Fluid Valve Position Control Using Flow Feedback
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Solution Overview
Problem
Microfluidic processing systems face challenges in accurately controlling relative valve positions due to manufacturing tolerances and malfunctions, which affect the quality and efficiency of fluid handling and separation processes.
Innovation Solution
The system uses previous measurements of fluid flow to adjust and control relative valve positions, considering manufacturing tolerances and detecting malfunctions by comparing actual and target relationships between fluid flow and valve positions, thereby reducing tolerance chains and improving process quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a drive chain with multiple interactive components is used to couple the actuator to the valve element, then the device complexity is reduced and ease of manufacture is improved, but manufacturing tolerances accumulate forming a tolerance chain that degrades valve position precision
Solution Approach 1:
The system performs a measurement of the actual valve position and uses this measurement feedback to calculate a compensation value that offsets the accumulated tolerance chain effects, thereby achieving precise valve positioning despite using a complex drive chain with multiple components
Solution Approach 2:
The system changes the control parameter by introducing a compensation value that adjusts the actuator position based on the measured deviation, transforming the relationship between actuator position and valve position to eliminate tolerance chain errors
2Device complexity
If the relative valve position is controlled without previous measurements, then the device complexity is reduced, but the quality and exactness of valve position adjustment deteriorates
Solution Approach 1:
The system performs a preliminary measurement of the actual valve position and stores this information as previous measurement data, which is then used to guide subsequent positioning operations and achieve high exactness without requiring overly complex real-time control mechanisms
3Manufacturing precision
If manufacturing tolerances are strictly controlled to eliminate tolerance chains, then valve position precision is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
Rather than attempting to eliminate tolerance chains through strict manufacturing control, the system measures the actual valve position and uses feedback to calculate compensation values that offset the tolerance errors, achieving precision through software compensation rather than manufacturing perfection
Data Source
AI summary
An assembly for handling a fluid, comprising a valve and a controller. The valve has at least one revolving valve element and a coupling device. The coupling device comprises at least one port coupled to a flow path and is adapted for interacting with said at least one revolving valve element in order to control a fluid flow through said at least one port using a relative valve position between the revolving valve element and the coupling device. The controller is adapted for controlling the relative valve position based on at least one of a current and a previous measurement of an amount of the fluid flow dependent on the relative valve position.