Engine Spark Timing Control for Driveline Torque Disturbance Reduction
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Solution Overview
Problem
Automatically starting an engine while the transmission is in gear can cause torque disturbances in the vehicle driveline, leading to inconsistent engine starting and increased NOx emissions during controller-initiated restarts.
Innovation Solution
Adjusting spark timing to be retarded of the top-dead-center compression stroke during controller-initiated engine starts and advancing it for operator-initiated starts, allowing for controlled engine torque delivery and reduced driveline disturbances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the engine is automatically started while the transmission is in gear, then fuel conservation is improved, but torque disturbances occur in the vehicle driveline
Solution Approach 1:
The patent applies parameter changes by adjusting spark timing to be retarded of top-dead-center compression stroke during controller-initiated automatic engine starts. This modification of the spark timing parameter reduces the peak torque output during engine cranking, thereby minimizing torque disturbances transmitted to the driveline while maintaining the fuel-saving benefit of automatic engine restart
2Speed
If spark timing is advanced for operator-initiated starts, then engine acceleration is improved, but driveline torque disturbances increase during controller-initiated starts
Solution Approach 1:
The patent applies local quality by implementing different spark timing strategies for different start types. For controller-initiated automatic starts, spark timing is retarded to reduce torque disturbances. For operator-initiated starts, spark timing can be advanced to provide robust engine acceleration. This localized optimization allows each start scenario to have its own optimal spark timing characteristics
Solution Approach 2:
The patent applies dynamics by making spark timing adjustable and adaptive based on the type of engine start request. The system dynamically selects between retarded spark timing for automatic starts and advanced spark timing for operator-initiated starts, allowing the engine control system to optimize performance for each specific operating condition
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
Improves engine starting consistency, reduces driveline torque disturbances, and lowers NOx emissions during controller-initiated engine restarts by managing spark timing differently based on start type.
Implementation Method 1
cranking the engine via a starter
Implementation Method 2
adjusting a spark timing for a cylinder of the engine
Implementation Method 3
combustion event in the cylinder
Data Source
AI summary
A method for improving starting of an engine that may be automatically started is provided. In one example, spark timing of an automatically started engine is in advance of spark timing for an operator requested engine start. The approach may reduce vehicle driveline disturbances.