• Title, Summary, Keyword: Position Control

Search Result 6,248, Processing Time 0.102 seconds

Study on the Effective Operating Method of on-off Valves for a Pneumatic Servo System (개폐식 밸브를 사용한 공기압 서보 시스템의 효율적 밸브 개폐 방법에 관한 연구)

  • 황웅태;최서호;이정오
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.15 no.1
    • /
    • pp.109-116
    • /
    • 1998
  • This paper is concerned with effective operating method of pneumatic on-off valves for improving position control accuracy, valve life-time and position settling time using modified pulse width modulation with dead-zone (MPWMD). The pneumatic system using on-off valves has advantage of simple construction and low cost compared with a system with servo-valves. The performance of the proposed control method is investigated experimentally for the position control of a pneumatic cylinder using on-off valves. Experimental results show that the proposed algorithm for valve operation can be used to obtain fast and accurate position control compared to the conventional PWMD algorithm. It is also shown that the use of the proposed MPWMD algorithm for the position control significantly reduces the number of valve switching and noise.

  • PDF

Position, Orientation, and Velocity Feedback Control Algorithms for Differential-Drive Bobile Robot (차동 구동형 이동 로보트의 위치, 방향 및 속도 궤환 제어 알고리즘)

  • 정용욱;박종국
    • Journal of the Korean Institute of Telematics and Electronics S
    • /
    • v.34S no.11
    • /
    • pp.63-72
    • /
    • 1997
  • The design and implementation of a drive wheel position, orientation, and velocity feedback control algorithm for a differential-drive mobile robot is described here. A new concept, the most significant error, is introduced as the control design objective. Drive wheel position, orientation, and velocity feedback control directly minimize the most siginificant error by coordinating the motion of the two drive wheels. The drive wheel position, orientation, and velocity feedback control algorithm is analyzed and experiments are conducted to evaluate its performance. The experimental results are shown that drive wheel position, orientation and velocity feedback control algorithm yields substantially smaller position and orientation errors than those of conventional methods.

  • PDF

A Study on the Modeling of a Position Control System with a Pneumatic Cylinder Considering Transfer Characteristics of a Transmission Line (전달 관로의 전달특성을 고려한 공기압 실린더 구동장치의 모델링에 관한 연구)

  • Kang B.S.;Jang J.S.
    • Transactions of The Korea Fluid Power Systems Society
    • /
    • v.1 no.2
    • /
    • pp.20-25
    • /
    • 2004
  • In this study, a position control characteristics of pneumatic cylinder with transmission line is analyzed. Dynamic characteristics of transmission line using compressible fluid is changed by the flowing stiles of the fluid the diameter and the length of the line. But, the effect of the change of dynamic characteristics of transmission line by the flowing states on the position control characteristics can be neglected because of the friction force of the pneumatic cylinder. So, We assume that the position control characteristics is affected by the diameter and length of the transmission line. The experimental results according to the change of parameter of the transmission line show that the relation between the parameter of the transmission line and the position control characteristics of pneumatic cylinder driving system with the transmission line.

  • PDF

Double Actuator Unit based on the Planetary Gear Train Capable of Position/Force Control (위치/힘 제어가 가능한 유성기어 기반의 더블 액츄에이터 유닛)

  • Kim, Byeong-Sang;Park, Jung-Jun;Song, Jae-Bok;Kim, Hong-Seok
    • The Journal of Korea Robotics Society
    • /
    • v.1 no.1
    • /
    • pp.81-88
    • /
    • 2006
  • Control of a robot manipulator in contact with the environment is usually conducted by the direct feedback control using a force-torque sensor or the indirect impedance control. In these methods, however, the control algorithms become complicated and the performance of position and force control cannot be improved because of the mechanical properties of the passive components. To cope with such problems, redundant actuation has been used to enhance the performance of position control and force control. In this research, a Double Actuator Unit (DAU) is proposed, with which the force control algorithm can be simplified and can make the robot ensure the safety during the external collision. The DAU is composed of two actuators; one controls the position and the other modulates the joint stiffness. Using this unit, it is possible to independently control the position and stiffness. The DAU based on the planetary gears is investigated in this paper. Performance using the DAU is also verified by various experiments. It is shown that the manipulator using this mechanism provides better safety during the impact with the environment by reducing the joint stiffness appropriately on detecting the collision of a manipulator.

  • PDF

Development of Position Indicator for System-Integrated Reactor SMART (일체형원자로 SMART의 제어봉 위치지시기 개발)

  • Yu, Je-Yong;Kim, Ji-Ho;Huh, Hyung;Kim, Jong-In;Chang, Moon-Hee
    • Proceedings of the KSME Conference
    • /
    • /
    • pp.921-926
    • /
    • 2001
  • The reliability and accuracy of the information on control rod position are very important to the reactor safety and the design of the core protection system. In this study, a thorough investigation on the RSPT(Reed Switch Position Transmitter) type control rod position indication system and its actual implementation in the exiting nuclear power plants in Korea was performed first. A design of the control rod position indication system using reed switch for the CEDM on the system-integrated reactor SMART was developed based on the position indicator technology identified through the investigation. The feasibility of the design was evaluated by test of manufactured control rod position indicator using reed switch for SMART.

  • PDF

Position Estimator Employing Kalman Filter for PM Motors Driven with Binary-type Hall Sensors

  • Lee, Dong-Myung
    • Journal of Electrical Engineering and Technology
    • /
    • v.11 no.4
    • /
    • pp.931-938
    • /
    • 2016
  • Application of vector control scheme for consumer products is enlarging to improve control performance. For the field-oriented control, accurate position detection is essential and generally requires expensive sensors. On the other hand, cost-reduction is important in home appliances, so that binary-type Hall-effect sensors are commonly used rather than using an expensive sensor such as an encoder. The control performance is directly influenced by the accuracy of the position information, and there exist non-uniformities related to Hall sensors in electrical and mechanical aspects, which result in distorted position information. Therefore, to get high-precision position information from low-resolution Hall sensors, this paper proposes a new position estimator consisting of a Kalman filter and feedforward compensation scheme, which generates a linearly changing position signal. The efficacy of the proposed scheme is verified by simulation and experimental results carried out with a 48-pole permanent magnet motor.

Eliminating Method of Estimated Magnetic Flux Offset in Flux based Sensorless Control Algorithm of Surface Mounted PM Synchronous Motor (표면부착형 영구자석 동기전동기의 자속기반 센서리스 제어 알고리즘의 추정자속 옵셋 제거 기법)

  • Kim, Hack-Jun;Cho, Kwan-Yuhl;Kim, Hag-Wone;Lee, Kwang-Woon
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.22 no.3
    • /
    • pp.216-222
    • /
    • 2017
  • The rotor position of a PM synchronous motor is commonly estimated from the mathematical model for the sensorless control without rotor position sensors. For the magnet flux-based rotor position estimator in the stationary reference frame, the magnet flux estimator for estimating rotor position and speed includes the integrator. The integrator in the magnet flux estimator may accumulate the offset of the current sensors and the voltage drift. This continuous accumulation of the offset may cause the drift and overflow in the integrator, such that the estimated rotor position and speed may fail to track the real rotor position and speed. In this paper, the magnet flux estimator without integrator is proposed to avoid overflow in the integrator. The proposed rotor position and speed estimator based on magnet flux estimator are verified through simulation and experiment.

Position Tracking Control of an Autonomous Helicopter by an LQR with Neural Network Compensation (자율 주행 헬리콥터의 위치 추종 제어를 위한 LQR 제어 및 신경회로망 보상 방식)

  • ;Om, Il-Yong;Suk, Jin-Young;Jung, Seul
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.11 no.11
    • /
    • pp.930-935
    • /
    • 2005
  • In this paper, position tracking control of an autonomous helicopter is presented. Combining an LQR method and a proportional control forms a simple PD control. Since LQR control gains are set for the velocity control of the helicopter, a position tracking error occurs. To minimize a position tracking error, neural network is introduced. Specially, in the frame of the reference compensation technique for teaming neural network compensator, a position tracking error of an autonomous helicopter can be compensated by neural network installed in the remotely located ground station. Considering time delay between an auto-helicopter and the ground station, simulation studies have been conducted. Simulation results show that the LQR with neural network performs better than that of LQR itself.

Disturbance Observer and Error Model-based Control of Ball Screw Drives

  • Cho, Chang-Nho;Lee, Chang-Hyuk;Kim, Hong-Ju
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.22 no.4
    • /
    • pp.435-445
    • /
    • 2019
  • Ball screw drives are widely used in industry, and many studies have been devoted on precise, fast and robust control of ball screw drives. In this study, a novel position control algorithm for ball screw drives is proposed, which consist of a PD controller, a friction feedforward and a disturbance observer. The dynamics and the position error of such controller are analyzed to establish an error model, which can be used to predict the resulting position error of the given desired trajectory. Using the proposed error model, the desired trajectory can be modified so that the predicted position error can be compensated in a feedforward manner. The proposed algorithm does not require the model of the system for the error prediction, and thus can be easily applied to conventional control systems. The performance of the system is verified through simulations and experiments.

Hybrid Position/Force Control of 3 DOF Robot (3자유도 로봇의 하이브리드 위치/힘 제어)

  • 양선호;박태욱;양현석
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • /
    • pp.772-776
    • /
    • 1997
  • For a robot to perfom more versatile tasks, it is invitable for the robot's end-effector to come into contact with its environment. In thos case, to achieve better performance, it is necessary to properly control the contact force between the robot and the environment. In thos work, hybrid control theory is studied and is verified through experiment using a 3 DOF robot. In the experiment, two position/force controllers are used. Fist, proportional-integral-derivative controller is used as the controller for both position and force. Second, computed-torque method is used as the position controller, and proportional-integral-derivative controller is used as the force controller. For a proper modeling used in computed-torque method, the friction torque is measured by experiment, and compensation method is studied. The hybrid control method used in this experiment effectively control the contact force between the end-effector and the environment for various types of jobs.

  • PDF