A mid(ish) week update

We’re working hard now to finialise our track deployment system. Unfortunately the Mobile Robots Pioneer 3-AT we’re using isn’t too accustomed to being rejigged inside, so we now have a large Pioneer jigsaw puzzle!

Pioneer Jigsaw Puzzle

This required some “delicate” modifications to achieve!

Gently does it...

Now we have individual components we can look at how to rearrange them inside the Pioneer chassis. We’ve done plenty of modeling using CAD to give us some confidence that our modifications *can* fit inside, however it is extremely difficult to tell without trying it on the actual rover, those cables really take up a lot of space! We’re looking at replacing our big, heavy lead acid batteries with much smaller Li-Poly ones, but other than that we need to rearrange all of the existing rover equipment to a way that allows us to fit the track pitch control motors and gearing, a slightly difficult feat due to the requirement for an axle to pass across the entire width of the rover at both the front and back.

We’ve also started range testing the 802.11-based wireless equipment we plan on using to control Selene once its out in the field. This has started with the nanorover we want to use as a comms relay/video link. With some new, high-gain antennae attached to my laptop and the Surveyor SRV1 we managed to boost the link strength a significant distance over its poorly performing standard configuration. It’s difficult to see in the picture below but the tiny rover made it all the way to the bus and was still going strong, giving us a live video link.

Long distance shot

Attaching a similar antenna to the Pioneer gave us a range of nearly 200m line of sight! Check out the pictures below.

A large chunk of our campus for reference

The SRV1 nanorovers 70m range

The 180m the Pioneer got before we ran out of field!

That’s it for now. Stay tuned for more updates soon!

CDR Done and Dusted

A little late coming but here’s the latest news from the Surrey camp!

Last week we attended the Critical Design Review at ESTEC in Noordwijk, Holland, with the other 7 competitors to present our work to date to ESA.  This was followed by discussion of our (and each of the other University entrants) designs.  Fortunately for us our design was met with mostly encouraging noises.  You can see an early CAD model of it below.

 

Selene Concept

We’re looking at taking the Pioneer 3-AT base and replacing the wheel with large, deployable tracks.  This will ensure the greatest amount of traction possible, while making tackling obstables far easier than our earlier designs.  We do this through a control mechanism allowing us to adjust the pitch of the tracks, this makes the rover retain its size constraints when stowed.  The video below shows the tracks deploying.

We’ve also been working hard to build a testing area for our rover designs.  We now have a (VERY) large sandpit giving us a 40° slope of sand to test our designs traction on.  Here’s a few photos of the pit being built.

Sandpit construction 1

Sandpit Construction 2

Sandpit construction 3

 Which has allowed us to try some preliminary track belt tests using one of our existing nanorovers using its standard tracks:

And the infamous video showing it is possible for a low, tracked rover to flip itself over trying to tackle a loose, sandy slope!

And finally our Qualisys motion capture equipment is up and running too, letting us accurately measure the traction properties of our rovers

We have also found out the challenge will be held on Mount Teide in Tenerife.  It’s a popular location for testing of this nature due to its similarities with the Martian and Lunar landscapes.  Here’s the view of our “crater” from Google Earth, it doesn’t look like much here but it definately is from the videos we were shown!

LRC Location

 Finally here’s the presentation we gave for info on all the work we’re doing.

We’re going to get back to work now to try and get our rover up and running for the Test Readiness Review in September!