Method for reducing computational time for calculating a noise-filtered average approximation of throttle position

A method for calculating an approximate value of a running average value of a process output from a plurality of sample values taken at a plurality of time intervals during operation of the process, comprising:

• a) calculating a value of said process output by summing a predetermined number of said sample values taken over a predetermined period of time to provide a current sum, and dividing said current sum by said predetermined number to provide a current filtered output value, said predetermined number of sample values defining a queue of said sample values;
• b) storing said queue of sample values in chronological order;
• c) storing said current sum as a most-recent sum for retrieval;
• d) storing said current filtered output value as a most-recent filtered output value for retrieval;
• e) taking a new sample value at a time interval after said predetermined period of time;
• f) retrieving said stored most-recent sum;
• g) retrieving said stored most-recent filtered output value;
• h) calculating a new current sum from said most-recent sum by:
• subtracting the oldest value of said sample values,
• subtracting said most-recent filtered output value, and
• adding twice the value of said new sample value;
• i) calculating a new filtered output value, defining said approximate value of a running average value, by dividing said new current sum by said predetermined number of sample values in said queue.

A system for obtaining an approximate value of a running average throttle position value from a plurality of sample throttle position values taken at a plurality of time intervals during operation of an engine, wherein said plurality of sample throttle position values includes an oldest sample throttle position value, the system comprising:

• a storage device operative to store said sample throttle position values taken over a predetermined period of time;
• and
• a processor programmed to:
• calculate a value of said throttle position by summing a predetermined number of said sample throttle position values stored in said storage device to provide a first sum, and dividing said first sum by said predetermined number to provide a first filtered output value;
• obtain a new sample throttle position value at a time interval after said predetermined period of time;
• calculate a second sum from said first sum by:
• subtracting the oldest sample throttle position value,
• subtracting said first filtered output value, and
• adding twice the value of said new sample throttle position value;
• calculate a second filtered output value by dividing said second sum by said predetermined number of said sample throttle position values,
• wherein said second sum represents the approximate value of the running average throttle position value.

A computer-readable medium having computer-executable instructions for performing a method for calculating an approximate value of a running average throttle position value from a plurality of sample throttle position values taken at a plurality of time intervals during operation of an engine, wherein said plurality of sample throttle position values includes an oldest sample throttle position value, the method comprising:

• calculating a value of said throttle position by summing a predetermined number of said sample throttle position values taken over a predetermined period of time to provide a first sum, and dividing said first sum by said predetermined number to provide a first filtered output value;
• obtaining a new sample throttle position value at a time interval after said predetermined period of time;
• calculating a second sum from said first sum by:
• subtracting the oldest sample throttle position value,
• subtracting said first filtered output value, and adding twice the value of said new sample throttle position value;
• calculating a second filtered output value by dividing said second sum by said predetermined number of said sample throttle position values, wherein said second sum represents the approximate value of the running average throttle position value.