Real-Time Deformation Measurements Using Single Image Photogrammetry

Most photogrammetric measurements are currently based on image acquisition in the field and subsequent processing in office environment with certain temporal delay. However, in some cases it is necessary to process the data real-time, or at least in-situ. Bridge load testing is an example of measurement processing directly at the place of imaging, where almost immediate information about the current state or change of the object is required. An algorithm is developed for these purposes, including a camera controlling software and a MATLAB code that identifies and quantifies the shifts of the observed points in the image plane. The observed points are in the shape of black disks on a white background. Using a horizontal camera position individual epochs are captured. Each image is immediately transferred to a computer via Wi-Fi. The MATLAB code then loads the image and binarizes it. Binarization of the image is performed by the Canny edge detector. Using normalized 2-D cross-correlation, the algorithm determines the approximate coordinates based on a target template. A function performs least squares ellipse fitting and determines the center of the target in sub-pixel accuracy, the semi-major axis, the semi-minor axis and the rotation angle of the ellipse. The target detection is executed in a while cycle loop, which compares the point coordinates from each epoch to the initial state, thus quantifying the deformations in pixels. If the next image is not yet available, the loop restarts. The deformations are calculated based on the known scale of each target. This paper presents a detailed description of the development of the algorithm, the results achieved and the proposed improvements going forward.

Research on Real-time Monitoring of Launch Vehicle Deformation Using Fiber Bragg Grating Sensor

To solve the problem that the curvature information of the large flexible rocket body affects the attitude control of the rocket body, a shape reconstruction method based on optical fiber strain sensing is proposed in this paper, which can measure the bow deformation and vibration state of the rocket in real time as the input data for adjusting the attitude control of the rocket. In this scheme, the dynamics of flexible rocket can be solved stably and quickly. In order to verify the reconstruction method, the beam model was used as the experimental analysis object, and the vibration information such as deformation of the beam model was identified through the strain value measured by fiber Bragg grating (FBG) sensors. The results show that the deformation reconstruction method can well restore the deformation and rotation angle of the beam system and has good stability and real-time performance. This method can provide a theoretical basis for the real-time deformation calculation and high-precision attitude control of future flexible launch vehicle.

Numerical and Experimental Predication of the Structural Cracking Within Reinforced Concrete Structure due to Conventional State of Loading

It has been well understanding that the occurrence of various crack patterns in the building during its construction life (from first time of construction up to finishing) then subjected to super imposed load or during the service life. Cracks developed due to exceeding of stresses more than the allowable strength, wherever happened on building component. This research works used the finite element method as a powerful tool to simulate the behavior of full constructed building with both concrete system and brick bearing wall. Where the adopted numerical procedure allows to the users to predict the response of building elements due to conventional state of loading. one of the most important response features was the cracking phenomenon, where the numerical model shown that its capability to predict the cracking sequence from the first time of initiating. The prediction of full response and behavior of each element and their connection, shown that the precise of factor of safety used by the designer, where the analysis prove that the design load was about 67% from the cracking load, and the ultimate load was about 260% from the design load. That will allow more sustainability and stability for long time deformation. Beside the numerical solution, there was an experimental part of study, where site investigation, it shown that all data recorded was constant values and the building was stable. Actually, with no increasing of loading, the building reach its stable state, and defect will not develop. That basically because of good design within conventional state of loading.

Application of Slope Radar (S-SAR) in Emergency Monitoring of the “11.03” Baige Landslide

On October 11 and November 3, 2018, the disaster chain of landslide-barrier lake occurred twice in Baige Village, Xizang Province. After the second sliding of the landslide, the danger of the landslide dam was eliminated by the manual excavation of the drain grooves. During this period, a ground-based interferometric synthetic aperture radar (GB-InSAR) called “S-SAR” was utilized for real-time monitoring and analyzing 48 selected target pixels on the residual deformation bodies of landslides (divided into K1, K2, and K3 deformation zones) for 8 days. Through the real-time deformation map of pixels in the monitoring area obtained by S-SAR, the ranges of five strong deformation regions were identified and delineated. Based on the apparent cumulative deformation-time curve of each target pixel, the overall deformation law of K1, K2, and K3 deformation zones could be monitored and analyzed in real time. Based on a curve graph of the deformation rate, acceleration, and time of each target pixel, the K1, K2, and K3 deformation zones were within a uniform deformation stage. Taking the target pixel point and the corresponding time in which the deformation rate and deformation acceleration had a large, abrupt jump at the same time as the position and time of the near-slip failure, the 11 positions and moments of the near-slip failure were counted. The results presented here may represent a workable reference for emergency monitoring and early warning of similar sudden geological disasters.

Hands-On Deformation of Volumetric Anatomical Imageson a Touchscreen

In this work, we propose a novel metaphor to interact with volumetric anatomical images, e.g., magnetic resonance imaging or computed tomography scans. Beyond simple visual inspection, we empower users to reach the visible anatomical elements directly with their hands, and then move and deform them through natural gestures, while respecting the mechanical behavior of the underlying anatomy. This interaction metaphor relies on novel technical methods that address three major challenges: selection of anatomical elements in volumetric images, mapping of 2D manipulation gestures to 3D transformations, and real-time deformation of the volumetric images. All components of the interaction metaphor have been designed to capture the user’s intent in an intuitive manner, solving the mapping from the 2D touchscreen to the visible elements of the 3D volume. As a result, users have the ability to interact with medical volume images much like they would do with physical anatomy, directly with their hands.

THE LASER TECHNOLOGY FOR EARTHQUAKE'S FORECAST AND FOR DIFFERENT APPROACHES OF SEISMIC HAZARD ASSESSMENT

Historically, the first laser-deformograph was developed by group of Geophysical Observatory of the Tavria National University named after I. Vernadsky (formerly Simferopol State University named after M.V. Frunze) and started to work in 1981. This laser complex allowed to carry out the measurements of the Earth’s long time deformation. The measuring volume of the observatory was located in an adit (depth of about 20 meters), which connects the right rangefinder post with the main battery structure and has a series of sealed baffles (doors, hatches) that isolate it from external influences. In the capacity of the main tools for studying oscillatory processes in the environment, the Geophysical Observatory used two-beam laser interferometers of the Michelson type with spaced beams, which have very high metrological characteristics and use the wavelength of a frequency-stabilized laser as a reference. Engineering support of the interferometric complexes’ functioning in the Geophysical Observatory was carried out by: F.N. Pankov, A.V. Buklersky, V.I. Tokarev [5].

q-SPACE (q-TIME)-DEFORMATION OF THE CONTINUITY EQUATION

A q-space (q-time)-deformation of the continuity equations are introduced using the q-derivative (or Jackson derivative). By quantum calculus, we solve such equations. The free cases are discussed separately.

Experimental analysis of the feasibility of deep slide monitoring with low-cost piezoelectric diaphragms-based EMI technique

Slope instability, especially the soil slope instability, is a common occurrence in mountainous areas. It poses a huge threat to people’s lives and properties under the slope body. Effective slope monitoring techniques can provide detailed information and precursor about the real-time deformation, which is of great importance to provide early warning to the public. In this paper, a novel electromechanical impedance (EMI)-based slope deep slide monitoring bar (DSMB) was proposed. The main purpose was to investigate the application of the EMI technique for deep slide detection. In this study, a small soil slope specimen with a DSMB embedded inside it was fabricated in laboratory. To verify the practicality of the low-cost piezoelectric diaphragms (commonly known as buzzers), four conventional lead zirconate titanate (PZT) patches and four buzzers were bonded onto the front surface and back surface of the bar at specific positions, respectively. The slope specimen was then subjected to a horizontal thrust to initiate an interlayer slide along the slip surface. The whole process was monitored with a precision impedance analyzer by measuring the admittance of these transducers at specific sliding displacement. In order to reduce the error and increase the reliability, the experiment was repeated three times under the same conditions. It was concluded that the conventional PZT patches and buzzers have similar sensitivities to interlayer slide damage. The results indicate that both the severity and sliding location could be identified via the two metrics including root mean square deviation (RMSD) and correlation coefficient deviation (CCD). The experimental results verify the feasibility and practicality of using novel and low-cost piezoelectric diaphragm-based EMI technique to detect the deep slide in soil slope.

A Real-Time Deformation Monitoring Method for Large-Scale Structure Based on Relay Camera

In the process of the deformation monitoring for large-scale structure, the mobile vision method is often used. However, most of the existent researches rarely consider the real-time property and the variation of the intrinsic parameters. This paper proposes a real-time deformation monitoring method for the large-scale structure based on a relay camera. First, we achieve the real-time pose-position relationship by using the relay camera and the coded mark points whose coordinates are known. The real-time extrinsic parameters of the measuring camera are then solved according to the constraint relationship between the relay camera and the measuring camera. Second, the real-time intrinsic parameters of the measuring camera are calculated based on the real-time constraint relationship among the extrinsic parameters, the intrinsic parameters, and the fundamental matrix. Finally, the coordinates of the noncoded measured mark points, which are affixed to the surface of the structure, are achieved. Experimental results show that the accuracy of the proposed method is higher than 1.8 mm. Besides, the proposed method also possesses the real-time and automation property.