Adaptive DC Canceller Filter for Pulsating Flow Valve Stability
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Solution Overview
Problem
Fluid-born noise (FBN) and vortex-induced perturbations in fluid flow control systems cause instability in proportional valves due to pulsating flows, which existing passive filters inadequately address, especially when pump speed and flow rates change.
Innovation Solution
A DC canceller (DCC) adaptive filter system that processes flow signals from sensors to generate a stable flow rate control signal by attenuating AC components, using a signal processor, controller, and signal generator to provide a valve signal that controls fluid flow rate effectively, even with pulsating flows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If passive filters are used to attenuate noise in flow rate signals, then noise attenuation is achieved, but rapid changes in flow rate measurements are undesirably attenuated causing inaccurate measurements
Solution Approach 1:
The patent applies dynamics by making the filter characteristics adaptive rather than fixed. The filter continuously adjusts its parameters based on the input signal characteristics, allowing it to dynamically respond to changing flow conditions. This enables the filter to distinguish between noise and rapid legitimate flow changes, attenuating noise while preserving accurate flow rate measurements.
Solution Approach 2:
The patent changes the parameters of the filter adaptively based on the signal being processed. By monitoring signal characteristics and adjusting filter parameters accordingly, the system optimizes noise attenuation at different operating conditions without sacrificing measurement accuracy. This allows the filter to maintain effectiveness across varying flow rates and pump speeds.
2Productivity
If the pump rotation speed increases to improve productivity, then flow rate increases, but the noise component's frequency also increases causing valve instability
Solution Approach 1:
The adaptive filter dynamically adjusts its characteristics to track the changing noise frequency that correlates with pump speed. As the pump rotates faster and generates higher frequency noise, the filter automatically adapts its frequency response to maintain effective attenuation. This preserves valve stability across the full operating range without limiting productivity.
Solution Approach 2:
The system uses feedback from the flow rate signal to continuously monitor noise characteristics and adjust filter parameters accordingly. This closed-loop approach ensures that the filter remains effective at attenuating noise across varying pump speeds, maintaining valve stability while allowing high productivity operation.
3Object-affected harmful factors
If adaptive filters are used to resolve noise attenuation issues, then noise attenuation improves, but device complexity increases
Solution Approach 1:
The adaptive filter is self-adjusting and automatically adapts to changing conditions without requiring external intervention or complex control systems. The filter monitors its own performance and self-corrects by adjusting its parameters based on the input signal characteristics. This self-service capability reduces the need for additional control electronics and simplifies the overall system architecture.
Data Source
AI summary
Electronics with a DCC adaptive filter for attenuating noise in a feedback path of a flow controller are provided. The electronics include a signal processor configured to receive a flow signal from a flow sensor, the flow sensor is configured to measure a flow rate of a pulsating fluid flow, receive a constant reference signal, and generate a flow rate signal using the constant reference signal and the flow signal. The electronics also include a controller communicatively coupled to the signal processor, which is configured to generate a flow rate control signal using the flow rate signal. The electronics additionally include a signal generator communicatively coupled to the controller. The signal generator is configured to receive the flow rate control signal, generate a valve signal based on the flow rate control signal, and provide the valve signal to a valve to control the flow rate of the pulsating flow.