Method for acoustic distance time of flight compensation
AssigneeSemiconductor Components Industries, LLC
InventorsTomas Suchy, Marek Hustava
Life of this patent
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Abstract
In one form, a method for acoustic distance measurement includes generating an acoustic signal with an acoustic transducer at a first time. A pulse is detected with the acoustic transducer in response to the acoustic signal encountering an obstacle within a predetermined distance. Detecting the pulse includes detecting a second time relative to the first time when a magnitude of the pulse rises above a predetermined threshold, and detecting a peak magnitude of the pulse. A correction ratio is determined as a ratio of the predetermined threshold to the peak magnitude of the pulse. A correction time is determined in response to the correction ratio. A corrected time-of-flight is determined by adjusting the second time by the compensation time.
Claims20
A method comprising:
- generating an acoustic signal for an acoustic transducer at a first time, wherein the acoustic transducer transmits the acoustic signal to determine a first position of an obstacle;
- detecting a pulse at the acoustic transducer in response to the acoustic signal encountering the obstacle within a predetermined distance;
- detecting a second time in response to a rising edge of the pulse intersecting a determined threshold, the determined threshold having a first magnitude;
- detecting a peak magnitude of the pulse;
- and
- determining a time of flight of the acoustic signal within the predetermined distance by extracting a compensation time from a correction look up table in response to detecting the first magnitude and the peak magnitude, and subtracting the compensation time from the second time to determine the time of flight, wherein the determining comprises determining a correction ratio of the determined threshold to the peak magnitude of the pulse, and wherein the correction look up table determines the compensation time corresponding to the correction ratio.
A method for acoustic distance measurement, comprising:
- generating an acoustic signal with an acoustic transducer at a first time;
- detecting a pulse with the acoustic transducer in response to the acoustic signal encountering an obstacle within a predetermined distance, wherein detecting the pulse comprises:
- detecting a second time relative to the first time when a magnitude of the pulse rises above a predetermined threshold, and
- detecting a peak magnitude of the pulse;
- determining a correction ratio as a ratio of the predetermined threshold to the peak magnitude of the pulse;
- determining a compensation time in response to the correction ratio;
- and
- determining a corrected time of flight by subtracting the compensation time from the second time.
Dependencies are inferred from the claim text.