Controller for homogenous charge compression ignition internal combustion engine

A controller for a homogeneous charge compression ignition internal combustion engine which includes a plurality of cylinders, and a fuel supply device capable of supplying respectively plural types of fuels with mutually different octane numbers to a combustion chamber in each of the plurality of cylinders and adjusting a supplied quantity of the respective plural types of fuels supplied to each of the plurality of cylinders, wherein a fuel-air mixture having a fuel supplied to the combustion chamber in each of the plurality of cylinders by the fuel supply device and air inhaled to the combustion chamber is ignited to make a combustion by compressing the fuel-air mixture, comprising:

• a combustion timing corresponded state value detection means for detecting a combustion timing corresponded state value which is a state value of a predefined type having a regular correlativity to a combustion timing of the fuel-air mixture for each cylinder;
• a desired state value setting means for setting a desired state value of the combustion timing corresponded state value for each cylinder according to a working state of the homogeneous charge compression ignition internal combustion engine;
• and
• a fuel supply control means for adjusting by using the fuel supply device a relative proportion of a supplied quantity of the respective plural types of fuels to each cylinder according to a deviation between the detected combustion timing corresponded state value and the desired state value set by the desired state value setting means so as to approximate the deviation to zero.