미모사 경촉 반응을 모사한 인공근육의 해석 · 실험 · 설계

김주희(Juhui Gim),명지영(Jiyoung Myung),전지나(Jina Jeon),성재경(Jaekyoung Sung),고민정(Minjung Go),김희경(Huikyeong Kim),임현지(Hyunji Lim),안창선(Changsun Ahn) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

This paper presents design of an artificial muscle inspired from leaf movements of Mimosa pudica, a sensitive plant. Mimosa pudica’s leaflets quickly contract by the osmosis pressure in the pulvinus when the leaflets are stimulated. The osmosis pressure of Mimosa pudica is based on Potassium ions and the contraction of leaflets happens in few seconds thanks to their high flux membranes. We analyze fast osmosis reactions of Mimosa pudica and design an exemplary artificial muscle based on the analysis results to mimic the fast osmosis responses. For the analysis of the fast osmosis responses, the osmosis phenomenon is mathematically modeled, analyzed and verified through several experiments. The analysis showed that the fast osmosis responses require large diffusion coefficient with high-flux membrane or small volume to surface ratio of osmosis system. Such high-flux membranes, as the Mimosa pudica’s membrane, are practically unavailable, we design micro-scaled system to achieve a small volume to surface ratio. The contraction and relaxation of the artificial muscle are realized by changes of local concentration of Potassium ions that can be aggregated by the controllable electric field. As a result, the designed artificial muscle shows speedy reactions as Mimosa pudica does.

공압형 종이 접기 방식 인공 근육의 특성 분석 및 형상 적응을 위한 소프트 그리퍼로의 응용

강봉수 대한기계학회 2020 大韓機械學會論文集A Vol.44 No.3

This paper presents the mathematical modeling of a pneumatic origami-inspired artificial muscle and experimental results identifying its dynamic characteristics. Since manufacturing the pneumatic origami-inspired artificial muscle involves a simple process with high power-to-weight efficiency it has great potential in various fields. Therefore, a soft gripper using the proposed artificial muscle was developed to attach on a conventional robot. Various tests confirmed that the soft gripper could grasp objects stably by adjusting its own flexible structure regardless of the shape or orientation of objects to be picked up. 본 논문에서는 공압형 종이 접기 방식 인공 근육의 구동력을 예측하는 수학적 모델링을 제시하고 실험을 통해서 근육의 동특성과 모델의 예측 성능을 확인한다. 공압형 종이 접기 방식 인공 근육은 제조 공정이 간단하고 가볍고 에너지 효율이 높기 때문에 여러 분야에서 응용성을 가질 수 있다. 제안된 인공 근육의 제조 원리를 적용하여 로봇의 말단 효과 장치에 부착 가능한 소프트 그리퍼를 개발하였다. 다양한 실험을 통해서 개발된 소프트 그리퍼는 외부 센서의 도움없이 물체의 형상과 위치에 맞도록 자신의 유연한 재질을 수동적으로 변형하여 물체를 손상없이 안정적으로 파지하였다.

공압형 인공근육을 이용한 상극구동의 동적 특성

강봉수(Bong-Soo Kang),송승(Seung Song) 대한기계학회 2009 大韓機械學會論文集A Vol.33 No.10

This paper presents dynamic characteristics of pneumatic artificial muscles. Since the actuating performance of a pneumatic muscle is closely related to the input pressure of a pneumatic muscle, the air flow model on a valve orifice and an elastic bladder of the muscle is formulated to estimate precisely the pressure variance of pneumatic muscles during deflating and inflating process. Frequency response experiments are performed with an antagonistic system consisting of two pneumatic muscles and fast pneumatic control valves. Comparing with experimental results, the proposed model yielded good performance in estimating dynamic motions of the antagonistic system as well as the pressure variance of the pneumatic artificial muscles

인공근육에 적용되는 압전복합재료 작동기의 탄소섬유 배향각과 작동변위의 관계

김철웅(Cheol-Woong Kim),이성혁(Sung-Hyuk Lee),윤광준(Kwang-Joon Yoon) 한국정밀공학회 2005 한국정밀공학회 학술발표대회 논문집 Vol.2005 No.10월

The aim of this research is to evaluate the relationship between the total effective moment (M<SUP>E</SUP>) and Bernoulli-Euler bending moment (M) when the ply orientations of UD CFRP in Piezoelectric Zirconate Titanate Composite Actuator (PZTCA) are changed. The obtained results as follows. Firstly, as the performance test results by the CFRP ply orientation, the performance of [0] and [90] were stable. However, while the performance of [+45] was suddenly decreased after 5 hours. Secondly, the change of M<SUP>E</SUP> by the CFRP ply orientation was evaluated. As the CFRP ply orientation was increased from [0] to [+60], the M<SUP>E</SUP> were gradually decreased. However, they became a little bit increased from [+60] to [90]. Finally, after the change of M by the CFRP ply orientation was evaluated, it was found that M<SUP>E</SUP>=2.2M was valid for just [0] and that there was a relationship between M<SUP>E</SUP> and M according to the ply orientation.

인공추간판 적용 시 인접 운동 분절에서의 변화 분석

김영은(Y. E. Kim),윤상석(S. S. Yun) 한국정밀공학회 2005 한국정밀공학회 학술발표대회 논문집 Vol.2005 No.10월

Although several artificial disc designs have been developed for the treatment of discogenic low back pain and used clinically, biomechanical change with its implantation seldom studied. To evaluate the effect of artificial disc implantation on the biomechanics of lumbar spinal unit, nonlinear three-dimensional finite element model of L1-L5, S1 was developed and strain and stress of vertebral body and surrounding spinal ligaments were predicted. Intact osteoligamentous L1-L5, S1 model was created with 1-㎚ CT scan of a volunteer and known material property of each element were applied. This model also includes the effect of local muscles which was modeled with pre-strained spring elements. The intact model was validated with reported biomechanical data. Two models implanted with artificial discs, SB Charite or Prodisc, at L4/5 via anterior approach were also developed. The implanted model predictions were compared with that of intact model. Angular motion of vertebral body, force on spinal ligaments, facet joint contact force with 2~12 Nm flexion-extension moment.

공압 인공근육 구동장치의 선형화 모델 기반 궤적추적제어

장지성(J.S. Jang),유원상(W.S. Yoo) 한국동력기계공학회 2006 동력시스템공학회지 Vol.10 No.3

In this study, a position trajectory tracking control algorithm is proposed for a pneumatic artificial muscle driving apparatus composed of a actuator which imitates the muscle of human, a position sensor and a control valve. The controller applied to the driving apparatus is composed of a state feedback controller and disturbance observer. The feedback controller which feeds back position, velocity and acceleration is derived from the linear model of pneumatic artificial muscle driving apparatus. The disturbance observer is designed to improve trajectory tracking performance and to reduce the effect of model discrepancy. The effectiveness of the designed controller is proved by experiments and the experimental results show that the pneumatic artificial muscle driving apparatus with the proposed control algorithm tracks given position reference inputs accurately.

공압 인공근육 구동장치의 선형화모델 기반 궤적추적제어

장지성(J. S. Jang),지상원(S. W. Ji),강보식(B. S. Kang) 한국동력기계공학회 2005 한국동력기계공학회 학술대회 논문집 Vol.- No.-

In this study, a position control algorithm being applied to a pneumatic artificial muscle driving apparatus is proposed. The position control algorithm is composed of a feedback controller and a feedforward controller. The feedback controller which feeds back position, velocity and acceleration is derived from the linear model of pneumatic artificial muscle driving apparatus. The feedforward controller is designed to improve position trajectory tracking performance. The effectiveness of the designed controller is proved by experimental results.

공압형 인공근육을 이용한 상극 구동의 모델 추정 및 정밀 위치제어

강봉수(Bong-Soo Kang) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.5

본 연구에서는 공압형 인공근육으로 이루어진 회전관절의 동적 특성을 파악하기 위해서 두 개의 공압형 인공근육으로 이루어진 상극구동 시스템의 주파수 응답특성실험을 수행하였다. 인공근육의 작동범위에서 수행한 주파수 응답결과에 최적으로 근사할 수 있는 선형모델을 추정하고 이를 이용하여 회전관절의 움직임을 정밀하게 제어할 수 있는 모델에 기초한 제어법칙을 제시하였다. 사각파, 정현파 기준궤적에 대한 회전관절의 추종실험을 수행한 결과 선형 추정모델에 의한 보상효과와 피드벡 이득에 의한 추종오차 제거효과를 통해서 우수한 궤적 추정성능을 보였다. This paper presents a frequency-response test performed on an antagonistic actuation system consisting of two Mckibben pneumatic artificial muscles and a pneumatic circuit with pressure valves. Varying switching frequency to pressure valves from 0.1 Hz to 5 Hz, parameters of a linear model were estimated optimally to predict dynamic characteristics of the antagonistic actuation. A model-base control scheme with estimated parameters was built for the precise trajectory tracking of the antagonistic structure and realized on a reconfigurable embedded control system, CompactRIO. Experimental results showed that the proposed model-based control scheme gave good performance in trajectory tracking comparing with a PD control scheme when square wave and sinusoidal wave were given as references to follow.

딥러닝을 이용한 공압형 인공근육의 모델링 및 정밀제어에 대한 연구

이재승(Jae Seung Lee),김경모(Kyeong Mo Kim),강봉수(Bong Soo Kang) 대한기계학회 2021 大韓機械學會論文集A Vol.45 No.1

본 연구에서는 특성데이타를 가지고 딥러닝 기법을 이용하여 수학적 모델링이 어려운 공압형 인공근육의 동특성을 정확하게 모델링하였다. 제안된 신경망 모델은 학습이 완료된 가중치로 구동력을 빠른 시간에 계산하므로 모델에 기초한 피드포오드 제어기법에 활용이 가능하다. 그리고 신경망 모델을 실시간 제어에 적용하기 위해서 딥러닝이 수행되는 파이썬 프로그램을 서버로 기계시스템의 운동제어를 수행하는 랩뷰 프로그램을 클라이언트로 사용하는 분산된 제어기법을 제시하였다. 실제 공압형 인공근육으로 구동되는 동적시스템에 제안된 제어기법을 적용하여 우수한 궤적추종성능을 보였다. In this study, the dynamic behaviors of pneumatic artificial muscles, which cannot be easily mathematically modeled were accurately predicted using a deep learning technique with characteristic data. As the proposed neural network model calculates the driving force with the weights of the neural network trained off-line, it can be applied to a model-based feedforward control scheme in real-time. In addition, a distributed control architecture, where a Python program for deep learning had the role of a server and a LabVIEW program for motion control had the role of a client, was implemented to a dynamic system driven by a single pneumatic artificial muscle. Experimental results showed that the proposed server/client control architecture with the deep learning model could yield a higher performance in trajectory following.

공압형 인공근육을 이용한 상극구동의 동적 특성

강봉수(Bong-Soo Kang),송승(Seung Song) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5