• 한국정밀공학회지
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• 제23권8호
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• pp.64-71
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• 2006

In this paper, a uniform speed controller for an ultrasonic rotary motor is developed using the phase-difference method. The phase difference method uses traveling waves to drive the ultrasonic motor. The traveling waves are obtained by adding two standing waves that have a different phase to each other. A compact phase-difference driver system is designed and integrated by combining VCO(Voltage Controlled Oscillator) and phase shifter. Theoretically the relationship between the phase difference in time and the rotational speed of the ultrasonic motor is sine function, which is verified by experiments. Then a series of experiments under various loading conditions are conducted to characterize the motor's performance that is the relationship between the speed and torque. Proportional-integral control is adopted for the uniform speed control. The proportional control unit calculates the compensating phase-difference using the rotating speed which is measured by an encoder and fed back. Integral control is used to eliminate steady-state errors. Differential control for reducing overshoot is not used since the response of ultrasonic motor is prompt due to its low inertia and friction-driving characteristics. The developed controller demonstrates reasonable performance overcoming disturbing torque and the changes in material properties due to continuous usage.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.945-950
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• 2007

This paper presents the design study of a rotary MRF(Magneto-Rheological Fluid) damper that can be conveniently used in the joints to control the damping torques. The basic design concept is to determine the geometric design variables allowing the magnetic flux to flow across the same sectional areas under volume constraint condition. The effects of each design variables for generating the torques were investigated by magnetic field analyses.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 B
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• pp.684-686
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• 1998

This paper consider fuzzy control of a single-inverted pendulum attached to the tip end of a rotating arm driven by a direct driven motor. Control objectives stabilization of the pendulum at the upright position and regulation of the arm at an arbitrary specified position. Fuzzy control is an effective method to achieve multiple control objectives in control of nonlinear systems. In this paper, fuzzy logic control is proposed to obtain increased control performance and stability.

• 한국항공우주학회지
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• 제48권1호
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• pp.55-62
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• 2020

회전익 헬리콥터의 안정성, 조종성 향상 및 증대를 보장하기 위해서는 디지털 제어기술에 의한 디지털 비행제어시스템의 개발이 필요하다. 헬리콥터 비행제어시스템 설계 및 개발 기술은 해외 선진 항공 개발사의 기술이전 기피 및 불가에 해당하는 핵심기술로써 헬리콥터 비행제어 시스템 운용소프트웨어인 OFP의 기능 요구조건 충족과 더불어 비행안전에 직결되는 시스템 신뢰도의 검증이 필요하며 비행제어 시스템 운용 소프트웨어의 검증 방안 연구는 무엇보다 중요하다. 본 논문에서는 회전익 자동비행제어시스템 소프트웨어의 FMET 수행 및 검증 방안에 관한 연구를 수행하였다.

• 로봇학회논문지
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• 제15권1호
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• pp.77-89
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• 2020

This paper proposes a simple and intuitive model-free torque-tracking control for rotary electro-hydraulic actuators. The undesirable natural-velocity-feedback effect is discussed by introducing mechanical impedance into the electro-hydraulic actuation system. The proposed model-free torque control comprises inner- and outer-loop control to achieve two control objectives. Inner-loop control reduces the mechanical impedance passively and optimally. To improve the tracking accuracy, a certain form of proportional-integral-derivative control is applied to the outer loop. The robustness of the proposed closed-loop system against external disturbances is demonstrated by transforming the two-loop control structure into a disturbance observer form. The proposed method is validated on a single joint electro-hydraulic actuator.

• 한국지능시스템학회논문지
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• 제19권3호
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• pp.329-336
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• 2009

본 논문은 회전형 역 진자 시스템(Rotary Inverted Pendulum System : RIPS)의 제어를 위한 Fuzzy cascade 제어구조를 제안하고 병렬유전자 알고리즘의 하나인 계층적 공정 경쟁 기반 유전자 알고리즘(Hierarchical Fair Competition-based Genetic Algorithms : HFCGA)을 이용한 최적화 방법을 제시한다. 회전형 역 진자 시스템은 Rotating arm의 회전을 통해 Pendulum의 각도를 제어하는 시스템으로써 제어 목적은 Rotating arm을 원하는 위치에 오게 하고 진자를 수직 위치의 불안정 평형 점에 위치하도록 하는 것이다. 본 논문에서는 회전형 역 진자 시스템의 제어를 위해 두개의 Fuzzy 제어기로 구성된 Fuzzy cascade 제어 구조를 설계하고, HFCGA를 이용하여 설계된 제어기의 파라미터를 최적화한다. 시뮬레이션 및 실험에서 SGA와 HFCGA의 성능비교를 통해 HFCGA의 우수성을 보이고, LQR 및 PD cascade 제어기와 제안된 Fuzzy cascade 제어기의 성능 비교를 통하여 제안된 방법의 우수성을 보인다.

• 한국CDE학회논문집
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• 제14권5호
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• pp.291-296
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• 2009

This paper presents a post-processing algorithm for 5-axis machines with three rotary axes (3R-2L type). 5-axis machining needs the postprocessor for converting cutter location (CL) data to machine control (NC) data. The existing methods for post-processing use inverse kinematics equations from for-ward kinematics. However in case of 5-axis machines with three rotary axes, the inverse kinematics equations are not induced directly since the forward kinematics equations are non-linear. In order to get the joint values from the forward kinematics equations, previous algorithms use numerical method for the post-processing, which needs searching algorithms with computation time and may result in fail. This paper proposes a geometric method for the post-processing of 3 rotary type 5-axis machines. Our algorithm has three advantages: first, it does not need establishing forward kinematics equations. Second, it is reliable method that eliminates any numerical methods for the inverse kinematics, resulting in the exact solution. Finally, the proposed algorithm can also be applied to 2R-3L type of 5-axis machines.

• 제어로봇시스템학회논문지
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• 제11권3호
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• pp.228-232
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• 2005

This paper presents the efforts of the studies for improvement of spin characteristics of KTX-1 #02 through rotary balance test, forced oscillation test and spin mode analysis. During the full scale development design stage, we had fullfilled a lot of spin flight test, spin mode analysis. Based on all of the efforts, KTX-1 had been developed as a successful trainer with excellent spin characteristics.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1005-1007
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• 2005

A Nonlinear approach to control of Small Scale Rotary Wing Unmanned Aerial Vehicle (R-UAV) is presented. Using Backstepping, a globally stabilizing control law is derived. We derive backstepping control law for angle of attack and sideslip control. The inherent nonlinear nature of the system are considered here which helps in naturally stabilizing without extensive external effort. Thus, the resulting control law is much simpler than if the feedback linearization had been used.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2019년도 추계학술대회
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• pp.59-61
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• 2019

유인등대 무인화 구축에 있어 효율적인 관리와 운영을 위해 표준화된 시스템 구축이 필요하며, 등대의 역할 중 가장 중요한 등명기에 대해 회전식 등명기를 효율적으로 관리운영시스템으로 관리하기 위해 상태 감시 및 제어를 위한 RTU 표준 프로토콜을 제정하여 효율적인 관리를 통해 해상교통안전에 만전을 기하고자 한다.