Abstract: A method for controlling an engine having multiple banks with separate catalysts is described. In particular, coordinate lean and rich operation between the banks is utilized. However, termination of rich operation may be different between the banks to prevent breakthrough of rich exhaust gasses due to lack of stored oxidants. In this situation, the bank that terminated rich operation is operated near stoichiometric. This minimizes breakthrough of emissions, while at the same time minimizing a torque imbalance between the cylinder banks. In particular, the torque imbalance can be further minimized by retarding ignition timing on the rich bank while the other operates near stoichiometry.

Abstract: A system and method for braking a vehicle 12 having a variable compression ratio engine 14 and a compression braking system 16. System 10 is adapted to utilize the variable compression ratio engine 14 and the compression braking system 16 in a synergistic manner to selectively control and/or vary the generated compression braking torque.

Abstract: A method of operating a variable compression, direct injection spark ignited internal combustion engine includes the steps of determining a demanded torque output of the engine, determining a current combustion mode and a current compression ratio mode of the engine; transitioning operation of the engine from the current combustion mode to a new combustion mode to produce the demanded torque output, and transitioning operation of the engine from the current compression ratio mode to a new compression ratio mode so as to minimize torque disturbances during the transitioning of engine operation from the current combustion mode to the new combustion mode.

Abstract: The air flow into an engine is estimated via a speed-density calculation wherein the volumetric efficiency is estimated on-line. There are three interconnected observers in the estimation scheme. The first observer estimates the flow through the throttle based on the signal from a mass air flow sensor (MAF). The second observer estimates the intake manifold pressure using the ideal gas law and the signal from a intake manifold absolute pressure sensor (MAP). The third observer estimates the volumetric efficiency and provides an estimate of the air flow into the engine.

Abstract: A system and method for braking a vehicle 12 having a variable compression ratio engine 14 and a compression braking system 16. System 10 is adapted to utilize the variable compression ratio engine 14 and the compression braking system 16 in a synergistic manner to selectively control and/or vary the generated compression braking torque.

Abstract: A method of controlling valve landing in a camless engine including a valve movable between fully open and fully closed positions, and an electromagnetic valve actuator for actuating the valve is provided. The method includes providing at least one discrete position measurement sensor to determine when the valve is at a particular position during valve movement. The velocity of the valve is calculated at the particular position based upon current and rate of change of current in the electromagnetic valve actuator when the valve is at the particular position. Valve landing is controlled based upon the calculated velocity.

Abstract: A torque control system for a lean burn engine utilizing a supplemental torque apparatus that is operable during the engine mode transition from a lean air/fuel ratio to a rich air/fuel ratio. The supplemental torque apparatus 34, STA, operates to maintain the basic engine torque equation: Te+Tsta=Td such that the device or a electrically connected battery 38 absorbs extra engine torque during a predetermined time period and generates engine torque at times other than the predetermined time period. During the predetermined time period, a Lean NOx Trap 26 in the exhaust system is purged.

Abstract: A control method for an internal combustion engine has multiple cylinder groups with at least one control device positioned between an intake manifold and a cylinder group. The engine operates the cylinder groups at different air/fuel ratios and uses the control device to balance torque produced by the different cylinder groups. In one aspect of the invention, one cylinder group is operated rich and another cylinder group is operated lean thereby providing heat the an exhaust system located downstream of the engine.

Abstract: A control method and system are disclosed for managing torque during a transition in an internal combustion engine. Spark timing and unequal delivery of fuel to engine cylinders both impact torque and are used to provide smooth torque during a transition.

Abstract: A control method for an internal combustion engine has multiple cylinder groups with at least one control device positioned between an intake manifold and a cylinder group. The engine operates the cylinder groups at different air/fuel ratios and uses the control device to balance torque produced by the different cylinder groups. In one aspect of the invention, one cylinder group is operated rich and another cylinder group is operated lean thereby providing heat to an exhaust system located downstream of the engine.

Abstract: An automobile cylinder balancing assembly 10 including a controller 36 which operates under stored program control and which substantially ensures that the torque produced by each of the cylinders 12, 14 is substantially equal, thereby causing the cylinders 12, 14 to be selectively balanced.

Abstract: A method of reducing turbo lag in a compression ignition engine having an exhaust gas recirculation system (EGR) and a variable geometry turbocharger (VGT). The method includes the steps of determining an intake manifold pressure and intake manifold mass airflow setpoint, MAPd and MAFd, as a function of the current engine speed and requested fueling rate (Wf,REQ). The method further includes modifying the setpoints by a transient governor to generate modified setpoints, MAFc and MAPc, as a function of MAFd and MAPd, respectively, and feeding the modified setpoints to the controller to drive the turbocharger and EGR valve to the desired setpoints, thereby maximizing the amount of fresh air admitted to the engine during transient operation. Another embodiment of the method for reducing turbo lag coordinates the controller gains between the EGR and VGT. The method speeds up the MAF response by using multivariable control of both the EGR and VGT to aggressively regulate airflow to the desired setpoint.

Abstract: A method of controlling the fueling rate of a compression ignition engine having an exhaust gas recirculation system (EGR) and a turbocharger. The method includes the steps of predicting the exhaust gas air/fuel ratio as a function engine operating characteristics and the operator-requested fueling rate. This value is compared to an air/fuel limit value stored in a table of values indexed by engine operating characteristics. The air/fuel limit is the value below which visible smoke occurs. The predicted air/fuel ratio is compared to the air/fuel ratio limit and either (1) the fuel is delivered at the requested rate, (2) the start of injection timing is modified and the fuel is delivered at the requested rate or (3) the fueling rate is limited as a function of the requested fueling rate and measured or determined engine operating parameters.

Abstract: A torque control system for a lean burn engine utilizing a supplemental torque apparatus that is operable during the engine mode transition from a lean air/fuel ratio to a rich air/fuel ratio. The supplemental torque apparatus 34, STA, operates to maintain the basic engine torque equation T.sub.e +T.sub.sta =T.sub.d, such that the device or a electrically connected battery 38 absorbs extra engine torque during a predetermined time period and generates engine torque at times other than the predetermined time period. During the predetermined time period, a lean NOx Trap 26 in the exhaust system is purged.

Abstract: A method of estimating the actuator position of a variable geometry turbocharger (VGT) of a compression ignition engine having an exhaust gas recirculation (EGR) system. The method includes the steps of determining the exhaust manifold temperature (T.sub.2), determining the mass flow rate (W.sub.2t) through the turbocharger turbine, determining the exhaust manifold pressure (p.sub.2), determining the turbine back-pressure (p.sub.exs), and generating a VGT actuator position estimate (.alpha..sub.vgt) as a function of W.sub.2t, T.sub.2, p.sub.2, and p.sub.exs. The estimated VGT actuator position is then used to generate an error term indicative of the difference between the estimated and desired VGT actuator position. The error term can then be used to drive the VGT actuator to its desired position to regulate the intake manifold pressure.

Abstract: A method of controlling the airflow into a compression ignition engine having an EGR and a VGT. The control strategy includes the steps of generating desired EGR and VGT turbine mass flow rates as a function of the desired and measured compressor mass airflow values and exhaust manifold pressure values. The desired compressor mass airflow and exhaust manifold pressure values are generated as a function of the operator-requested fueling rate and engine speed. The EGR and VGT turbine mass flow rates are then inverted to corresponding EGR and VGT actuator positions to achieve the desired compressor mass airflow rate and exhaust manifold pressure. The control strategy also includes a method of estimating the intake manifold pressure used in generating the EGR valve and VGT turbine positions.

Abstract: A method of estimating the airflow into a compression ignition engine having an exhaust gas recirculation system (EGR) and a variable geometry turbocharger (VGT). The method includes the steps of generating an EGR flow value as a function of the intake manifold pressure (MAP), exhaust manifold pressure (EXMP), position of the exhaust gas recirculation valve, and temperature of the gas flowing through the EGR. From this calculation, the method generates an intake airflow value (MAF) as a function of the EGR flow value and the intake aircharge temperature. The intake airflow value is used, in turn, to control the position of the EGR valve. The disclosed method thereby eliminates the necessity for a MAF sensor.

Abstract: A system for adjusting the operating timing of a cylinder valve system of a reciprocating internal combustion engine determines a static cylinder valve timing based upon at least two engine operating parameters and a time constant for governing the transient behavior of a valve phaser for adjusting valve timing according to the output of a filter.