Abstract: An apparatus and methods for effectively determining the start of combustion in a cylinder of an internal combustion engine where the start of combustion is calculated by obtaining cylinder pressure data (P), processing the cylinder pressure data (P) into a processed pressure value indicative of the occurrence of SOC, comparing the processed pressure value to a predetermined threshold value, if the processed pressure value crosses the predetermined threshold value, determining that SOC has occurred, and calculating a crank shaft location at which the predetermined threshold value was crossed by the processed pressure value thereby identifying the crank shaft location at which SOC occurred. In alternative embodiments, optional steps may be provided including a verification step, a windowing step, a filtering step, determining occurrence of misfire, and determining occurrence of retarded timing.

Abstract: A multi-mode internal combustion engine and method of operating the engine is provided which is capable of operating in a variety of modes based on engine operating conditions to enhance fuel efficiency and reduce emissions. The multi-mode engine include a fuel delivery system and control system for permitting the engine to operate in a diesel mode, a homogeneous charge dual fuel transition mode, a spark ignition or liquid spark ignition mode and/or a premixed charge compression ignition mode. The control system and method permits the engine operation to transfer between the various modes in an effective and efficient manner by controlling one or more fuel delivery devices or other engine components so as to move along a continuous transfer path while maintaining engine torque at a substantially constant level.

Abstract: A system is provided for limiting engine exhaust temperature to a maximum temperature limit. The system is operable to limit either a first or a second fueling parameter in accordance with an engine exhaust temperature estimation model. An engine exhaust temperature-limited fueling command is computed from the respective fueling parameter, and fuel supplied to the engine is limited thereby in order to maintain the actual engine exhaust temperature below the maximum temperature limit. In one embodiment, the engine exhaust temperature model is based on current values of engine speed, intake manifold temperature, mass charge flow, default fuel command parameters, and a first set of model constants. In an alternative embodiment, the engine exhaust temperature model is based on current values of engine speed, intake manifold temperature, intake manifold pressure, mass charge flow, default fueling parameters, and a second set of model constants including a lower heating value of fuel constant.

Abstract: A system is provided for estimating engine exhaust temperature in accordance with an exhaust temperature model based on a number of engine operating parameters. In one embodiment, the engine exhaust temperature model is based on current values of engine speed, intake manifold temperature, mass charge flow, default fuel command parameters, and a first set of model constants. In an alternative embodiment, the engine exhaust temperature model is based on current values of engine speed, intake manifold temperature, intake manifold pressure, mass charge flow, default fueling parameters, and a second set of model constants including a lower heating value of fuel constant.

Abstract: An apparatus and methods for effectively determining the start of combustion in a cylinder of an internal combustion engine where the start of combustion is calculated by obtaining cylinder pressure data (P), processing the cylinder pressure data (P) into a processed pressure value indicative of the occurrence of SOC, comparing the processed pressure value to a predetermined threshold value, if the processed pressure value crosses the predetermined threshold value, determining that SOC has occurred, and calculating a crank shaft location at which the predetermined threshold value was crossed by the processed pressure value thereby identifying the crank shaft location at which SOC occurred. In alternative embodiments, optional steps may be provided including a verification step, a windowing step, a filtering step, determining occurrence of misfire, and determining occurrence of retarded timing.

Abstract: A charge limit manager arbitrates between desired EGR system and/or turbocharger behavior and the actual capabilities of EGR system and/or turbocharger control mechanisms under current operating conditions. In one embodiment, the charge limit manager includes three limiter blocks producing offset signals as separate functions of turbocharger compressor outlet temperature, turbocharger speed and pressure differential (&Dgr;P) across an EGR valve. A charge limit selector block is responsive to the offset values produced thereby, and also to commanded values of charge flow and EGR fraction as well as operating values of EGR valve position and &Dgr;P, to limit the charge flow and EGR fraction commands to controllable values. These values are preferably subtracted from actual or estimated values of charge flow and EGR fraction to produce charge flow and EGR fraction error values for use in controlling one or more EGR system and/or turbocharger swallowing capacity/efficiency control mechanisms.

Abstract: A system is provided for estimating engine exhaust temperature in accordance with an exhaust temperature model based on a number of engine operating parameters. In one embodiment, the engine exhaust temperature model is based on current values of engine speed, intake manifold temperature, mass charge flow, default fuel command parameters, and a first set of model constants. In an alternative embodiment, the engine exhaust temperature model is based on current values of engine speed, intake manifold temperature, intake manifold pressure, mass charge flow, default fueling parameters, and a second set of model constants including a lower heating value of fuel constant.

Abstract: A closed-loop actuator control system includes a single PI controller for controlling one or more actuators to minimize an error between an engine operating parameter value and a reference parameter value. In multiple actuator systems, the control system of the present invention is operable to drive one actuator to its upper limit before transferring control to the next actuator. The proportional gain block of the PI controller preferably includes a bumpless gain feature operable to limit the rate of change of the proportional gain to thereby provide smooth gain scheduling. A feedforward block may optionally be included that preferably includes the bumpless gain feature. The actuator control system further includes anti-windup logic operable to disable the PI integrator if the actuator drive signal is upper or lower limit bounded and the error signal is greater or less than zero respectively, thereby creating dynamic saturation of the PI integrator.

Abstract: A charge limit manager arbitrates between desired EGR system and/or turbocharger behavior and the actual capabilities of EGR system and/or turbocharger control mechanisms under current operating conditions. In one embodiment, the charge limit manager includes three limiter blocks producing offset signals as separate functions of turbocharger compressor outlet temperature, turbocharger speed and pressure differential (&Dgr;P) across an EGR valve. A charge limit selector block is responsive to the offset values produced thereby, and also to commanded values of charge flow and EGR fraction as well as operating values of EGR valve position and &Dgr;P, to limit the charge flow and EGR fraction commands to controllable values. These values are preferably subtracted from actual or estimated values of charge flow and EGR fraction to produce charge flow and EGR fraction error values for use in controlling one or more EGR system and/or turbocharger swallowing capacity/efficiency control mechanisms.

Abstract: A system is disclosed for estimating the mass flow of recirculated exhaust gas (EGR) from an exhaust manifold to an intake manifold of an internal combustion engine via an EGR conduit disposed therebetween and a fraction of EGR attributable to a mass of charge flow entering the intake manifold. An engine controller is responsive to current values of various combinations of the engine exhaust temperature (ETE), intake manifold pressure (IMP), differential pressure (&Dgr;P) across an EGR valve, and EGR valve position (EGRP) to determine an estimate of EGR mass flow. The controller is further operable to estimate EGR fraction as a function of the estimated EGR mass flow value, mass flow of charge entering the intake manifold, and engine speed.

Abstract: A closed-loop actuator control system includes a single PI controller for controlling one or more actuators to minimize an error between an engine operating parameter value and a reference parameter value. In multiple actuator systems, the control system of the present invention is operable to drive one actuator to its upper limit before transferring control to the next actuator. The proportional gain block of the PI controller preferably includes a bumpless gain feature operable to limit the rate of change of the proportional gain to thereby provide smooth gain scheduling. A feedforward block may optionally be included that preferably includes the bumpless gain feature. The actuator control system further includes anti-windup logic operable to disable the PI integrator if the actuator drive signal is upper or lower limit bounded and the error signal is greater or less than zero respectively, thereby creating dynamic saturation of the PI integrator.

Abstract: An electric power generation system is disclosed, which includes a back-up electric power generator driven by a four-cycle internal combustion engine. The engine includes a plurality of reciprocating cylinders each rotatably coupled to a crankshaft, which drives the electric power generator. The engine also includes a compressor along an intake pathway to deliver pressurized air to the cylinders and a turbine along an exhaust pathway to power the compressor when driven by exhaust discharged from the cylinders. The engine is prepared to accept a generator load by increasing boost pressure provided by the compressor. This increase is accomplished by skip-firing the cylinders in a selected pattern, retarding ignition timing for the cylinders, or a combination of these techniques. A unique skip-fueling control pattern is also disclosed.

Abstract: A multi-mode internal combustion engine and method of operating the engine is provided which is capable of operating in a variety of modes based on engine operating conditions to enhance fuel efficiency and reduce emissions. The multi-mode engine include a fuel delivery system and control system for permitting the engine to operate in a diesel mode, a homogeneous charge dual fuel transition mode, a spark ignition or liquid spark ignition mode and/or a premixed charge compression ignition mode. The control system and method permits the engine operation to transfer between the various modes in an effective and efficient manner by controlling one or more fuel delivery devices or other engine components so as to move along a continuous transfer path while maintaining engine torque at a substantially constant level.