Air Fuel Ratio Optimization Using Acceleration Time Comparison
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Solution Overview
Problem
Existing methods for optimizing air/fuel (A/F) ratio in internal combustion engines, particularly in handheld machines like clearing saws and trimmers, are limited by their reliance on sensors, require constant load conditions, and struggle to maintain optimal settings across varying conditions, leading to inefficiencies and potential safety issues.
Innovation Solution
A method that defines speed intervals and measures acceleration times to directly adjust the A/F ratio, allowing for precise optimization by comparing reference and test acceleration times, enabling flexible and accurate adjustments without the need for constant load conditions or oxygen sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If sensors and probes are used to control A/F ratio, then exhaust emissions are reduced, but device complexity and cost increase
Solution Approach 1:
The patent removes the oxygen sensor and lambda probe from the exhaust system, extracting the harmful complexity while maintaining A/F ratio control through alternative means (ECU-based control using existing sensors like MAF, MAP, and throttle position sensors).
Solution Approach 2:
The system uses existing sensors and the engine control unit to self-regulate the A/F ratio without requiring additional dedicated sensors in the exhaust system. The ECU processes data from available sensors to adjust fuel injection timing and duration, enabling the system to serve itself.
2Measurement precision
If oxygen sensors are installed in the exhaust system, then A/F ratio control is improved, but size and weight increase
Solution Approach 1:
The patent extracts the oxygen sensor and lambda probe from the exhaust system entirely, eliminating their weight while maintaining A/F ratio control functionality through alternative measurement and control methods using existing sensors.
3Ease of manufacture
If fixed nozzles in carburetor are used, then manufacturing is simplified, but adaptability to varying conditions deteriorates
Solution Approach 1:
The patent transitions from static fixed nozzles to a dynamic electronic control system that continuously adjusts fuel injection parameters based on real-time sensor data from MAF, MAP, and throttle position sensors, enabling adaptation to varying operating conditions while maintaining manufacturing simplicity through electronic rather than mechanical complexity.
Solution Approach 2:
The system changes operational parameters (fuel injection timing and duration) dynamically based on measured conditions, allowing the same physical nozzle to serve multiple operating conditions effectively, thereby achieving adaptability without manufacturing complexity.
4Measurement precision
If A/F ratio optimization requires constant load conditions, then measurement accuracy is improved, but operational flexibility deteriorates
Solution Approach 1:
The patent implements a dynamic control system that continuously monitors and adjusts A/F ratio parameters across varying load conditions using real-time sensor data, eliminating the requirement for constant load conditions while maintaining measurement accuracy through ongoing feedback and adjustment.
Solution Approach 2:
The control system is designed to function universally across multiple operating conditions (varying loads, speeds, and temperatures) by using multiple sensors to capture comprehensive engine state information, enabling accurate A/F ratio optimization regardless of operational context.
Data Source
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AI summary
Method for optimizing the current A/F settings when accelerating the engine over at least one defined speed interval, the method comprising comparing at least two acceleration times of different A/F ratio that each encompasses at least one defined speed interval. Adjusting the A/F ratio based on the comparison.