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Development of robust behaviour recognition for an at-home biomonitoring robot with assistance of subject localization and enhanced visual tracking

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Scientific World Journal 2014年第1期2014卷 280207-280207页

作者： Imamoglu, Nevrez Dorronzoro, Enrique Wei, Zhixuan Shi, Huangjun Sekine, Masashi González, José Gu, Dongyun Chen, Weidong Yu, Wenwei Graduate School of Engineering Chiba University Chiba 263-8522 Japan Research Center for Frontier Medical Engineering Chiba University Chiba 263-8522 Japan Department of Electronic Technology University of Seville Seville 41012 Spain Institute of Robotics and Intelligent Information Processing Department of Automation Shanghai Jiao Tong University Shanghai 200240 China Department of Biomedical Engineering Shanghai Jiao Tong University Shanghai 200030 China Spanish National Research Council Bioengineering Group Madrid 28500 Spain

Our research is focused on the development of an at-home health care biomonitoring mobile robot for the people in demand. Main task of the robot is to detect and track a designated subject while recognizing his/her activity for analysis and to provide warning in an emergency. In order to push forward the system towards its real application, in this study, we tested the robustness of the robot system with several major environment changes, control parameter changes, and subject variation. First, an improved color tracker was analyzed to find out the limitations and constraints of the robot visual tracking considering the suitable illumination values and tracking distance intervals. Then, regarding subject safety and continuous robot based subject tracking, various control parameters were tested on different layouts in a room. Finally, the main objective of the system is to find out walking activities for different patterns for further analysis. Therefore, we proposed a fast, simple, and person specific new activity recognition model by making full use of localization information, which is robust to partial occlusion. The proposed activity recognition algorithm was tested on different walking patterns with different subjects, and the results showed high recognition accuracy. © 2014 Nevrez Imamoglu et al.

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Ultrasonic-assisted cylindrical grinding of Alumina-zirconia ceramics

Ultrasonic-assisted cylindrical grinding of Alumina-zirconia...

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ASME 2013 International Mechanical engineering Congress and Exposition, IMECE 2013

作者： Tawakoli, Taghi Akbari, Javad Zahedi, A.M. Furtwangen University Schwenningen Baden-Württemberg Germany Center of Excellence in Design Robotics and Automation School of Mechanical Engineering Sharif University of Technology Azadi Ave. 14588-89694 Tehran Iran Center of Advanced Manufacturing and Material Processing Department of Engineering Design and Manufacture University of Malaya 50603 Kuala Lumpur Malaysia

ISBN: (纸本)9780791856185

Due to its vast applications and stochastic nature, grinding has been the subject of investigations and modifications for decades. Applying ultrasonic vibration in grinding has been a successful innovation introducing benefits such as reduced forces and temperature, improved surface quality, and making higher removal rates possible. In this work a set-up is developed for utilizing ultrasonic vibrations in cylindrical grinding. This is done by rotating and simultaneously vibrating the workpiece material. The set-up is used for cylindrical grinding of Alumina-zirconia ceramic as a difficult-to-grind and widely used industrial ceramic. Optimized parameters for efficient grinding and surface characteristics of the ground ceramic are investigated and the effects of ultrasonic vibration are declared. Copyright © 2013 by ASME.

关键词： Surface roughness

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Analytical modeling of static behavior of electrostatically actuatednano/micromirrors considering van der Waals forces

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Acta Mechanica Sinica 2012年第3期28卷 729-736页

作者： Hamid Moeenfard Mohammad Taghi Ahmadian School of Mechanical Engineering Sharif University of Technology Center of Excellence in Design Robotics and AutomationSchool of Mechanical EngineeringSharif University of Technology

In this paper, the effect of van der Waals （vdW） force on the pull-in behavior of electrostatically actuated nano/micromirrors is investigated. First, the minimum po- tential energy principle is utilized to find the equation gov- erning the static behavior of nano/micromirror under electro- static and vdW forces. Then, the stability of static equilib- rium points is analyzed using the energy method. It is found that when there exist two equilibrium points, the smaller one is stable and the larger one is unstable. The effects of dif- ferent design parameters on the mirror＇s pull-in angle and pull-in voltage are studied and it is found that vdW force can considerably reduce the stability limit of the mirror. At the end, the nonlinear equilibrium equation is solved numer- ically and analytically using homotopy perturbation method （HPM）. It is observed that a sixth order perturbation approx- imation can precisely model the mirror＇s behavior. The re- suits of this paper can be used for stable operation design and safe fabrication of torsional nano/micro actuators.

关键词： Nano/micromirror Electrostatic actuation vdW force Pull-in. Homotopy perturbation method （HPM）

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Applying Ultrasonic Vibration to Decrease Drilling-Induced Delamination in GFRP Laminates

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Procedia CIRP 2013年 6卷 577-582页

作者： P. Mehbudi V. Baghlani J. Akbari A.R. Bushroa N.A. Mardi Center of Excellence in Design Robotics and Automation School of Mechanical Engineering Sharif University of Technology AzadiAve. 14588-89694 Tehran Iran Center of Advanced Manufacturing and Material Processing - Micro Mechanism Research Group Department of Engineering Design and Manufacture Faculty of Engineering University of Malaya 50603 Kuala Lumpur Malaysia

Delamination is a major problem in drilling of fiber-reinforced composite materials. Thrust force is an important factor leading to propagation of delamination during drilling process. One of effective methods to reduce machining forces is application of ultrasonic vibrations. In this study ultrasonic assisted drilling is applied to reduce thrust force in drilling of GFRP laminates. In order to conduct experiments a setup is designed and fabricated to apply both vibrations and rotation to drill bits. Using Taguchi method, a set of experiments is conducted with feed rate, spindle speed, and ultrasonic vibration amplitude as control factors. The results show that applying ultrasonic vibration reduces the thrust force and therefore the drilling induced delamination dramatically.

关键词： Ultrasonic assisted drilling GFRP laminates Drilling induced delamination Taguchi method

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Tool condition monitoring based on sound and vibration analysis and wavelet packet decomposition

Tool condition monitoring based on sound and vibration analy...

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2012 8th International Symposium on Mechatronics and its Applications, ISMA 2012

作者： Rafezi, Hamed Akbari, Javad Behzad, Mehdi Sharif University of Technology International Campus School of Science and Engineering Kish Island Iran Sharif University of Technology Department of Mechanical Engineering Center of Excellence in Design Robotics and Automation Tehran Iran

ISBN: (纸本)9781467308625

Tool Condition Monitoring (TCM) is a vital demand of advanced manufacturing in order to develop automated unmanned production. Continuing the machining operation with a worn or damaged tool will result in damages to the workpiece. This problem becomes more important in supplementary machining processes like drilling which the workpiece usually has passed a lot of machining processes and any damage to workpiece at this stage results in high production losses. In this research features of sound pressure and vibration signals in drilling process are recorded and analyzed in order to detect tool wear. Signal statistical features are extracted in time domain, and the features trends as the tool becomes worn are extracted. Frequency spectrum of signals is calculated and Wavelet Packet Decomposition (WPD) is applied to focus on specific frequency bands. In this research capability of both sound and vibration signals for drill wear detection are shown and the most informative features of the signals for wear detection are evaluated and introduced. The results showed that the wavelet packets features make a better contrast between the sharp and the worn tool compared to the primary time domain signal. © 2012 IEEE.

关键词： Vibration analysis

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TEMPERATURE DEPENDENCE STUDY OF NONCONTACT AFM IMAGES USING MOLECULAR DYNAMICS SIMULATIONS

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International Journal of Modern Physics: Conference Series 2012年第5期ijmpcs卷 418-432页

作者： HOSSEIN NEJAT PISHKENARI ALI MEGHDARI Nano-Robotics Laboratory Center of Excellence in Design Robotics and Automation School of Mechanical Engineering Sharif University of Technology Tehran P.O. Box: 11365-9465 Iran

The effect of temperature on the noncontact atomic force microscopy (NC-AFM) surface imaging is investigated with the aid of molecular dynamics (MD) analysis based on the Sutton-Chen (SC) interatomic potential. Particular attention is devoted to the tip and sample flexibility at different temperatures. When a gold coated probe is brought close to the Au (001) surface at high temperatures, the tip and surface atoms are pulled together and their distance becomes smaller. The tip and sample atoms displacement varies in the different environment temperatures and this leads to the different interaction forces. Along this line, to study the effect of temperature on the resulting images, we have employed the well-known NC-AFM model and carried out realistic non-equilibrium MD 3D simulations of atomic scale imaging at different close approach positions to the surface.

关键词： NC-AFM molecular dynamics simulation Sutton-Chen potential tip-surface interaction force temperature effect

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Data-driven fractional PID control: application to DC motors in flexible joints

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IFAC Proceedings Volumes 2012年第3期45卷 709-714页

作者： Jorge Villagra Blas Vinagre Inés Tejado AUTOPIA Program Center for Automation and Robotics (CAR UPM-CSIC) 28500 Arganda del Rey Madrid Spain Industrial Engineering School University of Extremadura 06006 Badajoz Spain.

Recent advances in data-driven (or model-free) control have permitted to enhance the closed loop behavior of linear and especially nonlinear systems using very simple control structures. As a result, unknown or badly known dynamics are compensated and disturbances are rejected without any learning or on-line identification procedure. However, the ultra-local phenomenological models on which this control technique rely have not yet exploited the fractional nature of many processes and the nonlocal nature of the fractional integrodifferential operators. In this paper, fractional derivatives are used in the so called model free control structure in order to explore the advantages they provide in terms of robustness and dynamic response. Fractional and integer order data driven PIDs will be compared for a DC motor in a robot flexible joint control application in a simulation environment.

关键词： PID control fractional control data-driven control

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Tool Condition Monitoring based on sound and vibration analysis and wavelet packet decomposition

Tool Condition Monitoring based on sound and vibration analy...

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International Symposium on Mechatronics and Its Applications, ISMA

作者： Hamed Rafezi Javad Akbari Mehdi Behzad School of Science and Engineering Sharif University of Technology Kish Island Iran Department of Mechanical Engineering Center of Excellence in Design Robotics and Automation Sharif University of Technology Tehran Iran

关键词： Vibrations Wavelet packets Feature extraction Drilling machines Time domain analysis Condition monitoring Wavelet analysis

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Taguchi's optimization in ultrasonic drilling of alumina ceramic

Taguchi's optimization in ultrasonic drilling of alumina cer...

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6th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2011

作者： Hoseini, S. Mehdi Akbari, Javad Department of Mechanical and Engineering Science and Research Branch Islamic Azad University Tehran Iran Center of Excellence in Design Robotics and Automation School of Mechanical Engineering Sharif University of Technology Tehran Iran

This paper outlines the effectiveness of the ultrasonic machining of alumina in terms of tool wear rate of the tool used and the material removal rate of work piece produced. The optimum combination of various input factors as type of abrasive slurry, their size and concentration, power and feed rate, in the machining of alumina has been determined by applying the Taguchi technique, also analysis is used to choose the best shape for horn. The study shows that among input parameters, power has the highest effect on MRR (material removal rate). Effects of grit size and feed rate on TWR (tool wear rate) also investigated.

关键词： Taguchi methods

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Cortex Inspired Model for Inverse Kinematics Computation for a Humanoid Robotic Finger

Cortex Inspired Model for Inverse Kinematics Computation for...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society

作者： Rodolphe J. Gentili Hyuk Oh Javier Molina James A. Reggia José L. Contreras- Vidal Department of Kinesiology School of Public Health Maryland Robotics Center Neuroscience and Cognitive Science Program University of Maryland College Park MD 20742 USA Neuroscience and Cognitive Science Program University of Maryland College Park MD 20742 USA Department of Systems Engineering and Automation Technical University of Cartagena 30202 Cartagena Spain Department of Computer Science University of Maryland Institute for Advanced Computer Studies University of Maryland College Park MD 20742 USA Department of Electrical and Computer Engineering University of Houston Houston TX 77004 USA

ISBN: (纸本)9781424441198

In order to approach human hand performance levels, artificial anthropomorphic hands/fingers have increasingly incorporated human biomechanical features. However, the performance of finger reaching movements to visual targets involving the complex kinematics of multijointed, anthropomorphic actuators is a difficult problem. This is because the relationship between sensory and motor coordinates is highly nonlinear, and also often includes mechanical coupling of the two last joints. Recently, we developed a cortical model that learns the inverse kinematics of a simulated anthropomorphic finger. Here, we expand this previous work by assessing if this cortical model is able to learn the inverse kinematics for an actual anthropomorphic humanoid finger having its two last joints coupled and controlled by pneumatic muscles. The findings revealed that single 3D reaching movements, as well as more complex patterns of motion of the humanoid finger, were accurately and robustly performed by this cortical model while producing kinematics comparable to those of humans. This work contributes to the development of a bioinspired controller providing adaptive, robust and flexible control of dexterous robotic and prosthetic hands.

关键词： reaching prosthetic providing

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