Ph.D. Thesis Defense by Chris M. Shumway
Friday, August 16, 2002

(Dr. Kok-Meng Lee , advisor)

"Dynamic Modeling and Analysis of the Body Inversion"


Body rotation under free fall along a desired trajectory can be found in many applications such as sports, entertainment, and manufacturing. In the meat processing industry, live objects are inverted before processing. An appropriate designed body path could lower the forces at the joints during inversion and thus minimizing potential injury. The objective is to develop dynamic models and computer algorithms to simulate the body rotation under the influences of gravity, initial momentum, and external forces. It is expected that in this thesis, the object being considered is modeled as a two-dimensional multi-limb serial manipulator. The equations of body rotational motion are derived by the Lagrangian method, which is subject to constraints imposed by the track on which the body is transported and the motion limit of the limbs. The dynamic models are validated by comparing the simulations against results obtained experimentally using a modeled bird and a live bird going through an inversion process on an existing system. The validated models are then used as a means to identify key parameters that could significantly influence joint forces and improve body dynamics. These parameters include initial orientation of the rotating body and the track profile. This thesis will have immediate applications in the meat industry. The outcome of this thesis will provide a basis for analyzing body rotational dynamics in other applications such as gymnastics and roller coasters.