Dynamics Modeling of Structure-Varying Kinematic Chains for Free-Flying Robots

2008 IEEE International Conference on Robotics and Automation Pasadena, CA, USA, May 19-23, 200

Zero Reaction Maneuver: Flight Validation with ETS-VII Space Robot and Extension to Kinematically Redundant Arm

Proceedings of the 2001 IEEE International Conference on Robotics & Automation, Seoul, Korea, May 21-26, 200

Odontogenic stem cells

Epithelial cell rests of Malassez (ERM) are quiescent epithelial remnants of the Hertwig’s epithelial root sheath (HERS) that are involved in the formation of tooth roots. ERM cells are unique epithelial cells that remain in periodontal tissues throughout adult life. They have a functional role in the repair/regeneration of cement or enamel. Here, we isolated odontogenic epithelial cells from ERM in the periodontal ligament, and the cells were spontaneously immortalized. Immortalized odontogenic epithelial (iOdE) cells had the ability to form spheroids and expressed stem cell-related genes. Interestingly, iOdE cells underwent osteogenic differentiation, as demonstrated by the mineralization activity in vitro in mineralization-inducing media and formation of calcification foci in iOdE cells transplanted into immunocompromised mice. These findings suggest that a cell population with features similar to stem cells exists in ERM and that this cell population has a differentiation capacity for producing calcifications in a particular microenvironment. In summary, iOdE cells will provide a convenient cell source for tissue engineering and experimental models to investigate tooth growth, differentiation, and tumorigenesis

Adaptive Control for a Torque Controlled Free-Floating Space Robot with Kinematic and Dynamic Model Uncertainty

Abstract-This paper proposes an adaptive controller for a fully free-floating space robot with kinematic and dynamic model uncertainty. In adaptive control design for the space robot, because of high dynamical coupling between an actively operated arm and a passively moving end-point, two inherent difficulties exist, such as non-linear parameterization of the dynamic equation and both kinematic and dynamic parameter uncertainties in the coordinate mapping from Cartesian space to joint space. The proposed method in this study overcomes the above two issues by paying attention to the coupling dynamics. The proposed adaptive controller does not involve any measurement of acceleration; but it is still possible for the system to be linearly parameterized in terms of uncertain parameters and a suitable input torque can be generated in the presence of model uncertainty. A numerical simulation was carried out to confirm the validity of the proposed adaptive control