Engine Idle Purge Control for RPM Stability
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Solution Overview
Problem
Existing engine control methods during canister idle purge fail to stabilize engine RPM and improve fuel efficiency, leading to uncomfortable driving conditions and increased reserve torque usage, especially when purge concentration learning is incomplete or during evaporation gas leak diagnosis.
Innovation Solution
A method and device that determine specific conditions for idle purge, adjust reserve torque based on purge concentration learning time and evaporation gas leak diagnosis, and control the purge valve to minimize RPM fluctuations, allowing for selective torque application to enhance fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reserve torque is increased to stabilize combustion during canister purge, then combustion stabilization is improved, but fuel efficiency deteriorates
Solution Approach 1:
The reserve torque is made dynamic rather than static. The control method calculates required reserve torque based on real-time purge gas concentration measurements and adjusts the torque accordingly. When purge gas concentration is high, more reserve torque is applied; when concentration is low, less reserve torque is applied, optimizing both combustion stability and fuel efficiency.
Solution Approach 2:
The system implements feedback control by continuously measuring purge gas concentration and using this information to adjust reserve torque. The oxygen sensor monitors exhaust gas oxygen levels, which serve as an indicator of purge gas concentration, and this feedback is used to dynamically adjust the torque controller's output, resolving the contradiction between stability and efficiency.
2Reliability
If reserve torque is applied during all idle purge operations, then combustion stabilization is improved, but fuel efficiency deteriorates
Solution Approach 1:
The control method applies different reserve torque strategies to different idle purge scenarios. Instead of uniform treatment, the system identifies specific purge conditions (high concentration vs. low concentration) and applies appropriate torque levels locally to each scenario, improving both stability where needed and efficiency where not required.
Solution Approach 2:
The system changes the parameter of reserve torque based on purge gas concentration levels. By monitoring oxygen sensor readings and adjusting reserve torque accordingly, the system adapts to varying purge conditions, applying torque only when and where it is necessary to maintain combustion stability.
3Object-generated harmful factors
If purge valve opening ratio is maximized to meet evaporation gas regulations, then evaporation gas control is improved, but engine RPM stability deteriorates
Solution Approach 1:
The purge valve opening ratio is made dynamic rather than fixed at maximum. The control method adjusts the opening ratio in real-time based on purge gas concentration measurements, allowing the system to meet emission regulations while maintaining engine RPM stability through adaptive control.
Solution Approach 2:
The system uses feedback from oxygen sensors to monitor exhaust gas composition and adjusts purge valve opening accordingly. This feedback loop enables the system to maintain proper evaporation gas control while preventing excessive RPM fluctuations by continuously adapting to actual purge conditions.
4Object-generated harmful factors
If purge gas concentration learning is incomplete during idle purge, then evaporation gas purging is improved, but engine RPM fluctuation increases
Solution Approach 1:
The control method performs preliminary actions by conducting purge concentration learning during part-load conditions before initiating idle purge operations. This preliminary learning phase calibrates the system's understanding of purge gas concentration characteristics, enabling more stable idle purge operations with reduced RPM fluctuations.
Solution Approach 2:
The system prepares for potential RPM fluctuations by conducting preliminary purge concentration learning and calibration before idle purge begins. This beforehand preparation cushions against unexpected RPM variations during actual idle purge operations, maintaining stability while achieving effective evaporation gas purging.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution stabilizes engine RPM, reduces uncomfortable noise and vibration, and minimizes reserve torque usage, thereby improving riding comfort and fuel efficiency by selectively applying torque only when needed during canister idle purge operations.
Implementation Method 1
the amount (concentration) of evaporation gas (HC) collected in the canister is determined by determining a feedback level of a fuel amount depending on the amount (concentration) of oxygen in exhaust gas detected by an oxygen sensor
Implementation Method 2
Evaporation gas (HC) is mostly produced when fuel remaining in a fuel tank volatilizes, so it is important to collect the evaporation gas (HC) produced by the volatilization in a canister
Implementation Method 3
supply the collected evaporation gas (HC) to an engine surge tank through a purge valve to send it to a combustion chamber
Implementation Method 4
supply the collected evaporation gas (HC) to an engine surge tank through a purge valve to send it to a combustion chamber
Data Source
AI summary
A method of controlling an engine during idle purge of a canister includes: determining whether current operation information of a vehicle satisfies an idle purge condition, determining whether canister purge learning time performed during a part load condition is a set time or more when a purge operation condition is satisfied, and performing idle purge of the canister when the canister purge learning time performed during the part load condition is the set time or more.