Abstract: A system includes first, second, and third microphones configured to receive sound waves from a source of the sound waves. The system includes a memory configured to store first, second, and third phase difference maps for the first and second microphones, the second and third microphones, and the third and first microphones. The system includes a processor configured to measure first, second, and third phase differences between the sound waves received from the source by the first and second microphones, the second and third microphones, and the third and first microphones; receive the first, second, and third phase difference maps from the memory; and identify a location of the source of the sound waves based on the first, second, and third phase differences and the first, second, and third phase difference maps for the first and second microphones, the second and third microphones, and the third and first microphones.

Abstract: A system includes first, second, and third microphones configured to receive sound waves from a source of the sound waves. The system includes a memory configured to store first, second, and third phase difference maps for the first and second microphones, the second and third microphones, and the third and first microphones. The system includes a processor configured to measure first, second, and third phase differences between the sound waves received from the source by the first and second microphones, the second and third microphones, and the third and first microphones; receive the first, second, and third phase difference maps from the memory; and identify a location of the source of the sound waves based on the first, second, and third phase differences and the first, second, and third phase difference maps for the first and second microphones, the second and third microphones, and the third and first microphones.

Abstract: A system according to the present disclosure includes a first crank angle module, a second crank angle module, and a spark control module. The first crank angle module determines a first crank angle of an engine at which a predetermined percentage of fuel in a first cylinder of the engine is combusted based on pressure in the first cylinder. The second crank angle module determines a relationship between the first crank angle and a second crank angle of the engine at which the predetermined percentage of fuel in a second cylinder of the engine is combusted based on pressure in the first cylinder and pressure in the second cylinder. The spark control module adjusts spark timing of the first cylinder based on the first crank angle, and adjusts spark timing of the second cylinder based on the relationship between the first and second crank angles.

Abstract: A method for controlling an internal combustion engine that includes sensing a characteristic of combustion in a cylinder of the engine, generating a combustion characteristic signal from the sensed characteristic, performing a principal component analysis on the combustion characteristic signal and a predetermined combustion characteristic trace to determine first mode coefficients for the combustion characteristic signal and the predetermined combustion characteristic trace, determining a difference between the first mode coefficient of the combustion characteristic signal and the first mode coefficient of the predetermined combustion characteristic trace, and controlling the internal combustion engine based upon the difference.

Abstract: A method for controlling an internal combustion engine that includes sensing a characteristic of combustion in a cylinder of the engine, generating a combustion characteristic signal from the sensed characteristic, performing a principal component analysis on the combustion characteristic signal and a predetermined combustion characteristic trace to determine first mode coefficients for the combustion characteristic signal and the predetermined combustion characteristic trace, determining a difference between the first mode coefficient of the combustion characteristic signal and the first mode coefficient of the predetermined combustion characteristic trace, and controlling the internal combustion engine based upon the difference.

Abstract: A system according to the present disclosure includes a first crank angle module, a second crank angle module, and a spark control module. The first crank angle module determines a first crank angle of an engine at which a predetermined percentage of fuel in a first cylinder of the engine is combusted based on pressure in the first cylinder. The second crank angle module determines a relationship between the first crank angle and a second crank angle of the engine at which the predetermined percentage of fuel in a second cylinder of the engine is combusted based on pressure in the first cylinder and pressure in the second cylinder. The spark control module adjusts spark timing of the first cylinder based on the first crank angle, and adjusts spark timing of the second cylinder based on the relationship between the first and second crank angles.