Sinister Resistance

Further to my previous update (Science & Engineering Day 2013), last Thursday presented the Astronautics Research Groups’ second event in in National Science and Engineering Week (NSEW) 2013, with the arrival of the Big Bang Solent science fair to the Garden Court at the University of Southampton. This post documents the major goings-on of the day, what we can do to improve for next time, and also to share a few photos from our activities and exhibits. So, without further ado, onwards!

Our stand and presenting team (Ben [spaceman_ben] and I, plus a few other stragglers) were once again out in full force at a brisk 0845 on Thursday morning  to put our stand and kit together; smugly earlier than most of the other stands exhibiting that day, leaving us plenty of time to soak up the free coffee and biscuits and to gently rib the other delegations who’d scheduled considerably less time to sort out their kit. Our setup was largely the same as for the previous Saturday, albeit with a few modifications to our LEGO Mindstorms demonstration, resulting in the substitution of Aquabot with a new, space-debris themed rover, Debrisbot:

Saturday’s headaches were largely derived from the fact that Aquabot‘s mission of collecting coloured balls into its jaws provided unexpected sources of unpredictability: for example, our demonstrations of placing balls in Aquabot‘s path meant that visiting children were inclined to try picking up the balls and rolling them (sometimes with great force) into the rover’s maw. This was fine, except when it happened just as Aquabot approached the edge of the ‘green’ area, such that a ball would get stuck under the NXT colour sensor when the rover reached the  green card and hence would not detect that it was imminently going to crash into the makeshift (albeit perhaps with one less ‘f’) cardboard wall we constructed to make sure balls did not roll everywhere. In addition, we hadn’t accounted for the fact that children would ‘lean’ on the cardboard wall and bend it completely out of shape, meaning that its ability to contain both Aquabot and the coloured balls to the table area was severely impaired.

Given these points, it’s not only a miracle that we did not have balls rolling loose all over Building 85 but that we actually managed to get to the end of the day without any of our balls inadvertently going home in children’s pockets (or worse, mouths) for a permanent holiday away from the University. So, to remedy these, we decided to get rid of both the balls and the cardboard wall – by eliminating the other functionalities of the NXT colour sensor aside from the ‘am I near the edge of the table?’ detection using the green card, we could reinstate our previously-abandoned ‘is there object in the way?’ detection function using the NXT ultrasonic sensor to make the rover recognise any solid objects that we placed in its path (which we couldn’t use before because it kept detecting the balls themselves and tried to avoid them rather than trying to collect them). So with that, Aquabot was gracefully retired and replaced with Debrisbot; a rover programmed to sense nearby objects (which we assumed were nearby space debris fragments) and perform “collision-avoidance” manoeuvres to avoid impact. And in most senses, Debrisbot worked pretty well.

Not brilliantly well, though. There were still quite a lot of issues arising due to the NXT ultrasonic sensor’s narrow field-of-view meaning that there would be an object to the left- or right-side of the sensor that wouldn’t be detected; or other cases where there was too little energy being reflected back to the sensor (where it was sometimes absorbed by the object, or reflected in a different direction), and the the rover didn’t detect object properly and would drive into it anyway. The idea was for Debrisbot to be roving around, avoiding bits of junk as necessary, but sometimes it would just clatter into it anyway, or turn around and get objects stuck under the tracks; doing ungainly pirouettes and wheelies before falling over like a boss.

So, an executive decision was made to transform Debrisbot from a debris-avoiding rover into a debris-sweeping rover; charging around the ‘black’ area, pushing the ‘junk’ objects into the ‘green’ zone like a giant space snowplough. And with that, a significantly greater level of success was observed, as within minutes, all of the bits of ‘junk’ (made from Tic Tac boxes stuck together and wrapped in black duct tape) would be pushed to the edge, leaving the black region of ‘space’ safe for satellite operations. Debrisbot was essentially just driving around in straight lines until it encountered the edge of the ‘green’ (and hence wasn’t aiming for objects at all, just ploughing them if they happened to be in the way) so it would be even better if Debrisbot was able to ‘look around’ for bits of junk and then explicitly move towards them, but that’s a larger task for another time. For the moment, though, Debrisbot demonstrated pretty much what we wanted it to in a nicely simple way and leaves plenty of room for improvement. Not bad, little buddy.

The event itself was pretty enjoyable – essentially an event to get schoolchildren interested in doing science and engineering, and involved around 600 children from the nearby area visiting for the day to do some fun, science-based activities, talk to people in college/academia/industry [delete as applicable] who ‘do’ science and stuff for a living and to get an idea about future careers and stuff.

Our main drive for exhibiting was to demonstrate our research activities and show the youngsters that activities in ‘space’ are happening here in the UK, and to prod them towards taking up such work in their future education, if they want to. It was also interesting to find out how many young people are aware of the  space debris problem, and to ask them for ideas about how we could go about resolving it: while Debrisbot was hardly the most efficient (or successful) method of demonstrating how a space debris sweeper system might work, it did the job and (I hope) gave the visiting public a new perspective of the space debris problem and the ‘sort of thing’ that could be done to manage it.

Anyway, an enjoyable day: the Space Junker stuff went down pretty well as usual, with some visiting students managing some staggeringly high scores, and we certainly gave out of a lot of our ‘Space Systems Engineering’ worksheets which contain information on our research, details of how to access Space Junker online, and also a few puzzles and stuff. So, to round off the event and, indeed, this post, here are a few of my other photographs from the day: we’re not sure when we’ll be taking Aquabot/Debrisbot out on the road again, but I’m sure he won’t be in the garage for too long. Hooray!

[Zinar7]

EDIT – Our activities were recently published as a blog post from LEGO Education UK! You can find it here: http://legoeducationuk.wordpress.com/2013/03/27/space-research-with-a-little-help-from-lego-mindstorms/

As part of the Astronautics Research Group‘s outreach and public engagement, last Saturday marked our first adventure in this year’s National Science and Engineering Week (NSEW), with our annual involvement in the University of Southampton’s Science & Engineering Day on campus. Each year, we’ve managed to significantly increase our display stand and materials, and this year marked our biggest and best exhibit yet. Here follows a short summary of the day’s events, what we had on show and some photographs from the day.

Having set up most of our banners and posters the night before, Ben (spaceman_ben) and myself (zinar7) arrived at a deathly-quiet Building 85 at 0800 hours prompt to set up the rest of our kit and get everything up and running. Thankfully for my sanity (and probably the safety of the general public), the University had elected to open the cafe in Building 85 at 8:00 am, and we were able to procure caffeine-filled beverages and sugary goods straight away to fortify us for the rest of the day, which was due to begin at 10:30 am and run until 4:30 pm, followed by packing up all the kit and hauling back to our offices for storage. A long day, then, but all in the name of science and trying to encourage the youngsters of today to get excited about all things ‘Space’.

Our touch-screen PCs were unpacked and booted up, our digital photo frames secured to our 2 m x 2 m backdrop banner, and the rest of our display materials dotted around our allocated ‘zone’, leaving us the remaining time to sort out the major new addition to our exhibit: Aquabot, the water-collecting Mars rover made from LEGO Mindstorms NXT 2.0:

Aquabot was conceived, built and programmed in the ten or so days prior to the event, after Ben and I had gotten hold of a current-generation Mindstorms kit in order to evaluate its usefulness in outreach for the Astro Research Group and in undergraduate teaching/projects: we’re hoping to use multiple kits when the next-generation is released later this year, to allow students to develop simple group projects looking at spacecraft control and formation flying (among other things). Our main focus, at least for NSEW, was on making something cool and vaguely space-related to encourage youngsters towards the space industry, and getting them excited about engineering in general. The result, then, was a rover of our own design (and vaguely anthropomorphic qualities) constructed to ‘rove’ around a table (without falling off), collecting up balls and doing some basic colour-sorting; something like this:

Attached to the front of the rover, pointing downwards between the ‘jaws’ of Aquabot‘s maw, was the NXT colour sensor. To simulate the Mars environment, we used black card as a base, placed on a few large tables to make an area around 7 x 5 feet of black landscape. The colour sensor was programmed to catalogue the colour of the table surface and also of any balls that happen to roll into Aquabot‘s gape; and to ‘carry on as normal’ if sensing a black response. The rover was powered using two motors, and was run on caterpillar tracks to aid manoeuvrability and response. At the front of the vehicle, a funnel was placed to collect balls as the rover moved around the environment (although it kind of just ‘punted’ balls across the landscape rather than funneling them in, but oh well). The third motor from the kit was installed at the front of the rover, to which was attached an arm with the NXT colour sensor: when a blue ball rolled into the ‘jaws’ and was detected by the sensor, the arm retreated to allow the “water molecule” into a storage area beneath the rover; when a yellow or red ball was collected, the arm rapidly swung forwards to ‘kick’ the unwanted “martian rock” away. When it worked, it worked pretty well; although if multiple balls rolled in at the same time, it would still be doing the operation for the first ball when the second ball arrived, and so wouldn’t accept/reject the second. Still, such times were comparatively rare, and it was always satisfying when the rover detected an unwanted ball and punted it away with great force.

Around the edges of the black card, we made a border of green card to make a ‘buffer’ around the edge of the table, which Aquabot would detect and subsequently turn round and return to the black region. But, because sometimes Aquabot would decide to choose its own fate and plough on through the green area regardless (for example, when there was already a ball in the jaws, and the sensor couldn’t see the ‘green’), we put up a barrier (of more card) around the edge to stop the rover (also any stray balls) from leaping off the table and plummeting to the floor. We managed to get to the end of the day with Aquabot pretty intact (minus the sum of around 12 fresh batteries) and all of the balls we started with, so I call that a success.

All in all, I think our LEGO Mindstorms experiment were rather well: the publicity of the recent Mars Science Laboratory (Curiosity) mission has highlighted the current activities using autonomous rover in space, and many visitors were familiar with this mission and could draw comparisons with our simple reconstruction of a Mars rover. It was also encouraging that so many children (and parents) grasped the basic concepts of the system, and how even a simple robot could be programmed to carry out a range of functions without human interaction.

In terms of our regular activities, we had a lot of kids try out our Space Junker game on the large touch-screen PCs (developed by the Science Museum with our involvement), and plenty of parents and other adults reading our research posters and talking to us about our research into space debris and the problems that ‘space junk’ poses to space operations. Our other display materials also went down pretty well, which included our big stand, leaflets & pamphlets about the undergraduate programs in Space Systems Engineering, and these natty little cubes which I made to communicate some of our research into space debris and some of the problems:

Anyway, a fun day was (I think) had by all, and we seemed to get a pretty great response from the Science & Engineering Day hordes that came to campus despite the dreary weather. For our point of view, it was yet again an entertaining, rewarding and uplifting outreach event, and getting a whole load of exposure for our research activities. A hugely exhausting event that seems to expend so much energy and brain/musclepower, but immensely fun.

Nonetheless, we’ll be doing it all tomorrow for our second activity in NSEW, which is the Big Bang Solent science fair, happening on campus at the University of Southampton. We’ve mainly got the same set-up, but this time Aquabot will be replaced by the second iteration of our Mindstorms display, Debrisbot: instead of wandering the Mars landscape looking for blue balls, Debrisbot will be navigating “outer space” (albeit an ‘outer space’ that has been transplanted into two dimensions), trying to “collision-avoidance” manoeuvres with various objects (“space debris”) placed in orbit. Not quite sure how Debrisbot will perform as yet, but hopefully it should be another entertaining and engaging day of science, engineering and being a big kid again.

Anyway, before I head off, here are some more photos from Saturday’s event; hopefully some of tomorrow will manifest in due course. Enjoy!

[Zinar7]