Boost Pressure Control Using Pseudo Setpoint Aperture

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Solution Overview

Problem

Existing methods for activating boost pressure control in internal combustion engines often result in premature activation of the turbocharger, leading to excessive fuel consumption and delayed torque delivery due to inaccuracies in determining the switchover from throttle valve control to boost pressure control.

Innovation Solution

A method that calculates a pseudo setpoint aperture of the throttle valve based on a simplified inverse flow characteristic and setpoint intake manifold pressure, controlling the turbine driving to avoid excessive aperture opening, thus optimizing the transition between throttle and boost pressure control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the boost pressure control is activated based on basic boost pressure model with hysteresis threshold, then the turbocharger activation timing is improved, but the precision of switchover determination deteriorates due to component variation and insufficient quality of the basic boost pressure module

Engineering Contradiction:

Improveturbocharger activation timingVSAvoidswitchover determination precision

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

The patent introduces a pseudo setpoint aperture as an intermediary parameter to determine the switchover point. Instead of directly using the basic boost pressure model with its inherent inaccuracies, the system calculates a pseudo setpoint aperture based on a simplified inverse flow characteristic of the throttle valve. This intermediary parameter serves as a more reliable trigger for activating the boost pressure control, resolving the contradiction between timely activation and precise determination.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Speed

If the boost pressure control is activated too early to ensure timely torque delivery, then the response time is improved, but the fuel consumption increases due to excessive exhaust gas back-pressure

Engineering Contradiction:

Improvetorque delivery response timeVSAvoidfuel consumption

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The patent performs a preliminary calculation of the pseudo setpoint aperture using the simplified inverse flow characteristic before the actual switchover occurs. This preliminary action establishes an accurate trigger point for boost pressure control activation, ensuring that the turbocharger is activated at the optimal moment - neither too early nor too late. By preparing the switchover condition in advance based on throttle valve characteristics rather than relying on imprecise boost pressure models, the system achieves timely torque delivery without premature activation that would cause excessive fuel consumption.

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If the basic boost pressure model is used for switchover determination, then the device complexity is reduced, but the manufacturing precision and quality consistency deteriorate due to component variation

Engineering Contradiction:

Improvecontrol system complexityVSAvoidswitchover point consistency

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent changes the parameter used for switchover determination from basic boost pressure (which is sensitive to component variations) to pseudo setpoint aperture based on throttle valve flow characteristics. The simplified inverse flow characteristic of the throttle valve provides a more stable and consistent reference that is less affected by component variations. This parameter change maintains relatively simple device complexity while significantly improving the consistency and reliability of the switchover point across different components and operating conditions.

Inventive Principle:

Principle #35Parameter changes

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 reduces unnecessary exhaust gas back-pressure, conserves fuel, and ensures robust boost pressure control by eliminating early turbocharger activation and ensuring timely torque delivery.

Implementation Method 1

a driving of the turbine being controllable by an exhaust gas flow

Methodology Applied

Scientific EffectExhaust gas flow:

Implementation Method 2

a compressor, a charge air line, a throttle valve, an intake manifold

Methodology Applied

Scientific EffectCompression: Compression

Data Source

PatentUS11629658B2Method for activating a boost pressure control

Publication Date: 2023.04.18 VOLKSWAGEN AG

AI summary

A method for activating a boost pressure control for an internal combustion engine, which contains, in a through-flow direction, a compressor, a charge air line, a throttle valve, an intake manifold, at least one combustion chamber and a turbine speed-coupled to the compressor, an aperture of the throttle valve being controllable, a driving of the turbine being controllable by an exhaust gas flow, and the method including: predefining a setpoint intake manifold pressure; calculating a simplified inverse flow characteristic of the throttle valve; calculating a pseudo setpoint aperture of the throttle valve, based on the simplified inverse flow characteristic and the setpoint intake manifold pressure; and controlling the driving of the turbine, based on an exceeding of a maximum aperture of the throttle valve by the pseudo setpoint aperture of the throttle valve.