• Title/Summary/Keyword: repetitive control

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Performance improvement of repetitive learning controller using AMN (AMN을 이용한 반복학습 제어기의 성능개선)

  • 정재욱;국태용;이택종
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1573-1576
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    • 1997
  • In this paper we present an associative menory network(AMN) controller for learning of robot trajectories. We use AMN controller in order to improve the performance of conventional learning control, e.g. RCL, which had studied by Sadegh et al. Computer simulations show the feasibility and effectiveness of the proposed AMN controller.

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A New Control Strategy for Distributed Generation under Nonlinear loads

  • Trinh, Quoc-Nam;Lee, Hong-Hee
    • Proceedings of the KIPE Conference
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    • 2012.07a
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    • pp.256-257
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    • 2012
  • This paper presents a new control strategy to improve voltage performance of distributed generation (DG) under nonlinear loads. The proposed voltage controller consists of a proportional-integral and a repetitive controller where the repetitive controller behaves as a bank of resonant controllers to compensate harmonic voltage drop on system impedance due to nonlinear load current. As a result, the voltage at the point of common coupling (PCC) of the DG is regulated to be sinusoidal waveform regardless of the presence of nonlinear loads. In order to validate the effectiveness of the proposed voltage controller, simulations are carried out using PSIM software and results are compared with those with the conventional PI controller.

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Precision servo control of a computer hard disk (컴퓨터 하드 디스크의 정밀 서보 제어)

  • 전도영
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.286-289
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    • 1996
  • Two servo control algorithms are suggested to reduce the tracking error of a computer hard disk drive. One is the repetitive control to reduce the repeatable tracking error which is not explicitly taken into account in the design of a conventional controller. This algorithm was successfully applied to a commercial disk using a fixed point DSP. The other is the multi-rate sampling control which generates the control output between each sampling times since the sampling time of hard disk drives is limited. These algorithms were shown effectively to reduce tracking errors.

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The Effects of Repetitive Transcranial Magnetic Stimulation Integrated Mirror Therapy on the Gait of Chronic Stroke Patients

  • Cha, Hyun-Gyu;Kim, Myoung-Kwon
    • Journal of Magnetics
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    • v.20 no.2
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    • pp.133-137
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    • 2015
  • This study was conducted to determine the effects of repetitive transcranial magnetic stimulation (rTMS) integrated mirror therapy on the gait of post-stroke patients. Thirty patients who were six months post-stroke were assigned to either the experimental group (n = 15) or the control group (n = 15). Stroke patients in the experimental group underwent rTMS and mirror therapy for the lower limbs, while those in the control group underwent rTMS and sham therapy. Participants in both groups received therapy five days per week for four weeks. A significant difference in post-training gains for the single support phase, step length, stride length and velocity was observed between the experimental group and the control group (p < 0.05). The experimental group showed a significant increment in the single support phase, step length, stride length, swing phase, velocity, cadence, double support phase and step width as compared to pre-intervention (p < 0.05). The control group showed a significant increment in step length, velocity, cadence and step width compared to preintervention (p < 0.05). Further investigation of the availability and feasibility of rTMS integrated mirror therapy for post-stroke patients as a therapeutic approach for gait rehabilitation is warranted.

A neural network architecture for dynamic control of robot manipulators

  • Ryu, Yeon-Sik;Oh, Se-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.1113-1119
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    • 1989
  • Neural network control has many innovative potentials for intelligent adaptive control. Among many, it promises real time adaption, robustness, fault tolerance, and self-learning which can be achieved with little or no system models. In this paper, a dynamic robot controller has been developed based on a backpropagation neural network. It gradually learns the robot's dynamic properties through repetitive movements being initially trained with a PD controller. Its control performance has been tested on a simulated PUMA 560 demonstrating fast learning and convergence.

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Application of Direct Learning Control to Feedback Systems (피드백시스템에 대한 직접학습제어의 응용)

  • 안현식
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2003.06a
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    • pp.173-176
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    • 2003
  • In this paper, a DLC method is suggested for linear feedback systems to improve the tracking performance when the task of the system is repetitive. DLC can generate the desired control input directly from the previously teamed control inputs corresponding to other output trajectories. It is assumed that all outputs considered in this paper have some relations called "proportionality. " To show the validity and tracking performance of the proposed method, some simulation are performed for the tracking control of a linear system with a PI controller.

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Tire Industry and Its Manufacturing Configuration

  • Lee, Young-Sik;Cpim;Lee, Jin-Kyu
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2000.04a
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    • pp.135-138
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    • 2000
  • This paper is intended to propose what manufacturing configuration (manufacturing planning and shop floor control) is suitable for the tire industry. Basically tire-manufacturing process is mixed-products, parallel-disconnected-flow-shop. Both throughput time and cycle tine are very short, the variety of tires is very high, the setup time is long, shop floor data reporting requirements is high, and there are many equipments and people working. And with no exception, tire industry also now confronts increasing requirements of delivery conformance with the above peculiar characteristics of tire manufacturing and changing market environments, this paper suggests, weekly master scheduling with no MRP is desirable and traditional kanban is right selection for shop floor control/scheduling. This paper describes why this configuration should be, using the manufacturing engineering principles and some new insights like four primitives of parallel flow shop. Generally known that shop with high parallel-product-mix and long setup time isn't good candidate for kanban. The four primitives of parallel flow shop explain why kanban is also useful scheduling technique in that environment.

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Effects of Mental Practice in Conjunction with Repetitive Transcranial Magnetic Stimulation on the Upper Limbs of Sub-acute Stroke Patients

  • Ji, Sang-Goo;Kim, Myoung-Kwon;Cha, Hyun-Gyu
    • Journal of Magnetics
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    • v.19 no.4
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    • pp.353-356
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    • 2014
  • The aim of the present study was to examine whether mental practice (MP) in conjunction with repetitive transcranial magnetic stimulation (rTMS) can improve the upper limb function of sub-acute stroke patients. This study was conducted with 32 subjects who were diagnosed with hemiparesis by stroke. The experimental group consisted of 16 members upon each of whom was performed MP in conjunction with rTMS, whreas the control group consisted of 16 members upon each of whom was performed MP and sham rTMS. Both groups received traditional physical therapy for 30 minutes a day, 5 days a week, for 6 weeks; additionally, they received mental practice for 15 minutes a day. The experimental group was instructed to perform rTMS, and the control group was instructed to apply sham rTMS for 15 minutes. A motor cortex excitability analysis was performed by motor evoked potentials (MEPs), and upper limb function was evaluated by Fugl-Meyer Assessment (FMA) and the Box and Block test (BBT). Results showed that the amplitude, latency, FMA, and BBT of the experimental group and the latency, FMA, and BBT of the control group were significantly improved after the experiment (p<0.05). Significant differences were found between the groups in amplitude and latency after the experiment (p<0.05). The results showed that MP in conjunction with rTMS is more effective in improving upper limb function than MP alone.

Comparative Analysis of Repetitive Elements of Imprinting Genes Reveals Eleven Candidate Imprinting Genes in Cattle

  • Kim, HyoYoung;Kim, Heebal
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.6
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    • pp.893-899
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    • 2009
  • Few studies have reported the existence of imprinted genes in cattle compared to the human and mouse. Genomic imprinting is expressed in monoallelic form and it depends on a single parent-specific form of the allele. Comparative analysis of mammals other than the human is a valuable tool for explaining the genomic basis of imprinted genes. In this study, we investigated 34 common imprinted genes in the human and mouse as well as 35 known non-imprinted genes in the human. We found short interspersed nuclear elements (SINEs), long interspersed nuclear elements (LINEs), and long terminal repeats (LTRs) in imprinted (human and mouse) and control (cattle) genes. Pair-wise comparisons for the three species were conducted using SINEs, LINEs, and LTRs. We also calculated 95% confidence intervals of frequencies of repetitive sequences for the three species. As a result, most genes had a similar interval between species. We found 11 genes with conserved SINEs, LINEs, and LTRs in the human, mouse, and cattle. In conclusion, eleven genes (CALCR, Grb10, HTR2A, KCNK9, Kcnq1, MEST, OSBPL5, PPP1R9A, Sgce, SLC22A18, and UBE3A) were identified as candidate imprinted genes in cattle.