Fuel Injector Pulse Width Adjustment for Injection Precision
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Solution Overview
Problem
Existing fuel injection systems face challenges in accurately delivering fuel mass due to residual energy and armature motion from previous pulses, leading to errors in subsequent injections, especially with closely-spaced multiple-injection operations in combustion engines.
Innovation Solution
The solution involves adjusting the commanded pulse width of subsequent fuel pulses based on the dwell time and fuel mass of preceding pulses to compensate for residual effects, using a combination of open-loop control strategies and feedback adjustments to achieve precise fuel mass delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple fuel pulses are delivered in close succession, then fuel injection productivity is improved, but fuel mass delivery precision deteriorates due to residual energy and armature motion from previous pulses
Solution Approach 1:
The controller pre-calculates and adjusts the pulse width of subsequent fuel pulses based on the dwell time since the preceding pulse. This preliminary adjustment compensates for residual energy and armature motion effects before they occur, ensuring accurate fuel mass delivery even when multiple pulses are delivered in close succession
Solution Approach 2:
The system uses feedback from the dwell time measurement (time since preceding pulse) to dynamically adjust the pulse width of subsequent injections. This closed-loop approach allows the controller to adapt to residual effects from previous pulses and maintain precise fuel mass delivery across multiple closely-spaced injections
2Quantity of substance
If pulse width is increased to deliver more fuel mass, then quantity of substance delivered is improved, but manufacturing precision deteriorates due to amplified residual effects from previous pulses
Solution Approach 1:
Before delivering each fuel pulse, the controller pre-adjusts the pulse width based on the dwell time since the preceding pulse. This preliminary compensation accounts for residual energy and armature motion, allowing accurate delivery of the desired fuel mass even when residual effects are present
Solution Approach 2:
The system dynamically changes the pulse width parameter based on the dwell time condition. By adjusting this critical parameter in response to the time since the preceding pulse, the system maintains precise fuel mass delivery across varying injection conditions and residual effect levels
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces fuel mass delivery errors, improving combustion efficiency and accuracy by aligning subsequent pulses with the performance of previous pulses, thereby enhancing overall fuel injection precision.
Implementation Method 1
A fluid delivery system includes a solenoid configured to selectively lift a pintle of a valve to allow a pressurized fluid to pass through the valve
Implementation Method 2
Certain example fuel injectors can be solenoid-actuated or piezo-electric valve devices disposed at a fuel intake portion of an engine
Data Source
AI summary
A vehicle includes a combustion engine having at least one cylinder to burn a fuel, and a fuel injector to supply a fuel mass to the at least one cylinder. The vehicle also includes a controller programmed to cause the fuel injector supply a series of fuel pulses that sum to an aggregate target fuel mass. The controller is also programmed to adjust a commanded duration of a subsequent pulse of the series of pulses from a target pulse duration value based on at least one of a dwell time since a preceding pulse, a fuel mass of the preceding pulse, and an opening delay of the preceding pulse.