RADAR APPARATUS AND SIGNAL PROCESSING METHOD

• US 20140313070A1
• Filed: 02/10/2014
• Published: 10/23/2014
• Est. Priority Date: 04/19/2013
• Status: Active Grant

• Current Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Inventors: ASANUMA, Hisateru
• Granted Patent: US 9,618,607 B2
• Time in Patent Office: Days
• US Class Current: 342/200
• CPC Class Codes: G01S 13/02 Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
• CPC Class Codes: G01S 13/345 using triangular modulation
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 7/41 using analysis of echo signal for target characterisation; Target signature; Target cross-section

Abstract

There is provided a radar apparatus capable of extracting a peak signal obtained from a difference frequency between a transmitting signal and a receiving signal during first and second periods and deriving target information based on the extracted peak signals. A pairing unit pairs the peak signals extracted in the first and second periods. A judging unit judges whether or not the derived target is an overhead object based on the number of paired data of a stationary object existing within a predetermined range from the radar apparatus, among the paired data obtained by pairing the peak signals in the pairing unit.

Claims

1. A radar apparatus capable of extracting a peak signal obtained from a difference frequency between a transmitting signal of which a frequency is changed in a predetermined period, and a receiving signal obtained by receiving a reflection wave of a transmission wave based on the transmitting signal at a target, during a first period in which the frequency of the transmitting signal ascends, and a second period in which the frequency of the transmitting signal descends, and deriving information about the target based on the extracted peak signals, the radar apparatus comprising:

a pairing unit configured to pair the peak signal extracted in the first period and the peak signal extracted in the second period; and

a judging unit configured to judge whether or not the derived target is an overhead object based on the number of paired data of a stationary object existing within a predetermined range from the radar apparatus, among the paired data obtained by pairing the peak signals in the pairing unit.

2. The radar apparatus according to claim 1, wherein the judging unit judges that the derived target is the overhead object, if the number of the paired data of the stationary object existing within the predetermined range is above a first threshold.

3. The radar apparatus according to claim 2, wherein the judging unit judges that the derived target is the overhead object, if a distance between the paired data of the stationary object is above a first distance.

4. The radar apparatus according to claim 2, wherein the judging unit releases a judgment that the derived target is the overhead object, if the number of the paired data of the stationary object existing within the predetermined range is below a second threshold.

5. The radar apparatus according to claim 2, wherein the judging unit releases a judgment that the derived target is the overhead object, if angular power of the target judged as the overhead object is above a predetermined value.

6. The radar apparatus according to claim 1, wherein if the target is judged as the overhead object above predetermined times within a predetermined time, the judging unit subsequently executes a judging process of which a condition is relaxed.

7. The radar apparatus according to claim 6, wherein the judging unit judges that the derived target is the overhead object, if the number of the paired data of the stationary object existing within the predetermined range is above a third threshold which is lower than first threshold.

8. The radar apparatus according to claim 7, wherein the judging unit judges that the derived target is the overhead object, if the distance between the paired data of the stationary object is above a second distance which is lower than the first distance.

9. The radar apparatus according to claim 6, wherein the judging unit continuously executes the judging process of which the condition is relaxed, for a predetermined time.

10. The radar apparatus according to claim 9, wherein if the target is not judged as the overhead object within the predetermined time, the judging unit releases execution of the judging process of which the condition is relaxed.

11. A signal processing method capable of extracting a peak signal obtained from a difference frequency between a transmitting signal of which a frequency is changed in a predetermined period, and a receiving signal obtained by receiving a reflection wave of a transmission wave based on the transmitting signal at a target, during a first period in which the frequency of the transmitting signal ascends, and a second period in which the frequency of the transmitting signal descends, and deriving information about the target based on the extracted peak signals, the signal processing method comprising:

(a) pairing the peak signal extracted in the first period and the peak signal extracted in the second period; and

(b) judging whether or not the derived target is an overhead object based on the number of paired data of a stationary object existing within a predetermined range from the radar apparatus, among the paired data obtained by pairing the peak signals in the step (a).