Title page for ETD etd-08292008-063803
|Type of Document
||Ganino, Anthony Joseph
||Mechanical design of the Carpal wrist :a parallel-actuated, singularity-free robotic wrist
||Master of Science
|Reinholtz, Charles F.
|Robertshaw, Harry H.
|Salerno, Robert J.
|Date of Defense
Parallel robotic manipulators offer potential advantages over the more conventional serial
manipulators, such as a higher stiffness-to-weight ratio and more precise control.
However, their use as base manipulators and robotic wrists has been limited by their more
complicated kinematic solutions and, especially in the case of a wrist, severely limited
work spaces. Due to these shortcomings, robotic wrists in existence today are typically
built as serial kinematic chains that provide large, spherical work spaces but suffer from
lower stiffness, higher mass, and interior singularities. A parallel mechanism consisting
of three sets of serial-chains can be manufactured that possesses characteristics suitable
for use as a robotic wrist. As a result of its parallel structure, it provides for the high
strength and low weight of a parallel manipulator, while its novel configuration gives it a
workspace comparable to that of serial-type wrists. Additionally, the configuration of the
links allows the wrist to have a large open center through which cables or hoses
supplying the end-effector can be routed. This tunnel-like similarity to a human wrist's
carpal tunnel leads to its name, the Carpal wrist. This thesis discusses the characteristics
of the Carpal wrist and develops simple tools for its design. A simple force analysis is
developed and used to solve for the required input forces and resulting internal forces in
the wrist. Computer algorithms are developed that facilitate the solution of both the
kinematic and force equations resulting from the analysis of the wrist. Using these tools,
a prototype wrist is designed such that it may serve as a proof-of-concept model capable
of denl0nstrating both the kinematic function and load-carrying capability of this device.
|| Approximate Download Time
| 28.8 Modem
|| 56K Modem
|| ISDN (64 Kb)
|| ISDN (128 Kb)
|| Higher-speed Access
next to an author's name indicates that all
files or directories associated with their ETD
are accessible from the Virginia Tech campus network only.
If you have questions or technical
problems, please Contact DLA.