Information processing apparatus and sensing method
An information processing apparatus which senses an object by using an FMCW radar, wherein the information processing apparatus comprises: a data processing unit acquiring an angle power spectrum by performing angle FFT on a received signal; an acquisition unit acquiring an angle peak bin indicating an angle with the object; an extraction unit extracting an output signal corresponding to the power spectrum signal; and a correction unit correcting a phase of the output signal in accordance with a bin number of the plurality of peak bins, wherein the data processing unit applies a window function higher in order than a rectangular window function when performing the angle FFT, and the correction unit corrects the phase of the output signal so that a phase difference to be added or subtracted is (N−1)/2×π×sin(θ(i)) [rad] in accordance with the bin number of the angle peak bin.
1 . An information processing apparatus which senses an object by using an FMCW radar, comprising:
a data processing unit which generates a power spectrum signal with a predetermined number of bins by processing a received signal of a plurality of antennas derived from a received wave of the FMCW radar, wherein the data processing unit acquires an angle power spectrum related to an angle with the object by performing angle FFT on the received signal;
an acquisition unit which acquires a plurality of peak bins corresponding to the object based on the power spectrum signal, wherein the acquisition unit acquires an angle peak bin indicating an angle with the object based on the angle power spectrum;
an extraction unit which extracts an output signal corresponding to the power spectrum signal; and
a correction unit which corrects a phase of the output signal in accordance with a bin number of the plurality of peak bins, wherein
the data processing unit applies a window function higher in order than a window function of a rectangular window when performing the angle FFT on the received signal,
the correction unit corrects the phase of the output signal so that a phase difference to be added or subtracted is (N−1)/2×π×sin(θ(i)) [rad] in accordance with the bin number of the angle peak bin,
N is a number of the plurality of antennas,
i is the bin number of the angle peak bin, and
θ(i) [rad] is an angle corresponding to the bin number of the angle peak bin.
2 . The information processing apparatus according to claim 1 , wherein
the plurality of peak bins include a peak bin of a predetermined first bin number, and a peak bin of a second bin number which is different from the first bin number, and
the correction unit corrects a phase of the peak bin of the second bin number without correcting a phase of the peak bin of the first bin number.
3 . The information processing apparatus according to claim 2 , wherein the data processing unit acquires a distance power spectrum related to a distance from the object by performing distance FFT on the received signal; and
applies a window function higher in order than a window function of a rectangular window when performing the distance FFT on the received signal; and wherein
the acquisition unit acquires a distance peak bin indicating the distance from the object based on the distance power spectrum.
4 . The information processing apparatus according to claim 3 , wherein
the acquisition unit acquires the angle peak bin in the angle FFT based on a data sequence corresponding to a position of the distance peak bin identified by the distance FFT.
5 . The information processing apparatus according to claim 3 , wherein
the correction unit corrects a phase of the output signal in accordance with the bin number of the distance peak bin.
6 . The information processing apparatus according to claim 3 , wherein the data processing unit:
acquires the distance power spectrum by performing the distance FFT on the received signal to which a first window function is applied; and
acquires the angle power spectrum by performing the angle FFT on the received signal to which a second window function that is different from the first window function is applied; and wherein
the second window function is a window function higher in order than a window function of the first window function.
7 . The information processing apparatus according to claim 2 , wherein
the data processing unit acquires a speed power spectrum related to speed of the object by performing speed FFT on the received signal; and
the acquisition unit acquires a speed peak bin indicating the speed of the object based on the speed power spectrum.
8 . The information processing apparatus according to claim 7 , wherein
the acquisition unit acquires the speed peak bin in the speed FFT based on a data sequence corresponding to a distance peak bin position identified by distance FFT.
9 . The information processing apparatus according to claim 2 , comprising a data conversion unit which converts a plurality of data corresponding to the object into clustered data.
10 . The information processing apparatus according to claim 1 , wherein the data processing unit:
acquires a distance power spectrum related to a distance from the object by performing distance FFT on the received signal; and
applies a window function higher in order than a window function of a rectangular window when performing the distance FFT on the received signal; and wherein
the acquisition unit acquires a distance peak bin indicating the distance from the object based on the distance power spectrum.
11 . The information processing apparatus according to claim 10 , wherein
the acquisition unit acquires the angle peak bin in the angle FFT based on a data sequence corresponding to a position of the distance peak bin identified by the distance FFT.
12 . The information processing apparatus according to claim 10 , wherein
the correction unit corrects a phase of the output signal in accordance with the bin number of the distance peak bin.
13 . The information processing apparatus according to claim 10 , wherein the data processing unit:
acquires the distance power spectrum by performing the distance FFT on the received signal to which a first window function is applied; and
acquires the angle power spectrum by performing the angle FFT on the received signal to which a second window function that is different from the first window function is applied; and wherein
the second window function is a window function higher in order than a window function of the first window function.
14 . The information processing apparatus according to claim 1 , wherein
the data processing unit acquires a speed power spectrum related to speed of the object by performing speed FFT on the received signal; and
the acquisition unit acquires a speed peak bin indicating the speed of the object based on the speed power spectrum.
15 . The information processing apparatus according to claim 14 , wherein
the acquisition unit acquires the speed peak bin in the speed FFT based on a data sequence corresponding to a distance peak bin position identified by distance FFT.
16 . The information processing apparatus according to claim 1 , comprising a data conversion unit which converts a plurality of data corresponding to the object into clustered data.
17 . The information processing apparatus according to claim 1 , comprising
a tracking unit which tracks the object based on past data of the object when data corresponding to the object is not obtained in a predetermined period.
18 . The information processing apparatus according to claim 1 , wherein the extraction unit extracts IQ data including an in-phase component and a quadrature component that is orthogonal to the in-phase component from the peak bin acquired by the acquisition unit.
19 . The information processing apparatus according to claim 1 , wherein the data processing unit:
processes the received signal by using a CAPON method or an algorithm of compressed sensing; and
applies a window function higher in order than a window function of a rectangular window when performing the CAPON method or the algorithm of compressed sensing on the received signal.
20 . A sensing method for sensing an object by using an FMCW radar, comprising:
generating a power spectrum signal with a predetermined number of bins by processing a received signal of a plurality of antennas derived from a received wave of the FMCW radar, wherein an angle power spectrum related to an angle with the object is generated by performing angle FFT on the received signal;
acquiring a plurality of peak bins corresponding to the object based on the power spectrum signal, wherein an angle peak bin indicating an angle with the object is acquired based on the angle power spectrum;
extracting an output signal corresponding to the power spectrum signal; and
correcting a phase of the output signal in accordance with a bin number of the plurality of peak bins, wherein
the generating the power spectrum signal includes applying a window function higher in order than a window function of a rectangular window when performing the angle FFT on the received signal,
the correcting the phase of the output signal includes correcting the phase of the output signal so that a phase difference to be added or subtracted is (N−1)/2×π×sin(θ(i)) [rad] in accordance with the bin number of the angle peak bin,
N is a number of the plurality of antennas,
i is the bin number of the angle peak bin, and
θ(i) [rad] is an angle corresponding to the bin number of the angle peak bin.