Engine Controller Combustion Mode Transition Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional diesel combustion modes struggle to meet future emission levels, and seamless switching between different combustion modes, such as HCCI, LTC, and PCCI, is challenging due to sensitivity to engine conditions and poor control over in-cylinder conditions, affecting drivability and emissions.
Innovation Solution
A dynamic engine model is developed to control in-cylinder conditions, using a graphical simulation environment to design an engine controller that manages intake and exhaust passage dynamics, with actuators like the turbocharger, intake manifold throttle, and EGR throttle, to achieve desired pressure and air fraction conditions for optimal combustion mode transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If alternate combustion modes (HCCI, LTC, PCCI) are implemented to reduce emissions, then emission levels are improved, but control over in-cylinder conditions deteriorates
Solution Approach 1:
The control system performs preliminary actions by predicting future in-cylinder conditions based on current operating parameters and proactively adjusting control variables (fuel injection timing, EGR rate, intake valve timing) before deviations occur. This predictive control approach prevents combustion mode instability rather than reacting to it after it occurs.
Solution Approach 2:
The system implements closed-loop feedback control by continuously monitoring in-cylinder pressure, temperature, and combustion phasing, then using this information to adjust control variables in real-time. The feedback mechanism maintains stable combustion modes by compensating for deviations caused by the inherent sensitivity of alternate combustion modes.
2Ease of operation
If seamless switching between combustion modes is achieved, then drivability is improved, but control complexity increases
Solution Approach 1:
The control system dynamically adapts control parameters based on the current combustion mode and transition state. Different control strategies are applied for different modes (HCCI, LTC, PCCI, conventional diesel), and the system smoothly transitions between these strategies as operating conditions change, enabling seamless mode switching that maintains drivability.
Solution Approach 2:
The control space is segmented into distinct combustion modes with specific control parameter ranges for each mode. The system identifies the current mode and applies mode-specific control strategies, making the overall complex control problem manageable by dividing it into smaller, mode-specific sub-problems that can be handled independently.
3Stability of the object's composition
If in-cylinder conditions are controlled more precisely, then combustion mode stability is improved, but response time decreases
Solution Approach 1:
The control system performs preliminary adjustments to control variables based on predicted combustion conditions, preventing instability before it develops. By anticipating required adjustments rather than reacting to deviations, the system maintains stability without requiring rapid corrective actions that would reduce response time.
Data Source
AI summary
A method of controlling a diesel engine that is capable of multiple combustion modes and equipped with a turbocharger and EGR loop. The control method avoids a singularity condition inherent in turbocharged diesel engine having multiple combustion modes. For different combustion modes, different system states, control variables, and actuators are carefully chosen for different controllers based on the characteristics of the corresponding combustion mode as well as sensor and measurement limitations.