Idle Speed Control Using Dual Moving Average Algorithms
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Solution Overview
Problem
Existing engine idling speed control methods fail to efficiently adjust fuel metering to achieve an optimal Air/Fuel (A/F) ratio, especially at low engine speeds, leading to potential instability and engine speed fluctuations.
Innovation Solution
A method involving moving average algorithms to monitor engine speed, with faster and slower reacting algorithms comparing engine speed data to adjust fuel metering between leaner and richer settings, using a fuel valve or air bleed valve to control fuel delivery, ensuring the A/F ratio is close to optimal and biased towards a slightly rich mixture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If manual fuel or air supply adjustment is used for idle speed control, then device complexity is reduced, but manufacturing precision of optimal A/F ratio is deteriorated
Solution Approach 1:
The control system automatically adjusts fuel metering during idle operation by comparing engine speed feedback with target speed, eliminating the need for manual adjustment while maintaining optimal A/F ratio. The system serves itself by continuously monitoring and correcting fuel delivery based on actual engine performance.
Solution Approach 2:
The system dynamically changes fuel metering parameters during idle operation to maintain optimal A/F ratio. By adjusting fuel delivery based on real-time engine speed measurements and comparing with target values, the system achieves precise control without manual intervention.
2Device complexity
If single engine speed value control is used, then device complexity is reduced, but manufacturing precision of optimal A/F ratio is deteriorated
Solution Approach 1:
The control system uses dynamic response characteristics with different time constants for speed measurement and target speed comparison. This dynamic approach allows the system to respond appropriately to engine speed changes while maintaining stability and achieving precise A/F ratio control during idle operation.
Solution Approach 2:
The system implements feedback control by continuously measuring actual engine speed, comparing it with target speed, and adjusting fuel metering accordingly. This closed-loop feedback mechanism enables precise A/F ratio control during idle operation without requiring complex manual adjustment procedures.
3Ease of operation
If existing idle control methods are used, then ease of operation is improved, but stability of engine speed is deteriorated
Solution Approach 1:
The control system uses feedback from actual engine speed measurements to continuously adjust fuel metering during idle operation. This feedback mechanism stabilizes engine speed by correcting deviations from target speed, preventing fluctuations while maintaining simple automated operation.
Solution Approach 2:
The system replaces manual mechanical adjustment with electronic control of fuel metering. By using electronic sensors and actuators to control fuel delivery based on digital speed measurements and comparisons, the system achieves both ease of operation and engine speed stability.
Data Source
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AI summary
Method for controlling fuel metering in a carburetor or a low pressure injection system of an internal combustion engine when the engine is operating at idle speed, the method comprising the steps of: a) monitoring the engine speed; b) determining a first variable (A) based on a first moving average algorithm using the monitored engine speed as input data; c) determining a second variable (B) based on a second moving average algorithm using the monitored engine speed as input data, where the first moving average algorithm is arranged to react faster to an engine speed change than the second moving average algorithm; d) comparing the second variable (B) to the first variable (A), where if 1) the second variable (B) is higher than the first variable (A): the fuel metering is set in a first leaner setting, and where if 2) the second variable (B) is lower than the first variable (A): the fuel metering is set in a second richer setting.