Variable Displacement Engine Cylinder Deactivation Control

Solution Overview

Problem

In variable displacement engines, fuel wastage occurs when continuing to fuel a partially regenerated catalyst to complete regeneration, leading to degraded fuel economy due to inefficient catalyst regeneration strategies.

Innovation Solution

Selectively deactivating the cylinder group coupled to the less regenerated catalyst, based on its regeneration state and temperature, to avoid unnecessary fuel consumption during catalyst regeneration, while alternating deactivation to balance engine and catalyst wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the catalyst on one cylinder group is partially regenerated and the other cylinder group is selected for disablement based on alternating pattern, then catalyst usage is balanced, but additional fuel is consumed to complete regeneration of the partially regenerated catalyst

Engineering Contradiction:

Improvefuel consumptionVSAvoidcatalyst regeneration efficiency

Core Design Contradiction:

Loss of energyVSProductivity

Solution Approach 1:

The control system performs preliminary assessment of catalyst regeneration status before selecting cylinder groups for deactivation. By checking the regeneration state in advance and selecting the more regenerated catalyst for deactivation, the system prevents the scenario where a partially regenerated catalyst would require additional fuel consumption to complete regeneration, thus avoiding unnecessary fuel waste while maintaining catalyst management effectiveness

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the regeneration state of catalysts in both cylinder groups and uses this feedback information to dynamically adjust deactivation selection. Instead of using a fixed alternating pattern, the control system adapts its decisions based on real-time catalyst conditions, ensuring that the selected catalyst for deactivation is already sufficiently regenerated and does not require additional fuel input

Inventive Principle:

Principle #23Feedback

2Loss of energy

If the cylinder group with the more regenerated catalyst is selected for deactivation, then fuel economy is improved, but catalyst wear is unbalanced

Engineering Contradiction:

Improvefuel economyVSAvoidcatalyst wear balance

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The control system performs preliminary assessment of catalyst regeneration status before selecting cylinder groups for deactivation. By checking the regeneration state in advance and selecting the more regenerated catalyst for deactivation, the system prevents the scenario where a partially regenerated catalyst would require additional fuel consumption to complete regeneration, thus avoiding unnecessary fuel waste while maintaining catalyst management effectiveness

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically changes the selection criterion from a fixed alternating pattern to a regeneration-state-based selection. By monitoring regeneration parameters and adjusting deactivation decisions accordingly, the system optimizes fuel economy by selecting the more regenerated catalyst for deactivation while still managing catalyst wear through adaptive control strategies

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8607544B2Methods and systems for variable displacement engine control

Publication Date: 2013.12.17 FORD GLOBAL TECH LLC

AI summary

Methods and systems are provided for selecting a group of cylinders for selective deactivation, in a variable displacement engine system, based at least on a regeneration state of an exhaust catalyst. The position of one or more valves and throttles may be adjusted based on the selective deactivation to reduce back-flow through the disabled cylinders while also maintaining conditions of a downstream exhaust catalyst. Pre-ignition and knock detection windows and thresholds may also be adjusted based on the deactivation to improve the efficiency of knock and pre-ignition detection.