Propulsion Transient Response Predictor for Engine Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electronic engine controllers face challenges in consistently detecting engine conditions and responding to pilot commands, particularly in identifying runaway engine situations, due to significant influences from engine and ambient conditions, and are limited by small perturbation models and high computational complexity.
Innovation Solution
An electronic engine controller with an open loop transient response predictor that includes a computer processor, memory, and prediction logic to determine a predictive value for the propulsion system's closed loop response, utilizing a lookup table for altitude corrections, acceleration and deceleration transfer functions, and a selector logic to differentiate between acceleration and deceleration commands, ensuring predictions are only made within a valid operating window.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional approaches use small perturbation models to detect engine conditions, then the model complexity is reduced, but the response time increases and the model is limited to small changes in speed
Solution Approach 1:
The patent changes the fundamental parameters of the response model from small perturbation assumptions to large perturbation capabilities. The transfer function model is enhanced to handle large changes in rotor speed while maintaining computational efficiency through optimized mathematical representations and pre-computed lookup tables for transient response characteristics.
Solution Approach 2:
The patent implements preliminary action by pre-computing transient response characteristics and storing them in lookup tables during system initialization or offline processing. This allows the real-time controller to quickly query pre-computed data rather than performing complex calculations during critical response moments, reducing response time while maintaining accuracy for large perturbations.
2Device complexity
If conventional approaches use deceleration rate limits to identify runaway engine conditions, then the detection method is simple, but the results are not consistent due to engine and ambient condition influences
Solution Approach 1:
The patent implements feedback by continuously monitoring actual engine response against predicted transient response characteristics. The system compares measured rotor speed changes with model predictions and uses this feedback to detect discrepancies indicating runaway conditions, adapting to varying engine and ambient conditions through real-time comparison rather than fixed thresholds.
Solution Approach 2:
The patent changes the detection parameters from fixed deceleration rate limits to dynamic predictions based on actual engine state and ambient conditions. The transfer function model adjusts prediction parameters according to operating conditions, enabling consistent detection across varying scenarios rather than relying on static thresholds that fail to account for condition variations.
3Device complexity
If conventional approaches do not capture closed loop acceleration response characteristics, then the control logic is simpler, but the system cannot accurately determine whether the engine is accelerating or decelerating
Solution Approach 1:
The patent replaces mechanical threshold-based detection with a mathematical transfer function model that captures the dynamic characteristics of closed-loop acceleration response. This substitution enables precise determination of acceleration versus deceleration states by analyzing the mathematical relationship between commanded and actual rotor speed changes, providing accurate detection without complex mechanical sensing systems.
4Measurement precision
If the prediction logic uses transfer functions with altitude correction terms, then the prediction accuracy across various altitudes is improved, but the computational complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-computing altitude correction terms and storing them in lookup tables during offline processing or system initialization. During real-time operation, the controller simply queries pre-computed correction factors based on current altitude, avoiding the need to perform complex altitude correction calculations in real-time while maintaining high prediction accuracy across various altitudes.
Data Source
AI summary
An electronic engine controller includes a commanded rotor speed input, an altitude input, and a current rotor speed input, a computer processor, and a memory storing a prediction logic. The prediction logic is operable to cause the processor to determine a predictive value representative of a closed loop transient response of a propulsion system's actual corrected low rotor speed in response to a commanded change in low rotor speed.