Dynamic Engine Lash Torque Filtering via Speed Variation

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Solution Overview

Problem

Existing engine clearance detection methods in vehicles with petrol or diesel thermal powertrains are static and do not account for the dispersion of engine blocks and wear of the traction chain, leading to suboptimal driving pleasure, especially as engines age.

Innovation Solution

A method that dynamically detects engine play by varying engine speed or correction torque gradients to adapt torque control, eliminating the need for fixed thresholds and accounting for wear, involving detection of entry and exit times based on noise levels and torque gradients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If fixed torque thresholds are used for engine clearance detection, then the control system is simple to implement, but the driving pleasure deteriorates as the engine ages due to wear and dispersion

Engineering Contradiction:
Improvecontrol system complexityVSAvoidadaptability to engine wear
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by transitioning from static fixed torque thresholds to dynamic adaptive thresholds. The system continuously adjusts the torque thresholds based on real-time detection of engine clearance passage events, allowing the control parameters to evolve with engine wear and maintain optimal performance throughout the vehicle's lifecycle.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements self-service through automatic adaptation mechanisms. The control unit autonomously detects engine clearance passages and adjusts torque thresholds without requiring manual recalibration or external intervention, enabling the system to self-optimize as the engine ages and wear patterns develop.

Inventive Principle:
Principle #25Self-service

2Loss of time

If static torque thresholds are used, then calibration time is reduced, but measurement precision deteriorates because dispersion and wear are not accounted for

Engineering Contradiction:
Improvecalibration timeVSAvoidtorque threshold accuracy
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The patent implements feedback by continuously monitoring engine operating parameters and using detected clearance passage events to adjust torque thresholds. This closed-loop approach ensures that the system maintains high measurement precision by adapting to actual engine conditions, eliminating the need for repeated manual calibration while preserving accuracy.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If fixed thresholds are applied, then the control system is easy to operate, but reliability deteriorates as the engine wears and thresholds become suboptimal

Engineering Contradiction:
Improveoperational simplicityVSAvoiddriving pleasure consistency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system applies preliminary action by proactively detecting engine clearance passages and adjusting torque thresholds before performance degradation becomes noticeable. This anticipatory adjustment ensures that the control system maintains reliability and consistent driving pleasure throughout engine wear, without requiring complex user intervention or recalibration.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2917544B1Method for filtering an engine reference torque when passing through engine lash
Publication Date: 2017.05.31 PSA AUTOMOBILES SA
  • EP2917544B1 patent drawingFigure 1
  • EP2917544B1 patent drawingFigure 2
  • EP2917544B1 patent drawingFigure 3.

AI summary

The invention relates mainly to a method for filtering an engine reference torque when passing through engine lash involving the following steps: - determining (101) an engine reference torque, - detecting (102) a time (t1) of entering engine lash and a time (t2) of exiting engine lash defining a zone (Z) of passing through engine lash, - filtering (103) the engine reference torque (Ce) in the zone (Z) of passing through engine lash, and - if need be, applying (104) a corrective torque (Ccor) in phase opposition with a speed (Wm) of the combustion engine. According to the invention, the time (t1) of entering engine lash is detected from a variation in the speed (Wm) of the combustion engine or from a variation in the corrective torque (Ccor).