Abstract: Method and system for detecting a high friction within a flow control device of a fuel system are disclosed. For example, the method includes receiving a service test sequence to execute a service test, performing, in response to receiving the service test sequence, the service test to generate test data, the service test including a first test cycle with a first dither level and a second test cycle with a second dither level, wherein the second dither level is different from the first dither level. The method further includes determining whether a performance difference between the first test cycle and the second test cycle exceeds a predetermined threshold based on the test data and detecting, in response to determining that the performance difference exceeds the predetermined threshold, a presence of high friction within the flow control device.

Abstract: An apparatus includes an input module structured to interpret a fuel pressure command indicative of a target fuel pressure within an accumulator and a target fuel injection characteristic, a pump module structured to control a pump assembly to provide fuel to the accumulator to maintain the target fuel pressure within the accumulator, an injector module structured to control a plurality of fuel injectors to inject fuel into an engine based on the target fuel injection characteristic, a pressure module structured to interpret pressure data regarding an actual fuel pressure within the accumulator and to determine a pressure difference between the target fuel pressure and the actual fuel pressure, and a modulation module structured to determine a final fuel injection command responsive to the pressure difference exceeding a first magnitude threshold where the final fuel injection command is based on the pressure difference and the target fuel injection characteristic.

Abstract: An apparatus includes an input module structured to interpret a fuel pressure command indicative of a target fuel pressure within an accumulator and a target fuel injection characteristic, a pump module structured to control a pump assembly to provide fuel to the accumulator to maintain the target fuel pressure within the accumulator, an injector module structured to control a plurality of fuel injectors to inject fuel into an engine based on the target fuel injection characteristic, a pressure module structured to interpret pressure data regarding an actual fuel pressure within the accumulator and to determine a pressure difference between the target fuel pressure and the actual fuel pressure, and a modulation module structured to determine a final fuel injection command responsive to the pressure difference exceeding a first magnitude threshold where the final fuel injection command is based on the pressure difference and the target fuel injection characteristic.

Abstract: An apparatus includes an input module structured to interpret a fuel pressure command indicative of a target fuel pressure within an accumulator and a target fuel injection characteristic, a pump module structured to control a pump assembly to provide fuel to the accumulator to maintain the target fuel pressure within the accumulator, an injector module structured to control a plurality of fuel injectors to inject fuel into an engine based on the target fuel injection characteristic, a pressure module structured to interpret pressure data regarding an actual fuel pressure within the accumulator and to determine a pressure difference between the target fuel pressure and the actual fuel pressure, and a modulation module structured to determine a final fuel injection command responsive to the pressure difference exceeding a first magnitude threshold where the final fuel injection command is based on the pressure difference and the target fuel injection characteristic.

Abstract: An apparatus includes an input module structured to interpret a fuel pressure command indicative of a target fuel pressure within an accumulator and a target fuel injection characteristic, a pump module structured to control a pump assembly to provide fuel to the accumulator to maintain the target fuel pressure within the accumulator, an injector module structured to control a plurality of fuel injectors to inject fuel into an engine based on the target fuel injection characteristic, a pressure module structured to interpret pressure data regarding an actual fuel pressure within the accumulator and to determine a pressure difference between the target fuel pressure and the actual fuel pressure, and a modulation module structured to determine a final fuel injection command responsive to the pressure difference exceeding a first magnitude threshold where the final fuel injection command is based on the pressure difference and the target fuel injection characteristic.

Abstract: An apparatus includes an input module structured to interpret a fuel pressure command indicative of a target fuel pressure within an accumulator and a target fuel injection characteristic, a pump module structured to control a pump assembly to provide fuel to the accumulator to maintain the target fuel pressure within the accumulator, an injector module structured to control a plurality of fuel injectors to inject fuel into an engine based on the target fuel injection characteristic, a pressure module structured to interpret pressure data regarding an actual fuel pressure within the accumulator and to determine a pressure difference between the target fuel pressure and the actual fuel pressure, and a modulation module structured to determine a final fuel injection command responsive to the pressure difference exceeding a first magnitude threshold where the final fuel injection command is based on the pressure difference and the target fuel injection characteristic.

Abstract: An apparatus includes an input module structured to interpret a fuel pressure command indicative of a target fuel pressure within an accumulator and a target fuel injection characteristic, a pump module structured to control a pump assembly to provide fuel to the accumulator to maintain the target fuel pressure within the accumulator, an injector module structured to control a plurality of fuel injectors to inject fuel into an engine based on the target fuel injection characteristic, a pressure module structured to interpret pressure data regarding an actual fuel pressure within the accumulator and to determine a pressure difference between the target fuel pressure and the actual fuel pressure, and a modulation module structured to determine a final fuel injection command responsive to the pressure difference exceeding a first magnitude threshold where the final fuel injection command is based on the pressure difference and the target fuel injection characteristic.

Abstract: A method for testing a fuel injector including providing an engine with a common rail fuel injection system having one or more fuel injectors; operating the engine at a selected set of operating conditions; conducting a motoring event; allowing a first settling duration; measuring a first rail pressure; operating a first selected injector including operating the first selected injector singly in response to a selected fuel quantity, a selected number of combustion cycles, and a selected number of injections per combustion cycle; allowing a second settling duration; measuring a second rail pressure; calculating a pressure difference value in response to the first rail pressure and the second rail pressure; inferring an amount of fuel delivered by the first selected injector in response to the pressure difference value; and evaluating a first performance factor of the first selected injector in response to the amount of fuel delivered.

Abstract: A method for testing a fuel injector including providing an engine with a common rail fuel injection system having one or more fuel injectors; operating the engine at a selected set of operating conditions; conducting a motoring event; allowing a first settling duration; measuring a first rail pressure; operating a first selected injector including operating the first selected injector singly in response to a selected fuel quantity, a selected number of combustion cycles, and a selected number of injections per combustion cycle; allowing a second settling duration; measuring a second rail pressure; calculating a pressure difference value in response to the first rail pressure and the second rail pressure; inferring an amount of fuel delivered by the first selected injector in response to the pressure difference value; and evaluating a first performance factor of the first selected injector in response to the amount of fuel delivered.

Abstract: A miniature optical scanner includes an electromagnetic drive having stationary magnets and stationary drive coils to minimize the rotational inertia of the scanner and increase the scanner's resonant frequency. The scanner is such that the resonant frequency is manually tunable as well as automatically adjustable to compensate for variables causing frequency drift. The optical scan angle is increased by employing a multiplying mirror with the optical scanner. For a two axis scanning system, the multiplying mirror may be formed of a second optical scanner to increase the optical scan angle relative to both of the axes.

Abstract: A miniature optical scanner includes an electromagnetic drive having stationary magnets and stationary drive coils to minimize the rotational inertia of the scanner and increase the scanner's resonant frequency. The scanner is such that the resonant frequency is manually tunable as well as automatically adjustable to compensate for variables causing frequency drift. The optical scan angle is increased by employing a multiplying mirror with the optical scanner. For a two axis scanning system, the multiplying mirror may be formed of a second optical scanner to increase the optical scan angle relative to both of the axes.

Abstract: A virtual retinal display utilizes photon generation and manipulation to create a panoramic, high resolution, color virtual image that is projected directly onto the retina of the eye. The virtual retinal display includes a source of photons, the photons being modulated with video information and scanned by a scanning system in a raster type of pattern directly onto the retina of the user's eye. A single, monofilament optical fiber of very small diameter couples light from the photon generator to the scanning system so as to provide to the scanning system a point source of light at the fiber's exit aperture. The photon generator may utilize coherent or non-coherent light. Further, the photon generator may utilize color light emitters so as to scan a colored virtual image directly onto the retina of the user's eye.