Designing an Actuated Metamorphic Mechanism based on Polyhedral Structures

Rik Koppelman
Presentation MSc presentation
Date 2018-10-18
Time 15:00
Location Ravelijn 2501

The robots which are currently used for pipe inspection, cannot continue their movement if there is an obstacle or change in diameter of the pipes. To solve this problem an investigation is done to check if it can be solved by metamorphic polyhedral robots. The goal of this thesis assignment is to design an actuated version of a polyhedral structure and to analyse its performance with regard to controlled expansion of the mechanism.

First, a literature review is done about different metamorphic polyhedral structures and a list of requirements is formulated accordingly.  The Hoberman sphere is chosen as the focus of this research.  Next a mathematical description is found for a planar Hoberman sphere and a model is created. A model is necessary for developing an interactive controller, which is suited for the problem set. A prototype of planar Hoberman sphere is designed based on the model. The main focus of this research is to verify the accuracy of the model. This is done by different tests that are performed and comparisons are made between experimental and theoretical results.

With the use of the Lagrangian method an Equation of Motion (EoM) is derived for the planar Hoberman sphere. The prototype does have a controlled expansion using a PID controller. This PID controller is used to verify the model. However, in the future the interactive controller should be implemented. In addition, the model can be further improved to better simulate the reality by incorporating the friction component among others.

Posted on Thursday, September 27, 2018