Cylinder Activation Sequences for Fuel and Vibration Trade-offs

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Solution Overview

Problem

Internal combustion engines face challenges in optimizing cylinder activation and deactivation to minimize fuel consumption and reduce accessory disturbances, such as crankshaft torsional vibrations and seat track acceleration, while maintaining efficient torque production.

Innovation Solution

A cylinder control system that determines a target number of activated cylinders based on driver inputs, calculates possible sequences for activating and deactivating cylinders, predicts fuel consumption and accessory disturbance values, and selects the sequence that minimizes fuel consumption and disturbances, thereby optimizing engine operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If cylinders are deactivated to decrease fuel consumption, then fuel efficiency is improved, but accessory disturbances such as crankshaft torsional vibrations increase

Engineering Contradiction:

Improvefuel consumptionVSAvoidcrankshaft torsional vibrations

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts cylinder activation sequences based on real-time operating conditions (engine speed, load, torque requests) to optimize the balance between fuel consumption and vibration levels. The control module evaluates multiple possible activation sequences and selects the optimal one that minimizes fuel use while maintaining acceptable vibration levels for the current operating state.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the activation parameters of cylinders by evaluating different activation sequences and selecting those that optimize fuel consumption while considering vibration characteristics. The control module modifies which cylinders are activated and in what order, changing the operational parameters to achieve the desired trade-off between fuel efficiency and vibration reduction.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If cylinders are deactivated to reduce fuel consumption, then energy efficiency is improved, but seat track acceleration increases

Engineering Contradiction:

Improvefuel consumptionVSAvoidseat track acceleration

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The control system dynamically evaluates multiple cylinder activation sequences based on current operating conditions and selects sequences that minimize fuel consumption while keeping seat track acceleration within acceptable limits. The system adapts its selection criteria based on real-time engine state, vehicle speed, and load conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of cylinder activation by evaluating different sequences and selecting those that optimize the trade-off between fuel consumption and seat track acceleration. The control module adjusts which cylinders are activated and when, modifying activation parameters to achieve optimal performance.

Inventive Principle:

Principle #35Parameter changes

3Use of energy by moving object

If multiple possible sequences are evaluated for cylinder activation, then fuel consumption optimization is improved, but device complexity increases

Engineering Contradiction:

Improvefuel consumption optimizationVSAvoidcontrol system complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The system evaluates multiple possible activation sequences (excessive action) to ensure optimal fuel consumption, accepting the additional computational complexity as necessary to achieve the fuel savings. The control module generates and evaluates several candidate sequences rather than relying on a single predetermined sequence, performing comprehensive optimization calculations.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The system uses feedback from engine operating conditions (speed, load, torque requests) to dynamically adjust which activation sequences are evaluated and selected. The control module continuously monitors engine state and uses this feedback to optimize sequence selection, adapting to changing conditions while managing computational complexity through intelligent feedback-driven decision making.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS9341128B2Fuel consumption based cylinder activation and deactivation control systems and methods

Publication Date: 2016.05.17 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A cylinder control method includes: generating a torque request for an engine based on at least one driver input; based on the torque request, determining a target number of activated cylinders of the engine; determining possible sequences for activating and deactivating cylinders of the engine to achieve the target number of activated cylinders; determining predicted fuel consumption values for the possible sequences, respectively; identifying first ones of the possible sequences having predicted fuel consumption values that are less than a predetermined amount from a lowest one of the predicted fuel consumption values; selecting one of the first ones of the possible sequences; setting a selected sequence for activating and deactivating cylinders of the engine to the selected one of the first ones of the possible sequences; based on the selected sequence, one of activating and deactivating a next cylinder in a predetermined firing order of the cylinders.