A variety of methods and arrangements for improving the fuel efficiency of internal combustion engines are described. Generally, an engine is controlled to operate in a skip fire variable displacement mode. Feedback control is used to dynamically determine the working cycles to be skipped to provide a desired engine output. In some embodiments a substantially optimized amount of air and fuel is delivered to the working chambers during active working cycles so that the fired working chambers can operate at efficiencies close to their optimal efficiency. In some embodiments, the appropriate firing pattern is determined at least in part using predictive adaptive control. By way of example, sigma delta controllers work well for this purpose. In some implementations, the feedback includes feedback indicative of at least one of actual and requested working cycle firings. In some embodiments, the appropriate firings are determined on a firing opportunity by firing opportunity basis. Additionally, in some embodiments, an indicia of the current rotational speed of the engine is used as a clock input for a controller used to selectively cause the skipped working cycles to be skipped.

Internal combustion engine control for improved fuel efficiency

An apparatus for controlling a lock-up clutch between pump and turbine impellers in a fluid-filled power transmitting device of a motor vehicle, such that a slip control device controls the actual slip speed of the lock-up clutch so as to coincide with a transient target slip speed, the apparatus including a device for calculating a final target slip speed of the lock-up clutch which assures a maximum fuel economy of the vehicle during a steady-state running, a device for setting, as an initial value of the transient target slip speed, a difference between the speeds of the pump and turbine impellers immediately before an operation of the slip control device is initiated, and a device for reducing the transient target slip speed toward the final target slip speed at a rate which decreases as the transient target slip speed approaches the final target slip speed.

Slip control apparatus for motor vehicle lock-up clutch

Methods and systems are provided for selecting a group of cylinders for selective deactivation, in a variable displacement engine system, based at least on a regeneration state of an exhaust catalyst. The position of one or more valves and throttles may be adjusted based on the selective deactivation to reduce back-flow through the disabled cylinders while also maintaining conditions of a downstream exhaust catalyst. Pre-ignition and knock detection windows and thresholds may also be adjusted based on the deactivation to improve the efficiency of knock and pre-ignition detection.

Methods and Systems for Variable Displacement Engine Control

A method for operating an internal combustion engine (10) is described, in which the fuel is injected by means of an injector (14) into a combustion chamber (12) of the internal combustion engine (10), wherein an injected fuel quantity of at least one injector (14) is corrected depending on a wear and a coking of the injector (14) relative to a target quantity, and wherein the method comprises the following steps: (a) Determining a variable (54) that characterises the degree of coking of the injector (14); (b) Changing an actuating signal of the injector (14) depending on the determined variable (54) that characterises the degree of coking ; (c) Thereafter determining an actual closing point of the injector (14); (d) Comparing the actual closing point with a target closing point; and (e) Changing the actuating signal of the injector (14) in such a way that the actual closing point is approximately equivalent to the target closing point.

Method and device for operating an internal combustion engine

A method of determining fuel consumption in a vehicle through the OBDII bus is described. The fuel consumption is determined by using mass air flow (MAF) sensor data or manifold air pressure (MAP) sensor data, and obtaining and applying long term and short term fuel trim values for the vehicle, which respectively characterize deviations of air-to-fuel stoichiometry in the vehicle due to aging and vehicle's current operating conditions to determine the corrected fuel consumption in the vehicle. For MAP based method, an independent determining of Volumetric Efficiency of a vehicle's engine is also provided. The method is further enhanced by providing various sensing patterns for various sensor data, which depend on the rate of change of the respective data.

Methods and system for determining consumption and fuel efficiency in vehicles

An engine toque estimator according to the invention includes a vehicle data bus that provides a plurality of engine operating inputs including at least one of engine RPM, spark and a dilution estimate. A steady state torque estimator communicates with the vehicle data bus and generates a steady state engine torque signal. A measurement model communicates with the vehicle data bus and compensates for errors associated with engine-to-engine variation. A dynamic torque estimator communicates with at least one of the vehicle data bus, the measurement model, and the steady state torque estimator and generates an actual torque signal.

Torque estimator for engine RPM and torque control

An engine system includes an engine having an intake manifold and a turbocharger that supplies compressed air to the intake manifold. An engine control module calculates a desired pre-throttle pressure of air before the throttle and calculates a desired manifold air flow into the engine. The engine control module determines a desired pre throttle pressure area based on the desired air per cylinder, desired manifold pressure and RPM and generates control signals to control the engine with the turbocharger.

Torque control of turbocharged engine

A solenoid diagnostic system includes a pressure monitoring module that determines a first pressure in an intake cam phaser for an intake camshaft and a second pressure in an exhaust cam phaser for an exhaust camshaft associated with a cylinder. A fuel injection monitoring module determines a fuel injection status associated with the cylinder. A fault determination module diagnoses a fault in a solenoid associated with the cylinder based on the first pressure, the second pressure, and the fuel injection status.

Solenoid diagnostic systems for cylinder deactivation control

A method and a control module for diagnosing an engine component function includes a comparison module comparing an in-cylinder pressure signal to a threshold and a fault indication module generating a diagnostic signal for an engine component in response to comparing.

Method and system for generating a diagnostic signal of an engine component using an in-cylinder pressure sensor

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.

Joseph R. Dulzo

Papers

Torque estimator for engine RPM and torque control

Torque control of turbocharged engine

Solenoid diagnostic systems for cylinder deactivation control

Method and system for generating a diagnostic signal of an engine component using an in-cylinder pressure sensor

Apparatus and methods for estimating vehicle fuel composition