Variable Displacement Engine Cylinder Mode Control

Solution Overview

Problem

Deactivating engine cylinders to improve fuel economy increases noise and vibration, making the driving experience objectionable for vehicle occupants, posing a challenge in achieving higher fuel efficiency without degrading vehicle comfort.

Innovation Solution

Increasing the actual total number of available cylinder modes in response to estimated road roughness exceeding a threshold, allowing the engine to operate in a cylinder deactivation mode when occupants are less likely to notice additional noise and vibration, by selectively deactivating cylinders based on road conditions and vehicle mass.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If engine cylinders are deactivated to improve fuel economy, then fuel efficiency increases, but noise and vibration increase making the driving experience objectionable

Engineering Contradiction:

Improvefuel economyVSAvoidnoise and vibration

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts the number of available cylinder modes based on real-time road roughness conditions. When road roughness exceeds a threshold, the controller increases the actual total number of available cylinder modes, allowing cylinder deactivation. This dynamic adaptation enables the system to exploit fuel economy benefits when occupants are less sensitive to noise and vibration, while maintaining comfort when road conditions are smooth.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The controller monitors road roughness as a varying parameter and uses this information to change the operational parameters of the engine cylinder modes. By changing the actual total number of available cylinder modes based on road roughness threshold exceedance, the system optimizes the balance between fuel economy and occupant comfort under different operating conditions.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If the actual total number of available cylinder modes is increased to allow cylinder deactivation, then fuel economy improves, but the disturbance to occupants from engine noise and vibration increases

Engineering Contradiction:

Improvefuel economyVSAvoiddisturbance to occupants

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts the number of available cylinder modes based on real-time road roughness conditions. When road roughness exceeds a threshold, the controller increases the actual total number of available cylinder modes, allowing cylinder deactivation. This dynamic adaptation enables the system to exploit fuel economy benefits when occupants are less sensitive to noise and vibration, while maintaining comfort when road conditions are smooth.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The controller continuously monitors road roughness conditions and uses this feedback to determine when to increase or decrease the actual total number of available cylinder modes. This feedback mechanism ensures that cylinder deactivation is enabled only when road conditions suggest occupants will be less disturbed by the associated noise and vibration, thereby optimizing fuel economy while protecting occupant comfort.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10006379B2Variable displacement engine control

Publication Date: 2018.06.26 FORD GLOBAL TECH LLC

AI summary

Systems and methods for operating an engine in a variety of different cylinder operating modes are presented. In one example, an actual total number of available cylinder modes is increased in response to a vehicle's suspension setting and road roughness. By increasing the available cylinder modes, the engine may be operated in a higher number of modes where one or more engine cylinders may be deactivated to conserve fuel. The number of cylinder modes is increased during conditions where vehicle occupants may be less likely to object to operating the engine with fewer active cylinders.