Scania Cv Ab (publ)

Fredrik Agrell

Johan Linderyd

An arrangement, a computer-readable medium and a method for controlling an HCCI (homogenous charge compression ignition) engine are disclosed. The arrangement comprises a control unit for initiating closure and/or opening of the inlet valve and/or the exhaust valve at a current crankshaft angle in such a way that self-ignition of the fuel mixture occurs when the crankshaft is at a target crankshaft angle. The arrangement comprises cards for storing relevant values of the current crankshaft angle as a function of at least one operation-related parameter such as engine speed, temperature and pressure, and an estimator estimating values of the operation-related parameter during operation of the combustion engine. The control unit can adjust the inlet valve and/or the exhaust valve depending on the stored value of the current crankshaft angle.

Arrangement and method for controlling a combustion engine

An arrangement and a method for controlling a combustion engine, e.g. of the type called HCCI engine. A control unit for controlling the self-ignition of the fuel mixture towards an optimum crankshaft angel (cad) within a load range (L). The load range (L) can be divided into at least two subranges (L, L) and the control unit is adapted to controlling the self-ignition of the fuel mixture towards an optimum crankshaft angle (cad) within a first subrange (L) by means of a strategy (I) which entails a variable amount of hot exhaust gases being supplied to or retained in the combustion chamber, and within a second subrange (L) by means of another strategy (II) which entails the effective compression ratio (c) in the cylinder being varied.

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) within a load range (L). The load range (L) can be divided into at least two subranges (L, L). The control unit is operable to controlling the self-ignition of the fuel mixture towards an optimum crankshaft angle (cad) within one of the subranges (L) by a strategy (II) which entails the effective compression ratio (c) in the cylinder being varied, and within the second subrange (L) 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) to control the self-ignition of the fuel mixture towards an optimum crankshaft angle (cad) by variation of the effective compression ratio (c) in the cylinder without it falling below a lowest acceptable value (C).

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Älvsjö, Sweden

Fredrik Agrell