Cylinder Activation Sequences for Engine Vibration Control
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Solution Overview
Problem
Internal combustion engines face challenges in minimizing powertrain-induced vibration and noise when deactivating cylinders to improve fuel efficiency, as this can lead to increased harmonic vehicle vibration and induction/exhaust noise.
Innovation Solution
An engine control module determines a target cylinder count and generates sequences for activating and deactivating cylinders over sub-periods to achieve a balanced torque production, minimizing vibrations and noise by selectively opening and closing intake and exhaust valves, and halting fuel injection in deactivated cylinders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If cylinders are deactivated to improve fuel efficiency, then fuel consumption decreases, but powertrain-induced vibration and noise increase
Solution Approach 1:
The patent implements periodic action by cycling cylinders between active and deactivated states in a predetermined sequence over multiple engine cycles. Instead of permanently deactivating cylinders, the system periodically activates them to maintain balanced torque production and minimize vibrations, then deactivates them to improve fuel efficiency during appropriate phases of the cycle.
Solution Approach 2:
The system dynamically adjusts cylinder activation status based on engine operating conditions and predetermined sequences. The cylinder actuator module continuously monitors and modifies which cylinders are active versus deactivated, creating a dynamic balance between fuel efficiency and vibration control rather than using a static deactivation strategy.
2Loss of energy
If cylinders are deactivated to reduce fuel consumption, then fuel efficiency improves, but torque production capability decreases
Solution Approach 1:
The predetermined sequence periodically activates specific cylinders to produce torque during phases when power demand requires it, then deactivates them during phases when fuel efficiency is prioritized. This periodic torque contribution from selectively activated cylinders maintains overall torque production capability while achieving fuel savings during deactivation phases.
Solution Approach 2:
The system changes the operational parameter of cylinder activation status between active and deactivated states according to a predetermined sequence. By strategically selecting which cylinders to activate or deactivate at different times, the system optimizes the balance between fuel consumption and torque production capability across varying engine operating conditions.
Data Source
AI summary
A target cylinder count module determines a target number of cylinders of an engine to be activated during a future period. The future period includes N sub-periods, and N is an integer greater than one. Based on the target number, a first sequence setting module generates a sequence indicating N target numbers of cylinders to be activated during the N sub-periods, respectively. A second sequence setting module retrieves N predetermined sequences for activating and deactivating cylinders during the N sub-periods, respectively, and generates a target sequence for activating and deactivating cylinders during the future period based on the N predetermined sequences. During the future period, a cylinder actuator module: activates opening of intake and exhaust valves of the cylinders that are to be activated based on the target sequence; and deactivates opening of intake and exhaust valves of the cylinders that are to be deactivated based on the target sequence.