• Journal of Biosystems Engineering
• /
• 제33권3호
• /
• pp.186-195
• /
• 2008

In this paper, a prototype tele-operative system with a mobile base was developed in order to automate cultivation of house melon. A man-machine interactive hybrid decision-making system via tele-operative task interface was proposed to overcome limitations of computer image recognition. Identifying house melon including position data from the field image was critical to automate cultivation. And it was not simple especially when melon is covered partly by leaves and stems. The developed system was composed of 5 major modules: (a) main remote monitoring and task control module, (b) wireless remote image acquisition and data transmission module, (c) three-wheel mobile base mounted with a 4 dof articulated type robot manipulator (d) exchangeable modular type end tools, and (e) melon storage module. The system was operated through the graphic user interface using touch screen monitor and wireless data communication among operator, computer, and machine. Once task was selected from the task control and monitoring module, the analog signal of the color image of the field was captured and transmitted to the host computer using R.F. module by wireless. A sequence of algorithms to identify location and size of a melon was performed based on the local image processing. Laboratory experiment showed the developed prototype system showed the practical feasibility of automating various cultivating tasks of house melon.

• Physical Therapy Rehabilitation Science
• /
• 제8권2호
• /
• pp.93-98
• /
• 2019

Objective: The purpose of this study was to investigate the effect of robot arm reach training on upper extremity functional movement in chronic stroke survivors. Design: One group pretest-posttest design. Methods: Thirteen chronic stroke survivors participated in this study. Robot arm reach training was performed with a Whole Arm Manipulator (WAM) and a 120-inch projective display to provide visual and auditory feedback. During the robotic arm reach training, WAM provided gravity compensation and assist-as-needed (AAN) force according to the robot control mode. When a participant could not move the arm toward the target for more than 2 seconds, WAM provided AAN force to reach the desired targets. All patients participated in the training for 40 minutes per day, 3 times a week, for 4 weeks. Main outcome measures were the Fugl-Meyer Assessment (FMA), Action Research Arm Test (ARAT) and Box and Block Test (BBT) to assess upper extremity functional movement. Results: After 4 weeks, significant improvement was observed in upper extremity functional movement (FMA: 42.15 to 46.23, BBT: 12.23 to 14.00, p<0.05). In the subscore analysis of the FMA upper extremity motor function domains, significant improvement was observed in upper extremity and coordination/speed units (p<0.05). However, there were no significant differences in the ARAT. Conclusions: This study showed the positive effects of robot arm reach training on upper extremity functional movement in chronic stroke survivors. In particular, we confirmed that robot arm reach training could have a positive influence by leading to improvement of motor recovery of the proximal upper extremity.

• Journal of Advanced Marine Engineering and Technology
• /
• 제33권8호
• /
• pp.1203-1211
• /
• 2009

무인잠수정의 동역학은 추진체의 동력학에 의해 큰 영향을 받는다. 무인잠수정의 호버링 또는 저속 상태의 움직임을 제어하는 것은 자동 도킹 혹은 잠수정의 매니퓰레이터의 제어에 있어서 매우 중요하다. 모터기반의 추진체 동역학은 비선형적이며 불확실한 매개변수를 가지고 있다. 결국, 추진기와 동적 커플링을 이루는 무인잠수정의 운동역학도 매우 비선형적이며 불확실한 매개변수를 가지고 있기 때문에 강인제어기가 무인잠수정의 모션제어에 있어서 효과적이라고 할 수 있다. 따라서 본 논문에서는 전기 추진체에 의해 추진되는 무인잠수정의 저속 또는 호버링 상태를 제어하기 위한 강인제어 기법을 보인다. 또한, 비선형성과 불확실한 매개변수가 결합된 무인잠수정의 상태도 강인제어를 이용하여 동시에 제어한다. 강인제어 방법 중에서 슬라이딩 모드 제어기를 설계하여 추진체와 무인잠수정의 불확실한 변수와 비선형성들을 보상하며 원하는 위치를 유지하는 제어방법을 제안하였다. 모의실험을 통하여 제안한 슬라이딩 모드 제어기는 선형제어기인 PD제어기 보다 성능이 우수함을 확인할 수 있었다.