Adaptive Engine Stoppage Detection via Variable Crankshaft Timeout
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Solution Overview
Problem
Existing methods for detecting the physical stoppage of an internal combustion engine require a fixed timeout period, which can lead to unnecessary delays in restarting the engine, especially in vehicles equipped with 'stop and start' systems, as they wait for 300 ms to confirm engine stoppage before allowing restart.
Innovation Solution
A method that adjusts the timeout value based on the angular position of the crankshaft and the number of teeth on the toothed wheel, with shorter timeouts for preferential stopping positions and longer timeouts for the signature zone, allowing for more rapid detection of engine stoppage while ensuring robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed timeout period of 300 ms is used to detect engine stoppage, then the detection reliability is ensured, but the engine restart is delayed
Solution Approach 1:
The patent applies dynamics by making the timeout value adjustable rather than fixed. The timeout is adapted based on the crankshaft angular position, using shorter timeouts for preferential stopping positions and longer timeouts for the signature zone, allowing the system to optimize between reliability and speed depending on the operational context
Solution Approach 2:
The patent implements local quality by assigning different timeout values to different angular positions of the crankshaft. Specifically, preferential stopping positions receive shorter timeout values (enabling faster restart) while the signature zone receives longer timeout values (ensuring reliable detection), thus optimizing each region's detection parameters according to its specific requirements
2Productivity
If a shorter timeout value is used to enable faster engine restart, then the productivity is improved, but the detection reliability may be compromised
Solution Approach 1:
The patent resolves this contradiction by applying different timeout values to different angular positions. Preferential stopping positions use shorter timeouts to enable faster restart (improving productivity), while the signature zone uses longer timeouts to maintain detection reliability, thus achieving both goals in their respective locations
Solution Approach 2:
The system dynamically adjusts the timeout value based on the detected angular position of the crankshaft, switching between short and long timeout regimes depending on whether the engine is at a preferential stopping position or in the signature zone, thereby optimizing both productivity and reliability
Data Source
AI summary
A method for detecting the physical stoppage of an internal combustion engine including a crankshaft that drives a toothed wheel having a plurality of teeth, each tooth corresponding to different angular positions of the crankshaft, a sensor positioned next to the toothed wheel generates a signal characteristic of the passage of a tooth. The method detects a tooth from the signal generated by the sensor, identifies the tooth detected, triggers a timeout, and detects stoppage of the engine if the passage of a tooth adjacent to the tooth detected has not been detected before the end of the timeout. The value of the timeout is dependent on the tooth identified, and including: determining crankshaft angular position depending on the tooth identified, the value of the timeout dependent on the angular position of the crankshaft, determining the preferential stopping positions of the crankshaft and assigning a first timeout value for the preferential stopping positions and assigning at least a second value for the other positions of the crankshaft. The first timeout value being less than the second timeout value.