• Title/Summary/Keyword: arm position

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End-point position control of a flexible arm by PID self-tuning fuzzy controller

  • Yang, G.T.;Ahn, S.D.;Lee, S.C.;Chonan, S.;Inooka, H.
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10b
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    • pp.496-500
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    • 1993
  • This paper presents an end-point position control of 1-link flexible robot arm by the PID self-tuning fuzzy algorithm. The governing equation is derived by the extended Hamilton's principle and based on the Bernoullie-Euler beam theory. The governing equation is solved by applying the Laplace transform and the numerical inversion method. The arm is mounted on the translational mechanism driven by a ballscrew whose rotation is controlled by dcservomotor. Tip position is controlled by the PID self-tuning fuzzy algorithm so that it follows a desired position. This paper shows the experimental and theoretical results of tip dispalcement, and also shows the good effects reducing the residual vibration of the end-point.

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Comparison of Distance of Subacromial Space Using Ultrasonographic Measurement on Arm Positions of Shoulder Injured Patients (견부손상환자의 팔의 자세에 따른 초음파 영상을 이용한 견봉하공간 거리의 비교)

  • Jee, Eun-Mi;Kim, Suhn-Yeop;Park, Ji-Whan
    • Journal of the Korean Society of Physical Medicine
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    • v.6 no.4
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    • pp.397-406
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    • 2011
  • Purpose : Recently ultrasound images has been used to measure the subacromial space with a linear measurement of the acromiohumeral distance. The purpose of this study was to comparison of distance of subacromial space using ultrasonographic measurement on arm positions of shoulder injured patients. Methods : The subjects were 30 shoulder injured patients (19 males and 11 females). Ultrasonography was performed to measure subacromial space during each shoulder resting position, $45^{\circ}$ abduction, internal rotation with $45^{\circ}$ abduction and external rotation with $45^{\circ}$ abduction. Results : Subacromial space was a significantly difference between injured arm and normal arm at shoulder resting position. At $45^{\circ}$ abduction, subacromial space was narrowing significantly between injured arm and normal arm. At external rotation with $45^{\circ}$ abduction, subacromial space were wider in normal arm than in injured arm but it was not significantly. Intra-observer reliability for ultrasonography measurement of subacromial distance was excellent (.96~.99). Conclusion : These results identified that positions of injured shoulder was related to subacromion space.

A Compatibility Study on Blank Support Structure for Large and Curved Thick Plate Forming (대곡면 후곡판 성형을 위한 블랭크 지지구조의 적합성 연구)

  • Lim, M.R.;Kwak, B.S.;Kang, B.S.;Ku, T.W.
    • Transactions of Materials Processing
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    • v.28 no.6
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    • pp.335-346
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    • 2019
  • Thick plate forming is presented to manufacture a large and curved member of steam turbine diaphragm. Due to three-dimensional asymmetry of target geometry, it is hard to consistently keep the blank position in die cavity between forming punch and die. In order to relieve the position instability of the blank during the thick plate forming, a blank support structure is proposed to be composed of guide pins and linear bearing, and blank guide arm enlarged from both longitudinal ends of the thick blank. In this study, parametric investigations with regard to the geometric position and width of the blank guide arm are carried out. As main geometric parameters, 2 positions such as maximum curvature region and minimum one on a curved cross-section profile of the target shape are selected, and 14 widths of the blank guide arm are considered. Using 28 variable combinations, three-dimensional numerical simulations are performed to predict the appropriate range of the process parameters. The compatibility and validity of the blank support structure with the blank guide arm for the thick plate forming is verified through the thick plate forming experiments.

A Comparative Study of Blood Pressure According to Cuff Size and Measurement Site (커프크기와 측정부위에 따른 혈압측정치 비교 연구)

  • Song, Mi-Ryeong;Kim, Eun-Kyung
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.16 no.1
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    • pp.6-13
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    • 2009
  • Purpose: The purpose of this study was to identify differences in blood pressure according to cuff size and measurement sites of the participants. Method: The participants consisted of 50 women and 50 men whose upper arm circumference was $26\sim30cm$. They had no chronic illness and gave consent to participate. Blood pressure of the wrist was measured in the sitting position, the upper arm with a standard cuff, large and small cuffs were used for measurement in supine position and the thigh in prone position. The data were analyzed with paired t-test using SPSS 12.0 program. Result: The data for the upper arm showed a difference in systolic and diastolic blood pressure depending on the site of measurement. There was a significant difference between measurements with a standard cuff and measurements with large and small cuffs. The systolic blood pressure of the wrist and the thigh were significantly lower than that of the upper arm. Conclusion: These results suggest that the selection of an appropriate cuff is an essential element in ensuring accuracy when measuring blood pressure and differences in systolic blood pressure for the upper arm, wrist and thigh indicate the need to record the measuring site when measuring blood pressure.

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Position control fo a flexible gantry robot arm using smart actuators (스마트 작동기를 이용한 갠트리형 유연로봇팔의 위치제어)

  • 한상수;최승복
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1800-1803
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    • 1997
  • This paper presents new feedback actuators to achieve an accurate position control of a flexible gnatry robot arm. the translational motion in the plane is generated by two d.c.motors and controlled by emplying elecor-rheological(ER) clutch acutators. The generated motion can be continuously controlled by controlling the intensity of lectric field imposed to the ER fluid domain which tunes the transmitted torque of the ER clutch. n the other hand, during control action of the translational motion a flexible arm attached to the moving mass produces undesirable oscillatins due to its inherent flexibility. The oscillations are actively suppressed by applying feedback voltages to piezoceramic acutators bonded on the surface of the flexible arm. The control electric fields to be applied to the ER clutch and the control voltage for the piezoceramic actuator are determined via the loop shaping esign procedures(LSDP) in the H.inf. control technique. Comsequently, an accuate positiion control at the end-point of the flexible am is achieved during planar motion.

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A FORCE/POSITION CONTROL FOR TWO-ARM MOTION COORDINATION AND STABILITY ROBUSTNESS ANALYSIS

  • 최형식
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1992.10a
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    • pp.215-219
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    • 1992
  • This paper presents a motion coordination of two robot manipulators coordinating an object. To coordinate the object, a force/position control scheme in a mode of leaer/follower is devised. The dynamics of the object are incorporated into the dynamics of the leader arm, which yields a reduced order model of two arm system. In order to regulate interaction forces between two arm, the dynamics of the follower arm are expressed as force dynamic equations such that a novel direct forces between two arms and two different type of bounded input disturbances, boundedness and asymptotic stability results based on a proposed Lyapunov function are shown. Also, a sufficient condition for a stability robustness is derived based on the Lyapunov approach.

A Disassembly Technique of ARM Position-Independent Code with Value-Set Analysis Having Symbol-Form Domain (기호 형태의 값-집합 분석을 이용한 ARM 위치 독립적 코드의 정교한 역어셈블리 기법)

  • Ha, Dongsoo;Oh, Heekuck
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.28 no.5
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    • pp.1233-1246
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    • 2018
  • With the proliferation of smart mobiles, disassembly techniques for position-independent code (PIC) composed of ARM architecture instructions in computer security are becoming more important. However, existing techniques have been studied on x86 architecture and are focused on solving problems of non-PIC and generality. Therefore, the accuracy of the collected address information is low to apply to advanced security technologies such as binary measurement. In this paper, we propose a disassembly technique that reflects the characteristics of PIC composed of ARM instructions. For accuratly collecting traceable addresses, we designed value-set analysis having symbol-form domain. To solve the main problem of disassembly, we devised a heuristic using the characteristics of the code generated by the compiler. To verify the accuracy and effectiveness of our technique, we tested 669 shared libraries and executables in the Android 8.1 build, resulting in a total disassembly rate of 91.47%.

A Development of Robot Arm Direct Teaching System (로봇팔 직접 교시 시스템 개발)

  • Woong-Keun Hyun
    • The Journal of the Korea institute of electronic communication sciences
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    • v.19 no.1
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    • pp.85-92
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    • 2024
  • In this paper, we developed an intuitive teaching and control system that directly teaches a task by holding the tip of a robotic arm and moving it to a desired position. The developed system consists of a 6-axis force sensor that measures position and attitude forces at the tip of the robot arm, an algorithm for generating robot arm joint speed control commands based on the measured forces at the tip, and a self-made 6-axis robot arm and control system. The six-dimensional force/torque of the position posture of the robot arm operator steering the handler is detected by the force sensor attached to the handler at the leading edge and converted into velocity commands at the leading edge to control the 7-axis robot arm. The verification of the research method was carried out with a self-made 7-axis robot, and it was confirmed that the proposed force sensor-based robot end-of-arm control method operates successfully through experiments by teaching the operator to adjust the handler.

The Effect of Postural Correction and Visual Feedback on Muscle Activity and Head Position Change During Overhead Arm Lift Test in Subjects with Forward Head Posture

  • Xu, Liwen;Hwang, Byoungha;Kim, Teaho
    • The Journal of Korean Physical Therapy
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    • v.31 no.3
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    • pp.151-156
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    • 2019
  • Purpose: This study aimed to investigate the immediate effects of posture correction and real-time visual feedback using a video display on muscle activity and change of head position during overhead arm lift test in individuals with forward head posture. Methods: Fifteen subjects with forward head posture and fifteen normal subjects who volunteered were included in this study. During both groups performed the overhead arm lift test, the muscle activity of the upper trapezius, serratus anterior, sternocleidomastoid, and lower trapezius muscle were measured using electromyography, and head position change was measured using photographs. Then, forward head posture group was asked to perform overhead arm lift test again after posture correction and real-time visual feedback using a video display respectively. One-way analysis of variance (ANOVA) was used to analyze four conditions: pre-test, posture correction, real-time visual feedback, and the control group. Results: The upper trapezius and lower trapezius muscle activity significantly decreased posture correction, real-time visual feedback, and control group than pre-test of forward head posture group (p<0.05). The sternocleidomastoid muscle significantly decreased real-time visual feedback and control group than pre-test of forward head posture group. Head position change significantly decreased three conditions than pre-test of forward head posture group and real-time visual feedback and control group significantly decreased than posture correction. Conclusion: This study recommend for maintaining cervical stability during the overhead arm lift test, postural control using real-time visual feedback is more effective in subjects with forward head posture.

Position Control of a One-Link Flexible Arm Using Multi-Layer Neural Network (다층 신경회로망을 이용한 유연성 로보트팔의 위치제어)

  • 김병섭;심귀보;이홍기;전홍태
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.29B no.1
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    • pp.58-66
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    • 1992
  • This paper proposes a neuro-controller for position control of one-link flexible robot arm. Basically the controller consists of a multi-layer neural network and a conventional PD controller. Two controller are parallelly connected. Neural network is traind by the conventional error back propagation learning rules. During learning period, the weights of neural network are adjusted to minimize the position error between the desired hub angle and the actual one. Finally the effectiveness of the proposed approach will be demonstrated by computer simulation.

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