Vehicle Shift Control with Stoichiometric Lean Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle control systems face challenges in managing torque fluctuation and catalyst deterioration during shifting operations, especially when the air-fuel ratio is switched between lean and rich states, leading to unstable engine operation, erroneous learning, shift shock, and catalyst degradation.
Innovation Solution
A controller is configured to maintain a lean air-fuel ratio closer to stoichiometric during shifting processes, suppressing torque fluctuation and minimizing catalyst deterioration by setting the air-fuel ratio to a value closer to stoichiometric only during shifting, while keeping it leaner than stoichiometric both before and after shifting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the air-fuel ratio is switched to a rich state during shifting to suppress torque fluctuation, then engine stability is improved, but catalyst deterioration accelerates
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the air-fuel ratio based on the shifting state. During shifting, the air-fuel ratio is set to a first value closer to stoichiometric (reducing catalyst deterioration), while during non-shifting lean operation, it is set to a second leaner value (maintaining engine stability and oxygen supply). This temporal parameter adjustment resolves the contradiction between engine stability and catalyst protection.
2Object-affected harmful factors
If the air-fuel ratio is maintained lean during shifting to supply oxygen to the catalyst, then catalyst regeneration is improved, but torque fluctuation increases
Solution Approach 1:
The patent resolves this contradiction by changing the air-fuel ratio parameter based on shifting detection. When shifting is detected, the system switches to a first air-fuel ratio value that is closer to stoichiometric, which reduces torque fluctuation while still allowing catalyst oxygen supply. This dynamic parameter adjustment enables simultaneous achievement of both catalyst regeneration and engine stability.
3Adaptability or versatility
If the air-fuel ratio is switched frequently between lean and rich states, then engine operation adaptability is improved, but system complexity increases
Solution Approach 1:
The patent applies dynamics by implementing a shifting state detection mechanism that dynamically adjusts the air-fuel ratio based on real-time shifting conditions. The controller detects shifting events and automatically switches between two air-fuel ratio values, providing adaptive engine operation without requiring complex multi-parameter control systems. This dynamic approach maintains simplicity while achieving high adaptability.
Data Source
AI summary
A controller is configured to control a vehicle that includes an internal combustion engine and an automatic transmission. The controller is configured to execute a shifting process that switches a gear ratio of the automatic transmission and a lean operation process that operates the internal combustion engine with an air-fuel ratio of the air-fuel mixture in a cylinder leaner than a stoichiometric air-fuel ratio. The controller is further configured to, when executing the shifting process during execution of the lean operation process, set an air-fuel ratio in a case in which the shifting process is being executed to a value closer to the stoichiometric air-fuel ratio than an air-fuel ratio in a case in which the shifting process is not being executed.