• Title, Summary, Keyword: Damper

Search Result 2,141, Processing Time 0.045 seconds

Enhanced Variable Structure Control With Fuzzy Logic System

  • Charnprecharut, Veeraphon;Phaitoonwattanakij, Kitti;Tiacharoen, Somporn
    • 제어로봇시스템학회:학술대회논문집
    • /
    • /
    • pp.999-1004
    • /
    • 2005
  • An algorithm for a hybrid controller consists of a sliding mode control part and a fuzzy logic part which ar purposely for nonlinear systems. The sliding mode part of the solution is based on "eigenvalue/vector"-type controller is used as the backstepping approach for tracking errors. The fuzzy logic part is a Mamdani fuzzy model. This is designed by applying sliding mode control (SMC) method to the dynamic model. The main objective is to keep the update dynamics in a stable region by used SMC. After that the plant behavior is presented to train procedure of adaptive neuro-fuzzy inference systems (ANFIS). ANFIS architecture is determined and the relevant formulation for the approach is given. Using the error (e) and rate of error (de), occur due to the difference between the desired output value (yd) and the actual output value (y) of the system. A dynamic adaptation law is proposed and proved the particularly chosen form of the adaptation strategy. Subsequently VSC creates a sliding mode in the plant behavior while the parameters of the controller are also in a sliding mode (stable trainer). This study considers the ANFIS structure with first order Sugeno model containing nine rules. Bell shaped membership functions with product inference rule are used at the fuzzification level. Finally the Mamdani fuzzy logic which is depends on adaptive neuro-fuzzy inference systems structure designed. At the transferable stage from ANFIS to Mamdani fuzzy model is adjusted for the membership function of the input value (e, de) and the actual output value (y) of the system could be changed to trapezoidal and triangular functions through tuning the parameters of the membership functions and rules base. These help adjust the contributions of both fuzzy control and variable structure control to the entire control value. The application example, control of a mass-damper system is considered. The simulation has been done using MATLAB. Three cases of the controller will be considered: for backstepping sliding-mode controller, for hybrid controller, and for adaptive backstepping sliding-mode controller. A numerical example is simulated to verify the performances of the proposed control strategy, and the simulation results show that the controller designed is more effective than the adaptive backstepping sliding mode controller.

  • PDF

Real-time Feedback Vibration Control of Structures Using Wireless Acceleration Sensor System - System Design and Basic Performance Evaluation - (무선 가속도센서 시스템을 이용한 건축물의 실시간 피드백 진동제어 - 시스템 구축 및 기초성능 평가 -)

  • Jeon, Joon Ryong;Park, Ki Tae;Lee, Chin Ok;Heo, Gwang Hee;Lee, Woo Sang
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.17 no.2
    • /
    • pp.21-32
    • /
    • 2013
  • This is a preliminary study for the real-time feedback vibration control of building structures. The study developed a wireless acceleration sensor system based on authentic technology capacities, to integrate with the Prototype AMD system and ultimately construct the feedback vibration control system. These systems were used to evaluate the basic performance levels of the control systems within model building structures. For this purpose, the study first developed a wireless acceleration sensor unit that integrates an MEMS sensor device and bluetooth communication module. Also, the study developed an operating program that enables control output based on real-time acceleration response measurement and control law. Furthermore, the Prototype AMD and motor driver system were constructed to be maneuvered by the AC servo-motor. Eventually, all these compositions were used to evaluate the real-time feedback vibration control system of a 2-story model building, and qualitatively measure the extent of vibrational reduction of the target structure within the laboratory validation tests. As a result of the tests, there was a definite vibrational reduction effect within the laboratory validation tests. As a result of the tests, there was a definite vibrational reduction effect within 1st and 2nd resonance frequency as well as the random frequency of the model building structure. Ultimately, this study confirmed the potential of its wireless acceleration sensor system and AMD system as an effective tool that can be applied to the active vibration control of other structures.

Study on the Assessment of the Criteria on a Door Closer for the Optimum Design of the Access Door of a Smoke Control Zone (제연구역 출입문의 최적 설계를 위한 도어클로저의 기준 산정에 관한 연구)

  • Lee, Jae-Ou;Choi, Chung-Seog
    • Fire Science and Engineering
    • /
    • v.27 no.3
    • /
    • pp.66-71
    • /
    • 2013
  • The purpose of this study is to assess the criteria on a floor hinge and door closer for the optimum design of the access door of a smoke control room. The door opening force due to differential pressure is 60.75 N, 40.5 N, 32.91 N and 12.66 N when the differential pressure is 60 Pa, 40 Pa, 32.5 Pa and 12.5 Pa, respectively. The door opening force of the floor hinge and door closer to which the criteria of KS F 2806 are applied is 27.5 N, 40 N, 75 N, 100 N and 125 N for the Nos. 1, 2, 3, 4 and 5 class floor hinges and door closers, respectively. This study compared the differential pressure and opening force limits of floor hinges and door closers with the values specified in NFSC 501A and found that they exceeded the criteria specified in NFSC 501A. Therefore, it is necessary to reflect the differential pressure and smoke control wind speeds as well as the opening forces specified in NFSC 501A on the design of floor hinges and door closers. The installation conditions of floor hinges and door closers of access doors differ depending on the type and name of a smoke control damper. This study found that Nos. 1, 2 and 3 floor hinges and door closers could be installed for access doors with low differential pressure and that Nos. 1 and 2 floor hinges and door closers could be installed for access doors with normal differential pressure.

Development of Buckling Restrained Brace Laterally Supported by Semicircular Springs (반원형 스프링으로 횡지지된 건식형 좌굴방지가새의 개발)

  • Park, Keum Sung;Lee, Sang Sup;Hong, Sung Yub;Bae, Kyu Woong
    • Journal of Korean Society of Steel Construction
    • /
    • v.26 no.6
    • /
    • pp.549-558
    • /
    • 2014
  • Buckling restrained braces(BRBs) developed as a seismic protection element, hysteretic damper, have been investigated in America and Japan mainly. BRBs are composed of a steel core and concrete-filled steel casing. It is one of the major causes of drop in productivity to fill the steel casing with concrete. To improve this problem, the BRB is introduced in which the steel core is restrained with a pair of semicircular springs. In this paper, the numerical and analytical investigation about the desirable configuration for a semicircular spring is presented. Firstly, the stiffness and strength of semicircular spring is determined theoretically to buckle into a very high-order modes. Then, the required stiffness and strength are calculated under the practical design conditions and considered as reference values to find a proper configuration. The material strength and thickness of semicircular spring are chose from the finite element analysis for 5 semicircular springs with varying height. Finally, the nonlinear buckling analysis of BRB with proper semicircular springs shows that the bucking strength of the whole BRB is very similar to the strength of steel core with length between semicircular springs.

Dynamic Modeling and Simulation of a Towing Rope using Multiple Finite Element Method (다물체 요소이론을 이용한 예인줄 동역학의 모델링 및 시뮬레이션)

  • Yoon, Hyeon-Kyu;Lee, Hong-Seok;Park, Jong-Kyu;Kim, Yeon-Gyu
    • Journal of Navigation and Port Research
    • /
    • v.36 no.5
    • /
    • pp.339-347
    • /
    • 2012
  • After towing rope connecting a barge to a tug was subdivided into multiple finite elements, then those dynamic models was established using Newton's second law and considering the external force and moment such as tension, drag, Coriolis force, gravity, buoyancy, and impact due to free surface acting on each element. While the previous research on the model of towing rope considered only translation, five-degree-of-freedom equations of motion except roll based on the body-fixed frame were established in this paper. All elements are connected by a spring and a damper, and the stiffness of the spring was set as the equivalent value of the real rope. In order to confirm the established multiple finite element model, various scenarios such as freely falling of towing rope in the air and above the free surface, accelerating of a tug which tows a barge connected by towing rope, and sinusoidal moving of a tug were set up and simulated. As the results, the trajectories of the tug, the barge, and the towing rope showed good tendencies to the ones of real expected situations.

Dynamic Behavior Modelling of Augmented Objects with Haptic Interaction (햅틱 상호작용에 의한 증강 객체의 동적 움직임 모델링)

  • Lee, Seonho;Chun, Junchul
    • Journal of Internet Computing and Services
    • /
    • v.15 no.1
    • /
    • pp.171-178
    • /
    • 2014
  • This paper presents dynamic modelling of a virtual object in augmented reality environments when external forces are applied to the object in real-time fashion. In order to simulate a natural behavior of the object we employ the theory of Newtonian physics to construct motion equation of the object according to the varying external forces applied to the AR object. In dynamic modelling process, the physical interaction is taken placed between the augmented object and the physical object such as a haptic input device and the external forces are transferred to the object. The intrinsic properties of the augmented object are either rigid or elastically deformable (non-rigid) model. In case of the rigid object, the dynamic motion of the object is simulated when the augmented object is collided with by the haptic stick by considering linear momentum or angular momentum. In the case of the non-rigid object, the physics-based simulation approach is adopted since the elastically deformable models respond in a natural way to the external or internal forces and constraints. Depending on the characteristics of force caused by a user through a haptic interface and model's intrinsic properties, the virtual elastic object in AR is deformed naturally. In the simulation, we exploit standard mass-spring damper differential equation so called Newton's second law of motion to model deformable objects. From the experiments, we can successfully visualize the behavior of a virtual objects in AR based on the theorem of physics when the haptic device interact with the rigid or non-rigid virtual object.

Regulatory Reform for Service Development (서비스발전을 위한 규제개혁의 새 패러다임)

  • Jeong, Ki-Oh
    • Journal of Service Research and Studies
    • /
    • v.6 no.3
    • /
    • pp.1-15
    • /
    • 2016
  • Despite that Korea has tried radical efforts in the global flow of regulatory reform in the past twenty years, the result was not radical at all, but rather disappointing. One examines the possibility of paradigm shift in regulatory reform based on new theoretic perspectives. Regulatory reform, one argues, is not just a neo-liberal approach to cut off overflowing regulation. It is a highly conflictual struggle in state order to move from industrial age paradigm to service age paradigm. In the process of the great shift states become integrated into the world of life constructed by the exercise of civil rights. The relation between the civic socio-economic life and the state apparatus became totally different. Past effort for deregulation missed this point without correct recognition of the role of civil freedom and rights in service economy. One treats three typical forms of regulation whereby conventional rules and regulations effectively damper the development of services: reciprocal perspective in contract management, industrial mind in urban and spaces design, and old way of human capital management. According these analyses a new initiative of regulatory reform is proposed to take place at the National Assembly.

평행식 진동탄환 암거 천공기의 연구 (IV)(V)-실기 설계 제작 및 보장실험-Development of Balanced-Type Oscillating Mole Drainer(IV)(V)

  • 김용환;이승규;서상용
    • Journal of Biosystems Engineering
    • /
    • v.2 no.1
    • /
    • pp.7-24
    • /
    • 1977
  • This paper is the forth and fifth one of the study on balanced type oscillating mole drainer. In the light of the results from previous reports about the model tests, some design criteria were established and a prototype machine was set up for experimental purpose. Motion characteristics and functionof the each parts of the machine were checked and analyzed. After that, performance tests of the prototype machine were carried out in thefield. Obtained results are summarized as follows ; 1. Ten centimeter of the bullet diameter was determined so as to be able to attach it to the tractors with capacity of 30 PS to 40 PS. 2. To maintain the balance between the moments of the front shank and rear shank, the oscillating amplitude of the rear bullet was determined to be larger than that of the front bullet. At the same time , the oscillating direction of the rear bullet was designed with the inclines of ten to thirty degrees. 3. An octagonal dynamo transduced was developed for measuring the compressive force of the upper link is measuring the draft force of the machine. Acceptable linear relationship between forces and strain responses from O.D.T. was obtained. 4. Analysing the balancing mechanism of the acting part of the machine , it was found that the total draft force of the machine was equal to the difference between the sum of the draft force produced from the right and left side bending moments of the lower drawber and the compressive force on the upper link. 5. There are acceptable linear relationship between the strain and twisting moment by driving shaft, and between strain and shank moment. Above results enable us to carry out the field experiment with prototype machine. 6. When the test machine was used in the field, it was possible to reduce the oscillating acceleration by forty percent in average as compared it with the single bullet mole drainer. 7. When the test machine was used under the oscillating condition, the dratt torce was reduced by 27 percent to 59 percent as compared it with the test machine under non-oscillating condition, while the draft force was increased by 7 percent to 20 percent as compared it with the mole drainer having oscillating single bullet. The reasoning behind this fact was considered as the resistance force due to the rear shank and bullet. 8. As the amplitude and frequency of the bullet were increased, the torque was increased accordingly. This tendency could be varied with the various characteristics of the given soils. And the larger frequency and amplitute, the more increasing oscil\ulcornerlating power but decreasing draft brce were needed, and draft force was increased as the velocity was increased.9. When the amplitude of the rear bullet was designed to be larger than that of the front bullet, the minimum value of the moment was lowered and oscillating acceleration was reduced. And when the oscillating direction of the rear bullet was declined back\ulcornerwards, oscillating acceleration was increased along with the increasing angle of decli\ulcornernation. When the test machine was operated in high speed, the difference between maximum moments and minimum ones became narrow. This varying magnitude of moments appeared on the moment oscillogram seems to be correlated to the oscillating acceleration and draft force. 10. From the analysis of variance, it was found that those factors such as frequency, amplitude, and operating velocity significantly affected in the oscillating acceleration, the draft resistance, the torque, the moment, and the total power required. And interaction between frequency and amplitude affected in the oscillating acceleration. 11. Within the given situation of this study, the most preferable operating conditions of the test machine were 7 Hz in oscillating frequency, 0.54 m/sec in operating velocity, and 39.1 mm in oscillating amplitude of front and rear bullets. However, it is necessary to select the proper frequency and magnitude of oscillation depending on the soil properties of the field in which the mole drainer is practiced by use of a bal1nced type oscillating mole drainer. 12. It is recommended that a comparative study of the mole drainers would be performed in the near future using two separate balanced oscillating bullet with the one which is operated by oscillating the movable bullet in a single cylinder or other balanced type which may be single oscillating bullet with spring, damper or balancing weight, and that of thing. To expand the applicability of the balanced type oscillating mole drainer in practical use, it is suggested to develop a new mechanism which perform mole drain with vinyl pipe or filling material such as rice hull.

  • PDF

Development of Mobile Vortex Wet Scrubber and Evaluation of Gas Removal Efficiency (기체상 유해화학물질 제거를 위한 이동형 와류식 세정장치 개발 및 가스 제거효율 분석)

  • Kwak, Ji Hyun;Hwang, Seung-Ryul;Lee, Yeon-Hee;Kim, Jae-Young;Song, Ki Bong;Kim, Kyun;Kang, Jae Eun;Lee, Sang Jae;Jeon, Junho;Lee, Jin Hwan
    • Korean Journal of Environmental Agriculture
    • /
    • v.34 no.2
    • /
    • pp.134-138
    • /
    • 2015
  • BACKGROUND: In recent years, several researchers have focused on odour control methods to remove the harmful chemicals from chemical accidents and incidents. The present work deals with the system development of the hazardous. METHODS AND RESULTS: For on-site removal of hazardous gaseous materials from chemical accidents, mobile vortex wet scrubber was designed with water vortex process to absorb the gas into the water. The efficiency of the mobile vortex wet scrubber was evaluated using water spray and 25% ammonia solution. The inlet air velocity (gas flow rate) was according to the damper angle installed within the hood and with increase of gas flow rate, consequently the absorption efficiency was markedly decreased. In particular, when 25% ammonia solution was exposed to the hood inlet for 30 min, the water pH within the scrubber was changed from 7 to 12. Interestingly, although the removal efficiency of ammonia gas exhibited approximately 80% for 5 min, its efficiency in 10 min showed the greatest decrease with 18%. Therefore, our results suggest that the ammonia gas may be absorbed with the driving force of scrubbing water in water vortex process of this scrubber. CONCLUSION: When chemical accidents are occurred, the designed compact scrubber may be utilized as effective tool regarding removal of ammonia gas and other volatile organic compounds in the scene of an accident.

Study on PM10, PM2.5 Reduction Effects and Measurement Method of Vegetation Bio-Filters System in Multi-Use Facility (다중이용시설 내 식생바이오필터 시스템의 PM10, PM2.5 저감효과 및 측정방법에 대한 연구)

  • Kim, Tae-Han;Choi, Boo-Hun
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.48 no.5
    • /
    • pp.80-88
    • /
    • 2020
  • With the issuance of one-week fine dust emergency reduction measures in March 2019, the public's anxiety about fine dust is increasingly growing. In order to assess the application of air purifying plant-based bio-filters to public facilities, this study presented a method for measuring pollutant reduction effects by creating an indoor environment for continuous discharge of particle pollutants and conducted basic studies to verify whether indoor air quality has improved through the system. In this study conducted in a lecture room in spring, the background concentration was created by using mosquito repellent incense as a pollutant one hour before monitoring. Then, according to the schedule, the fine dust reduction capacity was monitored by irrigating for two hours and venting air for one hour. PM10, PM2.5, and temperature & humidity sensors were installed two meters front of the bio-filters, and velocity probes were installed at the center of the three air vents to conduct time-series monitoring. The average face velocity of three air vents set up in the bio-filter was 0.38±0.16 m/s. Total air-conditioning air volume was calculated at 776.89±320.16㎥/h by applying an air vent area of 0.29m×0.65m after deducing damper area. With the system in operation, average temperature and average relative humidity were maintained at 21.5-22.3℃, and 63.79-73.6%, respectively, which indicates that it satisfies temperature and humidity range of various conditions of preceding studies. When the effects of raising relatively humidity rapidly by operating system's air-conditioning function are used efficiently, it would be possible to reduce indoor fine dust and maintain appropriate relative humidity seasonally. Concentration of fine dust increased the same in all cycles before operating the bio-filter system. After operating the system, in cycle 1 blast section (C-1, β=-3.83, β=-2.45), particulate matters (PM10) were lowered by up to 28.8% or 560.3㎍/㎥ and fine particulate matters (PM2.5) were reduced by up to 28.0% or 350.0㎍/㎥. Then, the concentration of find dust (PM10, PM2.5) was reduced by up to 32.6% or 647.0㎍/㎥ and 32.4% or 401.3㎍/㎥ respectively through reduction in cycle 2 blast section (C-2, β=-5.50, β=-3.30) and up to 30.8% or 732.7㎍/㎥ and 31.0% or 459.3㎍/㎥ respectively through reduction in cycle 3 blast section (C-3, β=5.48, β=-3.51). By referring to standards and regulations related to the installation of vegetation bio-filters in public facilities, this study provided plans on how to set up objective performance evaluation environment. By doing so, it was possible to create monitoring infrastructure more objective than a regular lecture room environment and secure relatively reliable data.