Pulsating Flow Cancellation Using Source Noise Reference Signals
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Solution Overview
Problem
Existing fluid control systems face instability due to fluid-born noise (FBN) from pulsating flows, which conventional pressure transducers cannot fully attenuate, especially high-frequency components, and require additional hardware, increasing costs.
Innovation Solution
Active cancellation of pulsating flow using a source noise reference, where the noise source provides a noise signal used to generate a cancelling signal that attenuates pulses, eliminating the need for a separate pressure transducer and effectively reducing high-frequency noise components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a pressure transducer is used to measure pulses and generate a noise reference for cancellation, then pulse attenuation can be achieved, but the device complexity and hardware cost increase
Solution Approach 1:
The noise source itself (pump motor) is used to generate the reference signal for cancellation, eliminating the need for external sensing devices like pressure transducers. The motor's own electrical signals are processed to create the anti-phase cancellation signal, making the system self-sufficient and reducing hardware requirements
Solution Approach 2:
Instead of directly measuring mechanical pulses with a pressure transducer, the patent uses electrical signals from the motor as an intermediary representation of the pulse generation. These electrical signals are then processed through filtering and phase inversion to create the cancellation signal, providing an indirect but effective measurement path
2Object-affected harmful factors
If a pressure transducer is used to generate noise reference, then pulse cancellation can be implemented, but high-frequency components greater than the cutoff frequency cannot be converted
Solution Approach 1:
The reference signal is obtained in advance from the motor's electrical signals before the pulses are generated in the fluid. This preliminary acquisition of the pulse pattern in electrical form allows for complete frequency content to be captured and processed, including high-frequency components that would be lost in mechanical measurement
Solution Approach 2:
The patent replaces the mechanical measurement system (pressure transducer) with an electrical signal processing system. By using electrical signals from the motor controller, the system can accurately represent high-frequency pulse components without the bandwidth limitations of mechanical sensors
3Device complexity
If conventional flow control is used, then the system is simple, but the flow rate signal includes noise causing controller instability
Solution Approach 1:
The cancellation signal is generated in advance and applied to the flow controller before the pulsating noise affects the flow rate measurement. By injecting the anti-phase signal into the control pathway, the harmful pulse effects are counteracted proactively, preventing instability rather than reacting to it
Solution Approach 2:
The system uses the motor's electrical signals as a feedback reference that directly correlates with pulse generation. This feedback loop allows the controller to continuously generate appropriate cancellation signals that counteract the pulsating flow, maintaining stability through active compensation
Data Source
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AI summary
An electronics (100) for active cancellation of a pulsating flow with a source noise reference is provided. The electronics (100) includes a signal processor (110) configured to receive a noise source signal (210a) from a noise source (210) that causes one or more pulses of the pulsating flow and a flow signal (230a) from a flow sensor (230) configured to measure a flow rate of the pulsating flow. The signal processor (110) is also configured to generate a cancelling signal (110a) based on the noise source signal (210a) and the flow signal (230a). The electronics (100) also includes a controller (120) communicatively coupled to the signal processor (110), the controller (120) being configured to determine a flow rate control signal (120a) for controlling the flow rate of the pulsating flow and a signal generator (130) communicatively coupled to the signal processor (110) and the controller (120). The signal generator (130) is configured to receive the flow rate control signal (120a), generate a valve signal (130a) based on the flow rate control signal (120a) and the cancelling signal (1 10a), and provide the valve signal (130a) to a valve (220) to control the flow rate and attenuate the one or more pulses of the pulsating flow.