Acoustic Impact Localization Using Exponential Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the location of an impact on a surface based on acoustic signals are compromised by spurious contributions from reflections at the object's border, leading to reduced localization accuracy due to signal dispersion and difficulty in separating direct and reflected signals.
Innovation Solution
The method involves weighting the acoustic signal by identifying a first wave front and applying a damping window, specifically an exponential damping window, to amplify direct signal contributions while suppressing reflections, thereby enhancing the precision and stability of impact location determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If signal cutting off or low pass filtering is applied to remove reflections, then spurious contributions are reduced, but localization accuracy deteriorates due to signal dispersion and loss of direct signal information
Solution Approach 1:
The patent applies different weighting factors to different time segments of the acoustic signal. The direct signal portion (before reflections arrive) is given higher weight, while reflected signal portions are given lower weight. This local differentiation in signal treatment allows selective enhancement of useful signal components while suppressing harmful reflections, resolving the contradiction between removing spurious contributions and preserving localization accuracy
Solution Approach 2:
The patent performs preliminary identification of the first wave front arrival time before applying the damping window. By determining when the direct signal first arrives at each transducer, the system can pre-calculate appropriate weighting factors that preserve the direct signal while preparing to suppress subsequent reflections. This preliminary action enables accurate localization before spurious contributions corrupt the signal
2Loss of information
If the entire acoustic signal is used for localization, then signal information is maximized, but reflection contributions falsify the impact location determination
Solution Approach 1:
The patent changes the parameter of signal weighting over time by applying a damping window function. Instead of uniformly weighting all signal portions, the system varies the weight assigned to each time segment, with higher weights for early arrivals (direct signal) and lower weights for later arrivals (reflections). This parameter change allows the system to retain useful signal information while eliminating harmful reflection contributions
Solution Approach 2:
The patent converts the harmful effect of reflections into a beneficial selection criterion. By analyzing the temporal structure of the signal and identifying when reflections arrive relative to the direct signal, the system uses the presence of reflections to inform the weighting strategy. The reflections, while harmful, provide temporal markers that help the system distinguish direct from reflected signal portions and apply appropriate weighting
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
This approach allows for more accurate and stable determination of impact location by prioritizing direct signal information over reflections, maintaining signal integrity and reducing computational complexity, while effectively suppressing spurious contributions.
Implementation Method 1
based on the analysis of an acoustic signal generated by the impact
Implementation Method 2
spurious contributions arising from reflections of the acoustic signal in the border region of the object
Data Source
AI summary
The invention relates to a method for determining the location of an impact on a surface of an object based on the analysis of an acoustic signal generated by the impact. This method further comprises a signal treatment step of weighting the acoustic signal to take into account spurious contributions in particular due to reflections at the border of the object.