58
th
ILMENAU SCIENTIFIC COLLOQUIUM
Technische Universität Ilmenau, 08 – 12 September 2014
URN: urn:nbn:de:gbv:ilm1-2014iwk:3
©2014 - TU Ilmenau
DESIGN OF A PHASE – SHIFTING DOUBLE – WHEG – MODULE
FOR QUADRUPED ROBOTS
Max Fremerey
1
, Sebastian Köhring
1
, Omar Nassar
1
, Manuel Schöne
1
,
Karl Weinmeister
1
, Felix Becker
2
, Goran orđević
3
and Hartmut Witte
1
1
Technische Universität Ilmenau, Chair of Biomechatronics, 98693 Ilmenau, Germany
{maximilian-otto.fremerey,sebastian.koehring,omar.nassar,
manuel.schoene,karl.weinmeister,hartmut.witte}@tu-ilmenau.de
2
Technische Universität Ilmenau, Chair of Technical Mechanics,
98693 Ilmenau, Germany
felix.becker@tu-ilmenau.de
3
University of Ni, Control Engineering Department and Robotic Lab,
18000 Nis, Serbia
goran.s.djordjevic@elfak.ni.ac.rs
ABSTRACT
Following mechatronic design methodology this paper introduces a phase-shifting double-
wheg-module which forms an alternative approach for wheg-driven robots. During
construction focus was placed on a smooth locomotion of the wheg-mechanism over flat
terrain (low alternation of the CoM in vertical y-direction) as well as the ability to overcome
obstacles. Simulations using the multi-body simulation tool ADAMS View
®
were executed in
order to prove estimations done. Using the results of simulation and calculation a first
prototype was designed, manufactured and tested by experiment.
Index Terms – whegs, mechatronic design, simulation
1. INTRODUCTION AND MOTIVATION
Stable and robust walking over unstructured and unknown terrain is still a challenging task for
a robot or an autonomously acting machine. Considering the issue the robot or the
autonomously acting machine has additionally to deal with different kinds of obstacles, the
implementation of (bio-inspired) legs for locomotion purposes displays a possible approach.
TEKKEN II [6], CHEETAH-CUB robot [14] or BIGDOG [11] are formidable examples for
successful bio-inspired walking machines. Thereby it is quite interesting that (while
neglecting other design criteria) robustness can be achieved either by complicated software
algorithms (BIGDOG), embodiment (well-designed, even compliant mechanics like in
CHEETAH-CUB), or a balanced mixture of both.
However, legged robots exhibits some disadvantages due to their kind of locomotion. One
major issue is the high number of actuators used. BIGDOG requires 16 [11] and even CHEETAH-
CUB featuring a bio-inspired pantograph-like mechanism (c.f. Witte & Fischer [4]) has two
actuators per leg and therewith eight in sum [14]. In addition, the proper synchronization of
the legs still needs effort in control.
Thus the authors want to highlight another possible, yet established approach for robust robot
locomotion: the concept of whegs (like shown in section 2), and their improvement. Fig.1
illustrates the principle of a wheg (wheel + leg) and its derivation from a wheel. Thereby a
URN (Paper): urn:nbn:de:gbv:ilm1-2014iwk-037:5