Turbocharger Throttle Control for Intake Pressure Stability
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Solution Overview
Problem
The existing turbocharger systems in internal combustion engines often lead to a sail-on condition, causing engine instability, increased exhaust emissions, and reduced fuel economy due to non-linear characteristics of pre-throttle intake airflow, which results in pressure drops in the intake manifold.
Innovation Solution
A system comprising a rate determination module, a limiting rate selection module, a throttle inlet absolute pressure (TIAP) calculation module, and a throttle control module that generates a pressure rate value, selects a limiting rate, calculates a TIAP signal, and actuates the inlet throttle valve to control air pressure, thereby minimizing the duration and preventing sail-on conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the BPV and/or wastegate are opened to reduce boost pressure, then the boost pressure is controlled, but a pressure drop in the intake manifold occurs causing sail-on condition
Solution Approach 1:
The system performs preliminary action by predicting future intake manifold pressure based on current pressure and rate of change before the pressure drop occurs. This allows the throttle controller to pre-adjust the ITV position to compensate for the upcoming pressure drop, preventing sail-on condition rather than reacting after it occurs.
Solution Approach 2:
The system dynamically adjusts the throttle control strategy based on real-time pressure conditions. When pressure drop is detected or predicted, the controller transitions from normal throttle control to a compensatory control mode that accounts for the non-linear airflow characteristics, making the system adaptable to changing operational states.
2Quantity of substance
If the throttle opening is increased to compensate for pressure drop, then air flow into cylinders is increased, but vehicle acceleration increases causing sail-on condition
Solution Approach 1:
The system implements feedback control by continuously monitoring intake manifold pressure and its rate of change, then adjusting the ITV position accordingly. The controller uses the predicted pressure trajectory to determine the appropriate throttle opening, creating a closed-loop system that prevents excessive acceleration by anticipating pressure drops before they affect engine performance.
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
The system effectively stabilizes air pressure upstream of the inlet throttle valve, reducing the duration of sail-on conditions and preventing engine instability, emissions, and fuel economy reduction by precisely controlling air pressure.
Implementation Method 1
The turbocharger system compresses and increases flow of inlet air based on flow rate of the exhaust gas
Implementation Method 2
A single-stage system may include a single turbine that increases boost pressure in an intake manifold
Implementation Method 3
Reducing boost pressure via the BPV and/or the wastegate can cause a pressure drop in an intake manifold
Data Source
AI summary
A system for an engine with a turbocharger system includes a rate determination module, a limiting rate selection module, a throttle inlet absolute pressure (TIAP) calculation module, and a throttle control module. The rate determination module generates a pressure rate value based on a pressure difference between a current TIAP signal from a TIAP sensor and a previous TIAP signal. The limiting rate selection module selects a limiting rate based on the pressure rate value. The TIAP calculation module generates a calculated TIAP signal based on the limiting rate and the current TIAP signal. The throttle control module generates a throttle control signal based on the calculated TIAP signal and actuates an inlet throttle valve of the engine based on the throttle control signal.