Ion Sense Feedback for Lean Combustion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engines with high dilution and lean air/fuel ratios face challenges in igniting combustible mixtures and achieving complete combustion, leading to premature spark plug wear and combustion performance degradation.
Innovation Solution
A system and method that adjust ignition energy and charge dilution simultaneously based on ionization sensing feedback to improve combustion quality, where the controller modifies ignition energy first and then charge dilution if necessary to prevent misfires and achieve desired combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ignition energy is increased to improve combustion quality, then combustion quality is improved, but spark plug wear and gap erosion increase leading to premature degradation
Solution Approach 1:
The system uses ionization signal feedback from the combustion chamber to monitor combustion quality in real-time. The controller adjusts ignition energy based on the ionization signal strength, providing closed-loop control that prevents excessive ignition energy application while maintaining reliable combustion, thereby extending spark plug life.
Solution Approach 2:
The ignition energy is made dynamic and adjustable rather than fixed. The system can adaptively increase or decrease ignition energy based on operating conditions and combustion feedback, allowing optimal combustion quality while minimizing spark plug wear under different operating scenarios.
2Productivity
If lean air/fuel ratio operation is used to increase power density, then fuel economy and power density are improved, but combustion stability and completeness deteriorate
Solution Approach 1:
The ionization sensing system provides real-time feedback on combustion quality and stability. The controller uses this feedback to adjust ignition timing and energy delivery to maintain stable combustion under lean air/fuel ratio conditions, enabling sustained high power density operation without combustion instability.
Solution Approach 2:
The system dynamically adjusts ignition parameters (timing, energy, duration) based on the lean air/fuel ratio operating conditions and ionization feedback, optimizing combustion stability while maintaining the benefits of lean operation for fuel economy and power density.
3Reliability
If multiple spark strikes are used to improve combustion of high dilution mixtures, then combustion quality is improved, but ignition system complexity and energy consumption increase
Solution Approach 1:
The ionization signal provides feedback on combustion development after each spark strike. The controller can determine whether additional spark strikes are necessary based on the ionization signal characteristics, reducing unnecessary multiple strikes and simplifying control while ensuring complete combustion when needed.
Solution Approach 2:
The system applies multiple spark strikes only when necessary, based on combustion conditions and ionization feedback. Rather than always using multiple strikes, the system applies partial action (single or multiple strikes) as needed, reducing overall system complexity and energy consumption while maintaining combustion completeness.
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 effectively manages fuel economy, performance, and emissions by accurately controlling combustion within individual cylinders, enabling engine downsizing while maintaining power density similar to larger engines.
Implementation Method 1
ionization signal sensing (or ion sense) uses a bias voltage applied across a sensor positioned within the combustion chamber to generate a signal indicative of the combustion quality and timing
Implementation Method 2
For spark-ignition engines, one or more spark plugs may be used as an ion sensor with the bias voltage applied across the air gap of the spark plug
Implementation Method 3
combustion quality and timing
Data Source
AI summary
A system and method for operating a multiple cylinder internal combustion engine having at least one actuator for controlling charge dilution of at least one cylinder and at least one spark plug per cylinder include attempting to improve combustion quality by modifying ignition energy of the at least one spark plug before modifying charge dilution of the cylinder, and modifying both ignition energy and charge dilution substantially simultaneously to establish combustion if an ionization sense signal associated with the cylinder indicates a misfire.