriminate between a motor vehicle and, say, a shopping trolley being wheeled through the space concerned.

The detector unit 10 here illustrated is of generally cylindrical outline shape for installation in upstanding condition, as indicated by the chaindotted lines in the drawings, so that its top surface is just flush with the surface of the ground. This is advantageous in the fact that it presents no safety hazard to pedestrians walking across the space concerned.

In Figure 1, since the parking space concerned is empty, there is general ambient magnetism only in the region of the parking space concerned. In Figure 2, there is shown to be a motor vehicle in the parking space concerned and the detector unit 10 will therefore detect considerable change in magnetic flux. In Figure 3 there is shown to be a shopping trolley being wheeled by a pedestrian; although affected by the change in magnetic flux, the detector unit 10 is able to detect that the change is relatively small and does not react in the way it reacts to the presence of a motor vehicle. Similarly, the detector unit does not react to the relatively small changes in magnetic flux produced by vehicles moving into or from adjoining parking spaces.

The detector unit is arranged to make periodic checks on the situation (that is to say checking on the situation every few seconds). Detection results from more than one periodic sample sensing a stationary body which has produced a change of magnetic flux. The detector unit is monitored by a base unit (so called because it is a unit from which the activity of the detector unit or units is directed) which will be described in detail presently, said base unit monitoring other detector units in other disabled parking spaces arranged in a group.

The foregoing detection apparatus, together with the required electronics which will be described presently, forms a part of what can be termed a deterrent system which is designed to deter the occupation of use restricted car parking spaces by drivers who are not properly entitled to use them. The remainder of said deterrent system can take various forms. For example, unless overridden as will presently be described, the detection of a vehicle in the parking space concerned can illuminate a sign or written notice to warn the motorist that he has occupied a use restricted space. If this is thought not to be sufficiently embarrassing to have the desired effect of causing the motorist to vacate the space, such a sign or notice could be augmented by a flashing light, by an audible alarm (possibly a voice message), or both. There may also be a radio link to alert someone charged with the duty of monitoring the use of the parking space concerned. As an ultimate deterrent, unless having been overridden, the detection of a vehicle in the parking space concerned may trigger the operation of a physical barrier (not shown in the accompanying drawings) designed to detain an offending vehicle, or a notice warning that such a barrier will be brought into use if the vehicle is not removed immediately.

In Figures I to 3 there is illustrated the provision of a sign arrangement, generally indicated 12, mounted on a post 14 to be within sight of a person driving a car into the parking space concerned. In Figure 4 it can be seen that the sign is an illuminated sign and displays the word WELCOME as it will do when the parking space concerned has been occupied by a person properly entitled to use the space and he or she has taken the appropriate action (as will presently be explained). However, it may be capable of displaying a variety of other messages when the system has failed to recognise a vehicle as being driven by a person properly entitled to use the space concerned. The sign arrangement 12 may conveniently incorporate the base unit referred to above.

The illuminated sign arrangement illustrated in Figure 4 is shown to have a plurality of solar cells 16 mounted on its top surface, these being provided to power the detector unit 10 and base unit, and the illumination of the sign arrangement (together with the powering of any audible or visual warning and the triggering into action of any physical barrier, if any of these are provided). It may also be provided with a battery for use when the solar cells are not sufficient in themselves, this preferably being a rechargeable battery able to be recharged by the solar cells.

The system cannot itself discriminate between a bona fide user of the parking space concerned and a person who is not a bona fide user. However, if by chance a disabled driver making use of the space has the required hand held signal transmitter, he can point the transmitter towards the base unit to be described presently (which may or may not be contained within the sign arrangement 12) and transmit a signal which will tell the system that he is a disabled driver. (Hand held infrared transmitters are already in use by a great many disabled drivers to indicate to the staf f of commercial premises provided with what is called a 'ServiceCall' installation that a customer is outside and waiting to be attended to, and for this reason, the system is such that it can respond to such commonly used hand held signal transmitters). On the other hand of course, a disabled driver not possessing such a hand held signal transmitter is perfectly entitled to use the parking space concerned and will simply ignore any warning messages which might be given out purely for the benefit of able bodied drivers.

Referring now to Figure 5, this illustrates the way in which a detector unit such as that described above, for monitoring changes of magnetic flux in only a single plane, might possibly be confused. In Figure 5a the magnetic flux in one plane is shown to vary above and below a neutral value; in other words, it shows typical changes in magnetic field strength measured at ground level along the length of a vehicle. However, should a vehicle be parked in a position where the transducer detects no change in magnetic field strength the vehicle will not be detected. To overcome this, the magnetic field strength may be measured in two geometric planes mutually at right angles, as shown in Figures 5a and 5b. It will be seen that, because of the way in which these values vary, in what may be termed a random fashion, the neutral values do not coincide. It is of course possible, but most unlikely, for one of these neutral points to coincide purely by chance; however, the likelihood of both neutral values in each graph coinciding exactly are so very small as to be ignored. Consequently, it is thought that a detector unit which can monitor changes in magnetic flux in at least two planes will be a complete answer to the possibility of the unit 'reading' only neutral points, and the likelihood of detecting the presence of a vehicle will be greatly enhanced.

Such a detector unit is illustrated in Figure 6 in which it will be seen that two transducers 18 and 20 are employed, these being located in mutually perpendicular relation so that they monitor changes in magnetic flux in mutually perpendicular planes. It will be seen that for space considerations this modified form of detector unit has been built into an outer casing comprising a generally cylindrical body part for installation below ground level and a relatively shallow head portion of greater diameter for location at ground level; the transducer 18, being vertically arranged, is located within the generally cylindrical body part and the transducer 20, being horizontally arranged, is located within the head portion of the casing. However, it is quite possible for such a modified detector unit to be built into outer casings of other shapes.

Referring now to Figures 7 and 8, the electronic circuits there illustrated respectively form a part of the or each detector unit 10 and a part of a base unit with which the or each detector unit 10 is associated.

In Figure 7 (the detector unit), U1 is a microcontroller with integral program and data memory. Switches 1 to 4 of SW1 allow for the setting of one of sixteen unique address codes to be transmitted by FM radio transmitter TX1. The different address codes avoid interference between adjacent base units, that is to say, they allow for sixteen independent systems to be used where each system consists of a combination of a base unit and any number of detector units. Switches 5 to 8 of SW1 allow changes to be made to variables associated with a vehicle detection algorithm.

U2 is a real time clock allowing the base unit to be effectively switched off during hours when the facilities provided by the detector unit are not required.

U3 converts signal levels between TTL (transistor transistor logic) levels and RS232 levels providing two-way communication for the setting up of variables such as the real time clock and business hours.

U4 and U5 are series regulator power supplies ensuring that the electronic components utilised are supplied with power at the correct voltage. U5 also controls the availability of power to the magnetic sensor.

CN1 supplies power to and connects the magnetic sensor to the microcontroller. The magnetic sensor may monitor either one or two magnetic axes.

In Figure 8 (the base unit), U6 is a microcontroller with integral program and data memory. Switches 1 to 4 of SW2 allow for the setting of one of sixteen unique address codes which are compared with the code received by the FM radio receiver RX1. The use of different address codes avoids interference between adjacent base units.

U7 is a real time clock which allows the base unit to be effectively switched off during hours when the facilities provided by the unit are not required.

U8 converts signal levels between TTL (transistor transistor logic) levels and RS232 levels providing two-way communication for the setting up of variables such as the real time clock and business hours.

U9 provides a speech message that is amplified by U10, the message being intended to deter the parking of vehicles by people not authorised to use the particular parking space.

Ull and U12 are series regulator power supplies ensuring that the electronic components utilised are supplied with power at the correct voltage. U12 also controls the availability of power to the radio receiver RX1.

Thus there is provided a system for the monitoring of use restricted parking areas, and for deterring the use of such areas by drivers who are not properly entitled to use them, which it is thought will be effective against even the most blatant offender, being dependent only on causing an offender some embarrassment. If powered by solar cells (possibly supplemented by battery power) it will be very economical to maintain, and can be installed virtually anywhere. There are many places where such a system may be used in addition to public car parks and supermarkets, for example hospitals and factories where certain groups of people other than disabled drivers must be given the exclusive use of designated parking spaces.

Various other modifications may be made. For example, the system may be capable of recording the time of arrival in and the time of departure from the car parking space concerned by an unauthorised vehicle; it could indeed be adapted to take a photograph of an offending vehicle.

The detector unit 10, instead of being constructed to be at least partially sunk into the ground, may be constructed in the form of a relatively shallow flat plate for installation on the ground surface, such a form of construction providing a minimum of danger to pedestrians and being easier and therefore cheaper to install than one requiring to be partially buried in the ground. (It will be understood that there are some instances where it is not possible for a detector unit to be sunk into the surface on which vehicles are driven, for example the reinforced concrete structure of a multi-storey car park or a parking structure made of metal). Such a construction may also be expected to operate more effectively, being closer to the ferrous structure of any vehicle driving over it and being entirely unshielded by the ground or Tarmac ground surfacing.

The planes in which the sample readings of magnetic field strength are taken may be any combination of the three geometric planes normally referred to as X,Y and Z.

Claims

1. means for monitoring use restricted parking areas, and for deterring their use by drivers who are not properly entitled to use them, said means being constituted by a deterrent system including a detector unit for detecting changes in a magnetic field in the region of a parking area to be monitored, said detector unit including decoding electronics for detecting the presence or absence of a motor vehicle in response to detected changes in said magnetic field, and a radio transmitter.

2. Means according to claim 1, including a hand held transmitter whereby said means can be overridden by a driver properly entitled to use the space concerned.

3. Means according to either one of the preceding claims, including a radio link to alert someone charged with the duty of monitoring the use of the parking area concerned.

4. Means according to any one of the preceding claims, in which decoding electronics include at least one transducer for detecting magnetic fields.

5. means according to claim 4, in which a multiplicity of transducers are provided, these being so arranged as to detect magnetic fields in planes at right angles to each other.

6. Means according to any one of the preceding claims, including a sign or notice, triggered by the radio transmitter, to warn a motorist that he is parked in a use restricted space.

7. Means according to any one of the preceding claims, including a flashing light, an audible alarm, or both.

8. Means according to any one of the preceding claims, in which the system can trigger into operation a physical barrier designed to detain an offending vehicle.

9. Means according to any one of the preceding claims, in which the detector unit for detecting changes in the magnetic field and the illumination of the sign arrangement (together with the powering of any audible or visual warning and the triggering into action of any physical barrier) are powered by a re-chargeable battery charged by a plurality of solar cells.

10. Means according to claim 9, in which the solar cells are mounted on the top surface of the sign arrangement.

11. Means according to claim 9, in which the detector unit is powered solely by batteries or by mains electricity.

12. Means for monitoring use restricted parking areas, and for deterring their use by drivers who are not properly entitled to use them, constructed, arranged and adapted to operate substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.