Cylinder Deactivation Pattern Control for Engine Efficiency
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Solution Overview
Problem
Internal combustion engines face challenges in optimizing fuel efficiency and reducing noise and vibration through cylinder deactivation, as existing systems struggle to achieve a desired average number of activated cylinders per sub-period effectively.
Innovation Solution
A cylinder control system comprising a cylinder control module and a fuel control module that select and adjust cylinder activation/deactivation patterns based on a desired average number of activated cylinders, activating intake and exhaust valves for some cylinders while deactivating them for others, and providing or disabling fuel accordingly, allowing for non-integer Effective Cylinder Counts by combining different base patterns across sub-periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If cylinders are deactivated to reduce fuel consumption, then fuel efficiency is improved, but the ability to achieve desired average cylinder counts is limited
Solution Approach 1:
The predetermined period is divided into multiple sub-periods, allowing the engine to activate a different number of cylinders in each sub-period. This segmentation enables the system to achieve non-integer average cylinder counts (e.g., 5.5 cylinders per period) by combining different activation patterns across sub-periods, thereby providing fine-grained control over fuel consumption while maintaining adaptability to desired torque outputs.
Solution Approach 2:
The system dynamically selects from multiple predetermined cylinder activation patterns and adjusts the duration of each pattern's application within the predetermined period. By varying the number of sub-periods and the specific patterns used, the system can adapt to different desired average cylinder counts in real-time, resolving the contradiction between fuel efficiency and adaptability.
2Object-generated harmful factors
If cylinder deactivation patterns are used to reduce noise and vibration, then noise and vibration are reduced, but control precision over average cylinder count is insufficient
Solution Approach 1:
By dividing the operation into sub-periods with different cylinder activation counts, the system can precisely control the average number of activated cylinders. For example, alternating between 5 and 6 cylinders across sub-periods achieves an exact 5.5 average, providing measurement precision that integer-based patterns cannot achieve.
Solution Approach 2:
The system changes the parameter of cylinder count from fixed integer values to variable averages by adjusting the proportion of sub-periods dedicated to each activation pattern. This allows continuous adjustment of the average cylinder count parameter, improving control precision while maintaining noise and vibration reduction benefits.
Data Source
AI summary
Based on a desired average number of activated cylinders per sub-period of a predetermined period including P sub-periods, a cylinder control module selects one of N predetermined cylinder activation/deactivation patterns. The selected cylinder activation/deactivation pattern corresponds to Q activated cylinders per sub-period, Q is an integer between zero and a total number of cylinders of an engine, inclusive, P is an integer greater than one, and the desired average number of active cylinders is a number between zero and the total number of cylinders of the engine. The cylinder control module also determines an adjusted cylinder activation/deactivation pattern based on the selected predetermined cylinder activation/deactivation pattern, generates a desired cylinder activation/deactivation pattern for the predetermined period using the selected predetermined cylinder activation/deactivation pattern during a first number of the P sub-periods and using the adjusted cylinder activation/deactivation pattern during a second number of the P sub-periods.