Vehicular rear and side warning device

• US 20060077052A1
• Filed: 03/11/2005
• Published: 04/13/2006
• Est. Priority Date: 09/24/2004
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Matsuoka, Katsuji
• Granted Patent: US 7,173,523 B2
• Time in Patent Office: Days
• US Class Current: 340/471
• CPC Class Codes: G01S 13/56 for presence detection presence detection using near field arrangements G01V3/00, e.g. G01V3/08, G01V3/12; burglar, theft or intruder alarms with electrical actuation G08B13/22 - G08B13/26
• CPC Class Codes: G01S 2013/9315 Monitoring blind spots

Abstract

There is provided a vehicular rear and side warning device which does not issue a warning against a roadside stationary body such as a guard rail or a wall, and certainly issues a warning against a vehicle approaching from behind or a vehicle existing in a blind spot region of an own vehicle. A warning object judgment unit includes a noted sampling timing setting unit for setting a noted sampling timing on the basis of a peak timing obtained by a peak detection unit, and a frequency judgment unit for judging whether a frequency component not lower than a frequency threshold set by a frequency threshold setting unit exists with respect to an FFT operation result at the noted sampling timing. In a case where a front approaching body recognition unit judges that a material body approaches from in front of the own vehicle, and when the frequency judgment unit judges that a frequency component not lower than the frequency threshold exists, it is judged that the material body is a stationary body and is not a warning object.

Claims

1. A vehicular rear and side warning device comprising:

a transmission unit for transmitting a pulse-like electric wave to an oblique rear portion at a lane change side of an own vehicle;

a reception unit for receiving a reflected wave of the electric wave transmitted from the transmission unit and reflected by plural material bodies and for outputting a beat signal;

a sampling unit for sampling the beat signal at specified time intervals from a time of transmission start;

an FFT operation unit for performing an FFT operation on sampling time series data at each of sampling timings obtained by the sampling unit;

a maximum amplitude component extraction unit for obtaining a maximum amplitude value and its frequency component on an FFT operation result at each of the sampling timings;

a detection threshold setting unit for setting a detection threshold on the basis of the maximum amplitude value at each of the sampling timings obtained by the maximum amplitude component extraction unit;

a peak detection unit for detecting a peak exceeding the detection threshold on the basis of the maximum amplitude value at each of the sampling timings obtained by the maximum amplitude component extraction unit;

a distance/relative speed operation unit for calculating a distance from a peak timing obtained by the peak detection unit and for calculating a relative speed from a frequency component at the peak timing;

a lane change intension detection unit for detecting a lane change intention of a driver;

a warning object judgment unit for judging whether a material body detected by the peak detection unit is a warning object for the driver; and

a warning judgment unit for issuing a warning to the driver when at least it is detected that a material body exists within a specified distance in a side and oblique rear portion of the own vehicle, the lane change intension of the driver is detected by the lane change intension detection unit, and the warning object judgment unit judges that the material body is the warning object for the driver,

wherein the warning object judgment unit includes;

a front approaching body recognition unit for recognizing, from a temporal history of distance, a material body approaching from in front of the own vehicle;

a frequency threshold setting unit for setting a threshold on a Doppler frequency according to a speed of the own vehicle;

a noted sampling timing setting unit for setting a noted sampling timing on the basis of the peak timing obtained by the peak detection unit; and

a frequency judgment unit for judging, with respect to an FFT operation result at the noted sampling timing, whether there is a frequency component not lower than the frequency threshold set by the frequency threshold setting unit, and

wherein in a case where the front approaching body recognition unit judges that the material body approaches from in front of the own vehicle, and when the frequency judgment unit judges that the frequency component not lower than the frequency threshold exists, the material body is judged to be a stationary body and not to be a warning object.

2. A vehicular rear and side warning device according to claim 1, wherein the noted sampling timing setting unit sets, as the noted sampling timing, the peak timing obtained by the peak detection unit and plural adjacent sampling timings at a farther side of the timing.

3. A vehicular rear and side warning device according to claim 1, wherein the noted sampling timing setting unit sets, as the noted sampling timing, plural adjacent sampling timings at a farther side of the peak timing obtained by the peak detection unit.

4. A vehicular rear and side warning device according to claim 1, wherein the noted sampling timing setting unit sets, as the noted sampling timing, the peak timing obtained by the peak detection unit.

5. A vehicular rear and side warning device according to claim 1, wherein the frequency judgment unit sets a specified amplitude threshold for the FFT operation result at the noted sampling timing, and compares a maximum frequency value of amplitudes exceeding the threshold with the frequency threshold set by the frequency threshold setting unit.

6. A vehicular rear and side warning device according to claim 1, wherein the frequency judgment unit calculates an average amplitude value in a specified frequency range for the FFT operation result at the noted sampling timing, sets an amplitude threshold on the basis of the value, and compares a maximum frequency value of amplitudes exceeding the threshold with the frequency threshold set by the frequency threshold setting unit.

7. A vehicular rear and side warning device according to claim 1, wherein the front approaching body recognition unit sets, as a reference distance, a distance at a time when the material body is detected for the first time, and recognizes that the material body is the material body approaching from behind in a case where there is a history in which detection occurs at a distance shorter than the reference distance, and recognizes, in the other case, that the material body is the material body approaching from front.

8. A vehicular rear and side warning device according to claim 1, wherein the front approaching body recognition unit sets, as a reference distance, a distance shorter by a specified distance than a distance at a time when the material body is detected for the first time, recognizes that the material body is the material body approaching from behind in a case where there is a history in which detection occurs at a distance shorter than the reference distance, and recognizes, in the other case, that the material body is the material body approaching from front.

9. A vehicular rear and side warning device according to claim 1, wherein in a case where the front approaching body recognition unit judges that the material body approaches from front, the warning object judgment unit monitors whether a frequency component not lower than the frequency threshold exists by the frequency judgment unit for a specified time, and judges, when the frequency component not lower than the frequency threshold exists in the time, that the material body is a stationary body and is not a warning object.