Event-driven dynamic trajectories reconstruction and measurement of mechanical parameters for fragments

2026-06-08

AI Summary

This study addresses the challenge of accurately measuring the mechanical parameters of high-density, high-speed fragments under intense explosion-induced glare and smoke interference, where mutual occlusions further complicate observation. To overcome this, the work introduces event cameras into fragment field analysis for the first time, establishing a multi-view event-based visual system. By integrating multiple geometric constraints—including epipolar geometry, trifocal tensors, and local homographies—it proposes a probabilistic matching model weighted by entropy to effectively eliminate false correspondences. High-precision 3D trajectory reconstruction is then achieved through spatial line-line intersection and nonlinear optimization, enabling accurate estimation of fragment velocities and kinetic energies. The proposed method significantly enhances the reliability of high-speed target tracking and mechanical parameter measurement in highly disruptive environments, offering critical technical support for warhead damage assessment and protective design.

Abstract

During warhead detonation, high-density, high-speed, and mutually occluded fragments are generated. Their mechanical parameters (position, velocity, kinetic energy) directly determine the lethality of the warhead fragment field. However, high-intensity flash and smoke in detonation scenarios severely hinder the accurate acquisition of these mechanical parameters. To address this challenge, this paper integrates experimental mechanics approaches and presents an event-driven method for reconstructing the dynamic trajectories of fragments and measuring their mechanical parameters. As a novel brain-inspired visual sensor, event cameras offer microsecond-level temporal resolution and high dynamic range lighting change perception, overcoming the difficulty of accurately measuring high-speed targets under strong flash interference. The method constructs a multi-event-camera vision system, adopting three geometric constraints: time-correlated epipolar constraint to find potential matching event point pairs, and trifocal tensor line constraint plus local homography constraint to eliminate mismatches. A comprehensive probability model is established, with entropy weight method determining the weight of each constraint's probability to quantitatively filter mismatches. 3D trajectory reconstruction is achieved via spatial line-line intersection and nonlinear optimization. Finally, the velocity and kinetic energy of the fragments are calculated based on the reconstructed trajectory. This method provides reliable technical support for the mechanical damage evaluation of warhead fragment fields and the tactical protection design.

Problem

• fragment mechanical parameters
• warhead detonation
• high-speed trajectory measurement
• flash interference
• occlusion

Innovation

• event camera
• dynamic trajectory reconstruction
• geometric constraints
• entropy weight method
• mechanical parameter measurement