Observation of the dynamic movement of fragmentations by high-speed camera and high-speed video

1995 ◽  
Author(s):  
Chul-Gi Suk ◽  
Yuji Ogata ◽  
Yuji Wada ◽  
Kunihisa Katsuyama
Keyword(s):  
High Speed ◽  
High Speed Camera ◽  
High Speed Video ◽  
Dynamic Movement

scholarly journals High-speed camera recordings uncover previously unidentified elements of zebrafish mating behaviors integral to successful fertilization

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Buntaro Zempo ◽  
Natsuko Tanaka ◽  
Eriko Daikoku ◽  
Fumihito Ono
Keyword(s):  
Mating Behavior ◽  
Teleost Fish ◽  
High Frequency ◽  
High Speed ◽  
Fertilization Success ◽  
Surgical Removal ◽  
High Speed Camera ◽  
High Speed Video ◽  
Dorsal Fin ◽  
Courtship Behaviors

AbstractThe mating behavior of teleost fish consists of a sequence of stereotyped actions. By observing mating of zebrafish under high-speed video, we analyzed and characterized a behavioral cascade leading to successful fertilization. When paired, a male zebrafish engages the female by oscillating his body in high frequency (quivering). In response, the female pauses swimming and bends her body (freezing). Subsequently, the male contorts his trunk to enfold the female’s trunk. This behavior is known as wrap around. Here, we found that wrap around behavior consists of two previously unidentified components. After both sexes contort their trunks, the male adjusts until his trunk compresses the female’s dorsal fin (hooking). After hooking, the male trunk slides away from the female’s dorsal fin, simultaneously sliding his pectoral fin across the female’s gravid belly, stimulating egg release (squeezing/spawning). Orchestrated coordination of spawning presumably increases fertilization success. Surgical removal of the female dorsal fin inhibited hooking and the transition to squeezing. In a neuromuscular mutant where males lack quivering, female freezing and subsequent courtship behaviors were absent. We thus identified traits of zebrafish mating behavior and clarified their roles in successful mating.

Development of a Low Cost High-Speed Video Motion Capture System for Planar Motion

2020 ◽  
Author(s):  
Heather L. Lai ◽  
Susan Ko
Keyword(s):  
Rigid Body ◽  
Motion Capture ◽  
High Speed ◽  
Field Of View ◽  
High Speed Camera ◽  
Motion Capture System ◽  
Position Sensing ◽  
High Speed Video ◽  
Acceleration Data ◽  
Position Data

Abstract This project focuses on the development and characterization of a high speed video motion capture system for the measurement of planar, rigid body motions. The ability to collect information related to the accelerations, velocities and positions of points on a rigid body as it moves in planar space is very important in the fields of science and engineering. Traditional techniques, including the use of accelerometers, extensors and lasers, either rely on contact between the rigid body and the sensor or only measure out of plane motion. In this project, an inexpensive monochromatic high speed camera was used in conjunction with markers adhered to the objects under investigation to measure the planar displacement of a point on a moving object. The high speed camera is able to capture video at a rate of up to 20,000 frames per second, however, at this speed the field of view is very small. For a larger field of view, the frames per second is diminished to close to 3,000 frames per second. The goal of this project was to develop the hardware parameters and software necessary to collect and process 2D motion data at different frequencies and then evaluate the efficacy of video motion capture through comparison with simultaneously captured acceleration data. The efficacy was evaluated over a range of accelerations using variable frequency oscillations. The video footage was processed, frame by frame in order to extract x and y position for the center of the marker. Extraction of the position data was completed using the MATLAB computer vision toolbox, which provides tools for identifying the x and y locations of corners, circle centers and other defining features. The project began by identifying size, shape, color and material of markers for effective data collection using the motion capture system. Additionally, camera settings, field of view, capture rate, lighting and mounting conditions were evaluated to determine what conditions would result in the most accurate position sensing. In order to validate the measurements from the motion capture system, position data were correlated with accelerations measured from a traditional accelerometer located on the object under test. In order for the position data collected through the high speed video capture to be compared with the acceleration data collected using measurement from accelerometers, numerical differentiation of the position signals gathered from the high speed footage was performed. The efficacy of different shape and size markers, along with other camera settings, will be demonstrated for specific oscillatory test profiles.

scholarly journals Design and Development of a Robotic Bee for the Analysis of Honeybee Dance Communication

2008 ◽  
Vol 5 (3) ◽  
pp. 157-164 ◽  
Author(s):  
T. Landgraf ◽  
H. Moballegh ◽  
R. Rojas
Keyword(s):  
Visual Feedback ◽  
High Speed ◽  
Tracking System ◽  
Feedback System ◽  
High Speed Camera ◽  
Video Cameras ◽  
High Speed Video ◽  
Successive Addition ◽  
Essential Properties ◽  
Dance Communication

We have designed a robotic honeybee to mimic the bee dance communication system. To achieve this goal, a tracking system has been developed to extract real bee dance trajectories recorded with high-speed video cameras. The results have been analysed to find the essential properties required for the prototype robot. Putative signals in the dance communication have been identified from the literature. Several prototypes were built with successive addition of more features or improvement of existing components. Prototypes were tested in a populated beehive results were documented using high-speed camera recordings. A substantial innovation is a visual feedback system that helps the robot to minimise collisions with other bees.

APPLICATION OF THE EARLY DAMAGE DIAGNOSTICS TECHNIQUE TO EXAMINATION OF THE AVIATION PANEL

2019 ◽  
Vol 85 (6) ◽  
pp. 53-63 ◽  
Author(s):  
I. E. Vasil’ev ◽  
Yu. G. Matvienko ◽  
A. V. Pankov ◽  
A. G. Kalinin
Keyword(s):  
Acoustic Emission ◽  
Damage Detection ◽  
High Speed ◽  
Early Stage ◽  
Video Data ◽  
High Speed Video ◽  
Damage Diagnostics ◽  
Subsurface Defect ◽  
Sensitive Coating ◽  
Early Damage

The results of using early damage diagnostics technique (developed in the Mechanical Engineering Research Institute of the Russian Academy of Sciences (IMASH RAN) for detecting the latent damage of an aviation panel made of composite material upon bench tensile tests are presented. We have assessed the capabilities of the developed technique and software regarding damage detection at the early stage of panel loading in conditions of elastic strain of the material using brittle strain-sensitive coating and simultaneous crack detection in the coating with a high-speed video camera “Video-print” and acoustic emission system “A-Line 32D.” When revealing a subsurface defect (a notch of the middle stringer) of the aviation panel, the general concept of damage detection at the early stage of loading in conditions of elastic behavior of the material was also tested in the course of the experiment, as well as the software specially developed for cluster analysis and classification of detected location pulses along with the equipment and software for simultaneous recording of video data flows and arrays of acoustic emission (AE) data. Synchronous recording of video images and AE pulses ensured precise control of the cracking process in the brittle strain-sensitive coating (tensocoating)at all stages of the experiment, whereas the use of structural-phenomenological approach kept track of the main trends in damage accumulation at different structural levels and identify the sources of their origin when classifying recorded AE data arrays. The combined use of oxide tensocoatings and high-speed video recording synchronized with the AE control system, provide the possibility of definite determination of the subsurface defect, reveal the maximum principal strains in the area of crack formation, quantify them and identify the main sources of AE signals upon monitoring the state of the aviation panel under loading P = 90 kN, which is about 12% of the critical load.

scholarly journals Tracking by Deblatting

2021 ◽  
Author(s):  
Denys Rozumnyi ◽  
Jan Kotera ◽  
Filip Šroubek ◽  
Jiří Matas
Keyword(s):  
High Speed ◽  
High Performance ◽  
Motion Blur ◽  
Velocity Estimation ◽  
High Speed Camera ◽  
Trajectory Function ◽  
Novel Approach ◽  
Blind Deblurring ◽  
Object Trajectories ◽  
Complex Trajectories

AbstractObjects moving at high speed along complex trajectories often appear in videos, especially videos of sports. Such objects travel a considerable distance during exposure time of a single frame, and therefore, their position in the frame is not well defined. They appear as semi-transparent streaks due to the motion blur and cannot be reliably tracked by general trackers. We propose a novel approach called Tracking by Deblatting based on the observation that motion blur is directly related to the intra-frame trajectory of an object. Blur is estimated by solving two intertwined inverse problems, blind deblurring and image matting, which we call deblatting. By postprocessing, non-causal Tracking by Deblatting estimates continuous, complete, and accurate object trajectories for the whole sequence. Tracked objects are precisely localized with higher temporal resolution than by conventional trackers. Energy minimization by dynamic programming is used to detect abrupt changes of motion, called bounces. High-order polynomials are then fitted to smooth trajectory segments between bounces. The output is a continuous trajectory function that assigns location for every real-valued time stamp from zero to the number of frames. The proposed algorithm was evaluated on a newly created dataset of videos from a high-speed camera using a novel Trajectory-IoU metric that generalizes the traditional Intersection over Union and measures the accuracy of the intra-frame trajectory. The proposed method outperforms the baselines both in recall and trajectory accuracy. Additionally, we show that from the trajectory function precise physical calculations are possible, such as radius, gravity, and sub-frame object velocity. Velocity estimation is compared to the high-speed camera measurements and radars. Results show high performance of the proposed method in terms of Trajectory-IoU, recall, and velocity estimation.

Influence of Main Swirler Vane Angle on the Ignition Performance of TeLESS-II Combustor

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Bo Wang ◽  
Chi Zhang ◽  
Yuzhen Lin ◽  
Xin Hui ◽  
Jibao Li
Keyword(s):  
High Speed ◽  
Inlet Temperature ◽  
Main Stage ◽  
Ignition Process ◽  
High Speed Camera ◽  
Fuel Distribution ◽  
Fuel Droplets ◽  
Planar Laser ◽  
Cfd Method ◽  
Vane Angle

In order to balance the low emission and wide stabilization for lean premixed prevaporized (LPP) combustion, the centrally staged layout is preferred in advanced aero-engine combustors. However, compared with the conventional combustor, it is more difficult for the centrally staged combustor to light up as the main stage air layer will prevent the pilot fuel droplets arriving at igniter tip. The goal of the present paper is to study the effect of the main stage air on the ignition of the centrally staged combustor. Two cases of the main swirler vane angle of the TeLESS-II combustor, 20 deg and 30 deg are researched. The ignition results at room inlet temperature and pressure show that the ignition performance of the 30 deg vane angle case is better than that of the 20 deg vane angle case. High-speed camera, planar laser induced fluorescence (PLIF), and computational fluids dynamics (CFD) are used to better understand the ignition results. The high-speed camera has recorded the ignition process, indicated that an initial kernel forms just adjacent the liner wall after the igniter is turned on, the kernel propagates along the radial direction to the combustor center and begins to grow into a big flame, and then it spreads to the exit of the pilot stage, and eventually stabilizes the flame. CFD of the cold flow field coupled with spray field is conducted. A verification of the CFD method has been applied with PLIF measurement, and the simulation results can qualitatively represent the experimental data in terms of fuel distribution. The CFD results show that the radial dimensions of the primary recirculation zone of the two cases are very similar, and the dominant cause of the different ignition results is the vapor distribution of the fuel. The concentration of kerosene vapor of the 30 deg vane angle case is much larger than that of the 20 deg vane angle case close to the igniter tip and along the propagation route of the kernel, therefore, the 30 deg vane angle case has a better ignition performance. For the consideration of the ignition performance, a larger main swirler vane angle of 30 deg is suggested for the better fuel distribution when designing a centrally staged combustor.

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