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US 7,352,171 B2Granted
Paddlewheel speed correction
AssigneeAirmar Technology Corporation
InventorsStephen G. Boucher, Frederic S. Boericke, II
Life of this patent
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Abstract
A speed sensor for a marine vessel includes a correction circuit to correct any sensor non-linearities so that the sensor produces an output with a pulse stream having a constant pulse rate, and reduces the pulse-to-pulse variations of the pulse stream. The circuit can standardize the pulse stream to have a frequency corresponding to a standard rate.
Claims6
An apparatus comprising:
- a housing;
- a magnetized paddlewheel rotatably mounted in the housing;
- a magnetic sensor located adjacent to the paddlewheel which generates pulses at an actual rate which is non-linearly related to the true speed of a moving vessel to which it is attached;
- and
- a correction circuit that corrects for the non-linearities by performing a polynomial curve fit to transform the actual pulse rate to a corrected speed having a constant pulse rate substantially linearly related to the true speed of the vessel.
2 more elements
Dependencies are inferred from the claim text.