가변 모멘트 암 기반의 소형 가변 강성 액추에이터 모듈

유홍선(Hong-Seon Yu),송재복(Jae-Bok Song) 대한기계학회 2013 大韓機械學會論文集A Vol.37 No.10

최근에 들어 로봇과 환경 사이의 상호작용이 다양하게 발생하는 작업에서 가변 강성 액추에이터의 연구가 활발하다. 기존의 다양한 가변 강성 액추에이터가 개발되었지만 크기와 중량 때문에 응용분야를 찾기가 어렵다. 따라서 다양한 분야에 쉽게 이용되기 위해 소형의 가변 강성 액추에이터(miniVSA)를 개발하였다. miniVSA는 모멘트 암 기반의 강성제어 장치와 두 개의 모터로 구성된 구동 장치로 구성된다. 강성제어 장치는 두 캠의 상대 운동을 제어하여 위치와 강성을 동시에 제어할 수 있다. 이를 실험을 통하여 강성 변화를 검증하였다. In recent years, variable stiffness actuation has attracted much attention because interaction between a robot and the environment is increasingly required for various robot tasks. Several variable stiffness actuators (VSAs) have been developed; however, they find limited applications owing to their size and weight. For realizing their widespread use, we developed a compact and lightweight mini-VSA. The mini-VSA consists of a control module based on an adjustable moment arm mechanism and a drive module with two motors. By controlling the relative motion of cams in the control module, the position and stiffness can be simultaneously controlled. Experimental results are presented to show its ability to change stiffness.

제어방식에 따른 다축 고정도 위치동기제어계의 성능비교

최봉석(B. S. Choi),정석권(S. K. Jeong),유삼상(S. S. You) 한국동력기계공학회 2004 한국동력기계공학회 학술대회 논문집 Vol.- No.-

This paper describes a comparison of control performance in multi-axes precise position synchronous system according to control methods. The control method is mainly divided as two manners such as master-slave and cooperative control in the multi-axes system. Also, each axis is divided as two types, current control type and acceleration control type, according to a kind of inner loop. Maximum error comparison as a coupling method is used to minimize position synchronous errors. The control performances of position synchronous control are investigated through numerical simulations under various control methods.

손상제어 구조를 위한 보 단부 설치형 댐퍼의 내력 및 강성평가

오상훈(Oh, Sang-Hoon),박해용(Park, Hae-Yong) 대한건축학회 2017 大韓建築學會論文集 : 構造系 Vol.33 No.2

The target in this study is damage-controlled system with damper installed at beam end. This system should have different design method about strength and stiffness of the damper compared with the general parallel connection damping system(such as braces type or stud type etc.), because both arrangement formats of damper are different. However, the design method of damper installed at beam end is not yet available. And relevant internal and external researches have been limited mostly to the structural performance verification by the shape of the connection detail. Therefore, in this paper, it consider the available design value of damper installed at beam end through the analytical study. The purpose of this study is to present the design range of the damper/beam yield strength ratio and stiffness ratio, presented rationale is based on the performance efficiency of the damper and results of the damage analysis of the beam member. It conducted time history analysis to target the structure made up of the presented design range, to verify the validity of the proposed design value.

CAE를 활용한 차체 외판의 강성예측 및 평가

이원모(Won-mo Lee) 한국자동차공학회 2018 한국자동차공학회 학술대회 및 전시회 Vol.2018 No.11

Stiffness on outer panel is increasingly important as the automotive industry continues to reduce vehicle weight and improve vehicle performance. Various type of steels are being used to outer panels for improving dent resistance and stiffness. Outer panels are required for proper dent performance, along with good formability. How can we evaluate automotive body panel to have stiffness or dent resistance. In order to evaluate automotive body panels to resist denting, we need to know about factors that have an effect on the stiffness. In stamping process, there are some influencing factors that are divided into two (categories)groups. One is controllable factor, another is uncontrollable (factor). There are no ways to deal with uncontrollable factor efficiently. So, by using the factors that is under control, we could achieve the purpose to meet our specifications easily and efficiently. The study shows how to handle controllable factors concerned with stiffness on outer panel and provides difference between simulation model and actual model.

손상제어구조를 위한 보 단부 설치형 댐퍼의 최적 구조특성치에 관한 연구

오상훈(Oh, Sang-Hoon),박해용(Park, Hae-Yong) 대한건축학회 2016 대한건축학회 학술발표대회 논문집 Vol.36 No.2

The target in this study is damage-controlled system installed at beam end. Compared with the general braces type or stud-type damping system, this system, because the arrangement format of the damper are different, difference in the design method according to the strength and stiffness of the damper is it is determined that there is. However, still the relevant national and international research has been limited mostly to the structural performance verification by the shape of the connection detail. Therefore, in this paper, we consider the optimum design value of the damper installed at beam end through the analytical method. The purpose of the study is to present the optimal design range of the damper/Beam yield strength ratio and stiffness ratio, presented rationale is based on the performance efficiency of the damper and results of the damage analysis of the beam member. It conducted time history analysis to target the structure made up of the optimal design range, to verify the validity of the proposed design value.

강성제어 구조물을 이용한 수평구동형 박막 PZT 엑츄에이터의 설계, 제작 및 특성평가

서영호(Y.H. Seo),최두선(D.S. Choi),이준형(J.H. Lee),이택민(T.M. Lee),제태진(T.J. Je),황경현(K.H. Whang) 한국정밀공학회 2004 한국정밀공학회 학술발표대회 논문집 Vol.2004 No.10월

We present a piezoelectric actuator using stiffness control and stroke amplification mechanism in order to make large lateral displacement. In this work, we suggest stiffness control approach that generates lateral displacement by increasing the vertical stiffness and reducing the lateral stiffness using additional structure. In addition, an additional structure of a serpentine spring amplifies the lateral displacement like leverage structure. The suggested lateral PZT actuator (bellows actuator) consists of serpentine spring and PZT/electrode layer which is located at the edge of the serpentine spring. The edge of the serpentine spring prevents the vertical motion of PZT layer, while the other edge of the serpentine spring makes stroke amplification like leverage structure. We have determined dimensions of the bellows actuator using ANSYS simulation. Length, width and thickness of PZT layer are 135㎛, 20㎛ and 0.4㎛, respectively. Dimensions of the silicon serpentine spring are thickness of 25㎛, length of 300㎛, and width of 5㎛. The bellows actuator has been fabricated by SOI wafer with 25㎛-top silicon and 1㎛-buried oxide layer. The bellows actuator shows the maximum 3.93±0.2㎛ lateral displacement at 16V with 1㎐ sinusoidal voltage input. In the frequency response test, the fabricated bellows actuator showed consistent displacement from 1㎐ to 1k㎐ at 10V. From experimental study, we found the bellows actuator using thin film PZT and silicon serpentine spring generated mainly laterally displacement not vertical displacement at 16V, and serpentine spring played role of stroke amplification.

변위민감도 해석기법을 이용한 아웃리거 구조시스템의 정량적인 횡변위 제어 평가

김호수(Kim Ho-Soo),이한주(Lee Han-Joo),남경연(Nam Kyung-Yun) 대한건축학회 2008 大韓建築學會論文集 : 構造系 Vol.24 No.9

This study presents an effective stiffness-based optimization technique to control quantitatively lateral drift and to evaluate the structural behavioral characteristics and efficiency for tall outrigger system subject to lateral loads. For this end, displacement sensitivity depending on behavioral characteristics of outrigger system is established and approximation concept that can efficiently solve large scale problems is introduced. Specifically, under the 'constant-shape' assumption, the resizing technique of member is developed. Six types of 60 story frameworks according to the location of outrigger and belt truss are presented to illustrate the features of the quantitative lateral drift control technique.

지능형 변환강성시스템 알고리즘 설계

이용훈(Lee, Yong-Hun),이상현(Lee, Sang-Hyun) 대한건축학회 2016 大韓建築學會論文集 : 構造系 Vol.32 No.12

Active Variable Stiffness(AVS) System, which has on-off elements whose connection state to the main structure can be modulated by control signal, is one of the methods for controlling dynamic responses induced by earthquake or wind loads. AVS system, however, an impulse is transmitted to the structure when the connection state of the on-off elements gets changed. In the previous research, a function composed of displacement and velocity was presented to solve this problem, but the frequent changes of the connection state were observed and it was difficult for the linkage of the on-off elements to be mechanically implemented since the locking signal was given even when the displacements of the main structure and the on-off elements were different. In this study, the effects of the sudden linkage and separation of the on-off element were investigated, and a control algorithm which lets on-off elements linked when the displacement is close to zero and separated when accumulated static energy of the on-off elements starts to decrease was proposed. Numerical analysis was carried out to verify the availability of the proposed algorithm and the results indicated that the control performance could be maintained as the level of the previous study and the number of the connection state change was greatly reduced. Furthermore, unnecessary response magnification did not occur and the mechanical implementation of the proposed algorithm is possible because the linkage of the on-off elements was conducted only when the displacement was close to zero.

고층가새철골조 구조물의 동적 횡변위제어를 위한 강성최적설계

김호수(Kim Ho-Soo),이한주(Lee Han-Joo),이성수(Lee Sung-Soo) 대한건축학회 2007 大韓建築學會論文集 : 構造系 Vol.23 No.10

This study presents stiffness-based optimal design to control quantitatively lateral drift of tall steel braced frames subject to seismic loads. The lateral drift constraints considering the approximation concept and the relationships of sectional properties to reduce the number of design variables are introduced. Also, resizing technique of H-shaped steel section is developed during repetitious process. And, for the reasonable dynamic lateral drift control, the derivatives of stiffness and mass matrices are first established and also the dynamic displacement sensitivities considering the response spectrum analysis are formulated. Several tall steel braced frame models are considered to illustrate the features of dynamic stiffness-based optimal design technique under seismic lateral loads.

Technologies to Realize High Stiffness Mechatronics Systems in Production Machines

이찬홍(Chan-Hong Lee),송창규(Chang Kyu Song),김병섭(Byung-Sub Kim),김창주(Chang-Ju Kim),허세곤(Segon Heo) Korean Society for Precision Engineering 2015 한국정밀공학회지 Vol.32 No.5

One of common challenges in designing modern production machines is realizing high speed motion without sacrificing accuracy. To address this challenge it is necessary to maximize the stiffness of the mechanical structure and the control system with consideration on the main disturbance input, cutting forces. This paper presents analysis technologies for realizing high stiffness in production machines. First, CAE analysis techniques to evaluate the dynamic stiffness of a machine structure and a new method to construct the physical machine model for servo controller simulations are demonstrated. Second, cutting forces generated in milling processes are analyzed to evaluate their effects on the mechatronics system. In the effort to investigate the interaction among the structure, controller, and process, a flexible multi-body dynamics simulation method is implemented on a magnetic bearing stage as an example. The presented technologies can provide better understandings on the mechatronics system and help realizing high stiffness production machines.