Engine Timing Map for Fuel Efficiency Within Combustion Limits
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Solution Overview
Problem
Existing engine control methods prioritize preignition, knocking, and combustion stability limits over fuel efficiency, leading to suboptimal performance.
Innovation Solution
A method for controlling engine fuel injection and ignition timing using a parameter map with multiple limit lines that optimize fuel efficiency while considering preignition, knocking, and combustion stability, allowing the ignition timing to be adjusted within a defined parameter region and shifted to maximum advance when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the preignition limit, knocking limit, and retard limit are used to restrict injection timing and ignition timing, then combustion stability and reliability are ensured, but fuel efficiency is suboptimal
Solution Approach 1:
The patent applies dynamics by making the parameter region dynamic rather than fixed. The parameter region is determined based on the current operating state of the engine (load, speed, temperature), allowing the boundaries for injection timing and ignition timing to adapt continuously. This enables the system to operate at the optimal edge of the stability region rather than being constrained by conservative fixed limits, thereby improving fuel efficiency while maintaining combustion stability.
Solution Approach 2:
The patent changes parameters by introducing a multi-dimensional parameter region defined by multiple limit lines (preignition limit line, smoke limit line, knocking limit line, retard limit line) on a parameter map. Instead of using single fixed timing values, the system selects optimal injection timing and ignition timing combinations within this parameter region, allowing flexible parameter adjustment to maximize fuel efficiency while ensuring reliable combustion under various operating conditions.
2Use of energy by moving object
If the ignition timing is advanced to improve fuel efficiency, then energy consumption is reduced, but preignition and knocking occur more frequently
Solution Approach 1:
The patent transitions from one-dimensional timing control to two-dimensional parameter space control. By plotting injection timing on the first axis and ignition timing on the second axis to form a parameter map, the system can optimize both parameters simultaneously within the parameter region. This dimensional expansion allows the system to find optimal combinations that advance timing for efficiency while staying within boundaries that prevent preignition and knocking.
Solution Approach 2:
The system uses feedback by determining the parameter region based on the current operating state of the engine and adjusting the control point (injection timing and ignition timing combination) accordingly. The controller monitors engine conditions and selects the optimal control point within the dynamically determined parameter region, enabling real-time adjustment to prevent harmful effects while maximizing efficiency.
3Use of energy by moving object
If the injection timing and ignition timing are optimized for fuel efficiency, then energy consumption is reduced, but combustion stability may be compromised
Solution Approach 1:
The patent makes the parameter region dynamic by determining it based on the current operating state (load, speed, temperature). This allows the system to adapt the boundaries for optimal timing combinations in real-time, ensuring combustion stability is maintained under varying conditions while maximizing fuel efficiency. The dynamic adjustment prevents the system from operating in unstable regions while capturing efficiency improvements.
Solution Approach 2:
The system changes parameters by defining a parameter region with multiple limit lines representing different constraints (preignition, smoke, knocking, retard limits). By selecting control points within this region rather than using fixed timing values, the system can adjust injection timing and ignition timing parameters to optimize fuel efficiency while the boundary lines ensure combustion stability is not compromised.
4Ease of operation
If a fixed control point is used for injection timing and ignition timing, then control simplicity is maintained, but fuel efficiency optimization is limited
Solution Approach 1:
The patent applies dynamics by replacing fixed control points with a dynamic parameter region that adapts to operating conditions. The controller determines the parameter region based on current engine state and selects optimal control points within this region, maintaining relatively simple control logic while achieving significant fuel efficiency improvements through adaptive timing optimization.
Solution Approach 2:
The system changes from fixed parameter values to a parameter region approach. Instead of using predetermined injection timing and ignition timing values, the system defines a region of acceptable values bounded by limit lines and selects optimal points within this region based on operating conditions. This parameter flexibility enables fuel efficiency optimization while the region-based approach keeps control complexity manageable.
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 enhances fuel efficiency by optimizing engine performance within various restrictions, ensuring stable combustion and minimizing adverse effects like preignition and knocking.
Implementation Method 1
a spark plug that ignites an air-fuel mixture containing the fuel injected from the injector
Data Source
AI summary
A method for controlling an engine includes selecting a control point consisting of a combination of an injection timing of injecting fuel and an ignition timing of igniting an air-fuel mixture, corresponding to a selection on a parameter map Mlim having the injection timing as a first axis and the ignition timing as a second axis, defines a parameter region Rlim surrounded by a first limit line Li1 indicating an advance limit at which preignition is restrained, a second limit line Li2 indicating an advance limit at which smoke is restrained, a third limit line Li3 indicating an advance limit at which knocking is restrained, and a fourth limit line Li4 indicating a retard limit at which combustion stability is ensured on the parameter map Mlim, and further includes a step of selecting the control point so the ignition timing is brought to maximum advance within the parameter region Rlim.