Variable Geometry Turbocharger Control for Boost Pressure Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing charging systems for internal combustion engines, particularly those with exhaust gas turbochargers, face challenges in optimizing starting performance due to limitations in controlling turbine actuators, leading to inefficiencies in engine torque and power delivery.
Innovation Solution
A method and controller that adjust the exhaust gas turbocharger geometry to limit exhaust gas back pressure, optimizing boost pressure build-up and reducing gas exchange losses by determining a maximum VTG setting criterion based on actual and target operating states, including driver requests and exhaust gas aftertreatment system conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the turbine geometry is adjusted to increase boost pressure, then the power output is improved, but the exhaust back pressure increases causing gas exchange losses
Solution Approach 1:
The patent implements dynamic adjustment of turbine geometry (VTG) based on real-time operating conditions. The control system continuously monitors engine parameters and adjusts the turbine vane position to optimize the balance between boost pressure generation and exhaust back pressure management, transforming a static system into a dynamically adaptive one that resolves the power-loss contradiction across varying operating conditions.
Solution Approach 2:
The patent changes physical parameters of the turbine system by adjusting the turbine geometry (vane angle, opening cross-section) to control the relationship between boost pressure and exhaust back pressure. By varying these parameters dynamically according to engine operating state, the system optimizes power output while minimizing gas exchange losses that would otherwise occur with fixed geometry.
2Speed
If the turbine geometry is adjusted rapidly to respond to load changes, then the response speed is improved, but the exhaust back pressure fluctuations increase
Solution Approach 1:
The control system performs preliminary adjustments to turbine geometry before full load changes occur, based on predicted engine operating conditions. This anticipatory control smooths out rapid back pressure fluctuations by gradually adjusting the turbine opening in advance, preventing sudden pressure spikes while maintaining fast overall response to driver demands.
Solution Approach 2:
The system employs dynamic control strategies that adapt the rate and magnitude of turbine geometry adjustments based on current operating conditions. The control algorithm modulates the response characteristics in real-time, allowing faster adjustments when conditions permit and smoother transitions when back pressure stability is critical, thereby resolving the contradiction between response speed and pressure stability.
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 enhances the effective torque and wheel acceleration torque, improving vehicle acceleration by optimizing boost pressure build-up and reducing component stress, while also minimizing gas cycle losses and emissions.
Implementation Method 1
a turbine driven by the exhaust gas from the ICE
Implementation Method 2
a compressor and can either be equipped with their own drive
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a method for controlling a charging system (3) with a charging stage (5) for an internal combustion engine (2), wherein the charging stage (5) comprises a compressor (6) and a turbine (8) and the turbine (8) is adjustable by means of a VTG control (11), wherein the method comprises: acquiring a target operating state value (MM-target); setting a maximum VTG control criterion (umax) for implementing the torque increase by increasing a boost pressure (p2), wherein setting the maximum VTG control criterion (umax) comprises: determining a target boost pressure (p2target); determining a target VTG position (ustarget) as a function of the target boost pressure (p2target); determining an actual exhaust back pressure (p3actual); determining an actual exhaust pressure (p4) after the turbine (8); Determination of a maximum exhaust back pressure (p3max) taking into account the actual exhaust pressure (p4) after the turbine (8);Determination of the VTG actuation criterion (umax) taking into account the difference between the actual exhaust back pressure (p3ist) and the maximum exhaust back pressure (p3max), wherein the VTG actuation criterion (umax) limits the VTG target position (usoll) in such a way that an accelerated adaptation of an actual boost pressure (p2ist) to the target boost pressure (p2soll) occurs compared to an adaptation of the actual boost pressure (p2ist) to the target boost pressure (p2soll) without taking the VTG actuation criterion (umax) into account. The invention also relates to a control unit (10) for carrying out such a method, as well as an internal combustion engine (2) with such a control unit (10) and a motor vehicle (1).