Electric Waste Gate Valve Control with Pre-Startup Position Learning
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Solution Overview
Problem
Conventional electric waste gate valve control systems struggle to accurately control the opening degree of the waste gate valve immediately after engine start, especially in cold conditions, due to thermal expansion and lack of sufficient time for fully closed position learning.
Innovation Solution
An electric waste gate valve control device that includes a position sensor, an actuator controller, and a fully closed position learning unit, which performs learning during engine stop and operation to acquire and update the fully closed position, allowing for precise control using either the first or second learned position based on threshold differences, and optionally includes temperature correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fully closed position learning is performed during engine start, then the opening degree control accuracy is improved, but the catalyst warming-up time is extended
Solution Approach 1:
The system performs fully closed position learning during the engine stop period before startup, rather than during engine operation. This preliminary action allows the learning process to complete before the engine starts, enabling immediate accurate control without extending the catalyst warming-up time.
Solution Approach 2:
The control device uses the engine stop period as an intermediary time window to perform the learning operation. This intermediary period serves as a buffer that decouples the learning process from both the engine shutdown and startup phases, allowing learning to occur without impacting catalyst warming-up duration.
2Measurement precision
If the waste gate valve is held fully closed during learning, then the learning accuracy is improved, but the exhaust gas flow to catalyst is reduced
Solution Approach 1:
The system performs the fully closed position learning operation during the engine stop period, which is before the engine starts and before exhaust gas flow to the catalyst begins. This timing ensures that the valve remains fully closed only during learning, and immediately after learning completes, the engine starts and exhaust gas flow resumes without restriction.
3Speed
If fully closed position learning is performed immediately before engine start, then the control response is improved, but the learning completeness is compromised
Solution Approach 1:
The system performs fully closed position learning during the engine stop period, which provides sufficient time for the learning operation to complete before the engine starts. This preliminary timing ensures both learning completeness and immediate control response upon startup, as the learning is finished in advance rather than rushed during a brief interval.
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
Enables accurate and immediate control of the waste gate valve opening degree after engine start, enhancing catalyst warming and exhaust gas processing performance while reducing the need for additional learning time and minimizing thermal deformation effects.
Implementation Method 1
a position sensor that detects a position of the waste gate valve
Implementation Method 2
opening/closing the waste gate passage by an electric actuator
Implementation Method 3
a waste gate valve (i.e. WGV) that opens/closes the waste gate passage
Data Source
AI summary
An electric waste gate valve control device controls a waste gate valve provided in a waste gate passage that bypasses a portion between an upstream and a downstream of a turbine driven by exhaust of an engine and opening/closing the waste gate passage by an electric actuator. The electric waste gate valve control device includes: a position sensor that detects a position of the waste gate valve; an actuator controller that controls the electric actuator such that an opening degree of the waste gate valve becomes a target opening degree; and a fully closed position learning unit that performs fully closed position learning to acquire the position of the waste gate valve at a time when the electric actuator is driven to bring the waste gate valve into a fully closed state.