• 제어로봇시스템학회논문지
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• 제7권10호
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• pp.806-811
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• 2001

The analysis and control algorithm of a new type unsymmetrical self-bearing step motor is presented. The motor actuator is used for both motor and bearing functionality without any redundant coil windings or redudant electromagnets for bearing functionality. Self bearing step motor layout and control current generation method for unsymmetrical position of electromagnets are described. This new current generation method without additional current for bearing functionality leads to minimize the power loss. As the result of the unbalance response approach, the constant torque is possible, even though the bearing functionality is added or not.

• 제어로봇시스템학회논문지
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• 제18권9호
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• pp.823-829
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• 2012

An excitation table is commonly used for vibration and ride tests for parts or assemblies of automobiles, aircrafts, or other heavy systems. The authors have analyzed several kinematic properties of an excitation table that is under development for heavy transport vehicles. It consists of one table and 7 linear hydraulic actuators. The authors have performed mobility analysis, inverse kinematics, forward kinematics, and singularity analysis. Especially, we have proposed a fast forward kinematic solution considering the limited motion of the excitation table. On the assumption that the motion variables such as rotation angles and displacements are small, the forward kinematic problem is converted to the observer problem of a linear system. This provides a fast solution. Also we have verified that there are no singularity points in the working range by numerical analysis.

• 한국정밀공학회지
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• 제29권4호
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• pp.426-432
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• 2012

In this study, kinematic analysis of forward kinematic, inverse kinematic and jacobian for 6-bar parallel robot was analyzed. In order to analyze the maximum workspace of 6-bar parallel robot, maximum revolution range of active joint was calculated. Also, to analyze forward dynamics and inverse dynamics of 6-bar parallel robot, recurdyn and simmechanics was utilized. Using a PI controller and Feedforward controller make an experiment with square motion of end_effector. The reference value of active joint and trace of end_effector were compared with actual experimental value.

• 한국정밀공학회지
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• 제30권11호
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• pp.1217-1224
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• 2013

In this paper, a hand exoskeleton actuated by air muscles(soft hand exoskeleton) is introduced. Some soft hand exoskeletons have already been developed to overcome the defects of hand exoskeletons based on linkage and pneumatic piston system-they are usually bulky and do not have enough degree of freedom(DOF). However, soft hand exoskeletons still have defects. Their motions are not precise as linkage based hand exoskeletons, because their actuator, such as air muscle is made of soft materials. So we developed a new linkage which is not bulky and has redundant DOF. It is combined with air muscle in a specific way so that it acts as a guide when air muscle is actuated. Some experiments were conducted to evaluate the validity and usability of our hand exoskeleton.

• 제어로봇시스템학회논문지
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• 제15권9호
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• pp.887-893
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• 2009

In this paper, a mask-panel alignment robot system is considered for IT industry applications. Two kinds of solutions are suggested which are required in constructing a control system for the alignment robot with actuation redundancy. First, the kinematic solution for the 4PPR parallel positioning mechanism is formulated for an arbitrary initial posture, which relates the mask-panel misalignment in the task space and the desired actuator displacements in the joint space. Secondly, in order to increase the stiffness of the control motion and also to avoid the mechanical lock which may happen due to the redundant actuation, a new synchronous control method is proposed which has the merit of coordinating joint control motions while not losing individual joint control performance. In addition, the engineering process to develop a visual alignment robot system is described with the results of experimental setup and GUI software. Finally, the experimental results demonstrate the effectiveness of the proposed alignment system control methodology and how much beneficial it will be in real industrial applications.

• 항공우주시스템공학회지
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• 제16권3호
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• pp.84-92
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• 2022

전기-정유압식 작동기(EHA)는 독립적으로 유동력원을 운용함에 따라, 복잡한 유압 배관을 제거할 수 있어 누유 및 중량 최소화, 안전성 향상의 장점이 있어 최근 항공기용 비행제어 분야에서 사용되고 있다. 이러한 EHA를 탑재하는 항공기의 경우, 기존 중앙 유압시스템을 탑재한 항공기에 비해 제한된 냉각원에 따른 EHA의 열관리 이슈가 대두된다. 이러한 열관리 이슈의 해결을 위해서는, EHA의 열특성을 예측할 수 있는 열해석 모델이 필요하다. 본 연구에서는 유압펌프 및 전기모터로 구성되는 EHA 유압동력모듈의 내부 회전체를 고압 하에서 고속으로 회전이 가능하도록, 유압동력모듈 내부에 유체 순환 회로를 적용하였다. 적합한 열해석 모델을 구축하고, 유냉식 또는 비유냉식 유압동력모듈 적용에 따른 해석 결과의 비교 및 검토를 통해 EHA의 열특성 영향성을 확인하고자 하였다.