Caterpillar Inc.

Sasidhar Rayasam

Kranti Kumar Nellutla

James Ulstad

Brian P Brennan

Daniel Reese Puckett

Ye Tian

Steven Y Tian

Michael E Sattler

Bradley Scott Bashore

Anand Krishnamurthygopalan

Gregory Lance Armstrong

Greg Armstrong

Michael Scott Marchionda

Purvarag S Shah

Purna Chandra Sekhar Mokkarala

Mohammed Rafi H

An engine has an injector communicating with a combustion chamber to introduce a plurality of dosing shots to mix with exhaust gases and regenerate an aftertreatment device downstream of the combustion chamber. An apportionment strategy can apportion a per cylinder quantity, representing the quantity of dosing fuel to introduce per cylinder per combustion cycle, among a predefined number of dosing shots each having a first per shot quantity. The strategy compares the predefined number of dosing shots with a temporal dosing window to determine if predefined number of dosing shots can be conducted within the temporal dosing window. If so, the strategy proceeds to introduce the predefined number of dosing shots and if not, the strategy may recalculate a reduced number of dosing shots and reapportions a second per shot quantity.

Fuel apportionment strategy for in-cylinder dosing

A fuel delivery system for an engine is provided. The fuel delivery system includes a fuel rail, a pressure sensor, a relief valve, and a controller. The controller is configured to receive a signal indicative of a fuel rail pressure, identify exceeding of the fuel rail pressure beyond a first threshold, identify the fuel rail pressure drop below a second threshold, and initiate a counter for a first predefined amount of time accordingly. The controller is also configured to identify if the fuel rail pressure drops below a third threshold within the first predefined amount of time, and identify if the fuel rail pressure remains below the third threshold for at least a second predefined amount of time. The controller is further configured to determine an open status of the relief valve based, at least in part, on the identification.

Fuel delivery system

A fuel system is disclosed for use with an engine. The fuel system may have a plurality of fuel injectors, a common rail fluidly, a pump, and an outlet valve associated with the pump. The fuel system may also have a sensor configured to generate a signal indicative of a pressure of fuel in the common rail, and an electronic control module. The electronic control module may be configured to detect a zero-fueling condition, to determine a first pressure decay rate of the common rail during the zero-fueling condition while the pump is rotating, and to determine a second pressure decay rate of the common rail during the zero-fueling condition after the pump has stopped rotating. The electronic control module may also be configured to selectively generate a diagnostic flag associated with wear of the outlet valve based on the first and second pressure decay rates.

Fuel system having pump prognostic functionality

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Peoria, IL, United States of America

Sasidhar Rayasam