In-Cylinder Pressure Injection Control for Engine Startup
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Solution Overview
Problem
Current engine systems face challenges in determining the readiness of cylinders for ignition/injection, particularly during engine startup, leading to delayed startup and increased emissions due to incomplete ignition in the first cylinder.
Innovation Solution
The method involves monitoring in-cylinder pressure to determine a pressure-related parameter exceeding a threshold, followed by a diagnostic test to assess the cylinder's readiness for injection/ignition, potentially replacing the cam sensor's function with in-cylinder pressure signals, and using these signals to phase the injection/ignition event.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cam sensor phasing is used to determine injection timing, then the system can identify cylinder readiness for ignition, but engine startup is delayed due to skipping the first cylinder to avoid incomplete ignition
Solution Approach 1:
The invention changes the decision parameter from cam sensor position signals to in-cylinder pressure parameters. By monitoring pressure-related parameters (such as pressure rise rate, peak pressure, or integrated pressure area) and comparing them against threshold values, the system can determine cylinder readiness based on actual thermodynamic conditions rather than fixed mechanical positions, enabling injection in the first cylinder when conditions are favorable
Solution Approach 2:
The invention replaces the mechanical cam sensor system with a pressure-based detection system. Instead of using mechanical position sensing to determine cylinder phase, the system uses in-cylinder pressure sensors to detect thermodynamic conditions, substituting mechanical position-based control with pressure-based control to eliminate startup delays
2Ease of operation
If the cam sensor is used to determine cylinder phasing for injection/ignition, then injection timing can be controlled, but the system complexity increases with additional sensors
Solution Approach 1:
The in-cylinder pressure sensor serves multiple functions: it determines cylinder readiness for injection, phases the injection/ignition event, and can be used for combustion analysis. This multi-functionality eliminates the need for separate cam sensors while maintaining injection timing control capability
Solution Approach 2:
The invention extracts the cylinder readiness determination function from the cam sensor system and implements it through pressure parameter analysis. By taking out this specific function and implementing it through pressure monitoring, the system reduces sensor complexity while maintaining control capability
3Object-generated harmful factors
If injection is performed in the first cylinder during engine startup, then emissions from unburned fuel are reduced, but incomplete ignition may occur due to low cylinder gas pressure and temperature
Solution Approach 1:
The system uses real-time pressure feedback from in-cylinder sensors to determine whether conditions are favorable for injection. By continuously monitoring pressure-related parameters and comparing against thresholds, the system receives feedback on cylinder readiness, enabling injection only when thermodynamic conditions support complete combustion, thus reducing emissions without sacrificing ignition reliability
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 reduces emissions from unburned fuel, enables a cleaner stop-start strategy, and allows for faster engine startup by identifying favorable gas conditions for injection, potentially eliminating the need for a cam sensor.
Implementation Method 1
monitoring, with the at least one pressure sensor, of the in-cylinder pressure
Data Source
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AI summary
A method of determining whether a cylinder (1, 2, 3, 4) in an engine system (90) comprising a plurality of cylinders is ready for injection/ignition, the method comprising: monitoring (122) the in-cylinder pressure of each of the plurality of cylinders within the engine system; determining (124) a pressure related parameter for each cylinder within the engine system; wherein, in the event that the pressure related parameter in a given cylinder exceeds a first threshold, the method further comprises performing a diagnostic test in order to determine whether the given cylinder is ready for injection/ignition.