• Title/Summary/Keyword: Robotics

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Application of Lookup Table Technique with PID Controller for East Flow Ratio Response

  • Klaynil, P.;Pannil, P.;Chaikla, A.;Julsereewong, P.;Tirasesth, K.
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.504-504
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    • 2000
  • The flow ratio in the industrial process is usually accomplished by using PID controller with series type ratio. But always the large overshoot and a long rise time may be achieved from this conventional control. These problems are involved to the inexact flow ratio control. In order to avoid this poor performance. the paper presents a designing of the two controller modes for the flow ratio plants. This proposed controller combine the lookup table technique and the well-known PID controller to obtain the fast response and low overshoot of flow ratio control. The PID controller mode will be operated when the flow ratio reaches the preset value while the lookup table technique mode is applied for initial operation. The data in tile table is calculated by the valve sizing equation and convened to the valve position control signal. The experimental results show that the transient and steady state responses of the control systems using the proposed technique can be efficiently obtained when compared with tile conventional controller.

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Correction of Image Distortion and Coordinate Calibration of the x-ray three dimensional imaging system (X선 3차원 영상 시스템에서의 영상 왜곡 및 영상 좌표계 보정)

  • 노영준;김재완;조형석;전형조;김형철;주효남
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.413-413
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    • 2000
  • In this paper, we propose a series of calibrations f3r the x-ray three dimensional imaging system. In the developed x-ray system, a three dimensional inner and outer shape of an object can be reconstructed out of two dimensional transmitted x-ray image set, which are acquired by projecting x-ray to the object from different views. To achieve this, a reconstruction algorithm which estimates and updates the three dimensional volume from x-ray images is developed. The algorithm is named as uniform and simultaneous algebraic reconstruction technique(USART) which is an iterative method estimating a 3D volume based on its projected images. In this method, it is assumed that the imaging conditions that are the relative positions between the x-ray sources, object and the image planes are blown. Practically it is not easy to know the three dimensional coordinate of the components of the system, since the x-ray is not visible and the image distortions are present due to the optical components in the system. In this paper, methods of correcting image distortions are present firstly. Then the coordinates of the x-ray systems are calibrated from the x-ray images of the grid pattern. Some experimental results on these calibrations are present and discussed.

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Modelling and Simulation for PIG Flow Control in Natural Gas Pipeline

  • Nguyen, Tan-Tien;Yoo, Hui-Ryong;Park, Yong-Woo;Kim, Sang-Bong
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.448-448
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    • 2000
  • This paper deals with dynamic behaviour analysis for pipeline inspection gauge (PIG) flow control in natural gas pipeline. The dynamic behaviour of the PIG is depending on the different Pressure between the rear and nose parts, which is generated by injected gas flow behind PIG's tail and expelled gas flow in front of its nose. To analyze the dynamic behaviour characteristics such as gas flow in pipeline, and the PIG's position and velocity, mathematical model is derived as two types of a nonlinear hyperbolic partial differential equation for unsteady flow analysis of the PIG driving and expelled gas, and nonhomogeneous differential equation for dynamic analysis of PIG. The nonlinear equation is solved by method of characteristics (MOC) with the regular rectangular grid under appropriate initial and boundary conditions. The Runge-Kuta method is used when we solve the steady flow equations to get initial flow values and the dynamic equation of PIG. The gas upstream and downstream of PIG are divided into a number of elements of equal length. The sampling time and distance are chosen under Courant-Friedrich-Lewy (CFL) restriction. The simulation is performed with a pipeline segment in the Korea Gas Corporation (KOGAS) low pressure system, Ueijungboo-Sangye line. The simulation results show us that the derived mathematical model and the proposed computational scheme are effective for estimating the position and velocity of PIG with different operational conditions of pipeline.

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A neuron computer model embedded Lukasiewicz' implication

  • Kobata, Kenji;Zhu, Hanxi;Aoyama, Tomoo;Yoshihara, Ikuo
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.449-449
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    • 2000
  • Many researchers have studied architectures for non-Neumann's computers because of escaping its bottleneck. To avoid the bottleneck, a neuron-based computer has been developed. The computer has only neurons and their connections, which are constructed of the learning. But still it has information processing facilities, and at the same time, it is like as a simplified brain to make inference; it is called "neuron-computer". No instructions are considered in any neural network usually; however, to complete complex processing on restricted computing resources, the processing must be reduced to primitive actions. Therefore, we introduce the instructions to the neuron-computer, in which the most important function is implications. There is an implication represented by binary-operators, but general implications for multi-value or fuzzy logics can't be done. Therefore, we need to use Lukasiewicz' operator at least. We investigated a neuron-computer having instructions for general implications. If we use the computer, the effective inferences base on multi-value logic is executed rapidly in a small logical unit.

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Precision indices of neural networks for medicines: structure-activity correlation relationships

  • Zhu, Hanxi;Aoyama, Tomoo;Yoshihara, Ikuo;Lee, Seung-Woo;Kim, Wook-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.481-481
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    • 2000
  • We investigated the structure-activity relationships on use of multi-layer neural networks. The relationships are techniques required in developments of medicines. Since many kinds of observations might be adopted on the techniques, we discussed some points between the observations and the properties of multi-layer neural networks. In the structure-activity relationships, an important property is not that standard deviations are nearly equal to zero for observed physiological activity, but prediction ability for unknown medicines. Since we adopted non-linear approximation, the function to represent the activity can be defined by observations; therefore, we believe that the standard deviations have not significance. The function was examined by "leave-one-out" method, which was originally introduced for the multi-regression analysis. In the linear approximation, the examination is significance, however, we believe that the method is inappropriate in case of nonlinear fitting as neural networks; therefore, we derived a new index fer the relationships from the differential of information propagation in the neural network. By using the index, we discussed physiological activity of an anti-cancer medicine, Mitomycine derivatives. The neuro-computing suggests that there is no direction to extend the anti-cancer activity of Mitomycine, which is close to the trend of anticancer developing.

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The Design of Sliding Mode Controller with Perturbation Estimator Using Observer-Based Fuzzy Adaptive Network

  • Park, Min-Kyu;Lee, Min-Cheol;Go, Seok-Jo
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.506-506
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    • 2000
  • To improve control performance of a non-linear system, many other researches have used the sliding mode control algorithm. The sliding mode controller is known to be robust against nonlinear and unmodeled dynamic terms. However. this algorithm raises the inherent chattering caused by excessive switching inputs around the sliding surface. Therefore, in order to solve the chattering problem and improve control performance, this study has developed the sliding mode controller with a perturbation estimator using the observer-based fuzzy adaptive network generates the control input for compensating unmodeled dynamics terms and disturbance. And, the weighting parameters of the fuzzy adaptive network are updated on-line by adaptive law in order to force the estimation errors to converge to zero. Therefore, the combination of sliding mode control and fuzzy adaptive network gives rise to the robust and intelligent routine. For evaluating control performance of the proposed approach. tracking control simulation is carried out for the hydraulic motion simulator which is a 6-degree of freedom parallel manipulator.

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Mechanical Properties of GMT-Sheet on Press joined Molding (프레스 접합성형 GMT-Sheet의 기계적 성질)

  • Kim, Hyuk;Choi, Yu-Sung;Lee, Dong-Ki;Han, Gil-Young;Kim, Yi-Gon
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.553-553
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    • 2000
  • The application as the parts of an automobile, using the property of GMT-Sheet, is increasing. In order to exchange the parts of an automobile for GMT-Sheet, at first, the establishment and joining problem of exact joining strength must be determined. We have studied it using composites which is not same each other fiber oriented condition so as to determine joining strength and joining condition of GMT-Sheet. h this study, the result of experiment of forming condition concerned joining problem of GMT-Sheet is this ; joining efficiency of of GMT-Sheet, increases as lap joint length L increases. Increase of compression ratio causes decrease of joining efficiency after of GMT-Sheet joining. In the viewpoint of recycling, randomly oriented composite of GMT-Sheet is desirable more than unidirectional oriented composite. We has better design the structure so as not to occur to stress centralizatien on the joining part.

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Fabrication and Characteristic Analysis of a Flexible Tactile Sensor Using PVDF (PVDF를 이용한 유연 촉각센서의 제작 및 특성해석)

  • 윤명종;권대규;유기호;이성철
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.390-390
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    • 2000
  • This research is the development of a skin-type tactile sensor for service robot using PVDF film for the detection of the contact state. The Prototype of the tactile sensor which has 8$\times$8 taxels was fabricated using PVDF film In the fabrication procedure of the sensor, the electrode patterns and common electrode of the thin conductive tape were attached to the both side of the 28 micro meter thickness PVDF film using conductive adhesive. The sensor was covered with polyester film for insulation and attached to the rubber base for making stable structure. The signals of a contact pressure to the tactile sensor were sensed and processed in the DSP system in which the signals were digitized and filtered. Finally, the signals were integrated for taking the force profile. The processed signals of the output of the sensor were visualized in PC, the shape and force distribution of the contact object were obtained. The reasonable performance for the detection of contact state was verified through the experiment.

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A New Inspection Method of PDP Electrode Pattern Defects

  • Kim, Taehong;Sunkyu Yang;Tak Eun;Park, Sehwa;Ilhong Suh
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.457-457
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    • 2000
  • The display module of PDP consists of a pair of fine electrode patterned panels. For example, in case of 42" PDP, thousands of electrode patterns should be placed on panel, where length, width, and height of each pattern m one meter, 50${\mu}{\textrm}{m}$, and 30${\mu}{\textrm}{m}$ respectively. And pitch between patterns is around 200${\mu}{\textrm}{m}$. Electrode patterns are frequently damaged during the production process, and thus might be broken. These breakage will result in open-circuited electrical characteristic of a pattern and/or open-circuited electrical characteristic between patterns. Therefore, inspection of pattern defects is the inevitable process to improve production yield rate of the panel. In this paper, we first review several types of PDP pattern defects which affects yield-rate of PDP. And, problems of inspecting such pattern defects by a typical inspection method is addressed. Then, a novel inspection method is proposed to overcome the difficulties, where some new components and the algorithm to detect the electrode defects are explored.ored.

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The Fabrication and Evaluation of SMA Ribbons for Micro Actuator Application (마이크로 엑츄에이터용 형상기억 리본 제조 및 제특성 평가)

  • 이영수;장우양
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.554-554
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    • 2000
  • To improve mechanical properties of Cu-Al-Ni alloy by the grain refinement, Cu-Al-Ni SMA ribbons were fabricated by melt spinning apparatus. The variations of microstructure, mechanical properties and transformation characteristics with the condition of rapid solidification and annealing time-temperature were investigated in Cu-Al-Ni SMA ribbons. The ribbons fabricated by melt spinning obtained around 1.5nm in width and 50-60${\mu}{\textrm}{m}$ in thickness. With increasing wheel speed in order of 10m/s, 15m/s, 20m/s, 30m/s and 3m/s, the grain size was decreased in order of 10${\mu}{\textrm}{m}$, 6.25${\mu}{\textrm}{m}$, 5.5${\mu}{\textrm}{m}$, 3${\mu}{\textrm}{m}$ and 3${\mu}{\textrm}{m}$. $M_{s}$ and $A_{s}$ temperature were decreased with decreasing grain size. By X-ray diffraction test, ordered $\beta$$_1$ phase was observed in all the SMA ribbons and the volume friction of it was increased with increasing wheel speed. With increasing wheel speed, strain was increased from 4.2% to 5.8% and fracture mode has changed from mixture of intergranular and dimple fracture to mixture of fiber structure and dimple fracture. The grain size of ribbon heat-treated at $600^{\circ}C$ was increased with increasing time. In the heat-treated ribbons at 55$0^{\circ}C$, ${\gamma}$$_2$ phases were observed.d.d.

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