Flexible crank angle position sensing
AssigneeWoodward, Inc.
InventorsWayne Hawken, Doyle Kent Stewart
Life of this patent
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Abstract
A flexible crank angle position sensing device and data structure is provided. The device allows a user to enter specific data into a data structure relating to an encoder wheel used to determine the position of the crank shaft. The specific data is stored in the device and can be recalled for use in specific engine implementations. Furthermore, a user can enter data to describe other encoder wheels associated with a cam shaft of an engine. A data structure relating to a cam shaft encoder wheel relates to the data structure relating to the crank shaft encoder wheel such that various positional information, regarding both the cam shaft and crank shaft, can be detected by the device.
Claims23
A device for determining angular position of an encoder wheel associated with a crankshaft of an internal combustion engine, the device comprising:
- a first encoder wheel having a plurality of teeth;
- a first sensor arranged in proximity to said first encoder wheel for detecting a first pattern from the first encoder wheel;
- a memory for storing a first encoder wheel pattern data wherein the first encoder wheel pattern data describes the first pattern in data;
- a control unit comprising a pattern match block communicatively coupled to the first sensor and compares the first pattern and the first encoder wheel pattern data;
- wherein the first pattern contains at least one encoder key, and the first encoder wheel pattern data defines a data key that corresponds to the encoder key;
- wherein the at least one encoder key comprises at least one ratio, wherein the at least one ratio is a period of time of a most recent encoder tooth of the plurality of teeth of the first encoder wheel sensed by the sensor to a period of time of an encoder tooth of the plurality of teeth sensed by the sensor immediately prior the most recent encoder tooth sensed.
A method of determining angular position of an encoder wheel associated with a crankshaft of an internal combustion engine, the method comprising the steps of:
- selecting a first encoder wheel pattern data;
- wherein the first encoder wheel pattern data contains a first encoder wheel data key;
- sensing a first pattern from a first encoder wheel, the first encoder wheel including a plurality of teeth, using a sensor situated in proximity to the first encoder wheel, the sensor configured to detect at least one of a rising and falling edge of each tooth of the plurality of teeth of the first encoder wheel;
- wherein the first pattern contains a first encoder key that corresponds to the first encoder wheel data key, wherein the first encoder key comprises at least one ratio, wherein the at least one ratio is a period of time of a most recent encoder tooth of the first encoder wheel sensed by the sensor to a period of time of an encoder tooth sensed by the sensor immediately prior the most recent encoder tooth sensed;
- comparing the first pattern and the first encoder wheel pattern data;
- calculating an angular position of the first encoder wheel when the first encoder wheel data key matches the first encoder key of the first pattern.
Dependencies are inferred from the claim text.