Engine Stop-Start Inhibition via Battery Load Assessment
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Solution Overview
Problem
Automatic engine stopping and starting in vehicles can fail due to battery degradation, leading to repeated failed restart attempts and potential engine misfires, especially when the battery is partially degraded, as the engine may not have sufficient power to restart.
Innovation Solution
A powertrain operating method that increases electrical loads on the battery during deceleration fuel shut-off and inhibits automatic engine stopping when battery voltage drops below a threshold, allowing the battery to be assessed for degradation without alternator interference, thus preventing engine misfires and ensuring successful restarts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If automatic engine stopping and starting is implemented to conserve fuel, then fuel efficiency is improved, but the system becomes unreliable when the battery is degraded
Solution Approach 1:
The system performs preliminary battery health assessment by applying electrical loads during deceleration fuel shut-off periods. This preliminary action detects battery degradation before it causes engine restart failures, allowing the system to prevent automatic stopping when the battery is weak, thus maintaining reliability while preserving fuel efficiency when the battery is healthy.
2Measurement precision
If electrical loads are applied to the battery during deceleration fuel shut-off to assess battery health, then battery degradation detection is improved, but the engine may experience misfires due to insufficient battery power
Solution Approach 1:
The system applies electrical loads partially - only during deceleration fuel shut-off periods when the engine is already rotating and does not require additional power for starting. This partial action allows battery assessment without causing engine misfires, as the engine is self-sustaining during these periods.
Solution Approach 2:
The control system acts as an intermediary by monitoring battery voltage during load application and comparing it against thresholds. This intermediary function allows the system to assess battery health while preventing excessive loading that would cause engine misfires, by adjusting or limiting the electrical loads based on real-time voltage measurements.
3Measurement precision
If the alternator output is reduced to zero during battery assessment, then battery health evaluation is improved without alternator interference, but the battery must be drained of charge more rapidly
Solution Approach 1:
The system uses periodic action by applying electrical loads only during deceleration fuel shut-off periods rather than continuously. This periodic loading allows battery health assessment while limiting the total charge drain, as the loads are applied intermittently during naturally occurring deceleration events rather than continuously.
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 method effectively diagnoses battery health, reduces engine no-start conditions, and prevents automatic engine stopping based on battery state, ensuring the engine operates without misfires and can be restarted successfully even in degraded battery conditions.
Implementation Method 1
A vehicle may include an engine, a battery, and an alternator
Implementation Method 2
A vehicle may include an engine, a battery, and an alternator
Data Source
AI summary
Systems and methods for operating a vehicle that includes an engine that may be automatically stopped and started are described. In one example, automatic stopping of the engine may be inhibited if voltage of a battery is reduced by more than a threshold voltage while an engine of the vehicle is operated in a deceleration fuel shut off mode.