In-vehicle radar device
AssigneeDenso Corporation
InventorsYusuke AKAMINE, Naoki KAWASAKI, Yasuyuki MIYAKE
Life of this patent
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Abstract
An in-vehicle radar device includes a transmission section, a reception section, an analysis section, an extraction section, a speed calculation section, a distance calculation section, and a folding detection section. The folding detection section detects occurrence of erroneous calculation of a distance, when reflection intensity at a frequency peak obtained by the extraction section is smaller than a preset intensity threshold for a distance calculated by the distance calculation section and a frequency width in a frequency spectrum calculated by the analysis section is smaller than a preset width threshold.
Claims6
An in-vehicle radar device mounted in a vehicle, the in-vehicle radar device comprising:
- a transmission section configured to alternately transmit two types of continuous waves having different frequencies;
- a reception section configured to receive a reflected wave generated by reflection by a target of the continuous wave transmitted from the transmission section and generate a frequency difference signal of the received reflected wave and the continuous wave;
- an analysis section configured to calculate a frequency spectrum of the frequency difference signal generated by the reception section;
- an extraction section configured to obtain a frequency peak in the frequency spectrum calculated by the analysis section and extract a moving object;
- a speed calculation section configured to calculate a relative speed to the vehicle of the moving object extracted by the extraction section, from the frequency peak in the frequency spectrum;
- a distance calculation section configured to calculate a distance from the vehicle to the moving object, from a phase difference between two types of the frequency difference signals corresponding to the two types of continuous waves;
- and
- a folding detection section configured to detect occurrence of erroneous calculation of the distance due to phase difference folding that causes the phase difference to be 2π or more, wherein
- the folding detection section is configured to detect occurrence of erroneous calculation of the distance, when reflection intensity at the frequency peak obtained by the extraction section is smaller than a preset intensity threshold for the distance calculated by the distance calculation section and a frequency width in the frequency spectrum calculated by the analysis section is smaller than a preset width threshold, the intensity threshold being set according to the distance, the frequency width being a frequency range in which the frequency peak is included and the reflection intensity exceeding a preset noise threshold continues.
Dependencies are inferred from the claim text.