• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
• /
• pp.1441-1444
• /
• 1996

This paper presents the position control of a double-rod cylinder system activated by an electrotheological(ER) valve unit. Following the composition of a silicone oil-based ER fluid, theological properties of the ER fluid are experimentally tested as a function of imposed electric fields to determine appropriate design parameters of the ER valve. The ER valves are then designed and manufactured. Subsequently, the pressure drop of the ER valve is evaluated with respect to the intensity of the electric field. Four ER valves bridge-cylinder system is formulated, and the governing equations for the system are derived. A neural network control scheme is then synthesized to perform the position control of the cylinder system. Tracking control responses are experimentally evaluated and presented in order to demonstrate the effectiveness of the proposed control system.

• 전산구조공학
• /
• 제3권3호
• /
• pp.141-146
• /
• 1990

본 연구에서는 다목적연구로 반응도제어장치의 제어봉에 대한 내진해석을 수행하였다. 해석모델은 물속에 잠겨있는 두개의 관(중성자흡수봉 및 유동관)이 동심축상에 있으며 부분적으로 중첩된 두 관끝단의 유체틈에 의해 서로 동적으로 연결되어 있다. 유체에 의한 동적질량을 고려한 고유진동수를 구하고 안전정지지진에 의해 발생하는 최대응력과 최대변위를 동위상 및 역위상 거동별로 각각 구하였다. 해석결과 최대응력은 허용치보다 작게 나타나 구조적인 건전성은 입증되었으나, 최대변위는 두 개의 관이 서로 부딪히고 중성자흡수봉은 주위의 다른 벽에도 부딪히는 현상을 수발함을 알 수 있었다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제29권3호
• /
• pp.251-259
• /
• 2005

A discrete time model reference adaptive control has been applied in order to compensate the nonlinear friction characteristics in a hydraulic proportional position control system. As nonlinear friction, static and coulomb friction forces are considered and modeled as dead zone and external disturbance respectively. The model reference adaptive control system consists of a cascade combination of the dead zone. external disturbance and linear dynamic block. For adaptive control experiment. the DSP(Digital Signal Processor) board has been interfaced the hydraulic proportional position control system. The experimental results show that the MRAC(Model Reference Adaptive Control) for compensation of static and coulomb friction are very effective.

• Journal of Mechanical Science and Technology
• /
• 제16권11호
• /
• pp.1379-1394
• /
• 2002

In case of a single input single output (SISO) system with a nonlinear term, a signal compression method is useful to identify a system because the equivalent impulse response of linear part from the system can be extracted by the method. However even though the signal compression method is useful to estimate uncertain parameters of the system, the method cannot be directly applied to a unique system with hysteresis characteristics because it cannot estimate all of the two different dynamic properties according to its motion direction. This paper proposes a signal compression method with a pre-processor to identify a unique system with two different dynamics according to its motion direction. The pre-processor plays a role of separating expansion and retraction properties from the system with hysteresis characteristics. For evaluating performance of the proposed approach, a simulation to estimate the assumed unknown parameters for an arbitrary known model is carried out. A motion platform with several single-rod cylinders is a representative unique system with two different dynamics, because each single-rod cylinder has expansion and retraction dynamic properties according to its motion direction. The nominal constant parameters of the motion platform are experimentally identified by using the proposed method. As its application, the identified parameters are applied to a design of a sliding mode controller for the simulator.

• 한국유체기계학회 논문집
• /
• 제17권6호
• /
• pp.109-114
• /
• 2014

After the Fukushima accident in 2011, it was revealed that nuclear power plant has the vulnerability to SBO accident and its extension situation without sufficient cooling of reactor core resulting core meltdown and radioactive material release even after reactor shutdown. Many safety systems had been developed like PAFS, hybrid SIT, and relocation of RPV and IRWST as a part of steps for the Fukushima accident, however, their applications have limitation in the situation that supply of feedwater into reactor is impossible due to high pressure inside reactor pressure vessel. The concept of hybrid heat pipe with control rod is introduced for breaking through the limitation. Hybrid heat pipe with control rod is the passive decay heat removal system in core, which has the abilities of reactor shutdown as control rod as well as decay heat removal as heat pipe. For evaluating the cooling performance hybrid heat pipe, a commercial CFD code, ANSYS-CFX was used. First, for validating CFD results, numerical results and experimental results with same geometry and fluid conditions were compared to a tube type heat pipe resulting in a resonable agreement between them. After that, wall temperature and thermal resistances of 2 design concepts of hybrid heat pipe were analyzed about various heat inputs. For unit length, hybrid heat pipe with a tube type of $B_4C$ pellet has a decreasing tendency of thermal resistance, on the other hand, hybrid heat pipe with an annular type $B_4C$ pellet has an increasing tendency as heat input increases.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
• /
• pp.2603-2605
• /
• 2005

This paper describes an experience on the equipment qualification of CRCS(control rod control system) that has been developed for nuclear power plants. A very high level criteria should be satisfied for the equipment to be used for nuclear power plants. We have developed a CRCS that is aimed to be applied to commercial plants. This system adopts a duplex system structure that is based on the state-of-the-art digital technology so that it has higher reliability than the existing systems. The CRCS has been tested at a licensed testing organization and finally qualified. In this paper, the procedures and some trial-and-errors we have been through in the qualification process are explained. It is expected that our experience will be a helpful tips to the industry that are developing various systems for safety-critical plants.

• 한국소음진동공학회논문집
• /
• 제20권7호
• /
• pp.658-664
• /
• 2010

A control element drive mechanism(CEDM) is a reactor regulating system, which inserts, withdraws or maintains a control rod containing a neutron absorbing material within a reactor core to control the reactivity of the core. The ball-screw type CEDM for the integral reactor has a spring-damper system to reduce the impact force due to the scram of the CEDM. This paper describes the experimental results to obtain the drop and damping characteristics of the CEDM. The drop tests are performed by using a drop test rig and a facility. A drop time and a displacement after an impact are measured using a LVDT. The influences of the rod weight, the drop height and the flow area of hydraulic damper on the drop and damping behavior are also estimated on the basis of test results. The drop time of the control element is within 4.5s to meet the design requirement, and the maximum displacement is measured as 15.6 mm. It is also found that the damping system using a spring-hydraulic damper plays a good damper role in the CEDM.

• 한국자동차공학회논문집
• /
• 제4권6호
• /
• pp.52-64
• /
• 1996

This paper presents an active position control of a single-rod cylinder system featuring an electrorheological(ER) fluid-based valve. The ER fluid consisting of silicone oil and chemically treated particles is firstly composed and its Bingham property is tested as a function of imposed electric field. A multi-channel plate type of ER valve is then designed and manufactured on the basis of the field-dependent Bingham model. Performance test of the ER valve is undertaken by evaluating pressure drop with respect to the number of electrode as well as the intensity of the electric field. Subsequently, the ER valve-cylinder system is constructed and its governing equation of motion is derived. A neural control scheme for position control of the cylinder is formulated by incorporating proportional-plus-derivative(PD) controller and implemented. Experimental results of both regulating and tracking control responses are presented in order to demonstrate the efficacy of the proposed ER valve-cylinder control system.

• 한국소음진동공학회논문집
• /
• 제26권5호
• /
• pp.552-558
• /
• 2016

A control rod drive mechanism(CRDM) is a reactor regulating system, which inserts, withdraws or maintains a control rod within a reactor core to control the reactivity of the core. The CRDM for Jordan Research and Training Reactor with 5MW power has been designed and fabricated based on the HANARO’s experience through KAERI and DAEWOO consortium. This paper describes the seismic test results to demonstrate the operability, the drop performance and the structural integrity of CRDM during or after seismic excitations. The seismic tests are carried out under 5 OBE and 1 SSE loads at three Test Rigs simulating the reactor structure and the pool top. From the tests, the CRDM is smoothly driven without a malfunction of stepping motor under OBE load. The pure drop time under OBE and SSE loads is measured as 1.169s and 1.855s to meet the design requirement. Also, it is found that the CRDM maintains the structural integrity without a change of the function and natural frequency before and after seismic loads.

• 한국자기학회지
• /
• 제26권5호
• /
• pp.154-158
• /
• 2016

원자력발전소의 원자로에는 노심 반응 속도를 제어하기 위하여 제어봉구동장치가 사용된다. 한국원자력연구원의 SMART 원자로는 원자로 가동 중 제어봉집합체의 위치를 확인하기 위하여 제어봉구동장치에 영구자석과 리드스위치로 구성되는 위치지시기가 설치된다. 원자로 가동 온도는 최대 $350^{\circ}C$로 고려되어 설계되며, 영구자석은 원자로 내에 설치된다. 반면에 리드스위치와 전기회로는 원자로 외부에 설치된다. Test coil은 리드스위치의 품질 검증을 위한 장비로서, 코일과 철심으로 구성되어 있다. 본 연구는 리드스위치에 미치는 Test coil과 영구자석의 자기 특성을 비교하고자 수행되었으며, 유한요소 전자기 시뮬레이션을 활용하였다.