Full-field wing deformation measurement scheme for in-flight cantilever monoplane based on 3D digital image correlation

Abstract

In this paper, a new non-contact scheme, based on 3D digital image correlation technology, is presented to measure the full-field wing deformation of in-flight cantilever monoplanes. Because of the special structure of the cantilever wing, two conjugated camera groups, which are rigidly connected and calibrated to an ensemble respectively, are installed onto the vertical fin of the aircraft and record the whole measurement. First, a type of pre-stretched target and speckle pattern are designed to adapt the oblique camera view for accurate detection and correlation. Then, because the measurement cameras are swinging with the aircraft vertical trail all the time, a camera position self-correction method (using control targets sprayed on the back of the aircraft), is designed to orientate all the cameras’ exterior parameters to a unified coordinate system in real time. Besides, for the excessively inclined camera axis and the vertical camera arrangement, a weak correlation between the high position image and low position image occurs. In this paper, a new dual-temporal efficient matching method, combining the principle of seed point spreading, is proposed to achieve the matching of weak correlated images. A novel system is developed and a simulation test in the laboratory was carried out to verify the proposed scheme.

A Novel Concentric Circular Coded Target, and Its Positioning and Identifying Method for Vision Measurement under Challenging Conditions

“… Vision system for an in-flight wing deformation measurement [ 54 , 55 ]: ( a ) the camera installed in the passenger compartment; ( b ) overexposure of the images owing to the changing illumination during the in-flight recording; ( c ) underexposure of the images; ( d ) the camera installed on the vertical fin for observing the wing speckle pattern and coded targets. Both of the two cases undergo flat viewing angles.…”

“…Another critical issue, apart from the poor illumination problem, is the flat viewing angle, by which, the object being observed by the camera is apparently very flat. In the case of measuring the wing deformation, the installation locations of the image acquisition equipment, i.e., camera, are very limited and can only be on top of the fuselage or in the passenger compartment ( Figure 2 a [ 54 ]) or on the vertical fin of the aircraft (see Figure 2 d [ 55 ]). Consequently, there is a tiny angle subtended between the plane of the coded target attached to the wing and the camera optical axis, and henceforth, the observation angle to the wing becomes flat.…”

A Real-time Monitoring Method of Prestressed Tubular Piles Construction Based on Machine Vision

“…In terms of longdistance large-scale object measurement, Liang Pu and others successfully used vision technology to realize real-time monitoring of aircraft body dynamic deformation in large aircraft wind tests [4]. Li et al used machine vision technology to realize real-time measurement and monitoring of airborne antenna [5]. Furthermore, Wei et al successfully realized the real-time monitoring of the vibration of the rotor system of a heavy helicopter in the working process by using machine vision technology [6].…”

Advanced utilization of 3D digital image correlation for thermal and impact reliabilities of electronics components

“…Initially, DIC was mostly adopted for measurement of deformation in large structures such as bridges (Tang et al , 2012; Travelletti et al , 2012; Yoneyama et al , 2007). Li et al (2014) measured in-flight wing deformation for an aircraft. Baqersad et al (2017) compared various photogrammetry techniques and investigated transient phenomena of vibrating structures and turbine blades.…”