Map aware adaptive automotive radar
A dedicated short range radar system is provided for use with a GPS system. The radar system includes a transmitter which transmits a microwave radio signal. A receiver is coupled to a horizontally scanning receiver antenna array which receives an echo, if present, from the radio signal transmitted by the transmitter. The radio receiver then generates an output signal representative of the echo. A control circuit then receives the output signal from the antenna array as well as the output signal from the GPS system. The control circuit then varies the mode of operation of the receiver and/or the transmitter as a function of the type of roadway for optimal radar performance.
1. An automotive radar system comprising:
a GPS system which generates an output signal representative of the type of roadway,
a transmitter which transmits a microwave radio signal,
a horizontally scanning receiver antenna array,
a receiver coupled to said horizontally scanning receiver antenna array which receives an echo, if present, from the radio signal transmitted by said transmitter and generates an output signal representative of the echo,
a control circuit which receives said output signal from said antenna array and the output signal from the GPS system linked with a map database indicative of the type of roadway currently traveled by the automotive radar system, said control circuit varying the mode of operation of said receiver or said transmitter as a function of the type of roadway from the GPS system.
2. The radar system of claim 1 wherein said control circuit varies the transmitter power as a function of the type of roadway.
3. The radar system of claim 2 wherein said control circuit increases the transmitter power when the roadway type is an urban road.
4. The radar system of claim 2 wherein said control circuit decreases transmitter power when the roadway type is a limited access highway.
5. The radar system of claim 1 wherein said control circuit varies the waveform of the microwave radio signal as a function of the type of roadway.
6. The radar system of claim 5 wherein said control circuit controls said transmitter to transmit a sawtooth waveform when the roadway type is a limited access highway.
7. The radar system of claim 5 wherein said control circuit controls said transmitter to transmit a repeating ramp waveform when the roadway type is an urban road.
8. The radar system of claim 1 wherein said antenna array receives echoes at a plurality of horizontal scan positions during a complete horizontal scan of the antenna array and wherein said control circuit varies the number of horizontal scan positions per complete receiver horizontal scan as a function of the type of roadway.
9. The radar system of claim 8 wherein said control circuit utilizes only a portion of the number of scan positions per complete horizontal scan when the roadway type is a limited access highway.
10. The radar system of claim 8 wherein said control circuit utilizes substantially all of the number of scan positions per complete horizontal scan when the roadway type is an urban road.
11. The radar system of claim 1 wherein said antenna array receives echoes at a plurality of horizontal scan positions during a complete horizontal scan of the antenna array and wherein said control circuit varies the selection of horizontal scan positions per complete receiver horizontal scan as a function of the type of roadway.
12. The radar system of claim 11 wherein said control circuit utilizes only scan positions directed forwardly and to one side per complete horizontal scan when the roadway type is a limited access highway.
13. The radar system of claim 1 wherein said control circuit varies the period of a complete horizontal scan of the receiver.
14. The radar system of claim 1 wherein the GPS system is contained in a navigation system of the automotive vehicle.
15. The radar system of claim 1 wherein said radar system is a continuous wave frequency modulated system.