Modular radar architecture film (FM/CW or pulse) for automobile collision avoidance applications

• US 5,517,197 A
• Filed: 10/24/1994
• Issued: 05/14/1996
• Est. Priority Date: 10/24/1994
• Status: Expired due to Term

• Current Assignee: Rockwell International Corporation
• Original Assignee: Rockwell International Corporation
• Inventors: Linstrom, Russell H., Algeo, Jerry A., Chen, Pileih, Waineo, Douglas K., Wong, Sam H.
• Primary Examiner(s): TUDOR, HAROLD JAY
• Application Number:
  US08/327,747
• Time in Patent Office: 568 Days
• Field of Search: 342/21, 342/70, 342/71, 342/72, 342/130, 342/194, 342/195, 342/200, 342/201
• US Class Current: 342/70
• CPC Class Codes: G01S 13/10 using transmission of interrupted, pulse modulated waves determination of distance by phase measurement G01S13/32
• CPC Class Codes: G01S 13/34 using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: G01S 2013/9325 for inter-vehicle distance regulation, e.g. navigating in platoons
• CPC Class Codes: G01S 7/032 Constructional details for solid-state radar subsystems

Abstract

A modular radar system using both FM/CW and pulse waveforms for automotive collision avoidance applications. The radar system comprises a transmit and a receive antenna for transmitting and receiving, respectively, either one of FM/CW waveform and pulse waveform, a voltage-controlled oscillator (VCO) for generating a pre-set waveform for the transmit antenna, a modulator for modulating the pre-set waveform of the VCO, a switch for allowing the pre-set waveform from the VCO to be transmitted for a predetermined interval so as to generate the pulse waveform, a timing generator for causing the modulator to execute through a pre-set sequence of frequencies for either one of the pulse and FM/CW modes of waveforms with the timing generator controlling the transmission of one of the FM/CW waveform and pulse waveform, a balanced mixer for signal conversion In both FM/CW and pulse modes, an IF/Baseband receiver for amplifying the received FM/CW waveform and for IF-amplifying the received pulse waveform to generate an in-phase and a quadrature baseband output, a coherent oscillator for generating a coherent oscillating signal of a predetermined frequency to the receiver for centering the IF-amplified received pulse waveform at the predetermined frequency during pulse mode, and a frequency control loop for causing the VCO to maintain an offset by a predetermined frequency in the pulse mode between receive and transmit.

Claims

1. A modular radar system for automotive collision avoidance applications, comprising:

a transmit antenna for transmitting one of FM/CW waveform and pulse waveform;

a receive antenna for receiving one of FM/CW waveform and pulse waveform;

a voltage-controlled oscillator (VCO) coupled to said transmit antenna for generating a predetermined waveform for said transmit antenna;

a modulator coupled to said VCO for modulating said predetermined waveform of said VCO;

a switch coupled between said VCO and said transmit antenna for allowing said predetermined waveform from said VCO to be transmitted for a predetermined interval so as to generate said pulse waveform;

a timing generator disposed to cause said modulator to execute through a pre-set sequence of frequencies for either one of pulse and FM/CW modes of waveforms, said timing generator also coupled to said switch for controlling the transmission of one of said FM/CW waveform and pulse waveform;

a balanced mixer coupled to said receive antenna for signal conversion, said balanced mixer operative in said FM/CW mode by converting a received FM/CW waveform to a baseband signal, said balanced mixer operative in said pulse mode by converting a received pulse waveform to an IF signal;

an IF/Baseband receiver coupled to said balanced mixer for amplifying said received FM/CW waveform and for IF-amplifying said received pulse waveform, generating an in-phase and a quadrature baseband output;

a coherent oscillator coupled to said IF/baseband receiver for generating a coherent oscillating signal of a predetermined frequency to said receiver for centering said IF-amplified received pulse waveform at said predetermined frequency during pulse mode; and

a frequency control loop coupled between said IF/Baseband receiver and said modulator for causing said VCO to maintain an offset by a predetermined frequency in said pulse mode between receive and transmit.

2. A radar system according to claim 1, further comprising:

a digital processor for providing clocking to said timing generator and for analyzing said in-phase and quadrature outputs from said balanced mixer.

3. A radar system according to claim 1, further comprising:

a first switch driver coupled to said transmit antenna for selecting from a plurality of beam positions;

a second switch driver coupled to said receive antenna for selecting from a plurality of beam positions.

4. A radar system according to claim 3, further comprising:

a power conditioner for providing a power source to said radar system from the automobile.

5. A radar system according to claim 1, wherein said frequency control loop comprises:

a frequency discriminator coupled to said IF/Baseband receiver for determining the frequency offset between said coherent oscillating signal and said received pulse waveform;

a loop filter coupled to said frequency discriminator for correcting said modulator when said frequency offset exists between said coherent oscillating signal and said received pulse waveform.

6. A method for a modular radar system for automotive collision avoidance applications, comprising the steps of:

a) transmitting through a transmit antenna one of FM/CW waveform and pulse waveform;

b) receiving through a receive antenna one of FM/CW waveform and pulse waveform;

c) generating a predetermined waveform through a voltage-controlled oscillator (VCO) coupled to said transmit antenna for said transmit antenna;

d) modulating through a modulator coupled to said VCO said predetermined waveform of said VCO;

e) allowing said predetermined waveform from said VCO to be transmitted for a predetermined interval through a switch coupled between said VCO and said transmit antenna so as to generate said pulse waveform;

f) said modulating caused by a timing generator disposed thereto execute through a pre-set sequence of frequencies for either one of pulse and FM/CW modes of waveforms, said timing generator also coupled to said switch for controlling the transmission of one of said FM/CW waveform and pulse waveform;

g) signal converting by a balanced mixer coupled to said receive antenna, said balanced mixer operative in said FM/CW mode by converting a received FM/CW waveform to a baseband signal, said balanced mixer operative in said pulse mode by converting a received pulse waveform to an IF signal;

h) amplifying said received FM/CW waveform and for IF-amplifying said received pulse waveform, through an IF/Baseband receiver coupled to said balanced mixer, to generate an in-phase and a quadrature baseband output;

i) generating a coherent oscillating signal of a predetermined frequency to said receiver through a coherent oscillator coupled to said IF/baseband receiver for centering said IF-amplified received pulse waveform at said predetermined frequency during pulse mode; and

j) causing said VCO to maintain an offset by a predetermined frequency, through a frequency control loop coupled between said IF/Baseband receiver and said modulator, in said pulse mode between receive and transmit.

7. The method according to claim 6, further comprising the step of:

k) providing clocking through a digital processor to said timing generator and for analyzing said in-phase and quadrature outputs from said balanced mixer.

8. The method according to claim 6, wherein:

step a) comprises selecting from a plurality of beam positions through a first switch driver coupled to said transmit antenna; and

step b) comprises selecting from a plurality of beam positions through a second switch driver coupled to said receive antenna.

9. The method according to claim 8, further comprising the step of using a power conditioner to provide power to said radar system from the automobile.

10. The method according to claim 6, wherein said frequency control loop comprises:

a frequency discriminator coupled to said IF/Baseband receiver for determining the frequency offset between said coherent oscillating signal and said received pulse waveform;

a loop filter coupled to said frequency discriminator for correcting said modulator when said frequency offset exists between said coherent oscillating signal and said received pulse waveform.