US 6,348,889 B1 · Radar apparatus

Abstract

A vehicular radar apparatus comprising a radar beam transmission device and a reception device, and a processing unit for detecting the position of a target object from transmission signals and reception signals. The processing unit has a preceding vehicle judgment circuit for judging if a vehicle travelling in front of a subject vehicle in the same direction is the same vehicle as previously detected or not, and a signal strength comparing device for comparing the signal strength of a current reception signal reflected from the preceding vehicle, with a signal strength of a reception signal reflected from the preceding vehicle a predetermined comparison reference time prior, to thereby calculate a change amount in signal strength. When the change amount calculated by the signal strength comparing device drops beyond a previously set threshold value and it is judged by the preceding vehicle judgment device that the preceding vehicle is the same vehicle, it is judged that the detection sensitivity of the radar apparatus has dropped.

Claims8

Dependent claims

A radar apparatus for being mounted on a subject vehicle comprising:

a beam transmission means for radiating a radar beam as a transmission signal;
a beam reception means for receiving a reception signal reflected from a target object which is within a radiation range of said radiated radar beam;
and
a processing unit for detecting a position of a target object from said transmission signal and said received reception signal, said processing unit comprising;
a preceding vehicle judgement means for judging if a preceding vehicle travelling in front of the subject vehicle in approximately a same direction as the subject vehicle is same vehicle as previously detected, and
a signal strength comparing means for comparing the signal strength of a reception signal reflected from said preceding vehicle, with a signal strength of a reception signal reflected from said preceding vehicle a comparison reference time prior, to thereby calculate a change amount in signal strength, and
when said change amount calculated by said signal strength comparing means drops beyond a previously set threshold value and it is judged by said preceding vehicle judgement means that said preceding vehicle is the same vehicle, said processing unit diagnoses that detection sensitivity of the radar apparatus has dropped.

4 more elements

A processing unit for a vehicular radar apparatus having means for radiating a radar beam as a transmission signal and means for receiving a reception signal reflected from a target object which is within a radiation range of said radiated radar beam, said processing unit determining a position of a target object from said transmission signal and said received reception signal and comprising:

means for judging if a preceding vehicle travelling in front of a subject vehicle on which the radar apparatus is mounted, in approximately a same direction as the subject vehicle is a same vehicle as previously detected, and
a signal strength comparing means for comparing the signal strength of a reception signal reflected from said preceding vehicle, with a signal strength of a reception signal reflected from said preceding vehicle in a prior reference time, to thereby calculate a change amount in signal strength, and
when said change amount calculated by said signal strength comparing means drops below a preset threshold value and it is judged by said preceding vehicle judgement means that said preceding vehicle is the same vehicle, said processing unit diagnoses that detection sensitivity of the radar apparatus has dropped.

Dependencies are inferred from the claim text.

Radar apparatus

Life of this patent

Radar apparatus

Life of this patent

Abstract

Claims8