Waste Gate Valve End-Stop Detection and Sensor Calibration
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Solution Overview
Problem
The existing electric actuation system for waste gate valves in turbochargers lacks accurate end-stop position detection, leading to potential valve impact, noise, vibration, and reduced boost pressure due to inaccurate positioning and temperature-induced sensor errors.
Innovation Solution
A method involving end-stop detection routines and position sensor calibration, where the waste gate valve is commanded through a full stroke to detect end-stop positions and adjust sensor gain based on feedback, ensuring precise alignment and reducing noise and vibration, and maintaining sensor accuracy amidst temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the waste gate valve is commanded to a closed position without end-stop detection, then the valve may be adjusted too much causing high impact between the valve and seat, but implementing end-stop detection requires additional sensor calibration procedures
Solution Approach 1:
The system performs self-calibration by automatically detecting end-stop positions through commanded valve movements and sensor feedback, eliminating the need for manual calibration procedures while establishing accurate reference points for future operation
Solution Approach 2:
The control system uses feedback from the position sensor during commanded valve movements to detect actual end-stop positions, comparing expected versus actual sensor readings to identify calibration offsets and automatically adjust the calibration data
2Temperature
If the gear box output shaft sensor is used for position detection, then the motor can be positioned remotely to reduce heat degradation, but the sensor provides no indication of the waste gate end-stop position
Solution Approach 1:
The system performs preliminary calibration movements to command the valve through its full range of motion before normal operation, detecting end-stop positions in advance and storing calibration data that compensates for thermal expansion effects during subsequent operation
Solution Approach 2:
The system detects and compensates for parameter changes in the position sensor output caused by thermal expansion of linkages, using calibration data to adjust the relationship between sensor readings and actual valve positions under different temperature conditions
3Ease of operation
If the waste gate valve is adjusted without accurate end-stop detection, then the control system is simpler to operate, but noise, vibration, and wear on the valve seat increase
Solution Approach 1:
The system automatically performs calibration and adjusts control parameters without requiring operator intervention, maintaining simple operation while eliminating harmful impacts through self-optimized valve positioning control
Data Source
AI summary
Various embodiments relating to detection of an end-stop position of a waste gate valve and calibration of a waste gate position sensor relative to the detected end-stop position are provided. In this way, it is possible to more accurately control the waste gate.