We are developing a novel autonomous mobile robotic system to emulate full 6 degree of freedom relative motion at high fidelity. An omni-directional base provides large 3-DOF motion with moderate precision, while a micron-class Stewart platform on top provides high precision, limited 6-DOF motion. This multi-vehicle robotic system is designed to accommodate multiple untethered vehicles simultan...

In this paper a modification of the time domain passivity controller is presented to improve its performance and transparency in case of multi degrees of freedom (dof) haptic interaction. In multi-dof application the concept needs to be extended by additional conditions to distribute the adaptive damping appropriately among the degrees of freedom. This can be solved by using the geometrical inf...

In this paper, three fundamental techniques to improve laminated passive elements are proposed for wearable haptic displays. First, a new shape of sheet surfaces in laminated passive elements is introduced. Sliding motion between laminated sheets causes unexpected bad effect to static stiffness. An effective triangle shape for sheet surfaces, which prevents from sliding, has been analyzed. This...

For the present paper, we developed an output feedback chattering position regulator for n-degreesof-freedom (DOF) robot manipulators with elastic and frictional joints. A stability analysis of the closed-loop dynamic system in question was developed within the framework of Lyapunov functions. Performance issues related to the chattering regulator are illustrated in numerical simulations and ex...

A recursive dynamic modeling of a three-DOF parallel robot, namely, threeRevolute-Prismatic-Spherical (3-RPS) parallel manipulator is reported in this work. Euler parameters are utilized to define the 3-DOF orientation of its moving platform, because the coordinates are free of singularity. For the dynamic modeling, the concept of the Decoupled Natural Orthogonal complement (DeNOC) matrices is ...

Design and Control of a 6-Degree-of-Freedom Levitated Positioner with High Precision. (May 2005) Tiejun Hu, B.S., Tsinghua University, China; M.S., Tsinghua University, China Chair of Advisory Committee: Dr. Won-jong Kim This dissertation presents a high-precision positioner with a novel superimposed concentrated-field permanent-magnet matrix. This extended-range multi-axis positioner can gener...

A Virtual Test Facility (VTF) for studying the three-dimensional dynamic response of solid materials subject to strong shock and detonation waves has been constructed as part of the research program of the Center for Simulating the Dynamic Response of Materials at the California Institute of Technology. The compressible fluid flow is simulated with a Cartesian finite volume method and treating ...