Caterpillar Inc.

Michael S Lukich

Travis E Barnes

Larry Ellis Kendrick

Darwin R Carrell

Scott E Nicholson

Brian G McGee

John Parker Timmons

Scott Richard Schuricht

Gregory J Speckhart

Rammohan Sankar

Eric A Hutchison

Salim A Jaliwala

John James Krone

Gerald N Coleman

Daniel Reese Puckett

Lonnie J Devier

Stephen V Lunzman

Mary Lou Kesse

James Joshua Driscoll

Howard A Marsden

James Harris Mutti

Amit Jayachandran

Larry E Schmidt

David M Milam

James B Maddock

Michael Steven Bond

Paul M Young

Zhiyong Wei

Kirk S Shively

George M Matta

Wade D Scrivner

Douglas E Handly

Lisa A Obermaier

Denis El Darazi

Nolan W Wartick

Chris L Wynkoop

Meixing Lu

A method for treating a flow of exhaust from an engine includes injecting reductant into the flow of exhaust with an injector disposed upstream from a catalytic device. The injector and the catalytic device are disposed in an exhaust system for the engine. The method also includes passing the flow of exhaust through the catalytic device, sensing a characteristic of at least one of the exhaust system and the engine, monitoring the sensed characteristic to recognize a condition associated with a formation of a decomposition material formed from the reductant, and controlling an operation of at least one of the engine and the exhaust system to increase a temperature in the exhaust system in response to the recognized condition.

Method and system of thermal management in an exhaust system

An exhaust system for use with a combustion engine is disclosed. The exhaust system may have an exhaust passageway, and a reduction catalyst disposed within the exhaust passageway. The exhaust system may also have a first sensor located to generate a first signal indicative of an operational parameter of the reduction catalyst, and a second sensor located to generate a second signal indicative of a performance parameter of the reduction catalyst. The exhaust system may further have an injection device located to inject reductant upstream of the reduction catalyst, and a controller in communication with the combustion engine, the first sensor, the second sensor, and the injection device. The controller may be configured to determine a NOproduction of the combustion engine, determine an amount of reductant that should be injected based on the NOproduction and the first signal, and adjust the amount based on the second signal.

Exhaust system implementing feedforward and feedback control

A method of estimating an injection delay of a fuel injector. A baseline injection delay curve representing an injection delay for a predetermined type of fuel injector is established for a range of rail pressures. At least one test rail pressure for the predetermined type of fuel injector is identified based on the baseline injection delay curve. An injection delay of a selected fuel injector of the predetermined type is measured at the at least one test rail pressure. The injection delay of the selected fuel injector is estimated based on the baseline injection delay curve and the measured injection delay of the selected fuel injector at the identified test rail pressure.

Method for estimating fuel injector performance

A method of estimating a performance characteristic of a fuel injector is provided. A baseline performance curve for a predetermined type of fuel injector is established. At least one test point for the predetermined type of fuel injector is identified based on the baseline performance curve. A performance characteristic of a selected fuel injector of the predetermined type is measured at the at least one identified test point. A performance characteristic of the selected fuel injector is estimated based on the baseline performance curve and the measured performance characteristics of the selected fuel injector at the identified test point.

Although injection timing accuracy is sensitive to rail pressure, injection quantity of the fuel injection event is strongly a function of rail pressure. Thus, delivery accuracy of each injection event depends strongly upon the accuracy of a rail pressure estimate used in determining the injection control signal characteristics. These injection control signal characteristics include a calculated delay between a start of control current and start of injection, as well as the duration of the control signal. The present invention takes a rail pressure measurement substantially before an injection event, and then utilizes a rail pressure predictor model to predict what the rail pressure will be at each injection event in a succeeding injection sequence. This estimated rail pressure is then used as the means for determining the fuel injection control signal characteristics for that succeeding injection event.

Utilization of a rail pressure predictor model in controlling a common rail fuel injection system

The present invention provides a method and apparatus for determining the oil grade of an actuating fluid in a fuel system. The method includes the steps of determining an actuating fluid temperature, a pump speed, and a peak pressure or a timing event of the actuating fluid, and responsively determining the oil grade of the actuating fluid.

Method and apparatus for determining an oil grade of an actuating fluid

A method of controlling a hydraulic system is preferably applied to common rail fuel injection systems. The problem in these systems is to control pressure in the common rail while at the same time maintaining the fluid supply to the rail in a way that precisely meets the dynamically changing consumption demands on the hydraulic system. In order to control the hydraulic system, the present invention contemplates the combination of a standard feedback controller with observer models of the various hardware items that make up the hydraulic system. Using this strategy, the system can generally be thought of as controlling fluid supply in an open loop type fashion based upon the consumption rates estimated by the various observer models, and utilizing a conventional feedback controller to make the slight pump adjustments needed to control pressure and to correct for any errors between the actual hardware performance and that predicted by the observer models.

Model based rail pressure control for variable displacement pumps

With reference to the drawings and in operation, the present invention is adapted to provide a method and apparatus for dynamically controlling the injection timing of a fuel injector connected to a fuel system located within an engine. The method includes the steps of establishing a desired injection timing of the injector,and determining an fuel injection command delivery time in response to the desired injection timing, and responsively delivering the fuel injection command. The actual injection timing is determined, and then the injection command delivery time is modified in response to comparing the actual and the desired injection timing. Comparing the actual and desired injection timing provides for closed loop control of the injection timing of the fuel system

Method and apparatus for dynamic trimming of fuel system

The present invention is an apparatus for controlling a variable geometry turbocharger (VGT) in closed loop and open loop modes, and a switching mechanism for determining whether open loop or closed loop control laws should be used. In the closed loop mode, a correction factor, obtained from a pressure correction map based on engine speed and atmospheric pressure, is subtracted from the desired boost pressure to prevent overspeed of the turbocharger at lower atmospheric pressures. The actual boost pressure is then compared to the desired boost pressure after correction to obtain a boost pressure error signal. The boost pressure error signal is used as an input to a proportional integral differential control law that responsively produces a desired VGT vane position. A minimum limit on the desired VGT vane position is based on engine speed and fuel quantity, whereas a maximum allowable vane position may be a predetermined constant or function. A linearization map is used to obtain a VGT current signal that is transmitted to an actuator for moving the vane position.

Device for controlling a variable geometry turbocharger

The present invention provides a method and apparatus for determining the viscosity range and/or oil grade of an actuating fluid in a fuel system. The method includes the steps of determining a flow, pressure, and temperature of the actuating fluid, and responsively determining the viscosity range and/or oil grade of the actuating fluid.

Method and apparatus for determining a viscosity of an actuating fluid

The present invention provides a method and apparatus for determining a performance characteristic of at least one of a plurality of fuel injectors located within a fuel system. The method includes the steps of determining a first desired fuel quantity to be delivered by the plurality of injectors, suspending fuel delivery by one of the injectors, determining a second desired fuel quantity to be delivered by the injectors in response to the suspension, and determining a performance characteristic of the suspended injector in response to said first and the second desired fuel quantity.

Electronically controlled fuel injector trimming

The present invention is an apparatus for controlling the amount of fuel delivered to an engine during operation at cold and warm temperatures using different sets of fuel rate maps designed to compensate fuel quantity signals to optimize engine performance. A switching mechanism based on engine coolant temperature is used to select which set of maps to use. When the engine coolant temperature is below a threshold level, a cold torque map provides a signal representing the duration limit of time that fuel is to be injected. A compensating factor derived from a cold temperature smoke map is used to adjust the cold torque map signal to limit the fuel amount to prevent excess smoke. When the engine coolant temperature is above the threshold, a fuel duration limit signal from a standard temperature torque map is compared to a fuel duration limit signal from a standard temperature smoke map, and the minimum between the two signals is selected for output to the fuel injectors.

Device for controlling fuel injection in cold engine temperatures

The present invention is adapted to provide a method for dynamically determining optimal governor dynamics, i.e., gains, for a fuel control system supplying fuel to an engine. The method determines a mode of the engine, then determines the governor gain in response to the engine mode. The mode or condition of the engine includes a transmission mode, a throttle mode, and a cruise control mode. The governor gains are determined by determining the current engine mode, selecting the appropriate gain look-up table in response to the engine mode, and responsively selecting a gain value from the look-up table in response to at least one of the desired and actual speed. The gain maps are determined using empirical data and classical control system design methods, and storing the results in gain maps, or tables. The governor gain values are used in a forward and a feedback path PID control algorithm. The forward path PID control algorithm determines a fuel command in response to at least one of the desired engine speed, and modified actual engine speed, and the governor gain values. The feedback path PID control algorithm determines a modified actual speed in response to at least one of the desired and actual speeds, and the appropriate governor gain values.

Method for determining governor gains for a fuel control system

The present invention is an apparatus for controlling exhaust gas recirculation in an internal combustion engine. The apparatus includes an exhaust gas recirculation controller that uses sensed engine operating parameters and the engine operational mode to determine whether to enable or disable the exhaust gas recirculation valve. When the valve is enabled, a closed-loop controller determines the desired amount of exhaust gas to recirculate and the corresponding position of the exhaust gas recirculation valve to introduce the desired amount of exhaust gas into the engine's air intake manifold. The desired valve position is converted to a current signal which is transmitted to an actuator to move the valve. When the valve is disabled, the current signal is set to a value to close the valve to prevent exhaust gas from being circulated in the engine's air intake manifold.

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Chillicothe, IL, United States of America

Michael S Lukich