Predictive Valve Timing Control for Engine Airflow Accuracy

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Solution Overview

Problem

Existing engine control systems fail to accurately adjust the fuel mixture during transient operating phases due to poor airflow estimation, leading to increased pollutant emissions, engine noise, and driving discomfort due to jerking.

Innovation Solution

Implement a predictive control method for the fuel mixture in engines with variable intake valve timing, using a response model to anticipate the valve position and adjust fuel injection accordingly, reducing the dead time in airflow estimation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional airflow estimation method is used during transient phases, then the control system is simple to implement, but the airflow estimation accuracy deteriorates leading to poor fuel mixture control

Engineering Contradiction:

Improveairflow estimation accuracyVSAvoidcontrol system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary actions by predicting the future position of the variable intake valve timing system before fuel injection occurs. A response model anticipates valve position changes during transient phases, allowing the control system to calculate airflow based on the predicted valve position rather than the current measured position, thereby improving airflow estimation accuracy during dynamic transitions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by continuously comparing the predicted valve position with actual valve position measurements. The response model is updated based on the difference between predicted and actual positions, allowing the system to learn and adapt to the specific characteristics of the valve timing system, thereby improving prediction accuracy over time while maintaining a relatively simple control structure.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If the fuel injection timing is not synchronized with actual valve position, then the control response is fast, but the fuel mixture richness control accuracy deteriorates

Engineering Contradiction:

Improvefuel mixture richness control accuracyVSAvoiddead time in airflow estimation

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary calculation of the valve position at the expected time of fuel injector opening. By using the response model to predict where the valve will be positioned when injection occurs, the system eliminates the time lag between measurement and control action, ensuring that fuel injection is precisely synchronized with the actual airflow conditions without adding delays to the control response.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If variable valve timing system position changes during transient phases, then the engine adaptability improves, but the airflow estimation accuracy deteriorates due to position variations

Engineering Contradiction:

Improveengine adaptabilityVSAvoidairflow estimation accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The response model performs preliminary prediction of the valve timing system position during transient phases. Instead of relying on current position measurements that become obsolete during rapid transitions, the model anticipates the future valve position based on the commanded change and system characteristics, allowing accurate airflow estimation even when the valve timing system is actively changing position to adapt to varying engine conditions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system changes the parameter used for airflow estimation from the current measured valve position to the predicted future valve position. This parameter change allows the system to maintain accurate airflow estimation during transient phases when the valve timing system is changing position, by using the predicted position that reflects the actual airflow-generating state of the engine at the time of fuel injection.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP4234909B1Method for controlling richness in a carburized mixture of an internal combustion engine of a motor vehicle

Publication Date: 2026.04.01 HORSE POWERTRAIN SOLUTIONS S L U

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AI summary

This method for controlling the air-fuel ratio of a fuel mixture in an internal combustion engine (10) of a motor vehicle equipped with a variable valve timing system (50) comprises the following steps: - detecting a change in the engine operating point; - calculating at least one setpoint for the position of said system; - measuring the current position of said system; - predictively calculating a position of said system; - estimating the airflow rate from said predictive calculation; - calculating, from the estimated airflow rate, the quantity of fuel to be injected for engine operation at air-fuel ratio 1, and opening the engine's fuel injectors to inject said quantity of fuel. The predictive calculation of the position of the variable valve timing system (50) corresponds to the position of said system at the moment the fuel injectors open.