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US 10,520,480 B2Granted
Deconvolution method for emissions measurement
AssigneeAvl Test Systems, Inc.
InventorFrank Berghof
Life of this patent
Estimating the term…
Abstract
Disclosed is a method of correcting a response of an instrument. The method includes determining an inverse convolution function, the inverse convolution function being in the time domain. A response of an instrument to an exhaust sample is recorded as a function of time. The recorded response is then convolved with the inverse convolution function, the result being a convolution corrected instrument response.
Claims20
A system comprising:
- an emissions measurement instrument configured to:
- measure a concentration of an emission in a sample of exhaust gas from an engine;
- and
- generate an uncorrected instrument response indicating the measured emission concentration as a function of time;
- memory configured to:
- record the uncorrected instrument response;
- and
- store an inverse convolution function, wherein the inverse convolution function is in the time domain and represents an inverse of the transient response of the emissions measurement instrument;
- and
- a processor configured to:
- retrieve the uncorrected instrument response and the inverse convolution function from the memory;
- convolve the uncorrected instrument response with the inverse convolution function to mitigate the effect of the transient response of the emissions measurement instrument on the uncorrected instrument response, the result of the convolution being a convolution corrected instrument response;
- and
- output a signal indicating the convolution corrected instrument response.
11 more elements
A system comprising:
- an emissions measurement instrument configured to measure a concentration of an emission in a reference gas sample;
- memory configured to:
- record a response of the emissions measurement instrument to the reference gas sample as a function of time;
- and
- store an idealized convolution function, the idealized convolution function being in the time domain and representing the transient response of an the emissions measurement instrument;
- and
- a processor configured to:
- retrieve the idealized convolution function from the memory;
- transform the idealized convolution function from the time domain to the frequency domain;
- divide a regularizing filter function by the transformed idealized convolution function, the result of the division being an inverse convolution function in the frequency domain;
- transform the inverse convolution function from the frequency domain to the time domain using the processor;
- output a signal indicating the inverse convolution function in the time domain, wherein the memory is configured to store the inverse convolution function in the time domain;
- convolve the recorded response with the transformed inverse convolution function to mitigate the effect of the transient response of the emissions measurement instrument on the recorded response, the result of the convolution being a convolution corrected instrument response indicating the measured emission concentration;
- and
- generate a signal indicating the convolution corrected instrument response.
12 more elements
Dependencies are inferred from the claim text.