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

2025-12-27

AI Summary

Accurately measuring shock waves with high spatiotemporal resolution remains challenging under highly dynamic, heterogeneous propagation conditions and unstable experimental environments. To address this, this paper proposes a novel multi-view shock wave measurement method based on an event camera array. We introduce a polar-coordinate event encoding scheme coupled with an adaptive region-of-interest (ROI) extraction framework, integrating an event-driven optical imaging model with 3D geometric reconstruction to precisely extract the shock front via iterative slope analysis. We further pioneer an event-offset-driven adaptive ROI mechanism and a continuous velocity-variation-guided shock front identification algorithm, enabling quantitative estimation of shock wave asymmetry. Experimental results demonstrate a shock velocity measurement error of 0.06%–5.20%, microsecond-level temporal resolution, and sub-millimeter spatial resolution—significantly outperforming conventional pressure sensors and empirical models.

Technology Category

• Computer Vision: Motion & Tracking
• Intelligent Robots: Multimodal Perception & Sensor Fusion
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems

Application Category

• Security and Privacy: Large-scale security measurements
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization

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.

Problem

• Measures shock wave motion with high spatiotemporal resolution
• Addresses fast, uneven propagation and unstable testing conditions
• Uses event cameras for asymmetry estimation and 3D reconstruction

Innovation

• Multiple event cameras estimate shock wave asymmetry
• Polar coordinate system encodes events for propagation patterns
• Iterative slope analysis extracts shock wave front events