Engine Start-Stop Threshold Control for Catalyst Purification
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Solution Overview
Problem
Existing power unit control systems for internal combustion engines with catalysts face challenges in maintaining high purification capacity while minimizing fuel consumption and driver discomfort, particularly when the catalyst's purification rate is low, leading to inefficient engine operation and increased fuel consumption.
Innovation Solution
A control apparatus that adjusts engine start and stop thresholds based on the catalyst's purification capacity, setting lower engine start thresholds when the capacity is low to ensure earlier engine operation and prolong operation duration, thereby maintaining catalyst temperature and purification efficiency, and higher stop thresholds when the capacity is high to optimize fuel economy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If engine operation is prohibited from being stopped when the purification rate of the catalyst is low, then the catalyst purification capacity is maintained, but fuel consumption increases
Solution Approach 1:
The control system dynamically adjusts the engine stop determination based on the catalyst purification rate. When the purification rate is high, the engine can be stopped to save fuel. When the purification rate drops below a threshold, the engine is prohibited from stopping to maintain purification capacity. This dynamic adjustment resolves the contradiction between fuel economy and emission control.
Solution Approach 2:
The system continuously monitors the catalyst purification rate and uses this feedback to control engine stop/start decisions. The purification rate serves as a feedback signal that determines whether the engine should be allowed to stop, creating a closed-loop control system that balances fuel consumption and emission purification.
2Reliability
If engine operation is started when the purification rate of the catalyst is low, then the catalyst temperature rises and purification rate increases, but fuel consumption increases
Solution Approach 1:
The system proactively starts the engine before the purification rate becomes critically low, based on predicted driving conditions and catalyst temperature trends. This preliminary action prevents the need for frequent engine restarts and maintains the catalyst in an optimal temperature range, reducing overall fuel consumption while ensuring purification capacity is maintained.
Solution Approach 2:
The engine start decision is dynamically based on the current purification rate and predicted future conditions. The system calculates whether starting the engine will result in net fuel savings by maintaining purification capacity, rather than following fixed start/stop schedules.
3Use of energy by moving object
If the engine stop threshold is set low to optimize fuel economy, then fuel consumption decreases, but the catalyst purification capacity may deteriorate
Solution Approach 1:
The engine stop threshold is not fixed but dynamically adjusted based on real-time feedback from the catalyst purification rate sensor. The control system continuously compares the current purification rate against threshold values and adjusts the engine stop decision accordingly, ensuring fuel economy is optimized without compromising purification capacity.
Solution Approach 2:
The control system changes the operational parameters (engine stop threshold) based on the catalyst state. When purification rate is high, a lower stop threshold is used to maximize fuel economy. When purification rate drops, the threshold is raised to prevent engine shutdown, thereby maintaining purification capacity while still optimizing fuel consumption.
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
This approach effectively maintains high catalyst purification capacity, reduces fuel consumption, and minimizes driver discomfort by optimizing engine operation based on the catalyst's purification rate, ensuring efficient energy use and prolonged catalyst temperature for enhanced performance.
Implementation Method 1
an internal combustion engine 10 and a catalyst 43 that purifies components in exhaust gas discharged from a combustion chamber of the internal combustion engine
Implementation Method 2
exhaust gas at a relatively high temperature flows into the catalyst. Therefore, the temperature of the catalyst rises
Data Source
AI summary
A control apparatus for a power unit equipped with an internal combustion engine and outputs a power. The control apparatus according to the invention starts engine operation when the required power becomes equal to or larger than an engine start threshold during engine stop, and stops engine operation when the required power becomes equal to or smaller than an engine stop threshold during engine operation. The internal combustion engine is equipped with a catalyst. When the purification capacity of the catalyst is lower than a start threshold correction threshold, a value smaller than a reference engine start threshold is set as the engine start threshold. When the purification capacity of the catalyst is equal to or higher than the start threshold correction threshold, a value equal to the reference engine start threshold or a value larger than the reference engine start threshold is set as the engine start threshold.