Broadband Beamforming Filter Bank Interpolation

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Solution Overview

Problem

Existing broadband beamforming techniques require significant computational resources, especially when performing operations for many focus points and large sensor arrays, and are not efficiently optimized for reducing sidelobe levels across varying frequencies.

Innovation Solution

A method is introduced that pre-computes optimized filter parameters for a mesh of focus points and stores them in a filter bank, allowing for interpolation to calculate focused output signals with reduced computational effort, using a subset of pre-defined mesh points to approximate the focused output at arbitrary focus points.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If optimal filter parameters are computed for each focus point using prior art methods, then sidelobe suppression is improved, but computational resources required increase significantly

Engineering Contradiction:
Improvesidelobe suppressionVSAvoidcomputational resources
Core Design Contradiction:
Measurement precisionVSPower

Solution Approach 1:

The patent pre-computes and stores optimized filter parameters for a discrete set of focus points (mesh points) before actual beamforming operations. This preliminary computation allows the system to avoid performing heavy optimization calculations during real-time or online beamforming, thereby reducing computational resources required during operation while maintaining effective sidelobe suppression through interpolation of pre-computed parameters.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates a filter bank that stores copies of optimized filter parameters for multiple focus points. Instead of重新computing parameters for each new focus point, the system retrieves and interpolates between stored parameter copies, significantly reducing computational load while preserving the sidelobe suppression benefits of optimized filters.

Inventive Principle:
Principle #26Copying

2Measurement precision

If beamforming operations are performed for many focus points with large sensor arrays, then measurement precision is improved, but computational burden becomes prohibitive

Engineering Contradiction:
Improvespatial precisionVSAvoidcomputational efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent performs preliminary computation of filter parameters for all mesh points in the region of interest before actual beamforming measurements. This offline preparation stage creates a comprehensive filter bank that enables rapid online queries for any focus point, thereby improving computational efficiency during productivity-critical operations while maintaining high spatial precision across many focus points.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a dynamic interpolation mechanism that adapts the selection and combination of pre-computed filter parameters based on the specific query focus point. This dynamic approach allows the system to efficiently handle arbitrary focus points within the mesh region by interpolating between nearby pre-computed parameters, maintaining high spatial precision without proportional increases in computational burden.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If FIR filters are used for broadband beamforming, then frequency range coverage is improved, but computational complexity increases

Engineering Contradiction:
Improvefrequency range coverageVSAvoidcomputational complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent pre-computes FIR filter parameters that cover the desired broadband frequency range for multiple focus points before operation. By storing these pre-optimized parameters in a filter bank, the system achieves broad frequency coverage during operation without the computational complexity of performing FIR filter optimization in real-time, thus resolving the contradiction between frequency range adaptability and computational complexity.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2774143B1Computationally efficient broadband filter-and-sum array focusing
Publication Date: 2018.06.13 BRUEL & KJAER SOUND & VIBRATION MEASUREMENT
  • EP2774143B1 patent drawingFigure 1
  • EP2774143B1 patent drawingFigure 2
  • EP2774143B1 patent drawingFigure 3

AI summary

A method of determining a focused output signal of a sensor array comprising a plurality of sensors, each sensor being operable to output a sensor output signal responsive to a measured quantity, the focused output signal being indicative of a calculated quantity at a focus point; the method comprising: receiving a respective measured sensor output signal from each of the sensors; computing the focused output signal by performing a focusing calculation with respect to the measured sensor signals; wherein the method further comprises determining a subset of mesh points of a set of predetermined mesh points, each mesh point having at least one pre- computed filter parameter associated with it; and wherein computing the focused output signal comprises performing an interpolation with respect to the subset of mesh points so as to obtain an interpolated focused output signal.