Virtual Lambda Sensing for Engine Manifold Mix Estimation
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Solution Overview
Problem
Current gas combustion engines face challenges in accurately measuring the oxidizer-fuel mix within the manifold, particularly in pre-mixed multi-staged turbocharged engines with gas recirculation, which affects engine performance and control, especially when physical sensors fail or are unavailable.
Innovation Solution
A method and system using a manifold model based on differential equations to derive gas concentration measurements from non-invasive sensors like pressure, temperature, and mass flow rate, enabling a virtual lambda sensor that predicts engine inlet conditions and provides fault-tolerant control, even without physical sensors, by employing an observer system with a Kalman filter for recursive estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If physical sensors are used to measure oxidizer-fuel mix in the manifold, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent creates a virtual copy of the physical lambda sensor by using a mathematical manifold model that replicates sensor functionality. The model uses readily available sensor data (pressure, temperature, mass flow rate) processed through differential equations to generate virtual lambda values, eliminating the need for expensive physical sensors in the manifold while maintaining measurement capability
Solution Approach 2:
The patent replaces the mechanical/physical sensor system with a computational model. Instead of using physical lambda sensors that require installation in the manifold, the system uses an electronic manifold model with differential equations that processes data from existing sensors to calculate gas concentration, substituting physical measurement with mathematical computation
2Measurement precision
If physical sensors are installed in the manifold, then measurement capability is improved, but reliability decreases due to sensor failure risk
Solution Approach 1:
The virtual sensor model serves as a backup copy that can provide measurement capability even when physical sensors fail. The manifold model continuously calculates gas concentration using alternative data sources, ensuring measurement functionality is maintained without dependency on any single physical sensor
Solution Approach 2:
The patent changes the measurement approach from direct physical sensing to indirect mathematical calculation. By using different parameters (pressure, temperature, mass flow rate) that are already measured by other sensors in the system, the model derives gas concentration through parameter transformation rather than direct measurement, bypassing physical sensor failure modes
3Device complexity
If a manifold model with differential equations is used to derive gas concentration, then device complexity is reduced, but measurement precision may be compromised
Solution Approach 1:
The patent implements feedback by using the manifold model to process real-time data from existing sensors and continuously update virtual sensor readings. The model receives feedback from the actual sensor measurements (pressure, temperature, mass flow rate) and adjusts calculations accordingly, maintaining accuracy while using a simpler virtual sensor approach
Solution Approach 2:
The manifold model serves multiple functions simultaneously: it processes data from various sensor types, handles different operating conditions, provides virtual sensor readings, and can adapt to different manifold configurations. This multi-functionality allows a single computational model to replace multiple specialized physical sensors while maintaining measurement quality
Data Source
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AI summary
In one embodiment, a method includes receiving, via a first sensor, a signal representative of at least one of a manifold pressure, a manifold temperature, or a manifold mass flow rate of a manifold. The method further includes deriving, via a manifold model and the first sensor signal, a gas concentration measurement at a first manifold section of the manifold. The method additionally includes applying the gas concentration measurement during operations of an engine, wherein the manifold is fluidly coupled to the engine.