Engine Controller Drift Detection Using Open-Loop Estimation
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Solution Overview
Problem
Conventional engine control systems face challenges in detecting and accommodating in-range drifts of effector parameters, which can lead to suboptimal performance and reduced robustness in gas turbine engines.
Innovation Solution
An engine control system utilizing an open-loop model (OLM) that synthesizes engine operating parameters based on measured effector and boundary condition vectors, with a gain map/function applied to detect errors and determine fault conditions, allowing for real-time detection and accommodation of in-range drifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional EPOS models are used to estimate engine parameters, then real-time control is achieved, but in-range drifts of effector parameters cannot be detected
Solution Approach 1:
The patent implements a feedback mechanism where the synthesized effector parameter from the open-loop model is compared against the measured effector parameter. This feedback loop enables detection of in-range drifts by continuously monitoring the difference between expected and actual values, resolving the contradiction between maintaining measurement precision and improving detection capability.
Solution Approach 2:
The open-loop model synthesizes the expected effector parameter in advance based on measured engine parameters before the actual measurement is taken. This preliminary calculation provides a reference value that can be compared with the measured value to detect drifts, enabling detection capability without compromising the precision of the measurement system itself.
2Measurement precision
If the gain map/function is made multi-dimensional to account for varying conditions, then detection accuracy improves, but computational complexity increases
Solution Approach 1:
The gain map is designed as a dynamic structure where the gain value changes based on operating conditions such as engine speed and load. This allows the system to adapt to varying conditions and maintain high detection accuracy across different operating ranges without requiring an excessively complex fixed structure, balancing accuracy with manageability.
Solution Approach 2:
The patent varies the gain parameter in the gain map/function based on engine operating conditions. By adjusting the gain dynamically according to parameters like engine speed and load, the system achieves high detection accuracy across different operating regimes while maintaining a relatively simple computational structure that can be managed in real-time control.
Data Source
AI summary
An engine control system includes an engine controller configured to execute an open-loop model of the engine control system. The open-loop model receives a measured effector and boundary condition parameter vector and generates a synthesized engine operating parameter based on the measured effector and boundary condition parameter vector. The engine controller calculates a corrector error value between the synthesized engine operating parameter and a measured engine operating parameter, and determines an open loop corrector error calculated as a difference between the corrector error and a vector-matrix product of corrector state vector and a gain map/function. The engine controller applies the gain map/function to the open loop corrector error to determine an effector and boundary condition error vector of the measured effector and boundary condition parameter vector.