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US 9,429,096 B2Granted
Predictive modeling and reducing cyclic variability in autoignition engines
AssigneesRobert Bosch GmbH, The Regents of the University of Wisconsin
InventorsErik Hellstrom, Anna Stefanopoulou, Li Jiang, Jacob Larimore
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Abstract
Methods and systems are provided for controlling a vehicle engine to reduce cycle-to-cycle combustion variation. A predictive model is applied to predict cycle-to-cycle combustion behavior of an engine based on observed engine performance variables. Conditions are identified, based on the predicted cycle-to-cycle combustion behavior, that indicate high cycle-to-cycle combustion variation. Corrective measures are then applied to prevent the predicted high cycle-to-cycle combustion variation.
Claims19
A method of controlling a vehicle engine to reduce cycle-to-cycle combustion variation, the method comprising:
- applying a predictive model to predict cycle-to-cycle combustion behaviour of an engine based on observed engine performance variables;
- identifying conditions that indicate high cycle-to-cycle combustion variation based on the predicted cycle-to-cycle combustion behaviour;
- and
- applying corrective measures to prevent the predicted high cycle-to-cycle combustion variation,
- wherein applying a predictive model to predict cycle-to-cycle combustion behaviour of an engine includes:
- applying a predictive model based on temperature of an engine cylinder and a cylinder charge composition at the end of a combustion cycle.
3 more elements
A method of controlling a vehicle engine to reduce cycle-to-cycle combustion variation, the method comprising:
- applying a predictive model to predict cycle-to-cycle combustion behaviour of an engine based on observed engine performance variables;
- identifying conditions that indicate high cycle-to-cycle combustion variation based on the predicted cycle-to-cycle combustion behaviour;
- and
- applying corrective measures to prevent the predicted high cycle-to-cycle combustion variation,
- determining a set of one or more engine operating conditions;
- comparing the set of one or more engine operating conditions to a set of defined operating regions;
- operating the engine in a spark ignition mode when the set of one or more engine operating conditions is within a first defined operating region;
- and
- operating the engine in a homogenous charge compression ignition mode when the set of one or more engine operating conditions is within a second defined operating region,
- wherein the acts of applying the predictive model, identifying conditions that indication high cycle-to-cycle combustion variation, and applying corrective measures are performed when transitioning from the spark ignition mode to the homogenous charge compression ignition mode.
7 more elements
A method of controlling a vehicle engine to reduce cycle-to-cycle combustion variation, the method comprising:
- determining a set of one or more engine operating conditions;
- comparing the set of one or more engine operating conditions to a set of defined operating regions;
- operating the engine in a spark ignition mode when the set of one or more engine operating conditions is within a first defined operating region;
- operating the engine in a homogenous charge compression ignition mode when the set of one or more engine operating conditions is within a second defined operating region;
- and
- when transitioning from the spark ignition mode to the homogeneous charge compression ignition mode,
- applying a predictive model to predict at least one of a combustion phasing and a mean effective pressure value of an engine cylinder for each of a plurality of future combustion cycles based, at least in part, on a determined cylinder temperature and a determined amount of unburned fuel remaining in a cylinder after a current combustion cycle is complete,
- identifying variations in the at least one of the combustion phasing and the predicted mean effective pressure values for the cylinder which indicate high cycle-to-cycle combustion variation, and
- adjusting at least one of an injected fuel quantity and a fuel injection timing for a subsequent combustion cycle to prevent the predicted high cycle-to-cycle combustion variation.
6 more elements
A method of controlling a vehicle engine to reduce cycle-to-cycle combustion variation, the method comprising:
- determining a set of one or more engine operating conditions;
- comparing the set of one or more engine operating conditions to a set of defined operating regions;
- determining that the engine is operating in a stable HCCI region when the set of one or more operating conditions is within a first defined operating region, wherein the engine is unlikely to exhibit high cycle-to-cycle combustion variation in the stable HCCI region;
- determining that the engine is operating in an unstable HCCI region when the set of one or more operating conditions is within a second defined operating region, wherein the engine is more likely to exhibit high cycle-to-cycle combustion variation in the unstable HCCI region as compared to the stable HCCI region;
- and
- when it is determined that the engine is operating in the unstable HCCI region,
- applying a predictive model to predict at least one of a combustion phasing and a mean effective pressure value of an engine cylinder for each of a plurality of future combustion cycles based, at least in part, on a determined cylinder temperature and a determined amount of unburned fuel remaining in a cylinder after a current combustion cycle is complete,
- identifying variations in the at least one of the combustion phasing and the predicted mean effective pressure values for the cylinder which indicate high cycle-to-cycle combustion variation, and
- adjusting at least one of an injected fuel quantity and a fuel injection timing for a subsequent combustion cycle to prevent the predicted high cycle-to-cycle combustion variation.
6 more elements
Dependencies are inferred from the claim text.