Internal Combustion Engine Cylinder Subset Measurement Injection
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Solution Overview
Problem
Internal combustion engines with multiple cylinders face issues due to individual variations in injection valves, leading to non-optimal fuel mixture and impaired engine performance, such as smooth running and emission problems, caused by measurement injections attempting to correct valve characteristic deviations.
Innovation Solution
A method where measurement injections are selectively performed on a subset of cylinders during ignition cycles, with the subset determined based on operating and environmental parameters, to minimize mix errors and adapt valve characteristic curves, allowing for efficient compensation of manufacturing tolerances and reduced production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If measurement injection is carried out for all cylinders to determine valve characteristic quantities, then manufacturing precision of injection valves can be compensated, but engine operating characteristics deteriorate due to mix errors and non-optimal fuel mixture
Solution Approach 1:
The set of all cylinders is segmented into a first subset and a second subset. Measurement injections are performed only on cylinders in the first subset during a first ignition cycle, while cylinders in the second subset operate without measurement injections. This segmentation allows selective adaptation of injection valve characteristics for only some cylinders, thereby compensating for manufacturing variations without subjecting all cylinders to the harmful effects of measurement injections, thus preserving overall engine operating characteristics.
2Measurement precision
If measurement injection is performed frequently to adapt valve characteristics, then injection precision improves, but engine smooth running and torque characteristics worsen due to increased mix errors
Solution Approach 1:
Measurement injections are performed periodically but not continuously. Specifically, during a first ignition cycle, measurement injections are carried out only for cylinders in the first subset, while cylinders in the second subset skip the measurement injection. This periodic and selective approach allows the control device to adapt valve characteristic quantities over time without subjecting all cylinders to measurement injections in every cycle, thereby reducing the frequency and total number of mix-error-inducing injections while still achieving adequate adaptation precision.
Data Source
AI summary
A method for operating an internal combustion engine having two or more cylinders to which fuel can be supplied via an injection valve, it being possible to carry out a measurement injection for a cylinder in order to determine and/or adapt a characteristic quantity of the injection valve, and all the cylinders being ignited in the course of an ignition cycle. To improve the operating characteristics, a measurement injection is carried out for those cylinders that are contained in a specifiable selected set selected from all the cylinders.