Biomedical Engineering Reference
In-Depth Information
Fig. 9.3
String walker
Each motor is equipped with a rotary encoder and the motor-pulley mechanisms
can measure position and orientation of the shoe. The strings pull the shoe in the
opposite direction of walking, so that the displacement of the step is cancelled.
The position of the walker is fixed in the real world by this computer-controlled
mechanism. The motor-pulley mechanisms are themselves mounted on a motor-
driven turntable that rotates according with the direction of the walker, thus enabling
omni-directional walking.
A major limitation of the String Walker concerns the difficulty in controlling the
tension in the strings. Durability of the strings is also a serious problem.
9.2.4 Evacuation Simulator Using the Virtual Perambulator
An “evacuation simulator” [
32
] based on the virtual perambulator was designed
in a collaboration between the author's lab and the Ship Research Laboratory of
the Ministry of transportation of Japan. The analysis of the evacuation of passengers
during maritime accidents is very important for ship safety. However, it is impossible
to carry out experiments with human subjects during an actual disaster. Consequently,
these researchers introduced virtual reality tools for simulation of disaster in order to
analyze evacuation of passengers. They built a virtual ship that models the generation
of smoke and the inclination of the vessel. Experiments of evacuation were carried out
for construction of mathematical model of passenger's behavior in disaster. Figure
9.4
shows the Virtual Perambulator integrated with the evacuation simulator.
