Automotive forward looking sensor blockage detection system and related techniques
First Claim
1. A Forward Looking Sensor (FLS) comprising:
- a transmit antenna for transmitting a first RF signal;
a receive antenna for receiving a second RF signal, said second RF signal including a portion of said first RF signal; and
a receiver circuit, coupled to said receive antenna, to determine whether any portion of the second RF signal corresponding to the first RF signal corresponds to a leakage signal and to use the portion of the second RF signal corresponding to the leakage signal to determine whether an antenna blockage exists.
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Accused Products
Abstract
An automotive Forward Looking Sensor (FLS) including a transmit antenna, a receive antenna and a receiver circuit for determining whether RF leakage from the transmit antenna to the receive antenna exceeds a predetermined threshold level. If the leakage exceeds the predetermined threshold level, then the antenna is blocked, as may be caused by mud, salt, ice, etc. In one embodiment, the received RF signal is processed by a digital signal processor performing a Fast Fourier Transform (FFT) and the energy content of the received RF signal within a predetermined range of frequencies corresponding to approximately zero Doppler is assessed to determine whether such energy content exceeds the predetermined threshold level.
73 Citations
19 Claims
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1. A Forward Looking Sensor (FLS) comprising:
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a transmit antenna for transmitting a first RF signal; a receive antenna for receiving a second RF signal, said second RF signal including a portion of said first RF signal; and a receiver circuit, coupled to said receive antenna, to determine whether any portion of the second RF signal corresponding to the first RF signal corresponds to a leakage signal and to use the portion of the second RF signal corresponding to the leakage signal to determine whether an antenna blockage exists. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for detecting antenna blockage in a Doppler radar system having a transmit antenna and a separate receive antenna, the method comprising the steps of:
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(a) transmitting a first RF signal with the transmit antenna; (b) receiving a second RF signal with the receive antenna, said second RF signal comprising a portion of said first RF signal; (c) determining whether any portion of said second RF signal corresponds to a leakage signal; and (d) comparing the energy level of the leakage signal portion of said second RF signal to a predetermined leakage signal threshold level. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A Forward Looking Sensor (FLS) comprising:
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a transmit antenna for transmitting a first RF signal; a receive antenna for receiving a second RF signal, said second RF signal comprising an RF signal reflection portion comprising signal reflections from objects within a field of view of the transmit antenna and a leakage portion comprising RF energy from said first RF signal; a digital signal processor responsive to said second RF signal for computing a Fourier Transform of said second RF signal to provide a plurality of output signals, each one representative of energy content of said second RF signal within a corresponding range of frequencies, wherein a first one of said plurality of output signals is representative of the energy content of said second RF signal in a range of frequencies corresponding to approximately zero Doppler; and a threshold detection circuit for comparing the amplitude of said first one of said plurality of output signals of said digital signal processor with a predetermined threshold level, wherein blockage of at least one of said transmit antenna and said receive antenna is indicated by said first one of said plurality of output signals exceeding said predetermined threshold level. - View Dependent Claims (17, 18, 19)
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Specification