Posted on November 28 2017
We are excited to announce our newest rover, the Explora!
The Explora is an eight-wheeled remotely operated robot. The main role of this new product is to act as a mobile Wi-Fi node for the Dropbear. However, we believe it can act as an exploration vehicle on its own as it is essentially a mini Dropbear.The evolution of the Explora:
How hard can it be build a robot for a mine? You throw a couple of wheels or tracks onto a chassis, a couple of motors and an RC system and off you go!
Building something that can survive in an underground mining environment has
been a challenge to say the least.
Yep, you can go out and buy a 50 tonne autonomous or remote control loader or truck for a few million, but you can’t fit them in small spaces and you have to spend a great deal of money making sure it doesn’t run into people. So, there you have the first principle of underground inspection robots;
Rule One: Robots have to be small enough not to run over people.
The next challenge one faces is that small vehicles struggle with uneven terrain.
Our first robot was an off-the- shelf tracked vehicle that we fitted with a camera
and battery powered light that was gaffa taped to the base.
The problem with this design was a lack of ground clearance; you need ground
clearance as the second you go over a decent sized rock, the robot is “beached”
and the tracks do nothing. So our next attempt at tracks had more ground
The other problem with tracks is that in a mining environment they quickly clog
up with mud and small rocks. Unless you have a robot that is the size of a skid
steer loader, the tracks just stall once they clog up.
Rule Two: Maximum Ground Clearance.
So, we went back to big wheels, our next attempt was a small-wheeled robot
with plenty of ground clearance.
However, the tyres were rigid with no suspension, which meant that you lost a
lot of traction as soon as one wheel climbed any kind of obstacle. So you need
large spongy wheels or independent suspension so that you maximise the
number of wheels in contact with the ground. This is particularly the case as the
robot is trying to climb any significant obstacle; the wheels that are still in
contact with the ground provide the force to drive the front wheels over the
obstacle. This also requires that each wheel is independently driven so that when
one may stall, the others are still driving.
Rule Three: Maximum Traction!
The Explora is the result of everything we have learned from years of playing in
the underground sandpit. It has ridiculous amounts of traction with eight
independently suspended and powered wheels, as much ground clearance as we
can manage and the right geometry for skid steering.