Topic: Motion Evaluation, Analysis and Generation 
Speaker: Dr. ChaoCHEN, 
Department of Mechanical and Aerospace Engineering, Monash University, Australia.
Inviter: Prof. WangHao
Time: 2013-08-05, 14:00 ~ 16:00
Venue: F307

Abstract:
In this talk, abriefly introduction will be given on theresearch activities in the Laboratory of Motion Generation and Analysis (LMGA) in the Department of Mechanical and Aerospace Engineering at Monash University, Australia.Then, three basic issues aboutthe evaluation, analysis and generation of motionwill be discussed in detail.

1）Evaluation of orientation workspace. The volume of an orientation workspace must be measured based on two invariant principles based on group theory and differential geometry. A method based on quaternions and Riemannian geometry is developed for the measurement of the volume correctly. The method is extended for an arbitrary orientation description by means of a mapping theorem proposed for the first time. An example of a serial spherical wrist shows that the volumes that are obtained by the proposed method are consistent with the two invariant principles.

2）Analysis of mobility. The mobility or degrees of freedom is a fundamental issue in mechanisms and robotics. Two different types of mobilities will be discussed. The first is the global or finite mobility, which have been studied intensively in the past half-century. A method of the pattern analysis based on constraints will be discussed. The second is the local mobility. The local mobilities with different orders were theoretically discovered recently. Weingarten map is used to explain the physical meaning of the second-order local mobility. The first spatial four-bar linkage with the second-order local mobility is disclosed, validating the theoretical analysis.

3）Generation of remote of center of motion (RCM). Robotic surgery requires mechanisms with a remote center of motion to ensure the safety of patient. In the application of robots in single-incision surgery, the size of surgical arm must be minimized to reduce the possibility of arm clashes during operation within a limited space. A novel linkage with RCM will be introduced. One feature of the linkage is that the size of the mechanism is independent on the distance of RCM from the base. This feature can significantly reduce the size of a surgical arm.
 
Introduction of speaker:
Dr. Chao Chen is the director of the Laboratory of Motion Generation and Analysis in the Department of Mechanical and Aerospace Engineering at Monash University since 2007. He received his Bachelor at Shanghai Jiao Tong University in 1996, and obtained his Master and PhD at McGill University in 2002 and 2006, respectively. Chen was a postdoctoral at the University of Toronto in 2007, and a visiting scientist in ESI, a company of robotics and automation in the same year. His rewards and research funds include ASME Quebec Scholarship, FQRNT Doctorate Scholarship, FQRNT Post-Doc Fellowship, and ARC Discovery Project. His current research interests are human-robot interaction, power transmission in hybrid electric vehicles, running dynamics of mobile robots, parallel manipulators, andmotionbase for flight simulators, haptic devices, and medical robots.