Functional model pendulum turner

Project staff:	Sven Hohlfeld (student) Dipl.-Ing. Erik Steindecker (former staff member) Dr.-Ing. Wolfgang Steger
Partner:	TU Bergakademie Freiberg

The Bergakademie Freiberg has a collection of historical models for studying metallurgical and mining processes. A VR (virtual reality) simulation can be used to illustrate the function while protecting the historical model. This is accessible in digital form to a wider circle of interests at the same time.

For the model of a Karlik pendulum wheel with gyroscopic rocker, the existing physical model was transferred into a VR simulation. The following steps led from the model to the VR scene:

• Model recording and creation of a CAD model according to the physical prototype
• Optimisation of the model structure
• Selection of material representation, textures and lighting
• Implementation of the movement sequences
• Development of an appropriate control of the scene
• Enriching the scene with environment and sound

The work provided information about the expenses involved in converting a museum technical object into a digital form. Additional profit results from the possible scaling of the digital model to the dimensions of the real prototype. In a stereoscopic projection system like the CAVE, it is possible to experience the Pendelrätter in a way that goes far beyond viewing the scaled-down historical model. The viewer stands on the working platform of the rocker and triggers the emptying of the transport hopper himself. A relatively large amount of effort was invested in the careful texturing and lighting in order to make the material look as close as possible to the original (machining marks, wood and brick structures, screen surface, surrounding leather belt, etc.). The equations of motion were not determined analytically in this model. After recording selected path points, suitable compensation functions were determined that represent the actual pendulum and swing movements sufficiently well.