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WABIAN series that realized various walking
motions by using moment compensation. Korea
Advanced Institute of Science and Technology
(KAIST) also developed a 41-DOF humanoid
robot— KHR-2 (Omer et. al, 2005).
The above mentioned human-size biped robots
achieved dynamic walking. If these humanoid robots
can use rehabilitation or welfare instruments as
shown in Figure 1(b), they will be able to help in
testing such instruments quantitatively. The main
advantages of the human simulator can be
considered to be as follows: (1) The measurement of
the angle and the torque required at each joint can be
measured easily and quantitatively as compared to
the corresponding values in the case of a human
measurement. (2) Experiments using such robots can
help identify leg defects of a human from an
engineering point of view. (3) A robot can replace
humans as experimental subjects in various
dangerous situations: experiments involving the
possibility of falling, tests with incomplete prototype
instruments, simulations of paralytic walks with
temporarily locked joints.
Such experiments require a humanoid robot that
enables it to closely replicate a human. However,
humans have more redundant DOFs than
conventional biped humanoid robots; this feature
enables them to achieve various motions. Therefore,
a DOF configuration that is necessary to reproduce
such motions is one of the very important issues in
the development of a humanoid robot (Ogura et. al,
2006).
The Waseda Bipedal Humanoid Robot
WABIAN-2R has been developed to simulate
human motion. WABIAN-2R performed human-like
walking motions (Figure 2). Moreover, WABIAN-
2R achieved to perform walking motion using walk-
assist machine. However, the walk-assist machine
was freely rolling without activating its wheels
motors. In this case, the robot faced the minimum
resistance or disturbance case by the walk-assist
machine. On the other hand, activating the walk-
assist machine may create a large disturbance for
robot due to separate control for each of them.
Conducting this experiment may be highly risky.
As we develop humanoid robot to coexist in the
human environment, we need to conduct many
experiments such as robot walking on uneven
surface, climbing the stairs, and robot interact with
other machine and instruments. Doing any new type
of experiment using WABIAN-2 might be risky.
Figure 2: WABIAN-2R.
Therefore, we need find a safer method for initial
experimental testing. Using a dynamic simulation is
useful method due to some reasons such as: (1) It is
safer in terms of cost and risk. (2) It is easy to
monitor and view motion outputs. (3) It can show
the variation cased by any external disturbances. In
this paper, a dynamic simulator is described, which
is able to easily simulate any new type of walking.
Using the dynamic simulator, we can monitor the
motion performance and output all needed data that
is useful for further development. This paper is
aimed to simulate the walking motions of
WABIAN-2 using walk-assist machine.
2 DYNAMIC SIMULATION
Dynamic simulation could be used to simulate the
dynamic motion of a mechanical structured model. It
can analyze the effects of the surrounding
environment on the mechanisms and objects. In
robotics researches, simulation software are used for
robotic simulation. There are many software used
for robotics simulation in different applications.
Most of those software are for industrial robot
applications. However, there are some software used
for mobile robot simulation. For examples,
RoboWorks, SD/FAST, OpenHRP, and Yobotics are
used for mobile and legged robot simulation.
Webots is high and advanced simulation software
used in Robotics simulation. It is use for prototyping
ICINCO 2008 - International Conference on Informatics in Control, Automation and Robotics
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