HCCI Engine Torque Estimation via Fuel Mass and EGR Flow
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Solution Overview
Problem
Current powertrain control systems are unable to estimate the torque output of homogeneous charge compression ignition (HCCI) engines, as they operate differently from spark ignition (SI) and stratified charge compression ignition (SCCI) engines, requiring a distinct model to account for multiple fuel injection pulses and shorter combustion duration.
Innovation Solution
A control system and method that includes a mass determination module and a torque estimation module, estimating torque output based on fuel mass injected, engine speed, mass flow rate through an exhaust gas recirculation valve, oxygen level in the intake manifold, valve overlap, and air/fuel ratio, using specific torque estimation models and lookup tables tailored for HCCI engines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional powertrain control systems are used, then control of SI and SCCI engines is achieved, but torque estimation for HCCI engines is not possible
Solution Approach 1:
The patent applies parameter changes by developing a specialized torque estimation model for HCCI engines that accounts for unique parameters such as multiple fuel injection pulses, shorter combustion duration, and different ignition mechanisms. The model uses HCCI-specific parameters including fuel mass injected, engine speed, mass flow rate through EGR valve, oxygen level in intake manifold, valve overlap, and air/fuel ratio to accurately estimate torque output where conventional models fail.
2Productivity
If HCCI engine operation is controlled without specialized torque estimation, then fuel efficiency and emissions control are limited, but system complexity increases with specialized models
Solution Approach 1:
The patent implements universality by integrating the HCCI torque estimation model into the existing powertrain control system architecture. The control system maintains a library of torque estimation models for different engine types (SI, SCCI, HCCI) and automatically selects the appropriate model based on operating conditions, allowing a single control system to handle multiple engine types without requiring separate dedicated systems for each.
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
Accurately estimates torque output of HCCI engines, allowing for precise control and optimization of engine performance, improving fuel efficiency and emissions control.
Implementation Method 1
Homogeneous charge compression ignition (HCCI) engines combine aspects of spark ignition (SI) engines and stratified charge compression ignition (SCCI) engines to achieve emissions similar to SI engines and fuel efficiency similar to SCCI engines. In SI engines, air and fuel are mixed together and spark ignites the air-fuel mixture. In SCCI engines, air and fuel are mixed together and combustion occurs at the boundary of the air/fuel mixing due to compression. In HCCI engines, ignition occurs at several places at a time, which combust the air/fuel mixture faster than SI or SCCI engines.
Implementation Method 2
In SCCI engines, air and fuel are mixed together and combustion occurs at the boundary of the air/fuel mixing due to compression. In HCCI engines, ignition occurs at several places at a time, which combust the air/fuel mixture faster than SI or SCCI engines.
Data Source
AI summary
A system includes a mass determination module and a torque estimation module. The mass determination module determines a fuel mass injected into a cylinder of a homogeneous charge compression ignition (HCCI) engine for a combustion event in the cylinder. The torque estimation module estimates a torque output of the HCCI engine based on the fuel mass.