GB2153124A - Apparatus for sensing the distance between two bodies, one of which is moving relative to the other - Google Patents

Abstract

An oscillator (2) supplies driving signals to a transmitting transducer (3) which transmits acoustic signals. A receiving transducer (4) is arranged on the same vehicle as the transmitting transducer (3) in such a manner that acoustic signals emitted from the transmitting transducer (3) are not received directly by the receiving transducer (4) but are only received by the transducer (4) after reflection from another vehicle. Signals received by the receiving transducer (4) are amplified and passed via an indicating circuit (6) to a warning device (7) which gives a warning to the driver of a vehicle when the distance sensed between two vehicles reaches a threshold level, and/or indicates the distance between the vehicles. <IMAGE>

Description

SPECIFICATION Apparatus for sensing the distance between two bodies, one of which is moving relative to the other This invention relates to an apparatus for sensing the distance between two bodies, one of which is moving relative to the other.

In particular, the apparatus of the present invention may be used to sense the proximity of two vehicles, with a view either to indicating the distance between them or to generating a warning signal to the driver of a vehicle to warn him of an impending collision.

It is known to provide an optical sensing apparatus using a light attached to one of the vehicles. However, such apparatus suffer from the disadvantage that at night, or in heavy fog, the light may be obscured thus reducing the effective operation of the apparatus.

According to the present invention there is provided an apparatus for sensing the distance between two bodies, one of which is moving relative to the other, the apparatus comprising, disposed on one of the bodies, transmission means which emits an acoustic signal, and receiving means which receives the acoustic signal after reflection back from the other of the bodies, the apparatus further comprising indicating means for indicating when the distance reaches a threshold value.

The transmission means may comprise a piezo ceramic transducer, and the drive means may comprise an oscillator adapted to supply driving signals to the transducer.

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 shows an embodiment of the apparatus according to the present invention; and Figure 2 shows another embodiment of the apparatus according to the present invention.

Referring to Fig. 1, an on/off switch 1 controls the supply of power to an oscillator 2 from a battery 10. This switch 1 may be operated manually or automatically in response to action taken by the driver of a vehicle.

The oscillator 2 supplies driving signals to a transmitting transducer 3, for example a piezo ceramic transducer, which transmits acoustic signals. A receiving transducer 4 is arranged on the same vehicle as the transmitting transducer 3 in such a manner that acoustic signals emitted from the transmitting transducer 3 are not received directly by the receiving transducer 4, but are only received by the transducer 4 after reflection from another vehicle. This may be done by either mounting the receiving transducer in a particular position relative to the transmitting transducer, or by the use of screens between the two transducers.

The frequency of signals emitted from the transmitting transducer 3 is controlled by the oscillator 2 and may be in any suitable frequency band.

The receiving transducer may be a piezo electric or electromagnetic transducer.

Signals received by the receiving transducer 4 are amplified in an amplifier 5 and passed via an indicating circuit 6 to a warning device 7. This warning device 7 is adapted to give an audible or visual warning or both to the driver of a vehicle when the distance sensed between two vehicles reaches a threshold level, and/or to indicate the distance between the vehicles.

The indicating circuit 6 determines whether the warning given is continuous or intermittent, and enables the warning to change in intensity as the distance between the two vehicles changes.

In Fig. 2, a modulator 8 is provided to modulate the signals from the oscillator, the signals received by the receiving transducer 4 being demodulated in a demodulator 9, before being amplified in amplifier 5.

The apparatus of the present invention thus allows the use of acoustic signals to sense the distance between two relatively moving bodies or vehicles, for use in avoiding collisions.

More than one transmitter/receiver arrangement may be used, in accordance with reqhuirements.

1. An apparatus for sensing the distance between two bodies, the apparatus comprising, disposed on one of the bodies, transmission means which emits an acoustic signal, and receiving means which receives the acoustic signal after reflection back from the other of the bodies, the apparatus further comprising indicating means for indicating when the distance reaches a threshold value.

2. An apparatus as claimed in claim 1, in which the transmission means comprises a piezo ceramic transducer.

3. An apparatus as claimed in claim 1 or 2, in which the drive means comprises an oscillator adapted to supply driving signals to the transducer.

4. An apparatus as claimed in claim 1, substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Apparatus for sensing the distance between two bodies, one of which is moving relative to the other This invention relates to an apparatus for sensing the distance between two bodies, one of which is moving relative to the other. In particular, the apparatus of the present invention may be used to sense the proximity of two vehicles, with a view either to indicating the distance between them or to generating a warning signal to the driver of a vehicle to warn him of an impending collision. It is known to provide an optical sensing apparatus using a light attached to one of the vehicles. However, such apparatus suffer from the disadvantage that at night, or in heavy fog, the light may be obscured thus reducing the effective operation of the apparatus. According to the present invention there is provided an apparatus for sensing the distance between two bodies, one of which is moving relative to the other, the apparatus comprising, disposed on one of the bodies, transmission means which emits an acoustic signal, and receiving means which receives the acoustic signal after reflection back from the other of the bodies, the apparatus further comprising indicating means for indicating when the distance reaches a threshold value. The transmission means may comprise a piezo ceramic transducer, and the drive means may comprise an oscillator adapted to supply driving signals to the transducer. For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 shows an embodiment of the apparatus according to the present invention; and Figure 2 shows another embodiment of the apparatus according to the present invention. Referring to Fig. 1, an on/off switch 1 controls the supply of power to an oscillator 2 from a battery 10. This switch 1 may be operated manually or automatically in response to action taken by the driver of a vehicle. The oscillator 2 supplies driving signals to a transmitting transducer 3, for example a piezo ceramic transducer, which transmits acoustic signals. A receiving transducer 4 is arranged on the same vehicle as the transmitting transducer 3 in such a manner that acoustic signals emitted from the transmitting transducer 3 are not received directly by the receiving transducer 4, but are only received by the transducer 4 after reflection from another vehicle. This may be done by either mounting the receiving transducer in a particular position relative to the transmitting transducer, or by the use of screens between the two transducers. The frequency of signals emitted from the transmitting transducer 3 is controlled by the oscillator 2 and may be in any suitable frequency band. The receiving transducer may be a piezo electric or electromagnetic transducer. Signals received by the receiving transducer 4 are amplified in an amplifier 5 and passed via an indicating circuit 6 to a warning device 7. This warning device 7 is adapted to give an audible or visual warning or both to the driver of a vehicle when the distance sensed between two vehicles reaches a threshold level, and/or to indicate the distance between the vehicles. The indicating circuit 6 determines whether the warning given is continuous or intermittent, and enables the warning to change in intensity as the distance between the two vehicles changes. In Fig. 2, a modulator 8 is provided to modulate the signals from the oscillator, the signals received by the receiving transducer 4 being demodulated in a demodulator 9, before being amplified in amplifier 5. The apparatus of the present invention thus allows the use of acoustic signals to sense the distance between two relatively moving bodies or vehicles, for use in avoiding collisions. More than one transmitter/receiver arrangement may be used, in accordance with reqhuirements. CLAIMS

1. An apparatus for sensing the distance between two bodies, the apparatus comprising, disposed on one of the bodies, transmission means which emits an acoustic signal, and receiving means which receives the acoustic signal after reflection back from the other of the bodies, the apparatus further comprising indicating means for indicating when the distance reaches a threshold value.

2. An apparatus as claimed in claim 1, in which the transmission means comprises a piezo ceramic transducer.

3. An apparatus as claimed in claim 1 or 2, in which the drive means comprises an oscillator adapted to supply driving signals to the transducer.

4. An apparatus as claimed in claim 1, substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.