• Title/Summary/Keyword: Soft control

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Human Reliability Analysis of Soft Control Operations in Nuclear Power Plants: Issues and Perspectives

  • Lee, Seung Jun;Jung, Wondea
    • Journal of the Ergonomics Society of Korea
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    • v.32 no.1
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    • pp.87-96
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    • 2013
  • Objective: The aim of this study is to describe several issues which should be considered in the human reliability analysis of soft control operations in nuclear power plants. Background: The operational environment of advanced main control rooms is totally different from that of conventional control rooms. The soft control is one of the major distinguishable features of the advanced main control rooms. The soft control operations should be analyzed to estimate the effects on human reliability. Method: The literatures, about task analysis, simulation data analysis, and a human reliability analysis method for the soft control, were reviewed. From the review, important issues for the human reliability analysis of the soft control were raised. Results: The results of task and simulation data analysis showed that the soft control characteristics could have large effect on human reliability and they should be considered in the human reliability analysis of the soft control operations. Conclusion: The soft control may affect human error and performance of operators. The issues described in this paper should be considered in the human reliability method for the advanced main control rooms. Application: The results of the soft control operation analysis might help to design more efficient interface and education/training program for preventing human errors. The described issues might help to develop a human reliability analysis method for soft control operations.

Iterative Learning Control of Trajectory Generation for the Soft Actuator (궤적 생성 반복 학습을 통한 소프트 액추에이터 제어 연구)

  • Song, Eunjeong;Koo, Jachoon
    • The Journal of Korea Robotics Society
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    • v.16 no.1
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    • pp.35-40
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    • 2021
  • As the robot industry develops, industrial automation uses industrial robots in many parts of the manufacturing industry. However, rigidity-based conventional robots have a disadvantage in that they are challenging to use in environments where they grab fragile objects or interact with people because of their high rigidity. Therefore, researches on soft robot have been actively conducted. The soft robot can hold or manipulate fragile objects by using its compliance and has high safety even in an atypical environment with human interaction. However, these advantages are difficult to use in dynamic situations and control by the material's nonlinear behavior. However, for the soft robot to be used in the industry, control is essential. Therefore, in this paper, real-time PD control is applied, and the behavior of the soft actuator is analyzed by providing various waveforms as inputs. Also, Iterative learning control (ILC) is applied to reduce errors and select an ILC type suitable for soft actuators.

Real-Time Centralized Soft Motion Control System for High Speed and Precision Robot Control (고속 정밀 로봇 제어를 위한 실시간 중앙 집중식 소프트 모션 제어 시스템)

  • Jung, Il-Kyun;Kim, Jung-Hoon
    • IEMEK Journal of Embedded Systems and Applications
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    • v.8 no.6
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    • pp.295-301
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    • 2013
  • In this paper, we propose a real-time centralized soft motion control system for high speed and precision robot control. The system engages EtherCAT as high speed industrial motion network to enable force based motion control in real-time and is composed of software-based master controller with PC and slave interface modules. Hard real-time control capacity is essential for high speed and precision robot control. To implement soft based real time control, The soft based master controller is designed using a real time kernel (RTX) and EtherCAT network, and servo processes are located in the master controller for centralized motion control. In the proposed system, slave interface modules just collect and transfer all sensor information of robot to the master controller via the EtherCAT network. It is proven by experimental results that the proposed soft motion control system has real time controllability enough to apply for various robot control systems.

Motion Analysis of Soft-Fingertip Manipulation Tasks

  • Kim, Byoung-Ho
    • International Journal of Control, Automation, and Systems
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    • v.2 no.2
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    • pp.228-237
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    • 2004
  • This paper provides a motion analysis of soft-fingertip object manipulation tasks by presenting a dynamic model of multi-fingered object manipulations with soft fingertips. It is fundamentally observed that soft fingertips employed in a multi-fingered hand generate some deformation effects during the manipulation process and also that those effects are closely related to the behavior of the manipulated object. In order to analyze the motion of using soft fingertips, a dynamic manipulation control scheme is presented. Simulation and experimental results demonstrate the motion of soft-fingertips applied in object manipulating tasks and are further used to discuss the characteristics of soft-fingertip motions.

Evaluation of the mandibular asymmetry using the facial photographs and the radiographs (방사선사진과 안모사진을 이용한 하악 비대칭의 평가)

  • Lee Sul-Mi
    • Imaging Science in Dentistry
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    • v.31 no.4
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    • pp.199-204
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    • 2001
  • Purpose : To assess the relationship between soft tissue asymmetry and bone tissue asymmetry using the standardized photographs and the posteroanterior (PA) cephalometric radiographs in mandibular asymmetric patients. And to clarify that the lack of morphologic balance among different skeletal components can often be masked by compensatory soft tissue contributions. Methods: Experimental group consisted of 58 patients whose chief complaints were facial asymmetry, they were taken with standardized facial photographs and PA cephalometric radiographs. Control group consisted of 30 persons in the normal occlusion. The reproducibility of the facial photograph was confirmed by model test. The differences of fractional vertical heightand horizontal width from standardized facial photographs and PA cephalometric radiographs were compared and analyzed. Results: The difference of fractional vertical bone height was 0.63 and fractional vertical soft height was 0.58 in control group, 3.10 and 2.01 in asymmetric group, respectively. The difference of fractional horizontal bone width was 0.52 and fractional horizontal soft width was 0.70 in control group, 2.51 and 1.70 in asymmetric group, respectively. Both soft and bone tissue showed significant difference between control and asymmetric group (p<0.05). The difference of bone tissue was greater than that of soft tissue (p<0.05) in the experimental group but, not in control group. Conclusions: Soft tissue components may compensate for underlying skeletal imbalances.

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Control of The Soft Starter using Bluetooth (Bluetooth를 이용한 Soft Starter 제어)

  • Bae, Jong-Il;Hwang, Yeong-Yeun;Lee, Dong-Cheol;Bae, Cheol-Min
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.2735-2737
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    • 2005
  • Been using widely Soft Starter control system is $Y-{\Delta}$ method, Reactor method, Resistor method etc. and this methods are big mobile warfare kind and voltage drop and can not operate because suspending load because smallest operation acceleration Torque is small.

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Automobile Power Seat Using Motor Current Profile Control Technology (모터 전류 형상 제어 기술을 적용한 차량용 전동 시트)

  • Chung, Myung-Jin
    • Journal of IKEEE
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    • v.23 no.1
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    • pp.224-229
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    • 2019
  • Seat of automobile is required to support the comfort to driver and passenger during the driving. The control method of the seat position is changed from manual type to power type, which means using the motor to increase the comfort of the driver. By using the motor, several problems, such as vibration, noise, and over-current, appeared. These problems can be reduced through the control of seat motor. In this study, a control technology of four control variables, which determine profile of the input voltage applying to the seat motor, is proposed to generate the current profile having soft-start and soft-stop. The current flowing through the coil by input voltage is described by mathematical modeling of power seat. It is confirmed that optimized current profile having soft-start and soft-stop can be generated from simulation using the mathematical model.

A study on Development of Soft-Motor Controller using EtherCAT (EtherCAT을 이용한 소프트 모터제어기 개발에 관한 연구)

  • Moon, Yong-Seon;Lee, Young-Pil;Seo, Dong-Jin;Lee, Sung-Ho;Bae, Young-Chul
    • Journal of the Korean Institute of Intelligent Systems
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    • v.17 no.6
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    • pp.826-831
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    • 2007
  • In this paper, we proposed new method of soft-motor control which is control method allowing motor control within control stage by using EtherCAT which is real time motion control network of high speed. We also evaluated performance of the system and verified possibility and effectiveness of application into real system through experiments.

Reliability Analysis of Interleaved Memory with a Scrubbing Technique (인터리빙 구조를 갖는 메모리의 스크러빙 기법 적용에 따른 신뢰도 해석)

  • Ryu, Sang-Moon
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.4
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    • pp.443-448
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    • 2014
  • Soft errors in memory devices that caused by radiation are the main threat from a reliability point of view. This threat can be commonly overcome with the combination of SEC (Single-Error Correction) codes and scrubbing technique. The interleaving architecture can give memory devices the ability of tolerating these soft errors, especially against multiple-bit soft errors. And the interleaving distance plays a key role in building the tolerance against multiple-bit soft errors. This paper proposes a reliability model of an interleaved memory device which suffers from multiple-bit soft errors and are protected by a combination of SEC code and scrubbing. The proposed model shows how the interleaving distance works to improve the reliability and can be used to make a decision in determining optimal scrubbing technique to meet the demands in reliability.

Post-disturbance Recovery Pattern in the Soft Corals-Macroalgae Mixed Habitat in Jeju Island, Korea

  • Kim, Junsu;Hong, Seokwoo;Yang, Kwon Mo;Macias, Daniela;Kim, Jeong Ha
    • Journal of Marine Life Science
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    • v.6 no.2
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    • pp.117-123
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    • 2021
  • Post-disturbance recovery pattern of subtidal soft corals-macroalgae mixed community and the role of water depth were investigated. The experiment was conducted in a subtidal rock wall of Munseom, Jeju Island, Korea for 2.5 years. Artificial disturbance was done at established treatment plots at depths of 10, 15 and 20 m and were then compared with undisturbed control plots. After disturbance, recovery of soft corals was very slow, whereas macroalgae quickly occupied the plots and reached a similar level as the control in 6 months, and this pattern was consistent at all water depths. This unbalanced speed of recovery caused higher macroalgae establishment than soft corals in treatment compared to control plots, indicating a possible phase shift in the community structure. This study provides an important implication for the necessity of monitoring the influence of disturbance at a larger scale, from a conservation perspective of soft corals in Jeju coast.