Engine Starting Control via Adaptive Spark Timing
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Solution Overview
Problem
Automatically stopped and started engines experience increased degradation due to reduced oil pressure and higher cylinder pressures during starting, leading to undesirable torque levels and potential engine component stress, which existing control methods struggle to manage effectively.
Innovation Solution
Retarding spark timing advanced from minimum spark timing for best torque (MBT) in response to sensor outputs exceeding or falling below threshold levels correlated to crankshaft, bearing, or rod degradation, using a knock sensor to adjust engine speed and reduce stress on engine components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If spark timing is advanced from MBT timing to reduce engine speed, then engine speed is controlled, but cylinder pressures increase causing engine degradation
Solution Approach 1:
The system uses a knock sensor to detect cylinder pressures and provides feedback to the controller. The controller adjusts spark timing based on this feedback, retarding timing when knock is detected to prevent excessive cylinder pressures while maintaining engine speed control during automatic starting.
Solution Approach 2:
The spark timing is made dynamically adjustable during the engine starting sequence. The controller can advance or retard timing from MBT based on real-time conditions, allowing optimization of both engine speed control and cylinder pressure management during the transient starting phase.
2Force
If engine speed is controlled via spark advance to reduce torque, then driveline torque is reduced, but engine degradation increases due to higher cylinder pressures
Solution Approach 1:
The knock sensor provides real-time feedback on cylinder pressure conditions, allowing the controller to adjust spark timing to balance driveline torque reduction with engine component protection during automatic starting sequences.
Solution Approach 2:
The system changes the spark timing parameter dynamically during starting, adjusting it from MBT timing based on detected conditions. This allows optimization of both torque delivery to the driveline and protection of engine components from excessive pressures.
3Use of energy by moving object
If engine is automatically stopped and started to conserve fuel, then fuel economy improves, but engine degradation increases due to low oil pressure and high cylinder pressures
Solution Approach 1:
The system prepares for potential engine degradation by having the knock sensor ready to detect excessive cylinder pressures during starting. The controller can immediately respond by retarding spark timing if degradation is detected, protecting components during the vulnerable starting phase after automatic stop.
Solution Approach 2:
Real-time feedback from the knock sensor allows the system to monitor engine component stress during automatic starting and adjust spark timing accordingly, balancing fuel economy benefits with engine protection during stop-start operation.
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 improves engine starting control, reduces degradation, and enhances vehicle drivability by managing engine speed and emissions through adaptive spark timing adjustments based on real-time sensor feedback.
Implementation Method 1
output of a sensor exceeding or being less than a threshold level correlated to crankshaft, bearing, or rod degradation... If output of the knock sensor is greater than a threshold level
Data Source
AI summary
Systems and methods for restarting an engine are presented. In one example, spark timing during engine starting is adjusted in response to engine speed and a second control parameter. The second control parameter may be correlated with crankshaft or rod degradation. Spark may be advanced from minimum spark for best torque when engine speed is greater than desired and when the second control parameter does not provide an indication of engine degradation.