TITLE: VEHICLE PROXIMITY ALARM

THIS INVENTION relates to an alarm. In particularly, it is directed to an alarm and its method of use to provide a warning in a first vehicle that a second vehicle, especially an emergency vehicle or a train, is approaching.

An emergency vehicle, such as that used by the police, ambulance and fire services, when engaged on an emergency call, is often travelling at a speed higher than the posted limit and other vehicles are legally obligated to give way to that emergency vehicle as soon as safely practical. To expedite this safe passage, the emergency vehicle has activated a siren and flashing lights. However, in today's modern automobile, improvements in sound proofing mean that the automobile occupants are less likely to hear readily any sounds exterior to the automobile. Further, the increased use of mobile telephones and high-powered radio and stereo systems within the automobile also reduce the likelihood of the driver hearing any such exterior sounds. Consequently, the siren of an approaching emergency vehicle may not be heard by the driver of another vehicle and it is not until the emergency vehicle is in close proximity to the other vehicle that its driver becomes aware of its presence by sighting the flashing lights, for example, in the rear view mirror. Consequently, the emergency vehicle has had to reduce speed because its clear passage is blocked by the other vehicle and the driver of that other vehicle, conscious of the requirement to create that clear passage, may react inappropriately with his vehicle increasing the risk of an accident.

Also, there is increasing concern at the number of collisions between motor vehicles and trains that are occurring at level crossings, particularly those crossings which do not yet incorporate warning barriers, lights and bells alerting the driver of a motor vehicle to an approaching train.

It is thus a general object of the present invention to overcome, or at least ameliorate, one or more of the above disadvantages and to provide a system that warns the driver of an automobile that a vehicle is approaching in sufficient time for that driver to act appropriately to provide safe and clear passage for that vehicle.

According to a first aspect of the present invention, there is provided a system for alerting a driver of an automobile of an approach of a vehicle, said system including:

a first transmitting means associated with said vehicle, said first transmitting means capable of transmitting a signal within a predefined range from said vehicle;

a receiving means associated with said automobile, said receiving means capable of receiving said signal; and

alerting means to alert said driver that said signal has been received.

Preferably, said first transmitting means is permanently mounted in said vehicle.

Preferably, said first transmitting means includes a visual alert when said signal is being transmitted.

Preferably, said signal is an encrypted signal.

Preferably, said encrypted signal is a two(2)-way trinary data stream.

Preferably, said signal further includes an identification means unique to the type of said vehicle.

Said identification means may be unique to a particular said vehicle.

Preferably, said identification means can be changed by a controller of said first transmitting means.

Preferably, said receiving means is adapted to identify said type of vehicle.

Preferably, said receiving means is permanently mounted in said automobile.

Preferably said alerting means provides an audible alert when said signal is received.

Preferably, said alerting means further includes a visual alert when said signal is being received.

Preferably, said alerting means is adapted to alert said driver of an automobile to said type of vehicle.

Said visual alert may be a flashing light within at least the peripheral vision of said driver of an automobile.

Said audible alert may be a spoken message identifying said type of vehicle approaching said automobile.

Preferably, said alerting means is muted, switched off or otherwise disengaged after a predefined period from ^J receipt of a said signal.

Preferably, said alerting means is adapted to operate to alert said driver should another of said vehicle approach said automobile within said predefined range during said predefined period.

In those embodiments of the present invention where a driver of said automobile is to be alerted of an approaching train as said automobile nears a level crossing, a second transmitting means is associated with said level crossing which transmits an initiating signal to said train as said train nears said crossing which activates said first transmitting means.

Said identification means may be linked to a global positioning satellite to enable the signal to be uniquely encoded to prevent misuse of the transmitter by parties other than the emergency services or rail transit authorities.

As second aspect of the present invention, there is provided method of alerting a driver of an automobile of an approaching vehicle that requires a clear passage, said method including:

providing said vehicle with a first transmitting means, said first transmitting means capable of transmitting a signal within a predefined range from said vehicle;

providing said automobile with a receiving means, said receiving means capable of receiving said signal from said vehicle when said automobile is within said predefined range;

transmitting from said vehicle said signal;

receiving said transmitted signal by said receiving means in said automobile when said automobile is within said predefined range; and

alerting a driver of said automobile that said signal has been received.

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings, wherein:

FIG. 1 is a block diagram of a transmitting means of the invention located in an emergency vehicle;

FIG. 2 is a block diagram of a receiving means of the invention located in an automobile;

FIG. 3 is a diagrammatic representation of the operation of the encoder and decoder used in the invention;

FIG. 4 is a diagrammatic representation of another embodiment of the present invention whereby the driver of a motor vehicle nearing a level crossing can be warned of an approaching train; and

FIG. 5 is a block diagram of a receiving/transmitting means component of the embodiment of FIG. 4.

In these embodiments, like features are referenced by like numerals.

Referring to FIG. 1 , the transmitting means (1) comprises a power supply (2) operable on the typical 12-48 volt system of ah emergency vehicle powering an encoder (3) and a transmitter (4) transmitting on a frequency of 433 Mhz through an antenna (5) mounted on an emergency vehicle. When power is supplied to the transmitter (4), the encoder (3) begins a 4-word transmission cycle, the cycle repeating until power is disengaged from the transmitter (4).

In this way, a unique code can be assigned to, and transmitted for, each of the police, fire and ambulance emergency services.

With reference to FIG. 2, the receiving means (6) comprises a power supply (7) operable on the typical 12 volt system of a motor vehicle powering a receiver (8) for receiving transmissions at 433 Mhz through an antenna (9) mounted on a motor vehicle, a battery of four (4) decoders 10A[police] 10B[fire], 10C[ambulance] & 10D[train], a microprocessor (11), a LED display (12), an amplifier (13) and an audio alarm (14).

In use, when on an emergency call, the emergency vehicle activates a siren or similar which initiates the generation of an encoded two word trinary data stream to the transmitter (4) which transmits the trinary data. When a motor vehicle is within a pre-set range from the emergency vehicle, the receiver (8) installed in the motor vehicle receives the data stream and outputs the data stream into the decoders (1OA ₁ B ₁ C) that decode the data stream. If the data received matches any one of the decoders' (10A ₁ B ₁ C) set instructions, the appropriate decoder (10A ₁ B ₁ C) will output to a programmed microprocessor (11) which determines the identity of the decoder (10A ₁ B or C) that sent the data. Once the decoder 10(A ₁ B ₁ C) has been identified, a programmed instruction specific for that decoder sends audible data to the amplifier (13) and speaker (14) and trigger data to the visible LED display (12) installed in the motor vehicle. A typical range for open air transmission of the data stream from the emergency vehicle is 500 metres. After a pre-set period of activation, typically, ten (10) seconds, the microprocessor (11) disables the audible and visual alarms.

In more detail, as illustrated in FIG. 3, the encoder (3) is programmed to recognise three states (low, high, and open) allowing 19,683 possible permutations. The transmit sequence is initiated by a low level on the TE input

pin (13). Upon activating the power supply (2) on the emergency vehicle, the encoder (3) transmits four-word sequences by pulsing TE low, each transmitted trinary digit being encoded into pulses. A logic 0 (low) is encoded as two consecutive short pulses, a logic 1 (high) as two consecutive long pulses, and an open (high impedance) as a long pulse followed by a short pulse. This information is serially transmitted via the D _out pin (14).

Each decoder (10) (only one illustrated) receives the serial data from the receiver (8) and outputs the data, if it is valid, that is, determines whether the signal emanates from an emergency vehicle. The transmitted data consists of two identical words. This word is examined bit by bit during reception. The first five trinary digits are assumed to be the address. If the received address matches the local address, the next four (data) bits are internally stored, but are not transferred to the output data latch. As the second encoded word is received, the address must again match. If a match occurs, the new data bits are checked against the previously stored data bits. If the two nibbles of data (four bits each) match, the data is transferred to the output data latch by VT and remains until new data replaces it. At the same time, the VT output pin is brought high and remains high until an error is received or until no input signal is received for four data periods Although the address information may be encoded in trinary, the data information must be either a 1 or 0. A trinary (open) data line is decoded as a logic 1. The VT output is used to indicate that a valid address has been received. For transmission security, two identical transmitted words must be consecutively received before a VT output signal is issued.

A timer program runs within the microprocessor (11 ). When the decoder (10) outputs match the 2 data words being transmitted, the VT output from the decoder (10) is sent to the microprocessor (11 ). The input pins on the microprocessor (11) to which the decoder (10) is connected are scanned on

a continuous clocking cycle and, when a logic high is detected on an input of the microprocessor (11), the microprocessor (11) recalls from its memory a message, and sends this message signal to the amplifier (13) and then on to the speaker (14). Simultaneously with sending this message signal, another program internal to the microprocessor (11) sends a further signal to the LED display (12) which flashes for the duration of the message signal.

After the message signal has been initially displayed within the motor vehicle, the microprocessor (11 ) suspends detection of a logic high on the same input that triggered the message signal for a period of 15 seconds, while still actively scanning the remaining inputs for a logic high. Should a logic high be detected within this period on any of the remaining inputs, a message signal is activated as described above and detection on this input is then suspended for a period of 15 seconds. This mode of operation prevents the continuous triggering of the same message signal on approach and passing of a particular emergency vehicle but also allows the retriggering if more than one emergency vehicle approaches. Although any valid received signal can trigger the visual LED display, the audible component is dependent on the identity of the message signal received and thus which of the decoders (10) is actually activated. In this way, the audible message can alert the driver of "approaching police vehicle", "approaching fire engine' or "approaching ambulance" as appropriate.

When the approaching vehicle is a train, as illustrated in FIGS. 4 & 5, a transmitter (17) is positioned close to a railway level crossing (18). Power for the transmitter (17) can be by any suitable means including solar and mains supply. The transmitter (17) continuously transmits a coded signal (19) which is detected by a receiver (20) in an approaching train (21 ). Once the coded signal (19) is detected, an alarm is triggered for the driver of the train (21 ) and a further signal (22) is transmitted from the train (21) for detection by any approaching motor vehicle (23).

In more detail (FIG.5), a receiver/transmitting means (15) is installed in a train. When a receiver (8) receives a signal via antenna (9), the data stream is outputted to the decoder (10E) that decodes the data stream. If the data received matches the decoder's (10E) set instructions to be the coded signal (19) from the transmitter (17) adjacent a level crossing (18), the decoder (1 OE) will output to a programmed microprocessor (11) that functions as described above with reference to FIGS. 1-3. A programmed instruction also sends audible data to the amplifier (13) and speaker (14) and trigger data to the visible LED display (12) installed in the train to warn the driver thereof that a level crossing is being approached. The incoming matched signal (19) is also encoded by an encoder (10F) to a transmitter (16) which transmits a further unique signal (24) from antenna (25) to be detected by any automobile (23) approaching the level crossing (18) which is fitted with a system similar to that described above with reference to FIGS. 1-3 which also includes an alarm(s) specific to warn the driver of the automobile that a train is approaching the nearby level crossing.

The present invention offers a number of advantages which include:

1. A driver of an automobile is alerted to one or more approaching vehicle(s) such as a police, fire or ambulance vehicle or a train in sufficient time to create a clear and safe passage for that vehicle(s) or train.

2. The driver of a train can also be notified of an approaching level crossing so that he is alerted to the possibility of having to take measures to avoid a possible collision with a motor vehicle approaching that same crossing.

3. The driver of an automobile is alerted of the approaching vehicle irrespective of whether that driver has heard or seen the vehicle approaching.

4. Multiple triggering of the alert system by any particular vehicle is prevented when within range of any given automobile.

5. The range of operation of the warning signal can be easily varied.

6. The transmitted signal avoids interference with other commonly used frequencies such as radio, video or telephone signals.

7. The system may be linked to a global positioning satellite to enable the signal to be uniquely encoded to prevent misuse of the transmitter by parties other than the emergency services.

It will be appreciated that the above described embodiments are only exemplifications of the various aspects of the present invention and that modifications and alterations can be made thereto without departing from the inventive concept as defined in the following claims.