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Robust Real-time Control of Autonomous Mobile Robot Based on Ultrasonic and Infrared sensors
Van-Quyet Nguyen(노연판쿠웨트),Sung-Hyun Han(한성현) 한국생산제조학회 2010 한국생산제조학회지 Vol.19 No.1
This paper presents a new approach to obstacle avoidance for mobile robot in unknown or partially unknown environments. The method combines two navigation subsystems: low level and high level. The low level subsystem takes part in the control of linear, angular velocities using a multivariable PI controller, and the nonlinear position control. The high level subsystem uses ultrasonic and IR sensors to detect the unknown obstacle include static and dynamic obstacle. This approach provides both obstacle avoidance and target-following behaviors and uses only the local information for decision making for the next action. Also, we propose a new algorithm for the identification and solution of the local minima situation during the robot’s traversal using the set of fuzzy rules. The system has been successfully demonstrated by simulations and experiments.
A Study on Obstacle Avoidance of Mobile Robot
Van-Quyet Nguyen,Se-Bong Oh,Hyen-Chul Ro,Chang-Jae Cho,Sung-Hyun Han 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10
We present a new technique to autonomous navigation based on ultrasonic sensors for mobile robots travelling through the narrow aisle that leave only a few centimeters on each side between the guides and the robot. In our current implementation the ultrasonic sensor system fires at a rate of 100 ms, that is, each of the 8 sensors fires once during each 100 ms interval. This is a very fast firing rate, implemented here for optimal performance. This paper presents an extensively tested and verified solution to the problem. Our solution is based on the optimal placement of ultrasonic sensors at strategic locations around the robot. Both the sensor location and the associated navigation algorithm are defined in such a way that only the accurate radial sonar data is used for servoing.
Obstacle Avoidance of Mobile Robot
Nguyen Van Quyet,Woo-Song Lee,Jun-Hong Kim,Sung-Hyun Han 한국생산제조학회 2009 한국공작기계학회 추계학술대회논문집 Vol.2009 No.-
This paper present the theoretical development of a complete navigation problem of a nonholonomic mobile robot by using sonar sensors. To solve this problem, a new method to compute a fuzzy perception of the environment is presented, dealing with the uncertainties and imprecision from the sensory system and taking into account nonholonomic constraints of the robot. Fuzzy perception, fuzzy controller are applied, both in the design of each reactive behavior and solving the problem of behavior combination, to implement a fuzzy behavior-based control architecture. Different experiments in populated environments have proved to be very successful. Our method is able to guide the RD_Robo safety and efficiently during long experimental time.
Preparation and properties of Bi-based lead-free ceramic multilayer actuators
Van-Quyet Nguyen 한양대학교 세라믹연구소 2012 Journal of Ceramic Processing Research Vol.13 No.S1
Lead-free (Bi0.5Na0.41K0.09)TiO3 (BNKT) multilayer ceramic actuators were prepared using tape-casting and screen-printing techniques. Co-firing behavior of BNKT/AgPd laminates was examined as a function of sintering temperature. It was found that co-firing induced bending and electrical properties were very sensitive to sintering condition. By optimizing sintering conditions, lead-free electrostrictive multilayer actuators with normalized strain Smax/Emax of 266 pm/V have been successfully fabricated, which is promising for lead-free actuator applications.
A Study on Robust control of Non-holonomic Mobile Robot Based on Fuzzy Perception
Van-Quyet Nguyen,Jun-Hong Kim,Woo-Song Lee,Sung-Hyun Han 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8
This paper present the theoretical development of a complete navigation problem of a non-holonomic mobile robot by using sonar sensors. To solve this problem, a new method to compute a fuzzy perception of the environment is presented, dealing with the uncertainties and imprecision from the sensory system and taking into accountnonholonomic constraints of the robot. Fuzzy perception, fuzzy controller are applied, both in the design of each reactive behavior and solving the problem of behavior combination, to implement a fuzzy behavior-based control architecture. Different experiments in populated environments have proved to be very successful. Our method is able toguide the KUM-Robo safety and efficiently during long experimental time.
Nguyen Van Quyet,Luong Huu Bac,Dang Duc Dung 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.8
In this work, a strong enhancement of the electric-field-induced strain in Bi0.5(Na,K)0.5TiO3- based ceramics was observed via lithium(Li) addition. The Li-added Bi0.5(Na,K)0.5TiO3-based ceramics exhibited a strain of 0.40% under an electric field of 6 kV/mm, which was almost twice the value without the Li dopant (0.21%). We obtained the highest Smax/Emax value of 668 pm/V for 4-mol% Li addition, which was due to the phase transition from pseudocubic to rhombohedral symmetry and/or to the distorted tetragonal structure. We suggest that controlling the phase transition in ferroelectric materials is a way to enhance the electric-field-induced giant strain and that the phase transition from the non-polar phase to the polar phase results in a giant electric-fieldinduced strain, which overcomes the result due to the phase transition from the polar phase to the non-polar phase and/or the distorted structure. We expect our work to open new ways to enhance the electric-filed-induced giant strain to a value that is comparable to the value for Pb(Zr,Ti)O3 (PZT)-based ceramics.
A Study on Visual Feedback Control of Robot Arm
Van-Quyet Nguyen,Jun-Hong Kim,Suk-Bum Yoon,Young-Gyun Yoo,Sung-Hyun Han 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10
This paper presents how it is effective to use many features for improving the speed and the accuracy of the visual servo systems. Some rank conditions, which relate the image Jacobian, and the control performance are derived. It is also proven that the accuracy is improved by increasing the number of features. Effectiveness of the redundant features is verified by the real time experiments on a Dual-Arm Robot manipulator made by Samsung Electronics Co. Ltd.
Van-Quyet Nguyen,홍창효,이현영,공영민,이재신,안경관 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.61 No.6
The effects of Li substitution on the crystal structure and the strain properties of Bi<sub>0.5</sub>-(Na<sub>0.82</sub>K<sub>0.18</sub>)<sub>0.5</sub>(Ti<sub>0.95</sub>Sn<sub>0.05</sub>)O<sub>3</sub> ceramics have been investigated. Li substitution enhanced the grain growth and densification, as well as the electric-field-induced strain (EFIS).Without Li substitution, the EFIS was 0.31% under a dc field of 6 kV/mm. However, the EFIS was enhanced to 0.39% when 4 mol% Na was replaced with Li, resulting in a normalized strain (<i>S<sub>max</sub>/E<sub>max</sub></i>) of 646 pm/V. The enhanced strain could be attributed to the increased flexibility in the lattice caused by simultaneous substitutions with both A-site Li ions and B-site Sn ions.
Travelling Control and Navigation of Mobile Robot by Using Multi - Sensors
Van-Quyet Nguyen,Lee, Woo-Song,Kim, Jun-Hong,Han, Sung-Hyun 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-
This paper present the theoretical development of a complete navigation problem of a nonholonomic mobile robot by using sonar sensors. To solve this problem, a new method to compute a fuzzy perception of the environment is presented, dealing with the uncertainties and imprecision from the sensory system and taking into account nonholonomic constraints of the robot. Fuzzy perception, fuzzy controller are applied, both in the design of each reactive behavior and solving the problem of behavior combination, to implement a fuzzy behavior-based control architecture. Different experiments in populated environments have proved to be very successful. Our method is able to guide the RD_Robo safety and efficiently during long experimental time.
A Study on Design of Three – Finger Hand System
Van-Quyet Nguyen,Se-Bong Oh,Jea-Uk Lim,Chang-Hak Kang,Sung-Hyun Han 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10
The focus of this paper is to design a flexible three fingered hand system with 16 D.O.F for dynamic manipulation with an intelligent controller, and to build a useful database for dynamic manipulation based on the experimental results. The weight of the hand module is only 0.7 kg, but flexible motion and powerful grasping are possible. To achieve such a dynamic motion in a robotic hand, we have developed a flexible fingered hand with a control system incorporating image recognition system in which we deal with the problems of not only accuracy and range of motion but also the flexibility of hand. The fingers are arranged so as to grasp both circular and prismatic objects. In order to achieve the light mechanism, we reduced the number of joints and fingers as much as possible. We used three fingers, which is the minimum number to achieve a stable grasp.