• Title/Summary/Keyword: Time step control

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Development and Assessment of Real-Time Quality Control Algorithm for PM10 Data Observed by Continuous Ambient Particulate Monitor (부유분진측정기(PM10) 관측 자료 실시간 품질관리 알고리즘 개발 및 평가)

  • Kim, Sunyoung;Lee, Hee Choon;Ryoo, Sang-Boom
    • Atmosphere
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    • v.26 no.4
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    • pp.541-551
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    • 2016
  • A real-time quality control algorithm for $PM_{10}$ concentration measured by Continuous Ambient Particulate Monitor (FH62C14, Thermo Fisher Scientific Inc.) has been developed. The quality control algorithm for $PM_{10}$ data consists of five main procedures. The first step is valid value check. The values should be within the acceptable range limit. Upper ($5,000{\mu}g\;m^{-3}$) and lower ($0{\mu}g\;m^{-3}$) values of instrument detectable limit have to be eliminated as being unrealistic. The second step is valid error check. Whenever unusual condition occurs, the instrument will save error code. Value having an error code is eliminated. The third step is persistence check. This step checks on a minimum required variability of data during a certain period. If the $PM_{10}$ data do not vary over the past 60 minutes by more than the specific limit ($0{\mu}g\;m^{-3}$) then the current 5-minute value fails the check. The fourth step is time continuity check, which is checked to eliminate gross outlier. The last step is spike check. The spikes in the time series are checked. The outlier detection is based on the double-difference time series, using the median. Flags indicating normal and abnormal are added to the raw data after quality control procedure. The quality control algorithm is applied to $PM_{10}$ data for Asian dust and non-Asian dust case at Seoul site and dataset for the period 2013~2014 at 26 sites in Korea.

Effect of Step-up and Step-down Hyperthermia on Skin of Mice (온열요법시 온도변화가 정상조직에 미치는 영향)

  • Choi, Ihl-Bohng;Kim, Choon-Yul;Bahk, Yong-Whee
    • Radiation Oncology Journal
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    • v.6 no.2
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    • pp.155-161
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    • 1988
  • The usefulness of hypertermia for cancer therapy have well been established. The purpose of the present investigation was to ascess the effect of step-up $(42^{\circ}{\rightarrow}44^{\circ}C$ sequence) and step-down $(44^{\circ}{\rightarrow}42^{\circ}C$ sequence) heating on the skin of the hind foot of the mouse. Hyperthermic treatments were given by immersion the hind foot of the mouse in circulating water baths. Skin response was studied by the leg reaction, which was scored according to a numerical scoring system proposed by Urano et al (1980). The results were as follows 1. The skin damage of $44^{\circ}C$ control group was more severe than $42^{\circ}C$ control group (P<0.05), except for 15 min. heating group. 2. The Skin damage of step-down group was more severe than step-up group (P<0.05). 3. The skin damage of $44^{\circ}C$ control group was more severe than step-up group when there is no difference in $44^{\circ}C$ heating time of step-up group from $44^{\circ}C$ control group (P<0.05). 4. In step-down group, the skin damage was more severe than $44^{\circ}C$ control group after preheating 45 min at $44^{\circ}C$ (P<0.05). Therefore, the above findings suggest the normal tissue damage by step-up heating was correlated with heating time of post step-up. The dropping of heating temperature in late phase had more severe damage of the skin than that in early phase during hyperthermia, and so contineous control of satisfactory temperature should be considered as the one of the most important factor for prognosis, complications of clinical hyperthermia

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Optimal trajectory control for robot manipulator using evolutionary algorithm (진화 알고리즘에 의한 로봇 매니퓰레이터의 최적 궤적 제어)

  • 김기환;박진현;최영규
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1181-1184
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    • 1996
  • As usual systems, robot manipulators have also physical constraints for operating. It is a difficult problem that we operate manipulator in the minimal time under these constraints. In this paper, we solve this problem dividing it into two steps. In the first step, we find the minimal time trajectories by optimizing qubic polynomial joint trajectories using evolutionary algorithms. In the second step, we optimize controller for robot manipulator to track precisely trajectories optimized in the previous step.

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Genetic Algorithm for Identification of Time Delay Systems from Step Responses

  • Shin, Gang-Wook;Song, Young-Joo;Lee, Tae-Bong;Choi, Hong-Kyoo
    • International Journal of Control, Automation, and Systems
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    • v.5 no.1
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    • pp.79-85
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    • 2007
  • In this paper, a real-coded genetic algorithm is proposed for identification of time delay systems from step responses. FOPDT(First-Order Plus Dead-Time) and SOPDT(Second-Order Plus Dead-Time) systems, which are the most useful processes in this field, but are difficult for system identification because of a long dead-time problem and a model mismatch problem. Genetic algorithms have been successfully applied to a variety of complex optimization problems where other techniques have often failed. Thus, the modified crossover operator of a real-code genetic algorithm is proposed to effectively search the system parameters. The proposed method, using a real-coding genetic algorithm, shows better performance characteristics when compared to the usual area-based identification method and the directed identification method that uses step responses.

A Study on the Manabe Standard Form Using the Evolutionary Strategy (진화전략을 이용한 Manabe 표준형에 관한 연구)

  • 강환일;정요원
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.2
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    • pp.65-71
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    • 2001
  • The step response of the Manabe standard form[2] has little overshoot and show almost same waveforms regardless of the order of the characteristic polynomials. In some situations it is difficult to control the rise time and settling time simultaneously of the step response of the Manabe standard form To control its rise time and settling time efficiently, We develop the Manabe standard form: We try to find out the SRFS(Slow Rise time & Fast Setting time) form which has the slower rise time and faster settling time than those fo the Manabe standard form. We also consider the other three forms: FRSS(Fast Rise time & Slow Settling time), SRFS(Slow Rise time & Fast Settling time) and SRSS(Slow Rise time & Slow Settling time) forms. In this paper, by using the evolutionary strategy, we obtain all the coefficient of the four forms we mention above. Finally, we design a controller for a given plant so that the overall system has the performance that the rise time is faster, the settling time is faster than those of the Manabe standard form.

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VME bus based control system for step & scan exposure tool (VME bus를 이용한 Step & Scan형 노광장비의 Control System 구성)

  • 최용만;오병주;김도훈;정해빈
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.672-675
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    • 1997
  • This paper proposes a structure of the control system for the step & scan exposure tool. The step & scan exposure tool is used for the manufacturing process of the semiconductor DRAM memory of giga bit. The control system employs the VME bus instead of the conventional ISA bus so that all control signals and data can be managed separately by the 4 VME-PCs for fast and fault-free flow of signals for multi-tasking. A high speed I/O card is equipped for the real-time monitoring and control of the sub module equipment. Then all the subsystems are integrated and aligned for the operation of the step & scan exposure tool with the VME bus and, I/O card.

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A High-Speed Autonomous Navigation Based on Real Time Traversability for 6×6 Skid Vehicle (실시간 주행성 분석에 기반한 6×6 스키드 차량의 야지 고속 자율주행 방법)

  • Joo, Sang-Hyun;Lee, Ji-Hong
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.3
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    • pp.251-257
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    • 2012
  • Unmanned ground vehicles have important military, reconnaissance, and materials handling application. Many of these applications require the UGVs to move at high speeds through uneven, natural terrain with various compositions and physical parameters. This paper presents a framework for high speed autonomous navigation based on the integrated real time traversability. Specifically, the proposed system performs real-time dynamic simulation and calculate maximum traversing velocity guaranteeing safe motion over rough terrain. The architecture of autonomous navigation is firstly presented for high-speed autonomous navigation. Then, the integrated real time traversability, which is composed of initial velocity profiling step, dynamic analysis step, road classification step and stable velocity profiling step, is introduced. Experimental results are presented that demonstrate the method for a $6{\times}6$ autonomous vehicle moving on flat terrain with bump.

An Enhanced Finite-Settling-Step Direct Torque and Flux Control (FSS-DTFC) for IPMSM Drives

  • Kim, Sehwan;Seok, Jul-Ki
    • Journal of Power Electronics
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    • v.16 no.4
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    • pp.1367-1374
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    • 2016
  • This paper presents a discrete-time version of voltage and current limited operation using an enhanced direct torque and flux control method for interior permanent magnet synchronous motor (IPMSM) drives. A command voltage vector for airgap torque and stator flux regulation can be uniquely determined by the finite-settling-step direct torque and flux control (FSS-DTFC) algorithm under physical constraints. The proposed command voltage vector trajectories can be developed to achieve the maximum inverter voltage utilization for the discrete-time current limit (DTCL)-based FSS-DTFC. The algorithm can produce adequate results over a number of the potential secondary upsets found in the steady-state current limit (SSCL)-based DTFC. The fast changes in the torque and stator flux linkage improve the dynamic responses significantly over a wide constant-power operating region. The control strategy was evaluated on a 900W IPMSM in both simulations and experiments.

Optimal Trajectory Control for RobortManipulators using Evolution Strategy and Fuzzy Logic

  • Park, Jin-Hyun;Kim, Hyun-Sik;Park, Young-Kiu
    • Transactions on Control, Automation and Systems Engineering
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    • v.1 no.1
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    • pp.16-20
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    • 1999
  • Like the usual systems, the industrial robot manipulator has some constraints for motion. Usually we hope that the manipulators move fast to accomplish the given task. The problem can be formulated as the time-optimal control problem under the constraints such as the limits of velocity, acceleration and jerk. But it is very difficult to obtain the exact solution of the time-optimal control problem. This paper solves this problem in two steps. In the first step, we find the minimum time trajectories by optimizing cubic polynomial joint trajectories under the physical constraints using the modified evolution strategy. In the second step, the controller is optimized for robot manipulator to track precisely the optimized trajectory found in the previous step. Experimental results for SCARA type manipulator show that the proposed method is very useful.

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Antenna Control System Using Step Tracking Algorithm with H$_{\infty}$ Controller

  • Cho, Chang-Ho;Lee, Sang-Hyo;Kwon, Tae-Yong;Lee, Cheol
    • International Journal of Control, Automation, and Systems
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    • v.1 no.1
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    • pp.83-92
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    • 2003
  • The outdoor antenna servo system is subject to has significant torque disturbances from wind pressures and gusts on the antenna structures, as well as bearing and aerodynamic frictions. This control system should provide a sharp directivity in spite of the environmental disturbances and internal uncertainties. Therefore, the implementation of a real-time controller is necessary for the precise generation of the reference signal and robust tracking performance. In this paper, the discrete-time controller for the quick tracking of a target communication satellite is designed by applying the sampled-data $H_{\infty}$ control theory along with the reference signal generated by an improved conventional step-tracking algorithm. The sampled-data $H_{\infty}$controller demonstrates superior robustness for the longer sampling period when compared with a simple PID controller.