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US 12,270,899 B2Granted
Trajectory estimation device, trajectory estimation system, trajectory estimation method, and program recording medium
AssigneeNEC Corporation
InventorsYumi Arai, Reishi Kondo
Life of this patent
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Abstract
A trajectory estimation device that includes an acquisition unit that acquires wave data based on a wave detected by a plurality of sensors; a generation unit that generates a spectrogram using the wave data; an extraction unit that extracts a Doppler shift from the spectrogram; a selection unit that selects, as a sensor pair, two of the sensors that satisfy a preset selection condition for the Doppler shift; and an estimation unit that estimates a trajectory of a wave source, which is a source generating the wave, based on a positional relationship between the sensors constituting the sensor pair and a relationship of the Doppler shifts between the two sensors constituting the sensor pair.
Claims9
A trajectory estimation device comprising:
- at least one memory storing instructions;
- and
- at least one processor connected to the at least one memory and configured to execute the instructions to:
- acquire wave data based on a wave detected by each of a plurality of sensors disposed at intervals according to a type of a wave source to be estimated;
- generate a spectrogram using the wave data, the spectrogram being a three-dimensional graph representing the wave detected by each of the plurality of sensor in a relationship of a time, a frequency, and an intensity;
- extract Doppler shifts from the spectrogram, the Doppler shifts being temporal changes of frequencies extracted based on a peak having a maximum or greatest intensity in the spectrogram;
- select, as a sensor pair, two of the sensors that satisfy a preset selection condition for the Doppler shifts;
- and
- estimate a trajectory of the wave source, which is a source generating the wave, based on a positional relationship between the sensors constituting the sensor pair and a relationship of the Doppler shifts between the two sensors constituting the sensor pair, wherein
- in a case where a frequency of the wave is known in advance, the at least one processor is configured to execute the instructions to:
- generate a plurality of bases by shifting the frequency of the wave within a certain frequency width;
- derive activation for the plurality of bases by non-negative matrix factorization;
- specify a basis for which the activation has a maximum value, among the plurality of bases;
- and
- calculate, as the Doppler shifts, curves obtained by plotting the frequency of the basis at which the activation has the maximum value.
12 more elements
A trajectory estimation method performed by a computer and comprising:
- acquiring wave data based on a wave detected by each of a plurality of sensors disposed at intervals according to a type of a wave source to be estimated;
- generating a spectrogram using the wave data, the spectrogram being a three-dimensional graph representing the wave detected by each of the plurality of sensor in a relationship of a time, a frequency, and an intensity;
- extracting Doppler shifts from the spectrogram, the Doppler shifts being temporal changes of frequencies extracted based on a peak having a maximum or greatest intensity in the spectrogram;
- selecting, as a sensor pair, two of the sensors that satisfy a preset selection condition for the Doppler shifts;
- and
- estimating a trajectory of the wave source, which is a source generating the wave, based on a positional relationship between the sensors constituting the sensor pair and a relationship of the Doppler shifts between the two sensors constituting the sensor pair, wherein
- in a case where a frequency of the wave is known in advance.
- generating a plurality of bases by shifting the frequency of the wave within a certain frequency width;
- deriving activation for the plurality of bases by non-negative matrix factorization;
- specifying a basis for which the activation has a maximum value, among the plurality of bases;
- and
- calculating, as the Doppler shifts, curves obtained by plotting the frequency of the basis at which the activation has the maximum value.
9 more elements
A non-transitory program recording medium storing a program executable by a computer to perform processing comprising:
- acquiring wave data based on a wave detected by each of a plurality of sensors disposed at intervals according to a type of a wave source to be estimated;
- generating a spectrogram using the wave data, the spectrogram being a three-dimensional graph representing the wave detected by each of the plurality of sensor in a relationship of a time, a frequency, and an intensity;
- extracting Doppler shifts from the spectrogram, the Doppler shifts being temporal changes of frequencies extracted based on a peak having a maximum or greatest intensity in the spectrogram;
- selecting, as a sensor pair, two of the sensors that satisfy a preset selection condition for the Doppler shifts;
- and
- estimating a trajectory of the wave source, which is a source generating the wave, based on a positional relationship between the sensors constituting the sensor pair and a relationship of the Doppler shifts between the two sensors constituting the sensor pair, wherein
- in a case where a frequency of the wave is known in advance,
- generating a plurality of bases by shifting the frequency of the wave within a certain frequency width;
- deriving activation for the plurality of bases by non-negative matrix factorization;
- specifying a basis for which the activation has a maximum value, among the plurality of bases;
- and
- calculating, as the Doppler shifts, curves obtained by plotting the frequency of the basis at which the activation has the maximum value.
9 more elements
Dependencies are inferred from the claim text.