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Development of Contact Force Measurement Algorithm for a 3D Printing-type Flexible Tactile Sensor (3D 프린팅 방식 유연 촉각센서의 접촉력 측정 알고리즘 개발)

  • Jeong, Kyeong-Hwa;Lee, Ju-Kyoung;Lee, Suk;Lee, Kyung-Chang
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.6
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    • pp.583-588
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    • 2015
  • Flexible tactile sensors can provide valuable feedback to intelligent robots regarding the environment around them. This is especially important when robots such as, service robots share a workspace with humans. This paper presents a contact force measurement algorithm of a flexible tactile sensor. This sensor is manufactured by a direct-writing technique, which is one 3D printing method, using multi-walled carbon nano-tubes. An analog signal processing circuit has been designed and implemented to reduce noise contained in the sensor output. In addition, a digital version of the Butterworth filter was implemented by software running on a microcontroller. Through various experiments, characteristics of the sensor system have been identified. Based on three traits, an algorithm to detect the contact and measure the contact force has been developed. The entire system showed a promising prospect to detect the contact over a large and curved area.

Development of a Bridge Transported Servo Manipulator System for the Remote Operation and Maintenance of Advanced Spent Fuel Conditioning Process (사용후 핵연료 차세대관리공정 원격 운전/유지보수용 천정이동 서보 매니퓰레이터 시스템 개발)

  • Park, Byung-Suk;Lee, Jong-Kwang;Lee, Hyo-Jik;Choi, Chang-Hwan;Yoon, Kwang-Ho;Yoon, Ji-Sup
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.10
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    • pp.940-948
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    • 2007
  • The Advanced Spent Fuel Conditioning Process(ACP), which is the process of the reduction of uranium oxide by lithium metal in a high temperature molten salt bath for spent fuel, was developed at Korea Atomic Energy Research Institute (KAERI). Since the ACP equipment is located in an intense radiation field (hot cell) as well as in a high temperature, it must be remotely operated and maintained. The ACP hot cell is very narrow so the workspace of the wall-mounted mechanical Master-Slave Manipulators(MSMs) is restricted. A Bridge Transported Servo Manipulator(BTSM) system has been developed to overcome the limitation of an access that is a drawback of the mechanical MSMs. The BTSM system consists ot a bridge crane with telescoping tubeset, a slave manipulator, a master manipulator, and a control system. We applied a bilateral position-position control scheme with friction compensation as force-reflecting controller. In this paper, the transmission characteristics on the tendon-and-pulley train is numerically formulated and analyzed. Also, we evaluate the performance of the force-reflecting servo manipulator.

Kinematic Analysis of a 6-DOF Ultra-Precision Positioning Stage Based on Flexure Hinge (플렉셔 힌지 기반 6-자유도 초정밀 위치 결정 스테이지의 기구학 해석)

  • Shin, Hyun-Pyo;Moon, Jun-Hee
    • Journal of the Korean Society for Precision Engineering
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    • v.33 no.7
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    • pp.579-586
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    • 2016
  • This paper describes kinematic analysis of a 6-degrees-of-freedom (DOF) ultra-precision positioning stage based on a flexure hinge. The stage is designed for processes which require ultra-precision and high load capacities, e.g. wafer-level precision bonding/assembly. During the initial design process, inverse and forward kinematic analyses were performed to actuate the precision positioning stage and to calculate workspace. A two-step procedure was used for inverse kinematic analysis. The first step involved calculating the amount of actuation of the horizontal actuation units. The second step involved calculating the amount of actuation of the vertical actuation unit, given the the results of the first step, by including a lever hinge mechanism adopted for motion amplification. Forward kinematic analysis was performed by defining six distance relationships between hinge positions for in-plane and out-of-plane motion. Finally, the result of a circular path actuation test with respect to the x-y, y-z, and x-z planes is presented.

Evaluation of Robot Calibration Performance based on a Three Dimensional Small Displacement Measuring Sensor (3차원 미소변위센서 기반 로봇 캘리브레이션 성능 검토)

  • Nguyen, Hoai-Nhan;Kang, Hee-Jun
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.12
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    • pp.1267-1271
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    • 2014
  • There have been many autonomous robot calibration methods which form closed loop structures through the various attached sensors and mechanical fixtures. Single point calibration among them has been used for on-site calibration due to its convenience of implementation. The robot can reach a single point with infinitely many configurations so that single point calibration algorithm can be set up and easily implemented relative to the other methods. However, it is not still easy to drive the robots' sharp edge to its corresponding edge of the fixture. This is error-prone process. In this paper, we propose a 3 dimensional small displacement measuring sensor and a robot calibration algorithm based on this sensor. This method relieves the difficulty of matching two edges in the single point calibration and improves the resulting robot accuracy. Simulated study is carried out on a Hyundai HA06 robot to show the effectiveness of the proposed method over the single point calibration. And also, the resulting robot accuracy is compared with that from 3D laser tracker based calibration to show the dependency of robot accuracy on range of the workspace where the measurement data are collected.

A Path Planning for Autonomous Excavation Based on Energy Function Minimization (에너지 함수 최적화를 통한 무인 굴삭 계획)

  • Park, Hyong-Ju;Bae, Jang-Ho;Hong, Dae-Hie
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.1
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    • pp.76-83
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    • 2010
  • There have been many studies regarding development of autonomous excavation system which is helpful in construction sites where repetitive jobs are necessary. Unfortunately, bucket trajectory planning was excluded from the previous studies. Since, the best use of excavator is to dig efficiently; purpose of this research was set to determine an optimized bucket trajectory in order to get best digging performance. Among infinite ways of digging any given path, criterion for either optimal or efficient bucket moves is required to be established. One method is to adopt work know-how from experienced excavator operator; However the work pattern varies from every worker to worker and it is hard to be analyzed. Thus, other than the work pattern taken from experienced operator, we developed an efficiency model to solve this problem. This paper presents a method to derive a bucket trajectory from optimization theory with empirical CLUB soil model. Path is greatly influenced by physical constraints such as geometry, excavator dimension and excavator workspace. By minimizing a energy function under these constraints, an optimal bucket trajectory could be obtained.

Development of the Hybrid Type Robot Using a Pneumatic Actuator For Physical Therapy Of Ankylosis (관절 경직 환자의 물리 치료를 위한 공압 구동형 하이브리드 로봇 개발)

  • 최현석;최철우;한창수;한정수
    • Journal of Biomedical Engineering Research
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    • v.24 no.2
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    • pp.127-132
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    • 2003
  • In this paper. the pneumatic service robot with a hybrid type is developed. A pneumatic has the advantages of good compliance , high Payload-to-weight and payload-to-volume ratios. high speed and force capabilities. Using pneumatic actuators. which have low stiffness. the service robot can guarantee safety. By suggesting a new serial-parallel hybrid type for the service robot which separates into Positioning motion and orienting motion, we can achieve large workspace and high strength-to-moving-weight ratio at the same time. A sliding mode controller can be designed for tracking the desired output using the Lyapunov stability theory and structural properties of pneumatic servo systems. Through many experiments of circular trajectory. the Pneumatic service robot is evaluated and verified.

Auto Sequencing User Interface for Mobile Robot Using Multi Sensor System (다중 센서 시스템을 이용한 이동로봇의 자동-절환 사용자 인터페이스)

  • Song, Tae-Houn;Park, Ji-Hwan;Park, Jong-Hyun;Jung, Soon-Mook;Hong, Soon-Hyuk;Kim, Gi-Oh;Jeon, Jae-Wook
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.319-325
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    • 2008
  • In this paper, we develop the multi sensor system, to get the sufficient information of mobile robot's environment. Mobile robot user interface, based on multi sensor system, can choice a suitable sensor by low-cost multi sensors and then acquisition information from remote robot's workspace using auto sequencing user display function. This research of multi sensor system is consists of ultrasonic sensor, position sensing detector, and low-cost CMOS camera module.

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A Passive Gravity-Compensation System for Articulated Robots (수직다관절 로봇의 중력보상장치 개발 및 성능 분석)

  • Lee, Yong-Ho;Sin, Yong-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.2 s.173
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    • pp.481-488
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    • 2000
  • This paper presents a new passive gravity -compensating system for articulated robot manipulators. The system, which consists of linear zero- free -length springs, achieves exact counterbalancing o f the gravitational loads throughout the entire range of the manipulator workspace, A basic concept is to design springs such that the total potential energy of the system including the manipulator and the springs should be maintained constant. A prototype has been developed for a direct-drive five-bar manipulator and its performances have been investigated. Results show that the gravity-induced motor torques have been reduced to less than 5% of those of uncompensated robots. Also, the gravity-compensating system simplifies the position control algorithm while maintaining the trajectory-tracking errors in a satisfactory level. In conclusion, the proposed system efficiently improves the manipulator performances by reducing the driving motor size and the energy consumption as well as by simplifying the control systems.

Path Design Method of Mobile Robot for Obstacle Avoidance Using Ceiling- mounted Camera System and Its Implementation (천장설치형 카메라 시스템을 사용한 장애물 회피용 이동 로봇의 경로설계법과 그 구현)

  • 트란안킴;김광주;중탄람;김학경;김상봉
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.8
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    • pp.73-82
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    • 2004
  • In this paper, implementation of obstacle avoidance of a nonholonomic mobile robot in unstructured environment is introduced. To avoid obstacles, first, a reference collision-free path for the MR is generated off-line using HJB-based optimal path planning method. A controller is designed using integrator backstepping method for tracking the generated reference path. To implement the designed controller, a control system are needed and composed of camera system and PIC-based controller. The workspace is observed by a ceiling-mounted USB camera as part of an un-calibrated camera system. Thus the positional information of the MR is updated frequently and the MR can get the useful inputs for its tracking controller. The whole control system is realized by integrating a computer with PIC-based microprocessor using wireless communication: the image processing control module and path planning module serve as high level computer control while the device control serves as low level PIC microprocessor control. The simulation and experimental results show the effectiveness of the designed control system.

Inverse Kinematic Analysis of a Binary Robot Manipulator using Neural Network (인공신경망을 이용한 2진 로봇 매니퓰레이터의 역기구학적 해석)

  • Ryu, Gil-Ha;Jung, Jong-Dae
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.1 s.94
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    • pp.211-218
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    • 1999
  • The traditional robot manipulators are actuated by continuous range of motion actuators such as motors or hydraulic cylinders. However, there are many applications of mechanisms and robotic manipulators where only a finite number of locations need to be reached, and the robot’s trajectory is not important as long as it is bounded. Binary manipulator uses actuators which have only two stable states. As a result, binary manipulators have a finite number of states. The number of states of a binary manipulator grows exponentially with the number of actuators. This kind of robot manipulator has some advantage compared to a traditional one. Feedback control is not required, task repeatability can be very high, and finite state actuators are generally inexpensive. And this kind of robot manipulator has a fault tolerant mechanism because of kinematic redundancy. In this paper, we solve the inverse kinematic problem of a binary parallel robot manipulator using neural network and test the validity of this structure using some arbitrary points m the workspace of the robot manipulator. As a result, we can show that the neural network can find the nearest feasible points and corresponding binary states of the joints of the robot manipulator

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