Homogeneous charge compression ignition engine and method for operating homogeneous charge compression ignition engine

A method for controlling a homogeneous charge compression ignition engine including a combustion chamber retaining a piston that compresses a mixture of fuel and oxygen-containing gas to ignite the compressed mixture, in which reciprocation of the piston is converted to rotation of an output shaft, and an intake air temperature adjustor for heating the drawn in oxygen-containing gas and/or mixture, the method comprising:

• determining the air-fuel ratio or the engine load;
• determining whether or not the air-fuel ratio or the engine load is changing in such a manner that there is a possibility of knocking occurring by using a first map or first relationship formula that defines a first range, in which stable homogeneous charge compression ignition operation is enabled, in relation with the air-fuel ratio or engine load and the intake air temperature;
• controlling the intake air temperature adjustor to decrease the intake air temperature based on the first map or the first relationship formula when there is a possibility of knocking occurring;
• determining whether or not the air-fuel ratio or the engine load is changing in such a manner that there is a possibility of misfires occurring by using the first map or first relationship formula;
• and
• controlling the intake air temperature adjustor to increase the intake air temperature based on the first map or the first relationship formula when there is a possibility of misfires occurring.