Engine Throttle Valve Area Estimation Using Deposit Learning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for calculating the throttle valve effective opening area in internal combustion engines fail to accurately reflect the influence of deposit accumulation, leading to errors in in-cylinder inflow gas flow rate calculations during transient operations, which affects the air-fuel ratio control.
Innovation Solution
A control device that identifies specific throttle valve opening degrees where the change rate of the effective opening area due to deposit adhesion occurs, estimates the deposit thickness at these degrees, and calculates the effective opening area using learned values and physical models to accurately account for deposit accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the throttle valve effective opening area is calculated using a standard intake measurement model without deposit correction, then the calculation is simple and fast, but the accuracy deteriorates due to deposit accumulation blocking the flow passage
Solution Approach 1:
The system performs preliminary learning of the throttle valve effective opening area characteristics under steady-state conditions before transient operations occur. The learned values are stored and then applied during transient operations to maintain accurate calculations without requiring complex real-time computations
Solution Approach 2:
The patent introduces an intermediary learning mechanism that mediates between the simple standard intake measurement model and the need for deposit correction. The learned values act as an intermediary layer that compensates for deposit effects without requiring direct modification of the standard model structure
2Measurement precision
If three throttle valve opening degrees with large intervals are used for quadratic curve approximation, then the model covers a wide range, but the accuracy deteriorates in the range between the first and third opening degrees
Solution Approach 1:
The patent segments the throttle valve opening degree range into multiple intervals, with each interval having its own learned values and quadratic curve approximations. This allows accurate local modeling in each segment while maintaining overall coverage across the full operating range
Solution Approach 2:
The system applies local quality by creating deposit correction characteristics specific to each throttle valve opening degree interval. Each interval has its own learned parameters that reflect the local deposit accumulation patterns, improving accuracy in each specific range
3Measurement precision
If the throttle valve effective opening area is not corrected for deposit accumulation, then the system operation is simple, but the air-fuel ratio control accuracy deteriorates during transient operations
Solution Approach 1:
The system performs self-service by automatically learning and updating its own deposit correction characteristics during normal operation. The ECU autonomously acquires learned values during steady-state conditions and applies them during transient operations without requiring external intervention or complex manual calibration
Solution Approach 2:
The patent implements feedback by continuously monitoring the throttle valve opening degree and using learned values to correct the effective opening area calculations. The system uses past learning results to improve current transient operation accuracy, creating a feedback loop that maintains precision over time
Data Source
AI summary
A processor (CPU 40e) of a control device (ECU 0) for an internal combustion engine identifies a first throttle valve opening degree θA and a second throttle valve opening degree θB at which a change rate (differential value) of an index (a deposit thickness, a decrease rate of an effective opening area, a flow rate decrease rate, and the like) correlated with a decrease rate of an effective opening area of a throttle valve changes (s109). The processor (CPU 40e) estimates an index at any throttle valve opening degree from the first throttle valve opening degree θA and the second throttle valve opening degree θB (s110), and calculates an effective opening area of the throttle valve from the estimated index (s112).