Radar apparatus and signal processing method

Patent metadata

Field	Value
Publication number	US-9348023-B2
Application number	US-201314071906-A
Country	US
Kind code	B2
Filing date	Nov 5, 2013
Priority date	Dec 7, 2012
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

There is provided a radar apparatus configured to extract peak signals which are obtained from a difference frequency between a transmission signal and a reception signal, and to derive information of the target on the basis of the extracted peak signals. A prediction unit predicts this time peak signal based on a peak signal obtained in previous time. An extraction unit extracts this time peak signal corresponding to the predicted peak signal from peak signals existing within a predetermined frequency range. The extraction unit extends the frequency range when this time peak signal corresponding to the predicted peak signal does not exist within the predetermined frequency range.

First claim

What is claimed is:

1. A radar apparatus configured to extract peak signals which are obtained from a difference frequency between a transmission signal of which a frequency changes with a predetermined cycle and a reception signal obtained by receiving a reflected wave coming from a target at which a transmission wave corresponding to the transmission signal is reflected, in a first period in which the frequency of the transmission signal ascends and in a second period in which the frequency descends, and to derive information of the target on the basis of the extracted peak signals, the radar apparatus comprising:
a prediction unit configured to predict this time peak signal based on a peak signal obtained in previous time; and
an extraction unit configured to perform an extraction process extracting this time peak signal corresponding to the predicted peak signal from peak signals existing within a predetermined frequency range,
wherein the extraction unit, when this time peak signal corresponding to the predicted peak signal does not exist within the predetermined frequency range, further performs the extraction process of extracting this time peak signal within another frequency range wider than the predetermined frequency range.

2. The radar apparatus according to claim 1 , further comprising a derivation unit configured to derive an angle with respect to the target on the basis of the peak signals,
wherein the extraction unit, when there is no peak signal having an angle corresponding to an angle derived from the predicted peak signal, further performs the extracting process within said another frequency range wider than the predetermined frequency range.

3. The radar apparatus according to claim 2 , wherein the extraction unit, when there is no peak signal having an angle of which a difference to an angle derived from the predicted peak signal is a predetermined value or smaller, further performs the extraction process within said another frequency range wider than the predetermined frequency range.

4. The radar apparatus according to claim 3 , wherein when the extraction unit further performs the extraction process within said another frequency wider than the predetermined frequency range, the extraction unit decreases the predetermined value.

5. The radar apparatus according to claim 2 ,
wherein the prediction unit predicts this time peak signal for the respective peak signals of the first and second periods, and
wherein when there is no peak signal having an angle of which a difference to an angle derived from the predicted peak signal for at least one of the respective peak signals of the first and second periods is a predetermined value or smaller, the extraction unit further performs the extraction process within said another frequency range wider than the predetermined frequency range.

6. The radar apparatus according to claim 1 , wherein the predetermined frequency range is a range in which a frequency of the predicted peak signal is a center thereof.

7. The radar apparatus according to claim 1 , further comprising a derivation unit configured to derive the information of the target on the basis of the extracted peak signals,
wherein when only an angle derived from the peak signal extracted in one of the first and second periods is an angle corresponding to an angle derived from the predicted peak signal, the derivation unit derives the information of the target on the basis of frequencies of the respective peak signals extracted in the first and second periods and the corresponding angle.

8. The radar apparatus according to claim 1 , wherein the predetermined frequency range is a predetermined limited range.

9. A signal processing method of extracting peak signals which are obtained from a difference frequency between a transmission signal of which a frequency changes with a predetermined cycle and a reception signal obtained by receiving a reflected wave coming from a target at which a transmission wave corresponding to the transmission signal is reflected, in a first period in which the frequency of the transmission signal ascends and in a second period in which the frequency descends, and deriving information of the target on the basis of the extracted peak signals, the signal processing method comprising:
(a) predicting this time peak signal based on a peak signal obtained in previous time; and
(b) perform an extraction process of extracting this time peak signal corresponding to the predicted peak signal from peak signals existing within a predetermined frequency range,
wherein the step (b), the extraction process is performed with another frequency range wider than the predetermined frequency range when this time peak signal corresponding to the predicted peak signal does not exist within the predetermined frequency range.

Assignees

• Fujitsu Ten Ltd

Inventors

• Asanuma Hisateru
• Ishimori Hiroyuki

Classifications

• G01S13/931 Primary

  of land vehicles · CPC title

• G01S13/34

  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 title

• G01S13/345 Primary

  using triangular modulation · CPC title

• G01S13/93

  for anti-collision purposes · CPC title