Abstract This paper describes mechanism and control of leg-wheel hybrid mobile robot. Legged locomotion has high adaptability for rough terrain, and wheeled locomotion posses speed and eficiency. A new locomotion mechanism that combines legs and wheels is proposed,and a prototype mobile robot that adopts the mechanism 10796
is introduced. The robot has four legs, and a wheel is
attached at the end of each leg. The front leg has three
joints and a passive wheel. The rear leg has one joint
and an active wheel. In order to make the best of the
mechanism, three locomotion modes, wheel mode, hybrid
mode, and step mode, are developed. In the wheel mode,
four wheels are used on flat terrain. On the rough
terrain, the hybrid mode is select, and two legs and two
active wheels are used for locomotion. To climb or
descend a large step, the step mode is used.
1. Introduction
Recently, works in manufacturing industry have been
automated. In the case of outdoor works, mechanization
such as construction machines has been done only on
relatively flat terrain. Japan is a mountainous country,
and seventy percent of the land is mountain area. Most
of works in the mountain sites depends on human labors.
For the future, the works in such area will become
important from the point of view of the prevention of
natural calamities or the environmental problems,. To
automate such works, development of the locomotion
system that can move in mountainous environment is
essential. The mountain environment includes steps,
inclined terrain, and easily deformed and collapsed
terrain.
Many mobile robots for outdoor environment are
equipped with wheels or crawlers. However, they
cannot move on discontinuous terrain like steps.
Although legged robots have great adaptability for
complicated environment, they have some difficulties
also. Generally, legged robots require large number of
actuators and complicated mechanism. Moreover, their
walking speed is slow even on flat terrain. Considering
these facts, authors propose a new locomotion
mechanism that combines legs and wheels.
Up to the present, several leg-wheel hybrid type
mobile robots have been developed. Hitachi, Ltd.
developed a five-legged robot, whose leg has two joints
and an active wheel at its tip [l]. It has fifteen degrees
of freedom. A robot that has four legs and six wheels
was developed by Mitsubishi Heavy Industries, Ltd. [2].
The robot body was equipped with two active wheel and
four legs that has two joints and an active wheel at their
end. It has fourteen actuators. Kobe Steel, Ltd.
constructed a six-leg-wheel type robot in the Japanese
national project named Advanced Robot Technology [3].
This robot has six two-degrees of freedom legs, and each
leg has a two-degrees of freedom (steerage and traction)
wheel. Totally, it has twenty-four degrees of freedom. 轮足复合式移动机器人英文文献和中文翻译:http://www.751com.cn/fanyi/lunwen_9943.html