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公开(公告)号:US11567167B2
公开(公告)日:2023-01-31
申请号:US16596323
申请日:2019-10-08
Applicant: Axis AB
Inventor: Johan Wennersten , Anders Lloyd
Abstract: A method for interference reduction in a stationary radar unit of a frequency-modulated continuous-wave (FMCW) type is provided. A sequence of beat signals is received, and a reference beat signal is calculated as an average or a median of one or more of the beat signals in the sequence. By comparing a difference between a beat signal and the reference beat signal, or a derivative of the difference, to one or more thresholds, a segment which is subject to interference is identified. The segment of the beat signal is replaced by one or more of a corresponding segment of an adjacent beat signal in the sequence, and a corresponding segment of the reference beat signal.
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公开(公告)号:US20170169306A1
公开(公告)日:2017-06-15
申请号:US14963792
申请日:2015-12-09
Applicant: Axis AB
Inventor: Jiandan Chen , Anders Lloyd , Niclas Danielsson
CPC classification number: G06K9/4647 , G06K9/46 , G06K9/6202
Abstract: A method may include determining a value indicative of an average intensity of blocks in an image. The blocks include a primary and outer blocks. Each of the outer blocks may have three, five, or more than five pixels. The image may describe an external pixel lying between the primary and at least one of the outer blocks. The external pixel may not contribute to the value indicative of the average intensity of any of the blocks. The image may also describe a common internal pixel lying within two of the blocks. The common pixel may contribute to the value indicative of the average intensity of the two of the blocks. The method may include comparing the value indicative of the average intensity of the primary block to the values of the outer blocks, and quantifying a feature represented by the image by generating a characteristic number.
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公开(公告)号:US12146981B2
公开(公告)日:2024-11-19
申请号:US18358215
申请日:2023-07-25
Applicant: Axis AB
Inventor: Anders Lloyd , Anders Mannesson , Bertil Roslund , Mattias Simonsson , Stefan Adalbjörnsson
Abstract: A TDM MIMO FMCW radar comprises an array of physical receivers with a first spacing in a first direction and a plurality of physical transmitters arranged with a second spacing in said first direction. A virtual array signal of a range-Doppler bin relating to a scene with a moving object is processed by a phase compensation method, which introduces a phase ambiguity between the subarrays. A positive or negative spatial phase change rate with respect to the first direction is computed based on elements of the compensated virtual array signal corresponding to one subarray at a time. From this, based on the spacings, a spatial phase change between a pair of the subarrays is predicted. Next, a residual phase shift between said pair of subarrays is determined by comparing an actual phase shift of the compensated virtual array signal and the predicted spatial phase shift.
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公开(公告)号:US20240103129A1
公开(公告)日:2024-03-28
申请号:US18446012
申请日:2023-08-08
Applicant: Axis AB
Inventor: Anders MANNESSON , Mattias Simonsson , Stefan Adalbjörnsson , Anders Lloyd , Bertil Roslund
Abstract: A TDM MIMO FMCW radar comprises an array of physical receivers with a first spacing in a first direction and a plurality of physical transmitters arranged with a second spacing in said first direction. A virtual array signal of a range-Doppler bin relating to a scene with a moving object is processed by a phase compensation method, which introduces a phase ambiguity between the subarrays. For each of the subarrays, a frequency spectrum is computed of those elements of the compensated virtual array signal which correspond to consecutive virtual antenna elements generated by physical receivers belonging to the same row. Next, an amplitude-peak frequency is identified jointly for the frequency spectra of the subarrays. Next, a residual phase shift between a pair of the subarrays is determined by comparing, at the amplitude-peak frequency, the respective phases of the frequency spectra.
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公开(公告)号:US09830528B2
公开(公告)日:2017-11-28
申请号:US14963792
申请日:2015-12-09
Applicant: Axis AB
Inventor: Jiandan Chen , Anders Lloyd , Niclas Danielsson
CPC classification number: G06K9/4647 , G06K9/46 , G06K9/6202
Abstract: A method may include determining a value indicative of an average intensity of blocks in an image. The blocks include a primary and outer blocks. Each of the outer blocks may have three, five, or more than five pixels. The image may describe an external pixel lying between the primary and at least one of the outer blocks. The external pixel may not contribute to the value indicative of the average intensity of any of the blocks. The image may also describe a common internal pixel lying within two of the blocks. The common pixel may contribute to the value indicative of the average intensity of the two of the blocks. The method may include comparing the value indicative of the average intensity of the primary block to the values of the outer blocks, and quantifying a feature represented by the image by generating a characteristic number.
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