Powertrain Control for Turbocharger Jerk Reduction

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Solution Overview

Problem

The existing powertrain systems with turbocharged internal combustion engines experience significant oscillations in intake air pressure during upshifts, leading to a 'jerk' phenomenon that causes discomfort for drivers and can result in acoustic noise complaints, particularly in spark-ignition and supercharged engines associated with automatic dual-clutch gearboxes.

Innovation Solution

A method is introduced to control the powertrain by modifying the action of exhaust gases through bypassing the wastegate valve or adjusting the turbocharger turbine geometry, synchronized with intake air pressure adjustments, to maintain engine speed derivatives above a setpoint threshold, thereby reducing pressure oscillations and minimizing the jerk effect.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the throttle body closes abruptly during gearshift, then the gearshift response is fast, but intake air pressure oscillations occur causing jerk phenomenon and acoustic noise

Engineering Contradiction:
Improvegearshift response speedVSAvoidintake air pressure oscillations and acoustic noise
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The control method applies preliminary anti-action by detecting the gearshift event and proactively modifying exhaust gas flow through the wastegate valve before the throttle body completes its closure. This preemptive adjustment of exhaust gas recirculation counteracts the pressure oscillations that would otherwise occur during the gearshift transition, preventing the jerk phenomenon and acoustic noise without compromising gearshift speed.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The invention implements feedback control by continuously monitoring engine operating parameters (intake air pressure, engine speed, throttle position) and dynamically adjusting the wastegate valve position in response to detected conditions. The control unit modifies exhaust gas flow based on real-time feedback from pressure sensors and engine management signals, maintaining stable intake pressure during gearshift events while preserving fast response characteristics.

Inventive Principle:
Principle #23Feedback

2Reliability

If the wastegate valve is used to regulate intake air pressure, then pressure control reliability is improved, but additional device complexity is introduced

Engineering Contradiction:
Improveintake air pressure control reliabilityVSAvoidvalve control system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The wastegate valve is designed to perform multiple functions: its primary role of regulating exhaust gas flow for turbocharger control is enhanced with a secondary function of stabilizing intake air pressure during gearshift events. By making the valve multi-functional, the system achieves improved pressure control reliability without adding separate dedicated components, thereby avoiding additional device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The control method merges the gearshift stabilization function with the existing wastegate valve control system. Instead of adding a separate pressure stabilization mechanism, the invention combines both functions into a unified control strategy that manages exhaust gas flow to simultaneously achieve turbocharger regulation and intake pressure stability during gear transitions.

Inventive Principle:
Principle #5Merging (Combining)

3Object-affected harmful factors

If exhaust gases are bypassed through the wastegate valve during gearshift, then intake air pressure oscillations are reduced, but engine power output may be affected

Engineering Contradiction:
Improveintake air pressure oscillationsVSAvoidengine power output
Core Design Contradiction:
Object-affected harmful factorsVSPower

Solution Approach 1:

The control method applies periodic or transient action by temporarily modifying wastegate valve position only during the specific time window of gearshift events. The exhaust gas bypass is activated periodically when gearshift is detected and deactivated when the gear transition is complete, thereby reducing intake pressure oscillations during the critical moment without sustaining power loss conditions that would affect overall engine performance.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The invention applies partial action by selectively adjusting the wastegate valve opening only to the extent necessary to stabilize intake pressure during gearshift, rather than maintaining a constant bypass position. The control unit modulates exhaust gas flow partially during the transition event, providing just enough adjustment to eliminate oscillations while minimizing impact on engine power output during normal operating conditions.

Inventive Principle:
Principle #16Partial or excessive action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach effectively limits the jerk phenomenon by regulating intake air and exhaust gas pressures, enhancing vehicle comfort and reducing acoustic disturbances during gear shifts, with improved performance and reliability.

Implementation Method 1

a turbocharger (3) having a compressor (3a) at an outlet of which intake air (F1) is supplied

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

a turbine (3b) of the turbocharger (3) before being led to vehicle exhaust

Methodology Applied
Scientific EffectTurbine: Turbine

Implementation Method 3

the pop-off valve (4) makes it possible to divert, by recirculation, part of the intake air upstream of the compressor (3a)

Methodology Applied
Scientific EffectRecirculation:

Implementation Method 4

the wastegate valve (5) is, when the vehicle is in operating condition, to regulate the intake air pressure around a set point by adapting its closing percentage

Methodology Applied
Scientific EffectPressure regulation:

Data Source

PatentEP2900988B1Method for controlling a power train, vehicle, associated recording medium and program
Publication Date: 2018.05.30 RENAULT SA
  • EP2900988B1 patent drawingFigure 1
  • EP2900988B1 patent drawingFigure 2~3
  • EP2900988B1 patent drawingFigure 4~5

AI summary

The invention relates to controlling a power train of an engine (1), a turbocharger (3) and a gear box for detecting (E1) a change in the gear box ratio, for evaluating (E2) the charge of the engine (1) in the detected change in ratio, then for adjusting (E3) the operation of the engine (1) by modifying the air inlet pressure (E3-1) and/or by modifying the action of the exhaust gases at the outlet of the engine (1) on the turbo charger (3). The adjustment (E3) of the operation of the engine is carried out if a condition associated with the evaluated charge is verified.