Emergency vehicle alert apparatus

• US 5,808,560 A
• Filed: 06/17/1996
• Issued: 09/15/1998
• Est. Priority Date: 06/17/1996
• Status: Expired due to Fees

• Current Assignee: Emergency Alert Technologies Incorporated
• Original Assignee: Emergency Alert Technologies Incorporated
• Inventors: Mulanax, Michael L.
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): Wu, Daniel J.
• Application Number:
  US08/664,531
• Time in Patent Office: 820 Days
• Field of Search: 340/902, 340/906, 455/34.1, 455/34.2
• US Class Current: 340/902
• CPC Class Codes: G08G 1/0965 responding to signals from another vehicle, e.g. emergency vehicle

Abstract

A simple and effective apparatus and method is disclosed for identifying the presence of an emergency vehicle in the immediate vicinity of a motor vehicle. This apparatus may be readily mounted and will not produce false alarms. The apparatus comprises: a transmitting unit, positioned within the emergency vehicle and having an activation circuit that turns on a digital identification data encoder that modulates an R.F. transmitter producing a digital data stream which is connected to a broadcast antenna; and, a receiving unit, carried by a motor vehicle so that it may be warned if the emergency vehicle is in its immediate vicinity having and having a R.F. receiver that demodulates a received digital data stream and then activates an alert pulse generator which is connected to an alarm means if the digital identification code matches the digital identification encoded in the transmitting unit. In a preferred aspect of this invention the digital identification data encoder modulates the R.F. transmitter with a data byte containing bits which identify the transmitting unit and the receiving unit comprises a data decoder which doubly checks the received digital data stream so that the alarm means only will be activated when two sequentially received data bytes are identical, thereby virtually eliminating any possibility of false activation of the alarm means.

Claims

1. An apparatus for warning a motor vehicle of an emergency vehicle in the immediate vicinity comprising:

a transmitting unit having an activation circuit that turns on a digital identification data encoder that modulates an R.F. transmitter producing a digital data stream which is connected to a broadcast antenna;

a receiving unit having a R.F. receiver that demodulates a received digital data stream and then activates an alert pulse generator connected to an alarm means if the digital identification code matches the digital identification encoded in the transmitting unit;

wherein the receiving unit comprises a data decoder which checks the received digital data stream first to determine if it contains a valid data byte by comparing it to a programmed data code inputted to a first data comparator;

if this data byte matches the programmed data code then it is placed in temporary data storage;

then the next data byte is compared at a second data comparator to the temporary data storage, and then finally if the sequential data bytes are identical an output is sent to an alert pulse generator connected to the alarm means so that the alarm means only will be activated when two sequentially received data bytes are identical thereby virtually eliminating any possibility of false activation of the alarm means; and

,

wherein use the transmitting unit is positioned within the emergency vehicle and the receiving unit is carried by a motor vehicle so that the motor vehicle is (it may be) warned if the emergency vehicle is in its immediate vicinity.

2. An apparatus as in claim 1 wherein the digital identification data encoder modulates the R.F. transmitter with a data byte containing bits which identify the transmitting unit.

3. An apparatus as in claim 1 wherein the second data comparator outputs to an activity timer as long as sequential data bytes match;

said activity timer outputs both to a duration timer and a flip flop which also receives input from the duration timer;

said flip flop in turn outputs to the alert pulse generator;

wherein use said duration timer sends a pulse to the flip flop after a programmed predetermined amount of time to reset the alarm means thereby avoiding a continuous annoying alarm and preventing the alarm from continually activating if the receiving unit remains within the immediate vicinity of the emergency vehicle for an extended time, by not allowing reactivation until there has been a valid data stream for a predetermined amount of time.

4. An apparatus as in claim 3 wherein the duration timer is a monostable generator.

5. An apparatus as in claim 4 wherein the alarm means comprises an audible alarm and a flashing lamp.

6. An apparatus as in claim 5 wherein the predetermined amount of time for the intermittent reactivation of the alarm means may be programmed independently of the prerequisite duration of a valid data stream so that if the receiving unit remains in the immediate vicinity of an emergency vehicle for an extended period of time the alarm may be deactivated for a longer period than the intermittent time.

7. An apparatus as in claim 6 wherein the receiving unit is equipped with a cigarette lighter power connection.

8. A method for warning a motor vehicle of an emergency vehicle in the immediate vicinity comprising the following steps:

transmitting a data stream through a transmitting unit having an activation circuit that turns on a digital identification data encoder that modulates an R.F. transmitter producing a digital data stream which is connected to a broadcast antenna;

receiving the data stream through a receiving unit having a R.F. receiver that demodulates a received digital data stream and then activates an alert pulse generator connected to an alarm means if the digital identification code matches the digital identification encoded in the transmitting unit;

wherein the receiving unit comprises a data decoder which checks the received digital data stream first to determine if it contains a valid data byte by comparing it to a programmed data code inputted to a first data comparator;

if this data byte matches the programmed data code then it is placed in temporary data storage;

then the next data byte is compared at a second data comparator to the temporary data storage, and then finally if the sequential data bytes are identical an output is sent to an alert pulse generator connected to the alarm means so that the alarm means only will be activated when two sequentially received data bytes are identical thereby virtually eliminating any possibility of false activation of the alarm means; and

,

wherein use the transmitting unit is positioned within the emergency vehicle and the receiving unit is carried by a motor vehicle so that the motor vehicle is warned if the emergency vehicle is in its immediate vicinity.

9. A method as in claim 8 wherein the digital identification data encoder modulates the R.F. transmitter with a data byte containing bits which identify the transmitting unit.

10. A method as in claim 8 wherein the second data comparator outputs to an activity timer as long as sequential data bytes match;

said activity timer outputs both to a duration timer and a flip flop which also receives input from the duration timer;

said flip flop in turn outputs to the alert pulse generator;

wherein use said duration timer sends a pulse to the flip flop after a programmed predetermined amount of time to reset the alarm means thereby avoiding a continuous annoying alarm and preventing the alarm from continually activating if the receiving unit remains within the immediate vicinity of the emergency vehicle for an extended time, by not allowing reactivation until there has been a valid data stream for a predetermined amount of time.

11. A method as in claim 10 wherein the duration timer is a monostable generator.

12. A method as in claim 11 wherein the alarm means comprises an audible alarm and a flashing lamp.

13. A method as in claim 12 wherein the predetermined amount of time for the intermittent reactivation of the alarm means may be programmed independently of the prerequisite duration of a valid data stream so that if the receiving unit remains in the immediate vicinity of an emergency vehicle for an extended period of time the alarm may be deactivated for a longer period than the intermittent time.

14. A method as in claim 13 wherein the receiving unit is equipped with a cigarette lighter power connection.