Ph.D. Dissertation Defense by Haihong Zhu
Monday, June 20, 2005

(Dr. Wayne Book, Chair)

"Practical Structural Design and Control for Digital Clay"


Digital Clay is proposed as a novel human-machine communication interface using on tangible and haptic shapes. At the current technique stage, the pin-rod planar array approach is most promising and hence under investigation. Per this approach, Digital Clay looks like a “stereo monitor” whose pixels can move perpendicularly out of the screen and form a morphable working surface. Digital Clay is named because of the similarity to the clay. The user can touch, reshape the working surface of Digital Clay and inspect the surface a three-dimensional form; beyond ordinary clay, Digital Clay also provides parameters that will represent the shape to the computer for further analysis, editing, etc. The user computer can also command Digital Clay to form the desired surface shape. The potential applications of Digital Clay cover a wide range from computer aided engineering design, scientific research to medical diagnoses, 3D dynamic mapping and entertainment.

Then the concept and features of the proposed Digital Clay will be provided. After that, two main research stages and a 5x5 cell array prototype will be presented on the structural design and control of Digital Clay. The first stage of research focuses on the design and control of a single cell system of Digital Clay. Control issue, (e.g. signal processing, control state switch, and user gesture interpretation) on a single cell system constructed using conventional and off the shelf components are discussed first in details followed by experimental results. Then practical structural designs of micro miniature actuators and sensors are presented. The second stage of research deals with the cell array system of Digital Clay. Practical structural design and control methods will be discussed which aims at a 100x 100 (even 1000X 1000) cell array. Conceptual design and detailed implementation methods and technologies will be presented including Hydraulic Matrix Drive, large scale signal multiplexing and control based on the Hydraulic Matrix Drive featured multi-cell system. Finally, a 5 x 5 cell array testing prototype is constructed using the discussed design solutions. Hardware and control methods will be introduced and results will be shown.