Recursive Cylinder Deactivation Algorithm for Torque Smoothness
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Solution Overview
Problem
Variable cylinder deactivation systems in internal combustion engines face challenges in minimizing noise and vibration (N&V) while maintaining torque delivery smoothness, as existing deactivation patterns can lead to undesirable vehicle vibrations and pulsating torque due to non-periodic and sometimes random deactivation sequences.
Innovation Solution
A cylinder control module generates a desired cylinder activation/deactivation sequence based on predetermined sub-sequences and operating conditions, selectively activating and deactivating intake and exhaust valves, and adjusting fueling to minimize N&V and maximize torque smoothness by selecting future deactivation patterns based on previous patterns and current vehicle conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If cylinders are deactivated to decrease fuel consumption, then fuel efficiency is improved, but noise and vibration increase due to non-periodic deactivation sequences
Solution Approach 1:
The patent applies periodic action by generating cylinder deactivation sequences that repeat after a predetermined number of crankshaft revolutions. The control module creates patterns where cylinders are deactivated in a periodic manner rather than randomly, which reduces noise and vibration while maintaining fuel efficiency benefits. The sequence is designed to repeat periodically, ensuring smooth torque delivery and minimizing harmful vibrations.
Solution Approach 2:
The patent implements dynamics by making the deactivation sequence adaptive to changing operating conditions. The control module continuously monitors engine parameters and dynamically adjusts the deactivation pattern in real-time. This dynamic adjustment allows the system to maintain optimal performance across varying load and speed conditions while preserving periodic characteristics that reduce noise and vibration.
2Object-affected harmful factors
If random deactivation sequences are used to reduce N&V, then noise and vibration are minimized, but torque delivery smoothness deteriorates
Solution Approach 1:
The patent resolves this contradiction by implementing periodic deactivation sequences instead of random patterns. The control module generates sequences that repeat after predetermined crankshaft revolutions, creating regular intervals between deactivation events. This periodicity simultaneously reduces noise and vibration while maintaining smooth torque delivery, as the regular pattern prevents the irregular torque pulses that would result from random deactivation.
Solution Approach 2:
The patent applies parameter changes by systematically varying the deactivation pattern parameters (which specific cylinders are deactivated, when they are deactivated, and for how long) based on operating conditions. The control module adjusts these parameters to maintain optimal torque smoothness while preserving the periodic characteristics that reduce N&V, rather than using fixed or random patterns.
3Object-affected harmful factors
If periodic deactivation patterns are implemented to reduce N&V, then noise and vibration are minimized, but adaptability to transient operating conditions is reduced
Solution Approach 1:
The patent resolves this contradiction through dynamic adaptation. The control module continuously monitors operating conditions and dynamically adjusts the periodic deactivation pattern in real-time. When transient conditions are detected, the system modifies the deactivation sequence parameters while maintaining periodic characteristics. This allows the system to adapt to changing conditions while preserving the noise and vibration reduction benefits of periodic operation.
Solution Approach 2:
The patent implements feedback by continuously monitoring engine operating parameters and using this information to adjust the deactivation pattern. The control module receives feedback on actual engine performance and operating conditions, then modifies the periodic sequence parameters accordingly. This closed-loop approach maintains periodicity for N&V reduction while adapting to transient conditions through real-time parameter adjustments based on feedback.
Data Source
AI summary
A cylinder control module generates a desired cylinder activation/deactivation sequence for a future period based on Q predetermined cylinder activation/deactivation sub-sequences used during a previous period, a desired number of cylinders to be activated during a predetermined period including the previous and future periods, and an operating condition. Q is an integer greater than zero. The cylinder control module activates and deactivates opening of intake and exhaust valves of first and second ones of the cylinders that are to be activated and deactivated based on the desired cylinder activation/deactivation sequence, respectively. A fuel control module provides and disables fuel to the first and second ones of the cylinders, respectively.