GB2140918A

GB2140918A - A detector for use on a vehicle to detect the proximity of other objects

Info

Publication number: GB2140918A
Application number: GB08312371A
Authority: GB
Inventors: Philip John Tomney; John Stuart Hendy; Brian David Edwards
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-05-05
Filing date: 1983-05-05
Publication date: 1984-12-05
Also published as: GB8312371D0

Abstract

A detector includes a unit (16) detachably mounted, for example, at the rear nearside of a lorry (10), which emits an ultrasonic pulsed signal beam (30) which will be reflected from any proximate surface, and the reflected signal is received and analysed to indicate the distance of the object from the detector. An output in the form of an audible and/or visible signal is produced by a unit (18) for the driver of the vehicle to warn him of the object. The beam is directed rearwards and downwards to detect overtaken vehicles or obstacles when reversing for example. A motorised wiper may be used to keep the unit (16) free of road dirt. The detector may also be used when towing other long trailers e.g. caravans or horse-boxes. <IMAGE>

Description

SPECIFICATION A detector for use on a vehicle to detect the proximity of other objects The present invention relates to a detector for use on a vehicle to detect the proximity of other objects. The detector can for example be used on a moving lorry to detect the proximity of another vehicle being overtaken, thus providing an indication to the driver of when he is safely past the other vehicle and can pull in. The detector can also sense the proximity of a fixed object, such as a wall so that, when reversing, a driver has an indication of when to stop.

Drivers of long vehicles always find it difficult to know when they are safely past another vehicle which they have overtaken. A practice has grown up whereby the driver being overtaken turns his lights off and on when it is safe for the overtaking lorry to pull in. Common courtesy of course then requires the overtaking driver to say "thank you", again by switching his lights on and off.

This practice is dangerous. When it is practiced at night, the lorries are momentarily left without lights.

Should an emergency arise in this brief period, the ability of the driverto deal with it is impaired. Also the flashing of lights at night is confusing to other road users, some of whom will be unaware of this lorry drivers' custom.

According to the present invention, there is provided a detector for use on a vehicle to detect the proximity of other objects, the detector having a first, emitter/receiver unit adapted to be mounted at the rear of a vehicle, a second, indicator unit in communication with the first unit and adapted to be mounted in the driver's cab, means for periodically producing a signal to be emitted from the first unit, to be reflected from any proximate object and to be received by the first unit, and means for evaluating the reflected signal and for producing an indication at the second unit indicative of the distance from the first unit at which the signal has been reflected.

The signal is preferably an ultrasonic signal. This will provide a reflected signal to the first unit which signal will not be too badly affected by the orientation or quality of the reflecting surface.

The emitter and receiver may be combined in a single device, and a rangefinding device as sold under the name Polaroid (Polaroid is a Registered Trade Mark) is particularly suitable. The first unit may also include an oscillator for use in producing the ultrasonic signal, a flip/flop for continually switching the range finding device from emit to receive and a comparator for comparing the reflected signal with the emitted signal to produce an output signal indicative of the distance the emitted signal travelled before being reflected.

The second unit may include a loudspeaker for producing an audible noise which may for example vary in pitch as the reflection distance of the emitted signal alters. Additionally, a digital readout could be provided.

The emitter is preferably arranged so that the emitted signal will be directed rearwards at about 45" to the centreline of the vehicle and downwards at about 10" below the horizontal.

The first unit may be detachable from the rear of the lorry, so that the device can be used on an articulated lorry, with the driver mounting the first unit, which is connected to a second unit in the cab of his tractor unit, at the back of the trailer which he will draw.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of a lorry bearing a detector in accordance with the invention; Figure 2 is a rear view of the lorry of Figure 1; and Figure 3 is a block diagram indicating the manner of operation of the detector.

An articulated lorry 10 has a tractor unit 12 and a trailer 14. At the back of the trailer, a first unit 16 of the detector is mounted, just beneath the trailer deck. In the cab of the tractor a second unit 18 is mounted. The units 16 and 18 are connected by a cable 20 which takes power to the first unit and passes a signal back to the second unit.

In use, the driver (of an articulated vehicle) extends the cable 20 down the nearside of his trailer and mounts the unit 16 in the position shown. A suitable quick and secure mounting for the unit will be provided. The cable will be supported along the length of the trailer.

The operative components are shown in Figure 3, in which the first and second units 16 and 18 are shown adjacent, for ease of explanation. Power is supplied from the vehicle power supply through a voltage regulator 22 which brings the voltage down to 5 volts. An oscillator 24 (e.g. 50 kHz) produccs an oscillating signal which passes a flip/flop 26 which has a frequency of about 20 Hzto a rangefinding device 28 which emits an ultrasonic signal (30 in Figures 1 and 2). The emitted signal also goes to a comparator 32 along a line 34.

The signal 30 is reflected from a distant object, and a reflected signal is picked up by the rangefinding device 28 when this is in "receive" mode. The received signal passes to the comparator 32 along a line 36. The comparator compares the emitted signal with the reflected signal and produces an analog output which is indicative of the distance from the vehicle at which reflection took place. This output can be processed through a voltage controlled oscillator 38 to produce an audible signal through a loudspeaker 40 in the cab. Additionally or alternatively, the output can be processed through an analog to digital converter 42 and through a counter converter 44 to produce a digital readout on an LED display 46 in the cab. A volume control 48 is provided to control the signal volume from the loudspeaker.Additionally, but not shown in the Figure, there may be a "power on" light and an ON/OFF switch.

The angle of the signal beam 30 should be set to reach the ground (in the absence of any nearer object) at a distance of about 5 metres from the vehicle.

The driver will probably only switch the detector on when passing another vehicle or when reversing.

As the back of his lorry passes the front of another, the pitch of the sound emitted from the loudspeaker will change indicating that he is clear. Since the beam is angled backward at 45", it is unlikely that he will pull in too soon. The angle also means that the device can be used when reversing.

It may be necessary to make provision for keeping the rangefinder unit 28 free from road dirt. Possibly a motorised wiper could be used for this purpose.

This detector may also be of use to drivers towing caravans or horse boxes or other long trailers. The manner or operation would be substantially as already described.

Claims

1. A detector for use on a vehicle to detect the proximity of other objects, the detector having a first, emitter/receiver unit adapted to be mounted at the rear of a vehicle, a second, indicator unit in communication with the first unit and adapted to be mounted in the driver's cab, means for periodically producing a signal to be emitted from the first unit, to be reflected from any proximate object and to be received by the first unit, and means for evaluating the reflected signal and for producing an indication at the second unit indicative of the distance from the first unit at which the signal has been reflected.

2. A detector as claimed in Claim 1, wherein the signal is an ultrasonic signal.

3. A detector as claimed in Claim 1 or Claim 2, wherein the emitter and receiver are combined in a single device.

4. A detector as claimed in any preceding claim, wherein the first unit includes an oscillatorfor use in periodically producing the ultrasonic signal, a flip/ flop for continually switching the range finding device from emitted receive and a comparator for comparing the reflected signal with the emitted signal to produce an output signal indicative of the distance the emitted signal travelled before being reflected.

5. A detector as claimed in any prededing claim, wherein the second unit includes a loudspeaker for producing an audible noise.

6. A detector as claimed in Claim 5, wherein a digital readout is also provided.

7. A detector as claimed in any preceding claim, wherein the emitter is arranged so that the emitted signal is directed rearwards at about 45" to the centreline of the vehicle and downwards at about 10" below the horizontal.

8. A detector as claimed in any preceding claim, wherein the first unit can be detachably mounted on the rear of a lorry.

9. A detector for use on a vehicle to detect the proximity of other objects, substantially as herein described, with reference to the accompanying drawings.