Abstract: Methods and systems, using a controller (20), for performing fuel pressure control operation of an engine (12) having at least one cylinder (16) is disclosed. The controller (20) includes a fuel system control unit (42) configured to control a fuel pressure applied to at least one injector (18) of the engine (12) during a motoring condition period (412) based on a commanded pulse train duration (410). During the motoring condition period (412), no combustion occurs in the at least one cylinder (16) of the engine (12). The commanded pulse train duration is a time period during which the at least one injector (18) of the engine (12) is activated for a drain operation. The fuel system control unit (42) is configured to command the at least one injector (18), for the commanded pulse train duration during the motoring condition period (412), to release fuel from the at least one injector (18) without injecting the fuel into the at least one cylinder (16) of the engine (12).

Abstract: Methods and systems, using a controller (20), for performing fuel pressure control operation of an engine (12) having at least one cylinder (16) is disclosed. The controller (20) includes a fuel system control unit (42) configured to control a fuel pressure applied to at least one injector (18) of the engine (12) during a motoring condition period (412) based on a commanded pulse train duration (410). During the motoring condition period (412), no combustion occurs in the at least one cylinder (16) of the engine (12). The commanded pulse train duration is a time period during which the at least one injector (18) of the engine (12) is activated for a drain operation. The fuel system control unit (42) is configured to command the at least one injector (18), for the commanded pulse train duration during the motoring condition period (412), to release fuel from the at least one injector (18) without injecting the fuel into the at least one cylinder (16) of the engine (12).

Abstract: Diagnostic systems including a pressure sensor, a determiner in communication with the pressure sensor, wherein the determiner is structured to estimate a sonic speed of a fuel based on identification of a fundamental oscillation frequency are disclosed. Also disclosed are diagnostic methods comprising receiving, by a pressure interpreter, a pressure signal, determining, by a determiner in communication with the pressure interpreter, a fundamental frequency of oscillation of the pressure signal, and determining, by the determiner, a sonic speed of a fuel based on the fundamental frequency of oscillation.

Abstract: A system and method for measuring fuel pressure decreases in a fuel accumulator caused by a fuel injector of an internal combustion engine is provided. The system includes the ability to stop a fuel flow to a fuel accumulator of the engine. Pressure signals are transmitted to a control system of the engine until the fuel pressure in the fuel accumulator drops by a predetermined amount, at which time fuel flow is re-enabled. The pressure signals are then analyzed to determine the amount or quantity of fuel delivered by each fuel injector. The system and method maintain engine and emissions performance by limiting the amount of fuel pressure decrease in the fuel accumulator.

Abstract: A system, apparatus, and method are disclosed for controlling a fuel injector using multipulse fuel injection. According to at least one aspect of the present disclosure, the system includes a fuel sequence controller configured for use with a fuel injector having an injector configuration modeled by a body pressure characteristic that includes a rail pressure and an injection rate shape, where the fuel sequence controller is structured to determine an estimate of the injected fuel quantity delivered from the fuel injector at the determined body pressure characteristic.

Abstract: Diagnostic systems including a pressure sensor, a determiner in communication with the pressure sensor, wherein the determiner is structured to estimate a sonic speed of a fuel based on identification of a fundamental oscillation frequency are disclosed. Also disclosed are diagnostic methods comprising receiving, by a pressure interpreter, a pressure signal, determining, by a determiner in communication with the pressure interpreter, a fundamental frequency of oscillation of the pressure signal, and determining, by the determiner, a sonic speed of a fuel based on the fundamental frequency of oscillation.

Abstract: A system and method is provided to analyze an intermediate pressure signal portion between an end of an injection event signal portion and a start of a subsequent injection event signal portion. The analysis is simplified by identifying a plurality of single cycle windows and calculating a single value, such as a mean or a median, for each of the windows. An intermediate portion single value is determined by averaging the single values for each of the windows. The intermediate portion single value may then be used to identify pumping events or leakage errors that occur during the intermediate pressure signal portion that affect further analysis of the intermediate pressure signal portion.

Abstract: A system and method for is provided to determine a fuel flow cutout delay between transmitting a signal to stop a fuel flow to a fuel accumulator of a fuel system and the actual stop of fuel flow to the fuel accumulator. The fuel flow cutout delay is used to determine when pressure data from a sensor associated with the fuel accumulator is unaffected by fuel flow to the fuel accumulator.

Abstract: A system and method for measuring fuel pressure decreases in a fuel accumulator of an internal combustion engine is provided. The system includes the ability to stop a fuel flow to a fuel accumulator of the engine. Pressure signals are transmitted to a control system of the engine until the fuel pressure in the fuel accumulator drops by a predetermined amount, at which time fuel flow is re-enabled. The pressure signals are then analyzed to determine the amount or quantity of fuel delivered by each fuel injector. The system and method maintain engine and emissions performance by limiting the amount of fuel pressure decrease in the fuel accumulator.

Abstract: A system and method for measuring fuel pressure decreases in a fuel accumulator of an internal combustion engine is provided. The system includes the ability to stop a fuel flow to a fuel accumulator of the engine. Pressure signals are transmitted to a control system of the engine until the fuel pressure in the fuel accumulator drops by a predetermined amount, at which time fuel flow is re-enabled. The pressure signals are then analyzed to determine the amount or quantity of fuel delivered by each fuel injector. The system and method maintain engine and emissions performance by limiting the amount of fuel pressure decrease in the fuel accumulator.

Abstract: A system and method for measuring fuel pressure decreases in a fuel accumulator of an internal combustion engine is provided. The system includes the ability to stop a fuel flow to a fuel accumulator of the engine. Pressure signals are transmitted to a control system of the engine until the fuel pressure in the fuel accumulator drops by a predetermined amount, at which time fuel flow is re-enabled. The pressure signals are then analyzed to determine the amount or quantity of fuel delivered by each fuel injector. The system and method maintain engine and emissions performance by limiting the amount of fuel pressure decrease in the fuel accumulator.

Abstract: A system and method for measuring fuel pressure decreases in a fuel accumulator of an internal combustion engine is provided. The system includes the ability to stop a fuel flow to a fuel accumulator of the engine. Pressure signals are transmitted to a control system of the engine until the fuel pressure in the fuel accumulator drops by a predetermined amount, at which time fuel flow is re-enabled. The pressure signals are then analyzed to determine the amount or quantity of fuel delivered by each fuel injector. The system and method maintain engine and emissions performance by limiting the amount of fuel pressure decrease in the fuel accumulator.

Abstract: A system, apparatus, and method are disclosed for controlling a fuel injector using multipulse fuel injection. According to at least one aspect of the present disclosure, the system includes a fuel sequence controller configured for use with a fuel injector having an injector configuration modeled by a body pressure characteristic that includes a rail pressure and an injection rate shape, where the fuel sequence controller is structured to determine an estimate of the injected fuel quantity delivered from the fuel injector at the determined body pressure characteristic.

Abstract: A system and method is provided to analyze an intermediate pressure signal portion between an end of an injection event signal portion and a start of a subsequent injection event signal portion. The analysis is simplified by identifying a plurality of single cycle windows and calculating a single value, such as a mean or a median, for each of the windows. An intermediate portion single value is determined by averaging the single values for each of the windows. The intermediate portion single value may then be used to identify pumping events or leakage errors that occur during the intermediate pressure signal portion that affect further analysis of the intermediate pressure signal portion.

Abstract: A system and method is provided to analyze an intermediate pressure signal portion between an end of an injection event signal portion and a start of a subsequent injection event signal portion. The analysis is simplified by identifying a plurality of single cycle windows and calculating a single value, such as a mean or a median, for each of the windows. An intermediate portion single value is determined by averaging the single values for each of the windows. The intermediate portion single value may then be used to identify pumping events or leakage errors that occur during the intermediate pressure signal portion that affect further analysis of the intermediate pressure signal portion.

Abstract: A boresight alignment system is disclosed. The system comprises a frame movement sensor operable to determine a reference position on an object, a frame alignment sensor operable to determine a first boresight position on the object, a data acquisition processing unit in communication with the frame movement and frame alignment sensors and a display processing unit in communication with the data acquisition processing unit. The display processing unit is operable to display near real time attitude data measured by the frame movement and frame alignment sensors. The data acquisition processing unit comprises program instructions to correct for angular differences with respect to a reference position.

Abstract: A system and method for measuring fuel pressure decreases in a fuel accumulator of an internal combustion engine is provided. The system includes the ability to stop a fuel flow to a fuel accumulator of the engine. Pressure signals are transmitted to a control system of the engine until the fuel pressure in the fuel accumulator drops by a predetermined amount, at which time fuel flow is re-enabled. The pressure signals are then analyzed to determine the amount or quantity of fuel delivered by each fuel injector. The system and method maintain engine and emissions performance by limiting the amount of fuel pressure decrease in the fuel accumulator.

Abstract: A system and method is provided to analyze an intermediate pressure signal portion between an end of an injection event signal portion and a start of a subsequent injection event signal portion. The analysis is simplified by identifying a plurality of single cycle windows and calculating a single value, such as a mean or a median, for each of the windows. An intermediate portion single value is determined by averaging the single values for each of the windows. The intermediate portion single value may then be used to identify pumping events or leakage errors that occur during the intermediate pressure signal portion that affect further analysis of the intermediate pressure signal portion.

Abstract: A system and method for measuring fuel pressure decreases in a fuel accumulator caused by a fuel injector of an internal combustion engine is provided. The system includes the ability to stop a fuel flow to a fuel accumulator of the engine. Pressure signals are transmitted to a control system of the engine until the fuel pressure in the fuel accumulator drops by a predetermined amount, at which time fuel flow is re-enabled. The pressure signals are then analyzed to determine the amount or quantity of fuel delivered by each fuel injector. The system and method maintain engine and emissions performance by limiting the amount of fuel pressure decrease in the fuel accumulator.

Abstract: A system and method for is provided to determine a fuel flow cutout delay between transmitting a signal to stop a fuel flow to a fuel accumulator of a fuel system and the actual stop of fuel flow to the fuel accumulator. The fuel flow cutout delay is used to determine when pressure data from a sensor associated with the fuel accumulator is unaffected by fuel flow to the fuel accumulator.