Present and future, without the sophisticated and highly automated mechanisms, it is
impossible to fulfil the humanity's destiny in space. Thus to determine the success of
ambitious space missions of the future, the humans and space robots have to form an
excellent integrated team. Generally space robotic systems are designed, developed and
operated to assist or replace humans in accomplishing tasks that are dangerous, costly or
simply impossible for humans. The nature and operation of space systems are totally
different from on earth such as zero gravity environments, have made the modifications
of design and usage of robotics in space very important. This research comprises an
analytical and experimental study of space robot locomotion.
The main objective of this research work is to build a test-bed for space robot emulation
that operates in the "zero gravity" situation. To experimentally study the locomotion of
space robot in the laboratory, one has to create a "zero gravity" or "less gravity"
environment. In order to perform simulations of partial or micro gravity environments on
earth requires some method of compensation for the earth's gravitational field. To achieve this, gravity-less 2 Degrees-Of-Freedom robot with an unique instrumental
arrangement was considered to compensate the gravity force.
The space robot kinematics and dynamics formulations are studied, especially the
Denavit-Hartenberg CD-H) parameters and Newton-Euler formulation. The feedbacks of
the robot's arms are detected by encoders at the servomotors and transducers around the
robot and sent to the computer through PC interface card. The space robot dynamic
algorithms were tested in simulation and as well as in practical. The data especially the
torque values, the joint positions and angular velocities of the robot's arm in the "zero
gravity" environment as well as with gravitational effect were taken from the
experimental and simulation. The simulation comprises the combination of mechanical
simulation and virtual prototyping software, Mechanical Desktop and MSC Working
Model. The graphs were plotted from data by using Excel. The Mathematical software
package, Mathematica is used to derive the equations of motion. Finally all the trend
graphs were plotted using Excel. The results were compared and analyzed with derived
equations to prove that the "zero gravity" condition is achieved. Moreover this
instrumental setup for emulation of space robot system can be used for various
algorithms study based on robotics, control and other areas
