PURPOSE: To calculate a target control value with a small memory capacity by determining maximum and minimum control values and compensation coefficient with a pair of mapping and interpolation mapping for two variables and the third variable, and using a particular equation.
CONSTITUTION: In the engine control of a FFD vehicle, for example, an engine 10 is controlled by a controller 25. A control program, two three-dimensional mappings and respective control value calculation mapping are memorized in the memory circuit 40 of the controller 25. The most suitable ignition timing for air-fuel ratio and engine speed of two variables is memorized in the three- dimensional mapping for maximum and minimum values. The interpolation coefficient K based on the blend rate which is the third variable is calculated with interpolation mapping. A target control value D is calculated according to D=D0+(K/100)(D100-D0) as the most suitable blend rate from the maximum and minimum values D100, D0 of the blend rate by a control circuit 39 in the controller 25. It is thus possible to calculate the most suitable value with a small capacity memory.
YOKOYAMA TAKANAO
NANBA MUNEYOSHI
KATO YOSHIHIKO
IIDA KAZUMASA
MIYAMOTO KATSUHIKO
