Abstract: A method of regulating operation of an internal combustion engine includes monitoring a manifold absolute pressure (MAP) of the engine, determining an engine torque based on the MAP, estimating an air per cylinder (APC) based on the torque, determining a volumetric efficiency of the engine based on the APC and regulating operation of the engine based on the volumetric efficiency.

Abstract: A method of achieving a desired torque output of an internal combustion engine includes determining a first air-per-cylinder (APC) value based on a first APC relationship and determining a second APC value based on a second APC relationship. An APC error is determined based on the second APC value. Operation of the engine is regulated based on the first APC value when the APC error is greater than a threshold error. Operation of the engine based on the second APC value when the APC error is not greater than the threshold error.

Abstract: A method of controlling a torque output of an internal combustion engine includes determining a pressure ratio, determining a reference torque based on the pressure ratio and a torque request, calculating a desired throttle area based on the reference torque and regulating operation of the engine based on the desired throttle area to achieve the desired torque.

Abstract: A temperature sensor rationality control system for an exhaust treatment system having an oxidation catalyst includes an oxidation catalyst inlet temperature sensor that generates an inlet temperature signal and an oxidation catalyst outlet temperature sensor that generates an outlet temperature signal. A control module determines whether a difference based on the inlet temperature signal and the outlet temperature signal is below a difference threshold when an exhaust temperature is within a threshold range.

Abstract: A method of estimating composition of fuel in the fuel tank of a vehicle. A refuel event is detected. Fuel consumption is monitored during a plurality of stages after the refuel event. A plurality of fuel trim shift values are determined relative to the stages. The fuel trim shift values are used to estimate a fuel composition change. This method eliminates a need for a hardware fuel composition sensor and also provides dynamic filtering of fuel trim values.

Abstract: A method of determining diagnostic limits for a vane position sensing system installed in a variable nozzle turbocharger (VNT). The method includes defining mechanical input probability distribution functions (PDFs) of the VNT, describing the vane position sensing system in terms of component models and defining component parameter PDFs for parameters associated with the component models. Vane position signal PDFs based are generated on the mechanical input PDFs, the component models and the component parameter PDFs, and diagnostic limits are set for the vane position sensing system based on the vane position signal PDFs.

Abstract: An engine control system and method maintains an optimum exhaust fuel to air ratio in an internal combustion engine. A secondary air injection (SAI) pressure is measured in an SAI system. The SAI pressure measurement is converted into an SAI flow value. A fuel compensation value is obtained based on the SAI flow value. Fuel delivery is compensated to the engine based on the fuel compensation value. In a second embodiment, the fuel compensation value is obtained based on the SAI pressure measurement. Fuel delivery is compensated to the engine based on the fuel compensation value. In a third embodiment, a primary flow value is calculated at an air intake of the engine. A fuel compensation value is calculated based on the SAI flow and primary flow values. Fuel delivery to the engine is compensated based on the fuel compensation value.

Abstract: A method and control system for verifying cold start emissions reduction control in a vehicle using an internal combustion engine utilizes measured engine speed and commanded ignition timing to calculate an estimated actual engine-out thermal energy flow. An expected thermal energy flow is calculated based on designed engine speed and ignition timing. A residual energy flow is calculated based on a difference between the estimated actual thermal energy flow and the expected thermal energy flow. Meanwhile, a system quality-weighting factor is calculated based on several measured engine parameters. A qualified energy flow residual is calculated based on the system quality weight and the residual energy flow. The qualified energy residual flow is accumulated, averaged based on the accumulated quality weight, and then filtered.

Abstract: A method and apparatus for determining the mass air flow into an internal combustion engine without the use of a mass air flow sensor. Speed density and throttle position methods of estimating mass air flow are combined using a first Kalman filter. In one aspect of the invention, the input throttle position into the throttle position mass air flow estimate is the measured throttle position obtained from the throttle position sensor. In another aspect of the invention, the input throttle position into the throttle position mass air flow estimate is the output of a second Kalman filter, which uses as its inputs the measured throttle position obtained from the throttle position sensor and the desired throttle position obtained from the pedal position sensor.

Abstract: A method and apparatus for determining the mass air flow into an internal combustion engine without the use of a mass air flow sensor. Speed density and throttle position methods of estimating mass air flow are combined using a first Kalman filter. In one aspect of the invention, the input throttle position into the throttle position mass air flow estimate is the measured throttle position obtained from the throttle position sensor. In another aspect of the invention, the input throttle position into the throttle position mass air flow estimate is the output of a second Kalman filter, which uses as its inputs the measured throttle position obtained from the throttle position sensor and the desired throttle position obtained from the pedal position sensor.

Abstract: A method and apparatus for controlling the throttle position of a vehicle by modifying the pedal to throttle progression typically used by the electronic throttle controller to a throttle progression based on the driver's target acceleration and vehicle speed. Target acceleration is determined using a lookup table with inputs current vehicle speed and accelerator pedal displacement. Another lookup determines the end vehicle speed the driver will attain if the pedal displacement does not change. A signal indicating the new throttle position is the output of a controller whose input is the difference between end vehicle speed and current vehicle speed and whose gain is based on the target acceleration. Changes in throttle position can be limited based on an arbitration incorporating information received from other vehicle control systems. Preferably, control of the throttle will revert to the idle control system whenever the accelerator pedal is not displaced.

Abstract: A method and apparatus for controlling the throttle position of a vehicle by modifying the pedal to throttle progression typically used by the electronic throttle controller to a throttle progression based on the driver's target acceleration and vehicle speed. Target acceleration is determined using a lookup table with inputs current vehicle speed and accelerator pedal displacement. Another lookup determines the end vehicle speed the driver will attain if the pedal displacement does not change. A signal indicating the new throttle position is the output of a controller whose input is the difference between end vehicle speed and current vehicle speed and whose gain is based on the target acceleration. Changes in throttle position can be limited based on an arbitration incorporating information received from other vehicle control systems. Preferably, control of the throttle will revert to the idle control system whenever the accelerator pedal is not displaced.