Active Acoustic Control Using Filtered Scattering Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems struggle to accurately separate and control scattered acoustic pressure components from total acoustic pressure, requiring complex setups and large computational power, and fail to effectively acoustically cloak objects as conditions change.
Innovation Solution
An active acoustic control system that uses a first sensor arrangement to sense total acoustic pressure, applies a filter to estimate the scattered acoustic pressure component, and controls it using a control source arrangement, with a processor determining a regularisation parameter based on a set of test parameters to enhance accuracy and adapt to changing conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If known systems separate scattered acoustic pressure components from total acoustic pressure, then control of scattered acoustic pressure is achieved, but measurement precision is insufficient and device complexity increases
Solution Approach 1:
The patent extracts the scattered acoustic pressure component from the total acoustic pressure measurement by applying a filter to the sensor output. The filter isolates the scattered pressure component, enabling control without requiring separate sensors for incident and scattered pressure measurements. This resolves the contradiction by achieving precise separation using a simple filtering operation rather than complex sensor arrays.
Solution Approach 2:
The patent replaces complex mechanical sensor arrangements with a signal processing approach. Instead of using multiple sensors or complex acoustic setups to separate the components, the invention uses a filter applied to the total pressure measurement to extract the scattered component. This substitution of mechanical complexity with computational filtering achieves the same goal with reduced device complexity.
2Reliability
If known systems control acoustic scattering, then acoustic cloaking is achieved under specific conditions, but adaptability to changing conditions deteriorates
Solution Approach 1:
The patent introduces a dynamic filter that adapts to changing acoustic conditions. The filter characteristics can be adjusted based on the operating environment, object properties, and acoustic parameters. This dynamic adaptation allows the system to maintain effective acoustic cloaking control across varying conditions, resolving the contradiction between reliable control and adaptability.
Solution Approach 2:
The patent employs parameter changes in the filter design to accommodate different operating conditions. By adjusting filter parameters such as frequency response, time constant, and other characteristics based on the specific acoustic environment and object properties, the system maintains optimal performance across a range of conditions. This parameter adaptation enables both reliable control and versatility.
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
Facilitates precise control of scattered acoustic pressure, enabling effective acoustic cloaking of objects by reducing scattered acoustic pressure, even under varying conditions, without the need for complex setups or real-time monitoring.
Implementation Method 1
When an acoustic wave impinges on an object, there is an interaction between the acoustic wave and the object known as 'acoustic scattering'. This interaction can take multiple forms. One form is 'backscatter', wherein the acoustic wave is reflected from the object. Another form is 'shadowing', wherein the object blocks the acoustic wave and prevents it from travelling further. Another form is 'refraction', wherein the acoustic wave 'bends' around the object.
Implementation Method 2
In effective control of the primary disturbance signal to reduce said signal, the primary acoustic disturbance signal 32 and control signal 36 exhibit destructive interference.
Data Source
AI summary
The present disclosure relates to an active acoustic control system comprising: a first sensor arrangement arranged to sense an acoustic signal in the region of an object, the acoustic signal having a scattered acoustic pressure component and a total acoustic pressure, the first sensor arrangement being arranged to sense the total acoustic pressure of the acoustic signal; a processor configured to: apply a filter to filter the total acoustic pressure and provide a filtered output signal; and estimate the scattered acoustic pressure component based on the filtered output signal from the filter; and a control source arrangement operable to control the scattered acoustic pressure component based on the estimation and a regularisation parameter determined based on a relationship between: level of control of the scattered acoustic pressure component of the acoustic signal when controlled using the control source arrangement of the system using a set of test regularisation parameters.