Event-based high temporal resolution measurement of shock wave motion field

TL;DR

This paper introduces a novel event-camera-based framework for high-resolution, high-speed measurement of shock wave motion fields, overcoming challenges of fast, uneven propagation and unstable conditions.

Contribution

It presents a new method utilizing multiple event cameras, adaptive ROI extraction, and geometric modeling for accurate shock wave measurement and 3D reconstruction.

Findings

Maximum speed measurement error of 5.20%

High spatial and temporal resolution achieved

Effective shock wave motion field reconstruction

Abstract

Accurate measurement of shock wave motion parameters with high spatiotemporal resolution is essential for applications such as power field testing and damage assessment. However, significant challenges are posed by the fast, uneven propagation of shock waves and unstable testing conditions. To address these challenges, a novel framework is proposed that utilizes multiple event cameras to estimate the asymmetry of shock waves, leveraging its high-speed and high-dynamic range capabilities. Initially, a polar coordinate system is established, which encodes events to reveal shock wave propagation patterns, with adaptive region-of-interest (ROI) extraction through event offset calculations. Subsequently, shock wave front events are extracted using iterative slope analysis, exploiting the continuity of velocity changes. Finally, the geometric model of events and shock wave motion parameters is derived according to event-based optical imaging model, along with the 3D reconstruction model. Through the above process, multi-angle shock wave measurement, motion field reconstruction, and explosive equivalence inversion are achieved. The results of the speed measurement are compared with those of the pressure sensors and the empirical formula, revealing a maximum error of 5.20% and a minimum error of 0.06%. The experimental results demonstrate that our method achieves high-precision measurement of the shock wave motion field with both high spatial and temporal resolution, representing significant progress.