GB2243511A

GB2243511A - Proximity detection apparatus

Info

Publication number: GB2243511A
Application number: GB9009468A
Authority: GB
Inventors: Harry Jackson
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-04-27
Filing date: 1990-04-27
Publication date: 1991-10-30
Also published as: GB9009468D0

Abstract

A vehicle is fitted with front and rear proximity detection apparatus each comprising an emitter (8) and a receiver (10). Each emitter emits a beam in the near infrared range, which may be reflected from an object (12, 16) back to the receiver. The driver is then given a warning of the proximity of the object. Warning may be given by LED's or a buzzer (24-28) mounted on an interior mirror (20, Fig. 3 not shown). <IMAGE>

Description

PROXIMITY DETECTION APPARATUS This invention relates to proximity detection apparatus, in particular to apparatus for detecting the proximity of a moving object from another object, the moving object typically being a vehicle.

In accordance with a first aspect of the present invention there is provided proximity detection apparatus comprising an emitter of an electromagnetic signal, a receiver therefor, and a carrier on which the emitter and receiver are mounted in fixed, spaced-apart relation, in such a manner that the receiver may receive a directed, angled signal emitted by the emitter and reflected by a fixed objection, the apparatus further comprising indication means for indicating to an operator that the emitter has received the signal.

The apparatus of the invention is of particular interest for use in relation to vehicles, in particular as an aid for parking. Thus, proximity detection apparatus in accordance with the invention may be employed to detect the proximity of the end of the vehicle from a fixed object, for example another vehicle or a wall or barrier.

Apparatus in accordance with the present invention is of particular interest in relation to the assessment of the proximity of the rear of the vehicle from a fixed object but could also be of benefit at the front of a vehicle.

A further aspect of the present invention therefore relates to a vehicle having proximity detection apparatus having a carrier, on which are mounted an emitter and a receiver, at the rear of the vehicle, and/or having a carrier, on which are mounted an emitter and a receiver, at the front of the vehicle.

The emitter and the receiver of the proximity detection apparatus could be mounted directly on the bodywork of a vehicle. Preferably, however, the emitter and the receiver are mounted on an elongate carrier which is secured to the vehicle. In certain embodiments of the present invention the elongate carrier may be a bumper for the vehicle. In other embodiments of the present invention the elongate carrier may be a number plate for the vehicle.

Preferably, the apparatus provides an indication to an operator that the carrier is within a particular distance range from the fixed object. It is undesirable to provide that the apparatus could only provide indication to an operator at one particular precise distance of the carrier from the fixed object, since this indication could easily be missed as the carrier moves through that particular point. When the proximity detection apparatus is for use on a vehicle, the detection range may suitably be, for example, between about 25 cm and about 100 cm. To this end the signal emitted by the emitter is a directed, beam-like signal, and the receiver is adapted to receive a signal at a relatively precise angle. Some scatter will generally occur on reflection from the fixed object.

Preferably, the apparatus comprises means for substantially eliminating the effects of stray radiation.

Such means may comprise filters associated with the receiver so as to register only the relatively narrow frequency band of the electromagnetic signal emitted by the emitter. Filters may comprise physical filters in front of the receiver and/or circuitry filters downstream of it. Physical filters may, for example, comprise filters to filter out visible light for example cross polaroid filters and/or a red-coloured filter. Such means may comprise a beam passage-defining part, for example a channel or tube, in front of the receiver. Such means may alternatively or additionally comprise pulsing the signal and providing circuitry downstream of the receiver to detect the pulsed signal and enable the indication means, but to reject a non-pulsed signal of similar frequency band.

Preferably, the electromagnetic signal is in the infrared range. The infrared range is between the limit of the visible spectrum (the near region) to the shortest microwaves (the far region). The frequency band may be regarded as from about 0.75 ijm to about 1,000 pm. The infrared range may be sub-classified as near infrared (about 0.75 pm to about 2.5 pom); intermediate infrared (about 2.5 wm to about 30 pm); and far infrared (about 30 pm to about 1,000 pm). Emitters/receivers operating within the near infrared band are particularly advantages and are readily available. For example, a suitable receiver/demodulator is coded GP1U52X available from Tandy Corporation.This unit comprises a pinphoto diode as infrared receiver feeding an amplifier and then a pass band filter rejecting all signals outside the pass band (40 KHz i 4 KHz), the signal then being fed to a demodulator, integrator and wave-shaper circuit. The supply voltage is 5 volts and the current dissipation 5 mA. The receiver and emitter may be powered in any standard way, and in a vehicle the vehicle battery would be the preferred source of power, with the voltage being transformed down as required.

The indication means may comprise visual indication means, for example an LED or lamp, or audible indication means, for example an alarm, or both. Although the indication means could give an indication of actual distance from a fixed object, it is thought to be adequate to give a simple indication of being within a certain range. For use in relation to a vehicle, the indication means should be within the vehicle compartment, and if visual indication means is employed, should be located so as to be readily seen by the driver. Suitably, visual indication means may be mounted on or built into the dashboard of the vehicle. Another suitable location, particularly useful for proximity detection of the rear of the vehicle, is on or adjacent to the interior rear-view mirror of the vehicle.When the vehicle has apparatus for proximity detection of the front of the vehicle and apparatus for proximity of the rear of the vehicle, the indication means suitably distinguishes between the front and rear; for example LED's or lamps of different colour are used. When visual detection means is employed, it is preferably arranged that a lamp or LED employed gives a flashing signal.

In certain, preferred, embodiments of the invention it may be desirable to control whether or not the proximity detection apparatus is operating at any particular time. In other embodiments it may be acceptable to provide that the apparatus is operative whenever the vehicle ignition is on, since the current drain is very small. If it is desired to control whether or not the proximity detection apparatus is operable, this may be done by the use of a switch or switches, suitably illuminated, under the control of the driver. The switches may suitably be operated through the gear selection apparatus of the vehicle. For example, proximity detection apparatus located at the front of a vehicle may become operative only when first gear is engaged. Similarly, proximity detection apparatus at the rear of the vehicle may become operative only when reverse gear is engaged.Suitably, an initial audible indication is given when the switch(es) is/are operated, indicating that the system is working.

Suitably, the emitter and the receiver are fixed on the carrier in such a manner that the operator cannot tamper with them, to change the angle at which they are set or their spacing. Suitably, they are spaced apart by a substantial distance, at least 40 cm. Thus, when mounted on a number plate, they are suitably mounted at the edge regions thereof.

The invention will now be further described, by way of example, with reference to the accompanying drawings in which: Fig. 1 shows in schematic perspective view an emitter and receiver of proximity detection apparatus, mounted on a number plate; Fig. 2 shows in schematic plan view a car having proximity detection apparatus for front and rear proximity detection; and Fig. 3 shows an interior rear-view mirror for the car, on which mirror indication means for the proximity detection apparatus is mounted.

The number plate shown in Fig. 1 comprises a conventional number and letter display region 2 recording the vehicle registration number. Covering the front of the number plate is a transparent acrylic sheet and comoulded with the sheet, at respective ends thereof, are acrylic wedge-shaped parts 4, 6. Each part 4, 6 has a face which is angled to the display region 2 and faces generally inwards. The angle is approximately 300. The part 4 contains, encapsulated within a plastics material, an infrared emitter 8 and the part 6 similarly contains an infrared receiver 10. The emitter 8 and receiver 10 may be of any standard available type, as described previously.The emitter 8 has a focusing lens and emits a relatively narrow, directed beam of infrared radiation of wave length about 1 pm. The receiver is selected to detect such radiation and to filter out stray infrared radiation.

In front of the emitter and the receiver is a respective tubular part 9, 11. Each tubular part has drain holes in its lower region. At the base of the part 11 are located a red-coloured filter and a pair of polaroid cross-filters.

-The number plate of Fig.l is shown in Fig. 2 at the front of the car. The beam emitted by the emitter 4, reflected from the fixed object 12 and detected by the receiver 10, is schematically indicated in dotted line.

Due to some beam divergence and also scatter at the fixed object 12, the emitter 10 detects the desired infrared radiation over a range of distances and accordingly a signal is provided to the driver. In this embodiment, the indication is given to the driver when the vehicle in front is between about 60 cm and about 25 cm from the fixed object 12.

At the rear of the vehicle, an emitter and a receiver are mounted towards the edges of the vehicle rear bumper 14, rather than on the number plate. The angle of inward inclination is approximately 200. Indication of proximity to fixed object 16 is given to the driver, between about 100 cm and about 25 cm from the fixed object.

Fig. 3 shows the interior rear-view mirror 18 of the vehicle. This comprises a mirrored surface 20 and a narrow region 22 extending along the top of the mirror, within which are mounted an LED 24, red in colour, indicating, when flashing, rear proximity, an LED 26, green in colour, indicating, when flashing, front proximity, and a buzzer unit 28, providing an alarm signal when either LED 24 or LED 26 flashes. Additionally the buzzer unit provides a short sound when the front or rear proximity apparatus is switched on, to indicate that the apparatus is operable.

In this embodiment the switches for the apparatus are associated with the gear selection mechanism, the front, on selection of first gear(or Drive, in an automatic gearbox), the rear, on selection of reverse.

The circuitry could be configured such that the buzzer 28 only sounds at the lower end of the proximity detection range, that is, when the vehicle front or rear is about 25 cm from a fixed object. For example, it could be arranged that, the buzzer 28 sounds when the LED 24 or 26 is no longer lit because the vehicle has been driven too close to the fixed object.

It is envisaged that the apparatus of the present invention will aid parking not merely by enabling drivers to park their vehicles in spaces which they might not attempt to park in without a parking aid, but will also enable drivers to park their vehicles closer to other vehicles at times when there is ample parking space, so leaving more room available for people parking their vehicles later.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIM8

1. Proximity detection apparatus for detecting the proximity of a vehicle from another object, the apparatus comprising an emitter of an electromagnetic signal, a receiver therefor, and a carrier on which the emitter and receiver are mounted in fixed, spaced-apart relation, in such a manner that the receiver may receive a directed, angled signal emitted by the emitter and reflected by a fixed objection, the apparatus further comprising indication means for indicating to a person that the emitter has received the signal.

2. Apparatus as claimed in Claim 1, wherein the electromagnetic signal is an infrared electromagnetic signal.

3. Apparatus as claimed in Claim 2, wherein the electromagnetic signal is in the range from about 0.75 pm to about 1,000 pm.

4. Apparatus as claimed in any preceding claim, comprising means for substantially eliminating the effects of stray radiation.

5. Apparatus as claimed in Claim 4, comprising filters associated with the receiver so as to register only the relatively narrow frequency band of the electromagnetic signal emitted by the emitter.

6. Apparatus as claimed in Claim 4 or 5, comprising a beam passage-defining part in front of the receiver.

7. Apparatus as claimed in Claim 4, 5 or 6, comprising means for pulsing the signal, and circuitry downstream of the receiver to detect the pulsed signal and enable the indication means, but to reject a non-pulsed signal of similar frequency band.

8. A vehicle fitted with apparatus as claimed in any preceding claim.

9. A vehicle as claimed in Claim 8, wherein the emitter and receiver are mounted on a number plate of the vehicle.

10. A vehicle as claimed in Claim 8, wherein the emitter and receiver are mounted on the bumper of the vehicle.

11. A vehicle as claimed in Claim 8, 9 or 10, wherein the apparatus is adapted to provide detection in the range from about 25 cm to about 100 cm from an object.

12. A vehicle as claimed in Claim 8, 9, 10 or 11, wherein the apparatus is made operative by switching on the vehicle's ignition.

13. A vehicle as claimed in Claim 8, 9, 10 or 11, wherein the apparatus is made operative by selection of a gear.

14. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.