Report Title: Assistive Knee Exoskeleton and Precision Machinery Using Smart Materials
Reporter: Wei-Hsin Liao, Ph.D.
Time: 10:00AM, Apr. 3rd
Address: Room 204, No.7 teaching building, Yuquan campus, Zhejiang University
Assistive Knee Exoskeleton and Precision Machinery Using Smart Materials
Wei-Hsin Liao, Ph.D.
Director, Smart Materials and Structures Laboratory
Professor, Department of Mechanical and Automation Engineering
The Chinese University of Hong Kong
Shatin, N.T., Hong Kong, China
http://www.mae.cuhk.edu.hk/~whliao/
Abstract
Exoskeletons that can enhance people’s performance or assist disabled people have been investigated in recent years. However, most exoskeletons use DC motors as actuators and batteries as power sources. A DC motor consumes a lot of power and limits the working time of the exoskeleton; it could also cause discomfort and danger to people. Magnetorheological (MR) fluid is a smart fluid that can change its rheological behavior under applied magnetic field. Rotary devices using MR fluids have the benefits of high torque, good controllability, and low power requirement, while having better safety. We have designed a novel multifunctional actuator. With MR fluids, the actuator possesses multiple functions as motor, clutch, and brake while meeting the requirement of normal human motion as well. On the other hand, positioning precision is crucial to today's increasingly high-speed, high-capacity, high data density, and miniaturized hard disk drives (HDDs) and optical disk drives (ODDs). The demand for higher bandwidth servo systems that can quickly and precisely position the read/write head on a high track density becomes more pressing. The idea of applying dual-stage actuators to track servo systems has been studied. The piezoelectrically actuated devices have been developed as micro actuators for fine and fast positioning, while the voice coil motor functions as a large but coarse seeking. We proposed a dual-stage servo system using active-passive hybrid piezoelectric actuators. The proposed actuators have higher precision and shock resistance, due to the incorporation of passive damping in the design. In this talk, related research projects and key results will also be presented.
Biography
Prof. Wei-Hsin Liao received his Ph.D. in Mechanical Engineering in May 1997 from The Pennsylvania State University, University Park, USA. Since August 1997, Dr. Liao has been with The Chinese University of Hong Kong (CUHK), where he is now a Professor and Director of MSc Programme in Biomedical Engineering. He was the Program Chair for the International Symposium on Smart Structures and Microsystems in 2000, as well as the 2005 IEEE International Conference on Information Acquisition. He was the Conference Chair for the 20th International Conference on Adaptive Structures and Technologies (ICAST 2009). Dr. Liao currently serves as an Associate Editor for Journal of Intelligent Material Systems and Structures, as well as Smart Materials and Structures. His research interests include smart structures, vibration control, energy harvesting, mechatronics, precision machinery, and medical devices. His research has led to publications of over 140 technical papers in international journals and conference proceedings, one China patent, four US patents, and 6 other China/US patent applications. He is a recipient of the T A Stewart-Dyer/F H Trevithick Prize awarded by the Institution of Mechanical Engineers (2006), the Best Paper Award in Structures from the American Society of Mechanical Engineers (2008), and three Best Paper Awards in the IEEE conferences (2009, 2010, 2011). He also received theResearch Excellence Award (2010-11) of CUHK. As the Chair of IEEE Hong Kong Joint Chapter of Robotics, Automation and Control Systems during 2011-13, Dr. Liao received 2012 Chapter of the Year Award from the IEEE Robotics and Automation Society. Dr. Liao is a Fellow of the American Society of Mechanical Engineers (ASME, USA) and Institute of Physics (IOP, UK).