23-09-2016, 10:24 AM
Generally the walking mechanisms are developed by imitating natures like insects movement. The
nature inspired the researchers and new innovative ideas come in mind but sometimes they are simple and
effective, sometimes cumbersome and critical. One of the first walking machines was developed in about 1870
by Russian Mathematician Chebyshev. This walking machine had four legs arranged into pairs. Legged machine
have been used for at least a hundred years and are superior to wheels. Legged locomotion should be
mechanically superior to wheeled or to tracked locomotion over a variety of soil conditions and certainly
superior for crossing obstacles. US army investigation reports that about half the earth surface is inaccessible to
wheeled tracked vehicles, whereas this terrain is mostly exploited by legged animals. Wheeled robots are the
simplest and cheapest also tracked robots are very good for moving, but not over almost all kinds of terrain.
There are different types of legged walking robots. They are roughly divided into groups according to the
number of legs they possess. Bipeds have two legs, quadrupeds four, hexapods six and octopods have eight legs.
Bipeds‟ robots are dynamically stable, but statically unstable, such robots are harder to balance, and dynamic
balance can only be achieved during walking. Hexapods are six legged robots, on the other hand, have
advantages of being statically stable. During walking they can move three legs at a time, thus leaving three other
legs always on the ground forming a triangle.