04-03-2013, 11:26 AM
AM24 Enhanced Mobility Robot
Enhanced Mobility.pdf (Size: 595.81 KB / Downloads: 78)
INTRODUCTION
In this day and age a greater emphasis has been placed on the safety and well-being
of soldiers. No longer are soldiers being put to unnecessary risks. Trainings and
exercises are carried out in controlled environments where by the risks or injury and
death are greatly minimized. This day and age is also one where weapons are getting
increasingly powerful and harder to detect. Examples of this include plastic antipersonnel
mines which cannot be detected using standard mine detecting equipment.
Hence with the advancement in technology, man has been starting to develop
machines to explore places that would be otherwise dangerous for him.
Presently, there are many robots on the market that do surveillance and monitoring
for soldiers. However, these robots tend to be heavy and bulky, making it difficult for
a single man to carry. Likewise, there are small-sized robots that exist, but due to
their small size; they are unable to overcome obstacles that a larger robot would have
no problem crossing. From these two points, we come to the main aim of this project
that is to design a small, light and relatively inexpensive robot that has mobility
superior to that of a typical similarly sized robot.
Performance in Incline Climbing
The Incline Climbing test was an additional test carried out to measure the EMR’s
climbing ability. An incline climbing ability was not part of the requirements of the
EMR. The EMR’s incline climbing performance was tested by setting up a wooden
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ramp. Rubber matting was place over the ramp the increase the traction of the EMR
as the test was to test if the EMR had enough torque at the wheels to allow it to climb
the slope. Figure 9 shows the process and results of the test conducted at a 30°, 40°
and 45°. The 45° slope was the steepest inclined tested as the EMR did not have
enough traction with the rubber matting at steeper inclines. As shown from Figure 9,
the EMR manages to climb up the 45° slope easily. The EMR took 5seconds to cover
a distance of 1m on the ramp; however, this was not a true gauge of the EMR’s
climbing ability as full throttle was not utilized for fear of losing traction and hence
control on the slope and possibly damaging the EMR.
Performance in Gap Crossing
The EMR manages to cross the 24cm gap requirement. However, it is still possible
for the EMR to fall into the gap 24cm wide. This can happen if the operator of the
EMR is not careful. If the EMR approaches the gap at an angle other than completely
perpendicular to it, it might be possible for it to fall in. Also if the EMR operator does
not fully extend the swing arms and lock them in place, the same thing could happen.
Therefore the EMR’s performance in gap crossing performance can be said to be
partially dependent on the skill of the EMR operator.
Performance in Obstacle Clearing
The EMR manages to meet the requirement of overcoming an obstacle of 10cm in
height. The EMR manages to clear the height obstacle rather easily most of the time;
however, there were some problems during some of the trial runs. During a few of the
trial runs, the EMR was left stuck on the horizontal bar. The part where the EMR was
stuck on was the length on its chassis where there was no track system. Even though
the EMR was perched on the horizontal bar, the EMR was still able to progress over
the bar by swinging its swing arms.
CONCLUSION
1) The EMR has performed well on both the gap crossing and vertical obstacle
crossing tests. As it has performed well in these two tests well, it means that
the EMR has satisfied the performance criteria that were presented at the
initial point of the project. However it falls slightly short of the projected
maximum speed that it should move at.
2) The EMR is not only able to accomplish the performance objectives but also
remain within the size constraint criteria.
3) There were some problems that surfaced during testing such as the EMR
getting stuck on the horizontal bar during the vertical test and also the
possibility that the EMR operator forgets to lock the swing arms in place.
Another problem that could arise is that the EMR has a low ground clearance.
4) The cost of the EMR can be further reduced if items were purchased in bulk
and certain components replaced with other more practical ones.