| 摘要 |
An arrangement and a method for controlling a combustion engine, e.g. of the type called HCCI engine. A control unit is operable for controlling the self-ignition of the fuel mixture towards an optimum crankshaft angle (cad<SUB>iopt</SUB>) within a load range (L<SUB>tot</SUB>). The load range (L<SUB>tot</SUB>) can be divided into at least two subranges (L<SUB>II</SUB>, L<SUB>III</SUB>). The control unit is operable to controlling the self-ignition of the fuel mixture towards an optimum crankshaft angle (cad<SUB>iopt</SUB>) within one of the subranges (L<SUB>II</SUB>) by a strategy (II) which entails the effective compression ratio (c) in the cylinder being varied, and within the second subrange (L<SUB>III</SUB>) by another strategy (III) which entails a variable amount of cooled exhaust gases (ceg) being led to the combustion chamber also enabling in the second subrange (L<SUB>III</SUB>) to control the self-ignition of the fuel mixture towards an optimum crankshaft angle (cad<SUB>iopt</SUB>) by variation of the effective compression ratio (c) in the cylinder without it falling below a lowest acceptable value (C<SUB>min</SUB>). |
