FM-CW radar processing device

• US 6,674,393 B2
• Filed: 10/22/2002
• Issued: 01/06/2004
• Est. Priority Date: 02/06/2001
• Status: Active Grant

• Current Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Inventors: Kishida, Masayuki
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US10/258,270
• Publication Number:
  US 20030128156A1
• Time in Patent Office: 441 Days
• Field of Search: 342/70, 342/71, 342/72, 342/82, 342/83, 342/98, 342/99, 342/107, 342/108, 342/109, 342/111, 342/112, 342/115, 342/116, 342/130, 342/131, 342/135, 342/192, 342/195, 342/196
• US Class Current: 342/70
• CPC Class Codes: G01S 13/345 using triangular modulation
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 7/352 Receivers
• CPC Class Codes: G01S 7/356 involving particularities of FFT processing

Abstract

An FM-CW radar processing system pairs up peaks obtained by fast-Fourier transforming a beat signal occurring on an up portion and a down portion of a triangular-shaped FM-CW wave, calculates a distance or relative velocity with respect to a target object based on the peak signal in the up portion and the peak signal in the down portion obtained by the pairing, and compares the distance or relative velocity, obtained after changing the modulating signal for the FM-CW wave, with the distance or relative velocity obtained before changing the modulating signal. If the distance or relative velocity differs before and after changing the modulating signal, the pairing is judged to be mispairing.

Claims

1. An FM-CW radar processing system which transmits an FM-CW wave and receives a reflected wave from a target object, comprising:

a modulating signal generating unit capable of changing a modulating signal to be applied to said FM-CW wave;

a pairing unit for pairing peak signals between an up portion and a down portion of said FM-CW wave;

a calculating unit for calculating a distance or relative velocity with respect to said target object, based on the peak signal in said up portion and the peak signal in said down portion obtained by said pairing; and

a comparing unit for comparing said distance or relative velocity, obtained by said calculating unit after changing said modulating signal, with said distance or relative velocity obtained before changing said modulating signal.

3. An FM-CW radar processing system as claimed in claim 1 or 2, wherein when said comparing unit has detected that said distance or relative velocity differs before and after changing said modulating signal, said pairing is judged to be mispairing.

4. An FM-CW radar processing system as claimed in claim 3, wherein said modulating signal generating unit changes a modulation frequency or frequency period for said modulating signal, and

said calculating unit calculates the distance to said target object after said change of said modulating signal.

5. An FM-CW radar processing system as claimed in claim 3, wherein said modulating signal generating unit changes a center frequency for said modulating signal, and

said calculating unit calculates the relative velocity with respect to said target object after said change of said modulating signal.

2. An FM-CW radar processing system which transmits an FM-CW wave and receives a reflected wave from a target object, comprising:

a modulating signal generating unit capable of changing a modulating signal to be applied to said FM-CW wave;

a pairing unit for pairing peak signals close in intensity between an up portion and a down portion of said FM-CW wave;

a calculating unit for calculating a distance or relative velocity with respect to said target object, based on the peak signal in said up portion and the peak signal in said down portion obtained by said pairing; and

a comparing unit for comparing said distance or relative velocity, obtained by said calculating unit after changing said modulating signal, with said distance or relative velocity obtained before changing said modulating signal.