Internal Combustion Engine Torque Imbalance Detection

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Solution Overview

Problem

Internal combustion engines with multiple cylinders face challenges in balancing rotation, leading to increased costs and vibrations, which affect vehicle performance and fuel efficiency, as existing methods are inefficient in identifying and correcting torque imbalances.

Innovation Solution

A method that uses frequency analysis of the drive shaft's rotation speed to detect imbalances by converting the signal into the frequency domain, identifying the half-order frequency, and calculating the phase to determine the imbalance-causing cylinder, allowing for corrections to operating parameters such as ignition advance or fuel injection to restore balance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If frequency analysis is used to detect torque imbalances, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvetorque imbalance detection precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical balancing systems with a control system that uses frequency analysis of existing rotation speed signals to detect and correct torque imbalances. Instead of adding mechanical components, the system processes electrical signals from the engine's rotation speed sensor through spectral analysis to identify imbalance sources.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system changes the operational parameters of cylinders (ignition timing, fuel injection) based on frequency analysis results to correct torque imbalances. By adjusting these parameters dynamically, the system achieves precise control over cylinder torque contributions without mechanical modifications.

Inventive Principle:
Principle #35Parameter changes

2Power

If multi-cylinder configuration is used, then power output is improved, but manufacturing cost increases

Engineering Contradiction:
Improveengine power outputVSAvoidmanufacturing cost
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The control system automatically detects and corrects torque imbalances in multi-cylinder engines through self-diagnosis and self-correction. By monitoring rotation speed variations and identifying problematic cylinders, the system adjusts their parameters to maintain optimal performance, reducing the need for expensive mechanical balancing during manufacturing.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If cylinder torque is corrected by parameter adjustment, then manufacturing precision requirements are relaxed, but control complexity increases

Engineering Contradiction:
Improvecylinder component precisionVSAvoidcontrol algorithm complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system continuously monitors engine rotation speed and uses feedback from frequency analysis to adjust cylinder parameters. The control algorithm processes spectral information from rotation speed signals, identifies torque imbalances, and implements corrective parameter adjustments, creating a closed-loop system that compensates for manufacturing variations.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3511554B1Internal combustion engine
Publication Date: 2021.08.18 FERRARI SPA
  • EP3511554B1 patent drawingFigure 1
  • EP3511554B1 patent drawingFigure 2~3
  • EP3511554B1 patent drawingFigure 4

AI summary

Method for the identification of a torque delivery imbalance of an internal combustion engine equipped with two or more cylinders under constant speed operating conditions of the internal combustion engine comprising an analysis procedure in the frequency domain of a rotation speed signal of said engine so that when an amplitude of a half-order frequency exceeds a predetermined threshold, the cylinder of said two or more cylinders that causes said imbalance is identified by calculating a relative phase.