| 主权项 |
1. A method for detecting a radar object with the aid of a frequency modulated continuous wave (FMCW) radar sensor of a motor vehicle, comprising:
generating, via an analysis unit, a measuring signal by mixing a transmitted signal with a received signal, as received by the analysis unit, the transmitted signal having a sequence of frequency modulations, wherein a partial signal of the measuring signal is assigned to each one of the frequency modulations; ascertaining, via the analysis unit, first information about a relative velocity and a distance of a radar object, based on a frequency spectrum of at least one of the partial signals, the first information including a relationship between the relative velocity and the distance of the radar object, which relationship assigns different relative velocities to different distances; ascertaining, via the analysis unit, second information about the relative velocity and the distance of the radar object, based on a frequency spectrum of a time curve of values of frequency spectra of the partial signals at a frequency position of the radar object in the frequency spectra of the partial signals; and ascertaining, via the analysis unit, the relative velocity and the distance of the radar object, based on matching of the first information with the second information; wherein in one measuring cycle the transmitted signal has a first sequence of frequency modulations and at least one second sequence of frequency modulations, a partial signal of the measuring signal being assigned to each of the frequency modulations of the two sequences, wherein a relationship between the relative velocity and the distance, which results for the radar object as the first information, differs for two sequences of frequency ramps, and wherein the second information about the relative velocity of the radar object, which are ascertained from the first sequence and the second sequence of the frequency ramps, have different ambiguity ranges, and wherein the frequency modulations are in a fast ramp and a slow ramp, wherein the sequence of frequency modulations of the transmitted signal is a sequence of frequency modulations in the form of linear frequency ramps having a ramp center frequency which changes linearly as a function of time, wherein (i) the change with respect to time of the ramp center frequency within the sequence and (ii) the individual frequency ramps of the sequence have opposite signs, and wherein if at least two sequences of frequency modulations are used in one measuring cycle, unambiguous ranges for the relative velocity of the second information are selected so that within one analysis range of relative velocity, no correspondences occur between integral multiples of the particular unambiguous ranges. |
