Vehicle Starter Control for Quiet Pinion Engagement
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Solution Overview
Problem
The existing vehicle control systems face challenges in accurately predicting engine rotation speed during inertial rotation, leading to suboptimal timing for engaging the pinion with the ring gear, which results in increased bite-in sound and delayed engine restart due to limitations in rotation sensor output intervals.
Innovation Solution
A vehicle control device that includes an automatic stop unit, an automatic start unit, and an engine rotation detection unit, which estimates the crank phase or rotation number of the engine, allowing for starter operation control at intervals shorter than the update interval of the engine rotation sensor signal, thereby optimizing starter operation timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the pinion is engaged in advance with the ring gear during inertial rotation to reduce bite-in sound, then the engagement timing can be optimized for quiet operation, but the engine restart cannot be performed quickly when a restart request is generated
Solution Approach 1:
The pinion is engaged with the ring gear in advance during inertial rotation before the engine completely stops, preparing the starter mechanism for quick operation. This preliminary engagement allows the starter to immediately begin cranking when a restart request is generated, reducing the overall restart time while maintaining quiet operation during the engagement phase
2Loss of time
If the pinion is engaged at high rotation speed to prepare for quick restart, then the engine restart can be performed quickly, but the bite-in sound increases
Solution Approach 1:
The pinion engagement is performed in advance during inertial rotation when the engine rotation speed is naturally decreasing, allowing the engagement to occur at an optimal timing that balances quiet operation with readiness for quick restart. The preliminary engagement ensures the starter is prepared while avoiding high-speed engagement that would generate noise
3Measurement precision
If the rotation speed of the engine is predicted during inertial rotation to determine optimal engagement timing, then the starter operation can be controlled precisely, but the prediction accuracy decreases when the output interval of the rotation sensor is long
Solution Approach 1:
The rotation speed prediction is performed in advance during inertial rotation using the rotation sensor output, allowing the engagement timing to be determined before the engine completely stops. This preliminary prediction enables precise control of the starter operation even when the sensor output interval is long, as the prediction is based on the rotational characteristics captured during the inertial phase
4Object-affected harmful factors
If the pinion engagement is delayed until the engine stops completely to reduce noise, then the bite-in sound is minimized, but the engine restart is delayed
Solution Approach 1:
The pinion engagement is performed in advance during inertial rotation rather than waiting for the engine to stop completely. This preliminary engagement allows the starter to be ready for immediate operation when a restart request is generated, reducing the overall restart time while maintaining acceptable noise levels during the engagement phase
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 solution enables precise starter operation control at optimal timing, reducing bite-in sound and accelerating engine restart, even in regions with long output intervals of the engine rotation sensor, ensuring efficient and quick engine reactivation.
Implementation Method 1
in a rotation sensor of an electromagnetic pickup type used generally for detecting the engine rotation number
Data Source
AI summary
Provided is a system of carrying out engagement of a pinion and a ring gear at optimal timing and suppressing a bite-in sound, in a vehicle including an idle stop system. In a vehicle control device including an automatic stop unit which automatically stops an engine on the basis of an operating state of a vehicle; an automatic start unit which controls a starter during a period until the engine completely stops after the automatic stop unit executes the automatic stop of the engine, and restarts the engine; and an engine rotation detection unit which detects or operates a crank phase or a rotation number of the engine, the automatic start unit determines a control command of the starter at an interval shorter than an update interval of a signal of the engine rotation detection unit.