Development of hybrid fire testing by real-time subdivision of physical and numerical substructures

2020 ◽  
Vol 11 (4) ◽  
pp. 481-497
Author(s):  
Nicolas Pinoteau ◽  
Duc Toan Pham ◽  
Hong Hai Nguyen ◽  
Romain Mège
Keyword(s):  
Real Time ◽  
Thermal Loading ◽  
Time Lag ◽  
Experimental Results ◽  
Fire Testing ◽  
Content Type ◽  
Finite Element Software ◽  
Experimental Campaign ◽  
Overshoot Phenomenon ◽  
The Difference

Purpose This study aims to evaluate the feasibility of a hybrid fire testing by real-time subdivision of physical and numerical substructures (NSs) on simplified structures as a milestone in the development of the method. Design/methodology/approach An interface where the data was exchanged between a finite element software and a hydraulic jack regulator using text files has been developed and applied to perform two experimental campaigns of nine tests on simple steel frame structures with different thermal loading conditions. In the first experimental campaign, the physical substructure (PS) was assumedly protected by insulating material, while the NS was uniformly exposed to ISO 834 fire on all sides. The difference of the second experimental campaign from the first one was that the PS was heated on one side. Findings The experimental results showed how a gap between the determined equilibrium position and the “real” position caused by the time lag, as well as an overshoot phenomenon due to the non-synchronized action of both substructures, may occur. From the identification of the overshoot, two paths of development spring to mind to reduce the delay of the NS. Originality/value In the context that the number of proposal theoretical algorithms continues to increase with the absence of real experimental adjustments, such experimental results and the associated analysis constitute additional understandings to identify possible paths of improvements that might have been missed or could not be accessed through previous studies.

Real-time parking slot availability for Bhavnagar, using statistical block matching approach

2020 ◽  
Vol 17 (6) ◽  
pp. 811-821
Author(s):  
Janak D. Trivedi ◽  
Sarada Devi Mandalapu ◽  
Dhara H. Dave
Keyword(s):  
Real Time ◽  
Region Of Interest ◽  
Mean Value ◽  
Block Matching ◽  
Computational Time ◽  
Maintenance Cost ◽  
Content Type ◽  
Block Matching Algorithm ◽  
The Difference ◽  
Parking Place

Purpose The purpose of this paper is to find a real-time parking location for a four-wheeler. Design/methodology/approach Real-time parking availability using specific infrastructure requires a high cost of installation and maintenance cost, which is not affordable to all urban cities. The authors present statistical block matching algorithm (SBMA) for real-time parking management in small-town cities such as Bhavnagar using an in-built surveillance CCTV system, which is not installed for parking application. In particular, data from a camera situated in a mall was used to detect the parking status of some specific parking places using a region of interest (ROI). The method proposed computes the mean value of the pixels inside the ROI using blocks of different sizes (8 × 10 and 20 × 35), and the values were compared among different frames. When the difference between frames is more significant than a threshold, the process generates “no parking space for that place.” Otherwise, the method yields “parking place available.” Then, this information is used to print a bounding box on the parking places with the color green/red to show the availability of the parking place. Findings The real-time feedback loop (car parking positions) helps the presented model and dynamically refines the parking strategy and parking position to the users. A whole-day experiment/validation is shown in this paper, where the evaluation of the method is performed using pattern recognition metrics for classification: precision, recall and F1 score. Originality/value The authors found real-time parking availability for Himalaya Mall situated in Bhavnagar, Gujarat, for 18th June 2018 video using the SBMA method with accountable computational time for finding parking slots. The limitations of the presented method with future implementation are discussed at the end of this paper.

Improving stability in physical human–robot interaction by estimating human hand stiffness and a vibration index

2019 ◽  
Vol 46 (4) ◽  
pp. 529-540 ◽  
Author(s):  
Feifei Bian ◽  
Danmei Ren ◽  
Ruifeng Li ◽  
Peidong Liang
Keyword(s):  
Time Delay ◽  
Real Time ◽  
Time Domain ◽  
Design Methodology ◽  
Interaction Force ◽  
Human Robot Interaction ◽  
Experimental Results ◽  
Human Hand ◽  
Robot Interaction ◽  
Content Type

Purpose The purpose of this paper is to eliminate instability which may occur when a human stiffens his arms in physical human–robot interaction by estimating the human hand stiffness and presenting a modified vibration index. Design/methodology/approach Human hand stiffness is first estimated in real time as a prior indicator of instability by capturing the arm configuration and modeling the level of muscle co-contraction in the human’s arms. A time-domain vibration index based on the interaction force is then modified to reduce the delay in instability detection. The instability is confirmed when the vibration index exceeds a given threshold. The virtual damping coefficient in admittance controller is adjusted accordingly to ensure stability in physical human–robot interaction. Findings By estimating the human hand stiffness and modifying the vibration index, the instability which may occur in stiff environment in physical human–robot interaction is detected and eliminated, and the time delay is reduced. The experimental results demonstrate significant improvement in stabilizing the system when the human operator stiffens his arms. Originality/value The originality is in estimating the human hand stiffness online as a prior indicator of instability by capturing the arm configuration and modeling the level of muscle co-contraction in the human’s arms. A modification of the vibration index is also an originality to reduce the time delay of instability detection.

Experiments of iterative learning control system using particle swarm optimization by new bounded constraints on velocity and positioning

2014 ◽  
Vol 31 (2) ◽  
pp. 250-266 ◽  
Author(s):  
Yi-Cheng Huang ◽  
Ying-Hao Li
Keyword(s):  
Particle Swarm Optimization ◽  
Real Time ◽  
Iterative Learning Control ◽  
Pid Controller ◽  
Learning Control ◽  
Iterative Learning ◽  
Experimental Results ◽  
Swarm Optimization ◽  
Content Type ◽  
Pid Algorithm

Purpose – This paper utilizes the improved particle swarm optimization (IPSO) with bounded constraints technique on velocity and positioning for adjusting the gains of a proportional-integral-derivative (PID) and iterative learning control (ILC) controllers. The purpose of this paper is to achieve precision motion through bettering control by this technique. Design/methodology/approach – Actual platform positioning must avoid the occurrence of a large control action signal, undesirable overshooting, and preventing out of the maximum position limit. Several in-house experiments observation, the PSO mechanism is sometimes out of the optimal solution in updating velocity and updating position of particles, the system may become unstable in real-time applications. The proposed IPSO with new bounded constraints technique shows a great ability to stabilize nonminimum phase and heavily oscillatory systems based on new bounded constraints on velocity and positioning in PSO algorithm is evaluated on one axis of linear synchronous motor with a PC-based real-time ILC. Findings – Simulations and experiment results show that the proposed controller can reduce the error significantly after two learning iterations. The developed method using bounded constraints technique provides valuable programming tools to practicing engineers. Originality/value – The proposed IPSO-ILC-PID controller overcomes the shortcomings of conventional ILC-PID controller with fixed gains. Simulation and experimental results show that the proposed IPSO-ILC-PID algorithm exhibits great speed convergence and robustness. Experimental results confirm that the proposed IPSO-ILC-PID algorithm is effective and achieves better control in real-time precision positioning.

The Improvement of Mean - Shift Algorithm in the Video of Global Visual Robotic Fish in Tracking Moving Targets

2013 ◽  
Vol 475-476 ◽  
pp. 947-951
Author(s):  
Zhi Yuan Mai ◽  
Kun Yu Tan ◽  
An Ting Xu ◽  
Wei Xiang
Keyword(s):  
Real Time ◽  
Mean Shift ◽  
Tracking Algorithm ◽  
Robotic Fish ◽  
Experimental Results ◽  
Moving Targets ◽  
Mean Shift Algorithm ◽  
Good For ◽  
The Difference

The tracking effect is not good for the faster track with Mean Shift tracking algorithm when the difference is not obvious between the track target and background pixels in the video of global visual robotic fish.To solve the difficulty of tracking drastically moving targets in this paper, determining the position of moving targets in the next frame through comparing with two bc coefficients which have been set when the Epanechnikov has been selected core to estimate is indeed. The experimental results show the proposed algorithm can track the moving targets efficiently and precisely in video,and also can meet high real-time situation with small calculation.

Energy-efficient scheduling algorithm for real-time job set

2016 ◽  
Vol 33 (6) ◽  
pp. 1753-1766 ◽  
Author(s):  
Chin-Fu Kuo ◽  
Yung-Feng Lu ◽  
Bao-Rong Chang
Keyword(s):  
Energy Consumption ◽  
Real Time ◽  
Energy Efficient ◽  
Scheduling Algorithm ◽  
Experimental Results ◽  
Total Density ◽  
Scheduling Problem ◽  
Two Phase ◽  
Content Type ◽  
Energy Efficient Scheduling

Purpose – The purpose of this paper is to investigate the scheduling problem of real-time jobs executing on a DVS processor. The jobs must complete their executions by their deadlines and the energy consumption also must be minimized. Design/methodology/approach – The two-phase energy-efficient scheduling algorithm is proposed to solve the scheduling problem for real-time jobs. In the off-line phase, the maximum instantaneous total density and instantaneous total density (ITD) are proposed to derive the speed of the processor for each time instance. The derived speeds are saved for run time. In the on-line phase, the authors set the processor speed according to the derived speeds and set a timer to expire at the corresponding end time instance of the used speed. Findings – When the DVS processor executes a job at a proper speed, the energy consumption of the system can be minimized. Research limitations/implications – This paper does not consider jobs with precedence constraints. It can be explored in the further work. Practical implications – The experimental results of the proposed schemes are presented to show the effectiveness. Originality/value – The experimental results show that the proposed scheduling algorithm, ITD, can achieve energy saving and make the processor fully utilized.

P-like controllers with collision avoidance for passive bilateral teleoperation of a UAV

2018 ◽  
Vol 45 (1) ◽  
pp. 152-166 ◽  
Author(s):  
Huiyu Sun ◽  
Guangming Song ◽  
Zhong Wei ◽  
Ying Zhang
Keyword(s):  
Real Time ◽  
Collision Avoidance ◽  
High Accuracy ◽  
Experimental Results ◽  
Linear Matrix ◽  
Time Varying ◽  
Bilateral Teleoperation ◽  
Content Type ◽  
Teleoperation System ◽  
The Stability

Purpose This paper aims to tele-operate the movement of an unmanned aerial vehicle (UAV) in the obstructed environment with asymmetric time-varying delays. A simple passive proportional velocity errors plus damping injection (P-like) controller is proposed to deal with the asymmetric time-varying delays in the aerial teleoperation system. Design/methodology/approach This paper presents both theoretical and real-time experimental results of the bilateral teleoperation system of a UAV for collision avoidance over the wireless network. First, a position-velocity workspace mapping is used to solve the master-slave kinematic/dynamic dissimilarity. Second, a P-like controller is proposed to ensure the stability of the time-delayed bilateral teleoperation system with asymmetric time-varying delays. The stability is analyzed by the Lyapunov–Krasovskii function and the delay-dependent stability criteria are obtained under linear-matrix-inequalities conditions. Third, a vision-based localization is presented to calibrate the UAV’s pose and provide the relative distance for obstacle avoidance with a high accuracy. Finally, the performance of the teleoperation scheme is evaluated by both human-in-the-loop simulations and real-time experiments where a single UAV flies through the obstructed environment. Findings Experimental results demonstrate that the teleoperation system can maintain passivity and collision avoidance can be achieved with a high accuracy for asymmetric time-varying delays. Moreover, the operator could tele-sense the force reflection to improve the maneuverability in the aerial teleoperation. Originality/value A real-time bilateral teleoperation system of a UAV for collision avoidance is performed in the laboratory. A force and visual interface is designed to provide force and visual feedback of the slave environment to the operator.

scholarly journals Soft labeling with quasi-Gaussian structure for training samples of deep classification trackers

2020 ◽  
Vol 17 (2) ◽  
pp. 172988142091502
Author(s):  
Yan Peng ◽  
Jiantao Gao ◽  
Chang Liu ◽  
Xiaomao Li ◽  
Baojie Fan ◽  
...  
Keyword(s):  
Real Time ◽  
Response Function ◽  
State Of The Art ◽  
Gaussian Function ◽  
Experimental Results ◽  
Training Samples ◽  
Comparable Accuracy ◽  
Real Time Tracking ◽  
The Difference ◽  
Combination Function

Deep classification tracking aims at classifying the candidate samples into target or background by a classifier generally trained with a binary label. However, the binary label merely distinguishes samples of different classes, while inadvertently ignoring the distinction among the samples belonging to the same class, which weakens the classification and locating ability. To cope with this problem, this article proposes a soft labeling with quasi-Gaussian structure instead of the binary labeling, which distinguishes the samples belonging to different classes and the same class simultaneously. Like as the binary label, the signs of labels for target and background samples are set to be plus and minus respectively to distinguish samples of different classes. Further, to exploit the difference among samples in the same class, the label values of samples in the same class are designed as a monotonically decreasing quasi-Gaussian function about Intersection over Union. Therefore, the corresponding response function is a two-piecewise monotonically increasing quasi-Gaussian combination function about Intersection over Union. Due to such response function, deep classification tracking trained with this proposed soft labeling achieves better classification and location performance. To validate this, the proposed soft labeling is integrated into the pipeline of the deep classification tracker SiamFC. Experimental results on OTB-2015 and VOT benchmark show that our variant achieves significant improvement to the baseline tracker while maintaining real-time tracking speed and acquires comparable accuracy as recent state-of-the-art trackers.

Optimization of Thermomechanical Loading by the Inverse Method

2006 ◽  
Vol 129 (2) ◽  
pp. 207-210
Author(s):  
Virginie Bogard ◽  
Philippe Revel ◽  
Yannick Hetet
Keyword(s):  
Numerical Simulations ◽  
Thermal Loading ◽  
Thermal Evolution ◽  
Industrial Process ◽  
Experimental Results ◽  
Thermal Loads ◽  
The Finite Element Method ◽  
The Difference ◽  
Technological Means ◽  
Infrared Pyrometer

This study presents 2D experimental results and the numerical simulations of thermal loads in order to observe their influences on the life of mechanical systems. The experimental and thermal evolution was measured using several thermocouples and an infrared pyrometer. In fact, the thermal loading was determined by the resolution of an inverse process where the parameters of thermal laws were identified by minimizing the difference between the experimental results and the numerical simulations. After this optimization process, the mechanical modeling by the finite element method was carried out by applying the optimized thermal loading. The laws of elastoviscoplastic behavior are applied in the working temperature range of a continuous casting rollers tool. This modeling constitutes a technological means to choose a type of a coating material and its optimum thickness and to test different thermal loads in order to optimize the industrial process and to improve the tool’s life.

Evaluation of superior layer configuration of titanium Ti-6Al-4V and aluminium 2024-T3 against soft projectiles

2021 ◽  
pp. 204141962110357
Author(s):  
K. Senthil ◽  
Rachit Sharma ◽  
S. Rupali ◽  
Ankush Thakur ◽  
M. A. Iqbal ◽  
...  
Keyword(s):  
Material Model ◽  
Experimental Results ◽  
Equivalent Thickness ◽  
Explicit Finite Element ◽  
Ballistic Resistance ◽  
Finite Element Software ◽  
Target Configuration ◽  
Titanium Target ◽  
The Difference ◽  
Good Agreement

The manuscript is focussed on the prediction of superior layer configuration on titanium and aluminium plates through numerical investigations using ABAQUS/Explicit finite element software. The target plate of titanium Ti-6Al-4V (Ti) and aluminium Al 2024-T3 (Al) were studied against 7.62 mm diameter soft lead core projectiles. The Johnson-Cook (JC) material model was employed to simulate the behaviour of the target as well as projectile material. The results thus predicted from the numerical simulations in terms of deformed profile, residual velocity and ballistic limit were compared with the experimental results available in literature. Overall, the results were found in good agreement with the experimental results. The simulations were performed on the target of 10, 12.7 and 15 mm thickness with three, five and ten layers in order to predict the superior layer configuration. In the case of Ti-6Al-4V, the difference in performance between three layers and monolithic was quite high, however the use of five or ten layers of equivalent thickness is not advisable as performance is reduced. For Al2024-T3, the performance of layer targets was quite similar to that of monolithic targets. It is also observed the resistance of TiTiAl target configuration found to be better as compared to AlTiTi target configuration. It is concluded that the Al plate as back layer has more efficiency for ballistic resistance of layered configuration. It is also concluded that with respect to thickness, the capacity of titanium target is approximately 1.5 times higher than aluminium target against given lead core projectile.

Intelligent motion control of voice coil motor using PID-based fuzzy neural network with optimized membership function

2016 ◽  
Vol 33 (8) ◽  
pp. 2302-2319 ◽  
Author(s):  
Syuan-Yi Chen ◽  
Cheng-Yen Lee ◽  
Chien-Hsun Wu ◽  
Yi-Hsuan Hung
Keyword(s):  
Neural Network ◽  
Real Time ◽  
Fuzzy Neural Network ◽  
Voice Coil Motor ◽  
Experimental Results ◽  
Membership Functions ◽  
Bacterial Foraging Optimization ◽  
Content Type ◽  
Fuzzy Neural ◽  
On Line

Purpose The purpose of this paper is to develop a proportional-integral-derivative-based fuzzy neural network (PIDFNN) with elitist bacterial foraging optimization (EBFO)-based optimal membership functions (PIDFNN-EBFO) position controller to control the voice coil motor (VCM) for tracking reference trajectory accurately. Design/methodology/approach Because the control characteristics of the VCM are highly nonlinear and time varying, a PIDFNN, which integrates adaptive PID control with fuzzy rules, is proposed to control the mover position of the VCM. Moreover, an EBFO algorithm is further proposed to find the initial optimal fuzzy membership functions for the PIDFNN controller. Findings Due to the gradient descent method used in back propagation (BP) to derive the on-line learning algorithm for the PIDFNN, it may reach the local optimal solution due to the inappropriate initial values. Hence, a hybrid learning method, which includes BP and EBFO algorithms, is proposed to improve the learning performance of the PIDFNN controller. Research limitations/implications Future work will consider reducing the computational burden of bacterial foraging optimization algorithm for on-line parameters optimization. Practical implications The real-time control system is implemented on a 32-bit floating-point digital signal processor (DSP). The experimental results demonstrate the favorable effectiveness of the proposed PIDFNN-EBFO controlled VCM system. Originality/value A new PIDFNN-EBFO control scheme is proposed and implemented via DSP for real-time VCM position control. The experimental results show the superior control performance of the proposed PIDFNN-EBFO compared with the other control systems.

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