Cylinder Fueling Coordination for Torque Estimation
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Solution Overview
Problem
Existing engine torque estimation and control systems face challenges in accurately managing torque transitions during partial cylinder deactivation, leading to abrupt torque reductions and potential noise, vibration, or harshness issues, especially when combined with hybrid applications.
Innovation Solution
An engine control system that coordinates cylinder deactivation with spark advance, where the spark advance is increased after fuel delivery is halted to a cylinder, smoothing torque transitions by offsetting the torque reduction and ensuring synchronized communication between cylinder deactivation and spark control to prevent erroneous torque estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If partial cylinder deactivation is used to reduce pumping losses, then fuel economy is improved, but torque estimation accuracy deteriorates due to abrupt torque reductions
Solution Approach 1:
The spark advance is increased in advance of the expected torque reduction from cylinder deactivation. The control system predicts when a cylinder will be deactivated and pre-adjusts the spark timing to compensate for the upcoming torque change, ensuring smooth torque transitions and maintaining accurate torque estimation.
Solution Approach 2:
The control system continuously monitors actual torque and compares it with estimated torque, using this feedback to dynamically adjust spark advance timing. This closed-loop control ensures that torque estimation remains accurate even during cylinder deactivation events by real-time compensation for torque variations.
2Use of energy by moving object
If cylinder deactivation is implemented to reduce fuel usage, then fuel consumption is reduced, but noise and vibration increase due to abrupt torque changes
Solution Approach 1:
The spark advance is adjusted in advance of cylinder deactivation to smooth torque transitions. By pre-modifying the ignition timing, the system prevents abrupt torque changes that would otherwise cause noise and vibration, allowing cylinder deactivation to proceed smoothly while maintaining comfort.
Solution Approach 2:
The control system applies a counteracting spark advance increase before the torque reduction from cylinder deactivation occurs. This preliminary anti-action compensates for the upcoming torque drop, preventing the harmful effects of abrupt torque changes on noise and vibration.
3Stability of the object's composition
If spark advance is increased after fuel delivery is halted, then torque transitions are smoothed, but control complexity increases due to coordination requirements
Solution Approach 1:
The control system merges the cylinder deactivation logic with the spark advance control logic into a unified control strategy. By integrating these two control functions, the system coordinates spark timing adjustments with fuel delivery halting automatically, smoothing torque transitions while managing complexity through consolidation rather than separate independent controls.
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 enables smooth torque reduction and increase, reducing noise and vibration, and improves torque estimation accuracy by synchronizing spark advance with cylinder deactivation, enhancing engine control and hybrid operation efficiency.
Implementation Method 1
The fueling control module halts fuel delivery to the first cylinder based on the deactivation signal
Implementation Method 2
The torque control module increases a spark advance of the engine at a first time after the fueling control module halts fuel injection for the first cylinder
Implementation Method 3
The torque produced by the activated (fueled) cylinders may be referred to as indicated torque or cylinder torque
Data Source
AI summary
An engine control system comprises a torque control module and a fueling control module. The torque control module selectively generates a deactivation signal for a first cylinder of a plurality of cylinders of an engine based on a torque request. The fueling control module halts fuel delivery to the first cylinder based on the deactivation signal. The torque control module increases a spark advance of the engine at a first time after the fueling control module halts fuel injection for the first cylinder. The first time corresponds to an initial time combustion fails to occur in the first cylinder because fuel delivery has been halted.