Patent ID: 7178507

Claim:
A cylinder balance control system for an engine having control of fuel delivery to individual cylinders of the engine, the system comprising: a cylinder pressure sensor connected to each engine cylinder and operative to feed cylinder pressure information to a first computer and a second computer; the first computer being operative to compute and supply cylinder output information to an engine set-point for combining with a desired output value to obtain an output error signal; the second computer being operative to compute and supply cylinder combustion phasing information to a phasing set-point for combining with a desired phasing value to obtain a phasing error signal; first and second PI controllers connected to receive the output error signals and supply correlated output and phasing values, respectively, to first and second summation points; third and fourth PI controllers connected to receive the phasing error signals and supply correlated phasing and output values, respectively, to the first and second summation points; the first summation point being operative to combine output values from the first and fourth PI controllers and compare them with base fuel quantity signals to determine an adjusted fuel quantity for delivery to each respective engine cylinder; and the second summation point being operative to combine output values from the second and third PI controllers and compare them with base start of combustion timing signals to determine an adjusted timing for delivery of fuel into each respective engine cylinder.