We had spent a whole year upgrading everything.  I designed a new ball kicking system that was more durable, more maintenance free, and more powerful than the year before.  The other mechanical systems were more robust as well.  The electrical system also had a huge upgrade.  Burning and smoking electrical boards were a thing of the past!  We have never had a design this robust – ever!

What is RoboCup?

For those who don’t know what RoboCup is, RoboCup is an international robotics competition aimed to further robotics research.  Their long-term goal is to have robots beat the World Cup Soccer team winners by 2050. There are various leagues within RoboCup, such as in robotic soccer (where we participate), home care, rescue, simulation, etc.  Our team, the UBC Thunderbots, compete in the small-size soccer league, which is probably has the fastest game play of all the different leagues.  The robots are generally cylinders with a diameter of about 18 cm and a height of 15 cm.  They can move at around 4 m/s and kick a golf ball at 8 m/s.

One of the other leagues, the Standard Platform League competes with standardized robots for all teams and the key difference between each is the software that is written for the robots.

Another league, the mid-size league in RoboCup Soccer competes with robots that are about a 1/3 of the size of a person. The game isn’t as quick as the small-size league game and they play with a real soccer ball instead of a golf ball. During the competition, it gathered quite the crowd too.

Preparing for the Games

Most teams arrived at the venue when it opened to get to work right away. Everybody wanted their robots in tip-top shape. Our team did the same. Even though our robots were ready mechanically and electrically, the key game changer was seeing which team had better artificial intelligence for their robots. Whenever got time to test on the field, we took advantage of it to make sure our AI was working well too.

Round Robin

In the round robin stage, each team gets four games against other teams in their bracket. Each bracket is made up of five teams and the skill level is spread out based on the rankings of the previous year.

We lost our first two games against a team called KIKS from the Toyota National College of Technology in Japan, and a team called STOx’s from the Universidad Santo Tomás in Colombia. In both of those games, we were simply outplayed because the other team had better software than we did. At the end of the game against the Japanese team, I spoke a bit of my horrible Japanese to them and they were super surprised and impressed that I knew a bit of Japanese!

Because our robots were finished not long before the competition began, the software team did not get a chance to test the code that was written, and so we found out the problems during the competition. Our robots were never able to drive up to a ball and take possession of it. The robots somehow always missed the ball. When the robot had the ball, it didn’t know what to do with it. It sat there holding onto the ball doing nothing. This was so frustrating for our team and even more so for the software team who wished they had more time to test.

We won our next two games against two lower tier teams. One is called RoboFEI, from the Centro Universitário da FEI in Brazil, and a team called RFC Cambridge from Harvard and MIT. It’s nice to be able to say that we beat a team from these two ivy league schools. Looks good when we look for sponsors too!

Lucky Loser Round

Because we had a 2-2 record during the group stage, we played a fifth game, the so-called Lucky Loser Round, to see if we could qualify for the quarter finals. Our match up was against a team called ODENS from the Osaka Electro-Communication University in Japan.  The game was so close that there was a dispute about the rules and whether what our team did was legitimate. Because our robots were not able to move up to a ball and shoot it at the net during the shootout, the referee introduced a workaround that the other team disputed.

Our referee’s native tongue was Portuguese, we spoke English, and the other team spoke Japanese. I didn’t know enough Japanese to translate. Eventually, members from other teams like the Thai and Chinese team came to help with the dispute. During the discussion that took about an hour, I heard people speak English, Japanese, Portuguese, Thai, Japanese, and Mandarin all at the same time. It seemed like nobody had the full picture of what was happening and how to resolve it.

The dispute was resolved when both teams agreed to a specific workaround that made it possible for our robots to do shootouts.  The game ended with a shootout and we lost on the very last shot of the shootout unfortunately. We almost made it to 8th place.  Still, achieving 9th place out of 22 teams was the best that the team has ever done before.

The Competition Ends

Skuba, from Kasetsart University in Thailand, had won the competition for four years in a row since 2009, but this year they had a surprising finish that was not even the top 4.  The second place team, ZJUNlict from Zhejiang University in China had beat them early in the quarterfinals.  ZJUNlict’s strongest opponent this year was CMDragons, from Carnegie Mellon University in USA.  In the final round, they were tied for the entire game and the game went to shootouts where CMDragons lost by one goal.  ZJUNlict had made first place in the RoboCup 2013 in the Small Size League.

As the competition came to a close, we said goodbye to the people on other teams that we met and as a parting gift from the German team ER-Force, they gave us a German flag with the names of all their team members signed onto it, with the message, “for our amazing friends, the Thunderbots, from team ER-Force”.

I realized now that the competition is over, I probably wouldn’t be going to competitions in the future because I’ve graduated from university. It made me feel a little bit sad that I couldn’t compete anymore, but at least I can still help out the team wherever they need it.

Link to photo album here

On the day I landed, Tobias picked me up from a train station near his house and I dropped off my stuff at his house.  Afterward, I went on my own to visit the Deutsches Museum.  He mentioned that the next day, we would be meeting up with two of his other friends that he met while on exchange at UBC and by sheer coincidence, they all happened to be in Munich at the same time.

A Very Stereotypical Bavarian Breakfast

In the morning, we rode bicycles to the English Garden to meet up with two of his UBC exchange friends. One of them was also from Munich and the other came all the way from Australia.

For breakfast, we had Bavarian white sausage (Weisswurst, or Weißwurst) with sweet mustard, giant pretzel (or Brezel), and of course, beer. There is a German phrase “Kein Bier vor vier”, which means “no beer before four”, but that does not apply on weekends. As good as that breakfast was, I saw a guy roasting an entire pig and that looked really good.

The English Garden

We biked around the English Garden enjoying the scenery for a little bit. While I’ve been there before (so I didn’t take many pictures), it was nice and relaxing to ride around with a bike in the scorching 38°C weather.

We passed by an area, known as the Eisbach (or ice brook), which is an area in the English Garden where people surf on standing waves. The difference between standing waves and the regular waves that people surf on is that standing waves pretty much stay in one spot and surfers try to surf on for as long as possible.

Friedensengel

Friedensengel can be translated as “Angle of Peace” and it is a reminder of the years of peace after the Franco-Prussian War. The German victory in the war united the German people and formed the German Empire.

Munich’s Birthday

It just so happened that when we were in Munich, the people were celebrating the city’s birthday, so there were quite a lot of people in the streets. People were dressed up in really traditional clothes and just dancing in the street!

Marienplatz

This is where the city hall is located. It’s probably one of Munich’s most recognizable buildings.

St. Peter’s Church Church Tower

Germany doesn’t really have a lot of skycrapers, so the tallest observation points that tourists can find are typically in church towers. It usually costs a few euros to go up, and there are no elevators since the architecture is so old. Going up is a pain too as the only way up is usually a very very long spiral staircase with a width that only fits one person going up and one person going down. But at the top, there is a really clear view of the city.

Lunch at the Hofbräuhaus

Every single time I’ve been to Munich, I’ve eaten at probably the most touristy restaurant in Munich. This time was no different. This makes it the third time I’ve been to this place. And of course, I order a pork knuckle with a liter of beer.

After a very filling lunch, we went back to the English Garden to just relax for a little bit before going home. For dinner, I had dinner with Tobia’s family. I met his parents and his brother and sister. His whole family was super nice. They totally did not have the typical German stereotypes that German parents were super strict. They joked around with their kids so much and even went as far as to making Nazi jokes, which I thought was completely taboo. In their family, it wasn’t.

During my stay, I got to practice my German with them and I was surprised that I could even say as much as I did, even if I talked slow. It definitely increased my confidence and ability with the language. All the time I spent learning German was paying off!

Link to photo album here

As I sat on the plane, my mind began to wander. I had this weird fear that something might go wrong like I would get mugged or something or maybe there was some fundamental mistake in my trip planning.  I was reminded of the time my wallet was stolen in Brussels and I certainly didn’t want anything like that to happen again.  And then I thought about how much fun I had when I lived in Stuttgart.  I have very fond memories of my experience in Germany.  I then felt a slight rush of emotion and almost reliving some of my experiences in my head.  Then I figured I just had to be confident with my trip preparations and let myself have fun on this trip.  After all, not many people get an opportunity like this.

Flying to Mexico City

When we got to Dallas Airport, we had a stopover of few hours, so we decided to have some Texan steak – or at least as Texan as we tried to get without leaving the airport.  We ended up at TGI Fridays.  It was the first steak that I’ve had in a long time, and I definitely could use another one.  The steak even came with “Jack Daniel’s Sauce”, which made it that much better.

After eating, we met up with two others on the team who had flown from San Jose and Toronto.  After a four hour flight to Dallas, and other few hours of stopover there, we had to fly for another two and a half hours to get to Mexico City.

As my friend said, “it’s like China happened”.  The Benito Juárez International Airport was probably the most disorganized airport I’ve ever seen.  It’s as if every single flight landed at the same time.  The lineup to grow through customs took at least forty-five minutes.  During this whole time, everyone was tired and wanted get their sleep.  A lot of the people on the team hadn’t slept the night before (rather than sleep 2 or 3 hours to wake up early for the flight right?).  While in this lineup, we saw a couple of other RoboCup teams landing as well (Skuba, MRL, among others).  After finally getting through customs and a security check, we got a ride to our hostel via transportation that we organized with the hostel prior to our departure.

Hostel Mundo Joven Catedral

The hostel we stayed had very nice staff that really cared about making its guests feel safe there.  It’s a common feeling among travelers to think that Mexico City is definitely not one of the safer places to travel to.  To combat that, the hostel had its own security guards, security cameras, and they even called legitimate taxi’s for its guests.  They even told us which direction to walk when leaving the hostel to avoid going to the shadier parts of town.  Furthermore, it was situated in the historic center of Mexico City, within walking distance of the Metropolitan Cathedral of the Assumption of Mary of Mexico City and the Plaza de la Constitución.  From some of the rooms at the hostel, there was a nice view of the cathedral.

Work Day

We spent the next day working on the robots to make sure none of the mechanical parts had been affected during the flight from Vancouver.  We had packed all the robots in a regular suitcase with packing foam all around it to protect it.  Looking over the mechanical parts, everything was in order.  The main things we had to fix were tightening screws, adjusting the wiring etc.  The software team had very little to do because they’ve written all the code they could, and just needed robots to test with.  The electrical team on the other hand, toiled tirelessly to troubleshoot all the boards and make sure they were all functioning properly.

RoboCup Begins!

We arrived at the competition venue, the World Trade Center at 8 AM to find a slew of other teams patiently waiting to register.  After probably an hour long wait, we all finally moved in and set up our work places.  When we looked at the field the robots would be playing on, we noticed that the organizers hadn’t yet set up the cameras yet (required for the robots to “see” where they’re going).  This meant that no teams could test.  Teams that were ready could only wait until the organizers got those set up.  Because of this delay, the games had to be delayed as well.  This gave us more time to get the robots ready.  For the next little while, we were the first team to arrive and the last team to leave everyday.  The electrical team needed all the time they could get to finish everything.

Because we had already finished most our maintenance work the day before, there wasn’t a whole lot we could do.  The electrical team had to continue working on their stuff to get as many robots ready as possible.  For the next day and a half, we let the electrical team do their work and we’d help them along the way by replacing parts that were broken (encoders and such).  Otherwise, there wasn’t much we could help with.

Food for the next Week

When we got hungry during the competition, we did a little bit of exploration to find food.  Eventually, all the teams wound up at the same shopping mall for food.  There was a supermarket downstairs to buy water and a food court upstairs with a variety of foods.  We went to this mall pretty much everyday for as long as we were at the World Trade Center.  One day we’d try Mexican food, other days we’d try plain-old hamburgers and other days we’d try even Chinese food (at least the white person’s interpretation of it).  It wasn’t really healthy for us, but we figured it was only for a week.

For dinner, most teams ended up ordering pizza from the nearby Domino’s.  We ate it so much that everybody got sick of having pizza.  Sometimes, we’d have dinner with other teams at our hostel restaurant so we could get to know them a little bit better.  After all, the competition is more about mutual learning and robotics advancement rather than about winning.

Let the Games Begin

Because our team wasn’t that ready to begin with, we had to forfeit our first game against the Immortals from Iran.  By the time we got three robots up and running, we played against the RoboJackets from Georgia Tech.  They only fielded five robots out of the total six.  For most of the game, both teams played pretty evenly, despite their two-robot advantage.  All was going well until one of the opponent’s robots chipped the ball that hit the top of one of our robots, bounced off and rolled into the goal.  In that particular situation, the referee had called an “indirect free kick”, meaning the shot, even if it went in the net, would not count.  But unfortunately, that rule was not applicable because it hit off of another robot.  It was an unlucky goal for us, and we definitely could not score a goal to tie up the game.  We ended up losing one-nil.  For the next few days, we kept complaining about that goal.

In our third game, we played against RoboFEI from Brazil.  There were so many good scoring chances in this game from both our teams that made this game so intense.  Even though we were only watching machines play, everybody cheered them on.  We had four robots on the field this game and they all worked like a charm.  The mechanical system, electrical system, and the artificial intelligence worked so well together.  It was a great feeling for everyone on our team – to see our design work.  After almost a year of hard work, this was it.  We saw our robots move, intercept balls, shoot on the goal, etc.  A lot of the robot shortcomings from the North American Open were also dealt with, such as the problem of the break beam sensors not working, and the robot not moving accurately on the field.  When we scored, we cheered so loud that every single person in the room could hear us (there were probably about 1000 people in that room).  We all got an immense feeling of satisfaction in seeing our working robots score their first goal.  A few minutes later, the other team scored a goal.  It didn’t matter to us, we were still high in the clouds in terms of our mood.  The game ended 1-1.  Despite the tie game, everyone on the team was so happy in seeing our robots work, it didn’t matter what the result was.

This was a great morale boost for the team because for our forth and last game, we played against BRocks from Turkey.  This time, we had our full fleet of robots.  We played our first six on six game.  Yet again, we saw our robots work.  Nothing broke down during the game and everything just worked.  It was quite rare for us to just put our robots on the field and have nothing go wrong.  At one point, our robot shot the ball into the opposing robot and a piece fell off of it.  We knew our design worked when stuff like this happens.  This game was less intense for us than our previous game, but we did end up winning.  That put our record at 1 win, 1 tie, and 2 losses – a total of 4 points.  Unfortunately, this wasn’t enough for us to advance to the next round of the competition and as a result we finished 13th out of 20 teams in the league.  Not so bad for having zero working robots when we got to Mexico.

After the official games, we played a couple friendly games with other teams.  The first game we played was against the Mannheim Tigers.  The game was going well, until we found problems where some of the screws on the robot weren’t tightened sufficiently.  As a result, things well off the robot when we played.  It was quite embarrassing to see.  At least it was only  something minor like putting in a screw, and not something major like a design problem.  In our second friendly game, this time against ER-Force from Erlangen, we found some electrical parts frying randomly on the board, which wasn’t good either.  Out of six working robots, we now had three – still a net gain I guess.

After we were done playing, we watched the other teams play for first place.  From watching their games, it was clear that they played on a way higher level than we did.  Everything that their robots did were way better than ours.  Shooting was faster, chipping went further, robots moved faster, kicks were more accurate, etc.  Everything about their robots was just better.  There is definitely a lot we could learn from these teams.  The final winner of this year’s competition ended up being Skuba from Thailand, who beat ZJUNLict from China.  Both teams analyzed each others strategies for days, but only one team could come out on top.  And now for the fourth year in a row, Skuba remains the undefeated winner of the competition.

Other Leagues in RoboCup

During our idle time, we walked around the other rooms to see how the other teams were working.  RoboCup has many different competitions under its name, while our Small Size League competition is only one small part of it.  Leagues range from soccer robots, rescue, simulation, to even home care robotics.  In the home care robotics league, the competition involved a robotic navigating through a mock house to perform certain chores such as picking up objects to hand to people, speaking and hearing instructions, etc.  It was an admittedly difficult task to do for these robots, but many teams were quite successful at it.

Accidents Happen

Just like in the North American Open, there was yet again another accident involving batteries.  Except this time, nobody noticed and the whole battery lit up in flames.  Somebody just yelled “fire, fire!” and started trying to pat it down with something.  Knowing that I was too far away to do anything, I just took out my camera and snapped a picture of the whole thing.  Eventually, someone just poured lots of water over it to put our the fire.  In retrospect, that might not have been a good idea since water in an electrical fire is not really a good thing.  Nobody got hurt though, which is good.  Afterward, the organizers didn’t let us charge batteries nearby our work space anymore.

Some Design Shortcomings

Knowing that our ball kicker would be able to withstand impacts of the ball, what we had forgotten to analyze was how well the kicker would hold up if it hit a object fixed to the ground.  We found out the hard way at the competition after a few games when we discovered that our robot kicker head was bent out of shape.  We also had a lot of turf buildup inside the robot that was enough to slow down the wheel during the game.  This turf had to be cleaned out after every match.

For the kicking mechanism, the robot uses a solenoid/plunger mechanism.  Activating the coil would cause the plunger inside the core to move quickly to hit the ball.  A rubber band secured to the end of it would allow the plunger to return to its initial position.  The problem with this setup was that the rubber band would easily break and had to be replaced after every game.  When we took out the rubber band, we could always see cut marks along it.  In another instance, a chipper solenoid on a robot almost popped out.  It’s not really clear why this happened at all, but it could have been a screw that was not very tight to begin with.

RoboCup Closing

To close the competition, there was a soccer game where humans played against the middle size league robots.  It was pretty funny to see the robots struggle to take the ball away from people who could handle the ball way better.  At the same time, the humans were really scared of the robots since if a human ever got hit by the kicker head from the robot, it would break bones.  The robot goalie however, proved quite competent in blocking shots – better than the human goal from what I saw.  Or maybe the human goalie wasn’t trying very hard.  I’m not sure who won the game since I didn’t watch the whole thing, but it was still really interesting to see.

Afterward, all the teams packed up their things and waited for the closing banquet.  At the closing banquet, they served a standard meal for everyone.  It was a really good chance for teams to celebrate their achievements and finally relax a little bit after the competition.  Everyone deserved a rest after all of that.

First Real Tour of Mexico – Teotihuacan

After the competitions ended, most teams stayed an extra day or two to see the sights in Mexico City.  The organizers of the Small Size League were nice enough to organize a tour for everyone the day after the competition ended.  Most of the SSL teams went with us to the Aztec pyramids in Teotihuacan.  The tour first showed us how their predecessors used different plants and minerals to make tools such as knives and sewing thread.  That part was interesting at first, but I think what a lot of us really wanted to see were the pyramids.  Afterward, the tour guide led us to the gift shop.  For some reason, most of the people were so interested there, it took about an hour for everyone to finish so that we could move on with the tour.  After the gift shop, we finally made it to the pyramids.

After walking up and down the pyramids, we had lunch and went back to Mexico City to see the Basilica of Our Lady of Guadalupe.  This was one of the most visited Catholic shrines in the world.  But because I had already visited so many churchs and cathedrals from my tour around Europe, this part of the tour was less interesting for me.

Historic City Center

The team would fly back to Vancouver on the day after visiting the pyramids.  But before leaving, we made sure to visit the Metropolitan Cathedral of the Assumption of Mary of Mexico City and the Plaza de la Constitución.  In the plaza, hung a giant flag of Mexico.  This is where the city center used to be, at least during the 19th century.

Going Home

After 10 days in Mexico, we all longed to go home.  It had been a long week – full of stress, adrenaline pumping excitement and overall a good experience.  But after all that, we were ready to go.  We flew out in the afternoon from Mexico City.  Apparently, at around the same time that we were at the airport in Mexico City, three cops had been shot to death.  While we were there though, we didn’t hear anything of it.  We safely arrived in Dallas for a brief stopover and arrived back in Vancouver at about 8:30 PM, just in time to go home, wash up and go to bed.

More photos here

Beginning of the Competition

On the first day of the competition, there was a work day for all the teams to use to get their robots ready again after a long flight to Canada.  As the current mechanical team lead for the Thunderbots, I too had to get our own robots ready to play.  The mechanical systems had already been completed some weeks ago, but unfortunately, even now, the electrical board testing and firmware coding still had not been completed yet and some parts that we needed were still not in.  For the next day and a half, the team was scrambling to get everything finished in preparation for the first game on Sunday.  Because, the only critical tasks remaining were the electrical testing and coding, only the electrical team had the know-how to tackle those tasks.  The mechanical and software teams could only wait for results.  As the electrical team worked, everybody else on the team became more and more stressed.  We all kept wondering whether the team would have working robots for the first game.  We were all helpless in this situation.  The electrical team worked throughout the day and night trying to finish.  Some of the other team members stayed in anticipation while others went home to rest hoping for results in the morning.

Throughout this work day, the Chinese team continued testing their robots on the field.  They seemed like the most ready team.  The German team however, had lots of work to do as well.  Their flight to London from Germany was delayed and as a result, they missed their flight from London to Vancouver.  They arrived in Vancouver on Saturday night.  They  had even less time than we did to get their robots working.  When each team set up their work space, they each made sure to put up their mascots.  For the Chinese team, they had a panda plush of about 1.5 ft tall and the Germans had a full size German flag.

Game Days

On the game day, I woke at up 5:30 AM and arrived bright and early on campus at 8 AM.  When I arrived, the electrical team was still at it and seemingly not even close to finishing.  This led to a change in the team’s strategy to the competition.  We would try to repair the electrical boards from last year’s robots.  These old boards had a different size than the new ones and had different mounting holes, but luckily, somebody on the team had the great idea of including mounting holes for these old boards for this year’s robots.  Otherwise, we would have had a really hard time hacking that together.  Given only the few hours we had to hack this set up together, the mech team and I worked as fast as we could to finish.  We each probably ran up and down the stairs at the UBC Engineering Design Center about 20 times that day looking for tools and delivering robots.

The first game was supposed to be at 9:30 AM, but my team certainly was not ready.  It seemed like the other teams weren’t completely ready either, so the game was postponed until the afternoon.  The Thunderbots was supposed to play the first game, but due to our lack of readiness, China and Germany played each other instead.  When it became our turn we play, we managed to get three robots out of six on the field.  None of these robots had a working break beam sensor (the sensor on the robot that is designed to detect ball possession).  Without break beams, the robots did not know they could kick the ball, since it would never know if it had ball possession.  The robots did not have a controller that worked well either (the controller determines how much voltage to apply to each of the motors such that the robot can move smoothly from A to B).  A controller that didn’t work well meant the robots drove about on the field seemingly confused.  “Derp” is probably the best word to describe it.  Despite the shortcomings of these three robots, they played their best against ZJUNLIct from China and the Thunderbots were defeated 10-0.

On the following few days, the mech team tried to help the electrical team the best they could with tasks such as building extra connectors.  We also tried to get the old break beam sensors working again.  It was something that had to be on the robot if it were to ever kick the ball properly.  After toiling for a few hours, we managed to get two out of three of them working.  We probably could have gotten more if we knew more about the electrical design.  There was little to go on in terms of the wiring schematic and spare parts.  It was also hard to troubleshoot since ambient lighting largely affected the sensor.  If it worked upstairs in our work space, it wouldn’t work downstairs on the playing field.  It took us a while to figure that out.

In our second game, we played against ER-Force from Deutschland.  For this game, we still only had three robots, but this time they were a little bit better equipped.  Even then, the robots still had trouble kicking because the lights being used on the field emitted too much infrared light, which obstructed the break beam sensors.  It was very frustrating to see the robots not knowing when to kick even though they were handling the ball perfectly. But somehow, we still managed to score a goal.  In the end we lost the game 6 to 1.

In the final game between China’s ZJUNLict and Germany’s ER-Force, the Chinese team was victorious.  Both teams had a full fleet of robots to play six on six.  A modest crowd of spectators also watched the whole game being played and in general people were quite impressed at this engineering feat.

Team Social

To allow the teams to better know one another, there was a social event planned by the organizers of the North American Open.  There, I met a lot of the members of the German and Chinese teams.  It was nice that that I could talk to each team in their native languages.  Although my German wasn’t that good to keep up a conversation for a long time, it was enough to get the Germans wondering how I knew it at all.  The last thing they’d expect is for a Chinese guy to start speaking German to them.  My Mandarin was at a level that I could talk to people in it, but there were still some occasions where I didn’t understand what they said.  It was probably because of me not having a lot of practice with Mandarin (I speak Cantonese normally) and them having an accent from their region that I didn’t recognize.

Press Conference

The organizers made sure to invite as much of the press as they could.  More publicity meant that the team could potentially get more money in sponsorship.  More money means better robots.  The administrative members of the team were in the spotlight and talked to most of the people from the press, while the technical members of the team continued to do their work.  The team leads from mech, software and electrical also had a brief interview with the 24 Hours Vancouver newspaper.  The team was also featured in the Ubbyssey here and on MacLean’s magazine here.

The Chinese team also put on a show for the press by putting all 12 of their robots on the field so they could they play against themselves six on six.  The performance went quite smoothly as there were not random break downs and the press were very impressed.

Engineering Failures

As with these student projects, an accident was bound to happen.  This one was with a battery.  There was have been a defective battery that the Chinese team unknowingly brought and when they charged it, the battery started puffing up – not a good sign for a battery.  One of our team members was quick to notice and instantly dunked it in soap water and disposed of it.

For our team, we had problems where the solenoid kicker would get stuck after being used repetitively.  Heat from the power dissipation in the solenoid windings would heat up the whole assembly and cause the solenoid housing to permanently deform.  The solenoid was produced out of stacked layers of poly-carbonate sheets.  This stacking of layers allowed each layer to deform individually.  To fix this problem, we printed out new housings made of ABS plastic.  By having one solid solenoid housing, it was more difficult for it to deform.

The German team had some problems with the turf getting dug out of the carpet and getting everywhere inside the problem and also with their robot shells not staying on properly.  The turf inside the robot meant that gears could get stuck intermittently and could also get in the way of other mechanical components.  Their solution solution for now was to clean it all out every game.  During games, the shells of the robot would pop out randomly whenever there was an intense impact with a ball or another robot.

Getting Ready for Mexico

On the Friday before all three teams left for Mexico City, everybody had to pack up all of their things.  The German and Chinese teams could pack everything easily since they had packed everything once before when they had to fly to Vancouver.  For us, our tools were scattered all over the place.  It took us about 4 hours to find all tools to pack into the the luggage containers.  The approach to packing was that we would pack any tool that was ours and was already lying out on the table.  This is because if we took it out of the tool closet, it meant that the team used it for something.  Naturally all of the hex keys, screw drivers and the like were packed.  All spare parts were packed.  Every tool that we had sitting around was packed.  Even electrical equipment like a power supply and an oscilloscope was packed.  We had everything we needed for RoboCup 2012 in Mexico City.  Even though not everything was done in time for this competition, everybody was confident that things would be better in the competition in Mexico.

More photos here

This year’s competition problem involved the following scenario: normally solar panels are able to rotate toward the sun, but sometimes they get stuck, therefore it requires people to go out there and rotate them manually.  Also, undersea transmission lines sometimes get severed and also require manual repairs.  Our task was to build an autonomous vehicle using a VeX Robotics Kit in about 5 hours to use in a small scale arena emulating similar conditions.  A wooden pole represented the solar panel, that we had to rotate and a plastic pipe represented the transmission line.  To “repair” the transmission line, we had to build a repair module using newspaper and popsicle sticks that could physically cover up the pipe.  Additionally, in order to reach the transmission line, the vehicle would have to cross a rice field (represented by uncooked rice) and cross a river (ensuring that no electronics get damaged, they had to be above the “water line” at all times – represented by the dip in the arena).  After designing our vehicle, we would also have to present our design to the judges.

When I heard what the problem was, I thought to myself, “this is an impossible problem given the time we have to build it ands lots of teams aren’t going to be able to perform the task”.  I guess it was supposed to be like that.  The problem couldn’t be too easy or otherwise everyone would be able to do it.  Despite the difficult task, we approached it with a super chill attitude throughout the entire competition.

As a group, we planned out what we wanted to do.  We thought that it would be straightforward to go across the river, but it turned out that it wasn’t that straightforward.  We had trouble keeping our electronics above the “water”.  The line follower kit we used could follow the black line quite accurately, but it had to be about an inch above the ground.

To make matters worse, the wheels kept falling out.  Normally, one should just have to insert the shaft into the motor clutch and connect the clutch to the motor, but the connection was quite loose. 

One of our teammates spent about 3 and a half hours trying to fix the wheels and he succeeded. It took up a lot of time that we needed for the other design tasks, but we couldn’t leave that alone since movement along the ground was a critical function.

In the meantime, we brainstormed how we would rotate the vehicle to face different directions when needed, how we would pick up the repair module, and how we would rotate the solar panel, and how to protect the line followers while crossing the river.    We also had to think of what we were going to say for the presentation.

We couldn’t really get the rotation to be accurate without using an encoder (which would increase our product cost), so we tried to see what we could do without being able to rotate the vehicle.  We could drive straight toward the solar panel, rotate it, and return to the base.  If we focused on just this task, we didn’t have to figure out how to figure out the other tasks.  We figured that most teams wouldn’t be able to perform that task anyway.  With that in mind we modified our design drastically and came up with something that kind of worked.

The end reached high enough such that we could just bump into the top of the solar panel and rotate it and then go back to the base.  We didn’t need to worry about the other task of repairing the underwater transmission line.  There wasn’t enough time for that.

When it came to the presentation, we talked about our design and answered the questions quite well, but one of the competitors asked us a question that a lot of people seemed to feel was a very jerk question to ask.  He asked “how would the client feel that we delivered a product that could not meet all the stated requirements?”  I guess he was bitter that my team beat his team last year and felt threatened by me this time around.  We answered the question by saying that it’s better to do one task well, than to fail at both. 

In the competition, a lot of teams did in fact fail the tasks and did absolutely nothing.  When it came time for our device to compete, we did what we could.  It did reach the solar panel and rotate it a bit, but not enough to rotate it all the way.   It couldn’t even complete one task, although we had tested it before and saw that it did work.

The winning team (the same team as the guy who asked us that terrible question), used a design that would travel align the walls, past the river and to the broken line.  It picked up the repair module (shaped like a table) using a flat pad to slide underneath to pick it up.  It managed to do a 90 degree turn by following the wall (push sensors would tell the vehicle that it had in fact touched a wall).  It was clear that their design won out over everyone else’s, and they totally deserved the win.

A couple weeks ago, a classmate of mine invited me to participate in the UBC Engineering Competition in Senior Design.  After checking the calendar to see if I was free that day, I accepted.  I later found out that the winners of this competition would represent UBC in the Western Engineering Competition in Saskatoon, which will take place in January.  The problem with this was that three out of the four people on my team had a Co-op work term (myself included).  Despite the fact that we knew we weren’t going to the competition, we went to compete anyway.  There was little pressure for us, and winning or losing didn’t matter.

Some time later, I realized that my friend’s birthday party was the day before the competition, which meant I probably wasn’t going to get a lot of sleep.  Indeed I was right.  I got home at about 2:30 in the morning and had to arrive at the competition at 8:30.  Before I slept, I read an email that told us to read over the competition materials and to prepare a PowerPoint presentation template for the competition.  Seeing that we weren’t aiming to win the competition, I neglected to do any of this preparation.  My teammates neglected this as well.

On the morning of the competition, we went through all the registration procedures and find out what the design problem was.  Our task was to build an autonomous vehicle that could transport an object and bring it back to the starting location.  The only parts we were given was the Vex Robotics Kit, which came with a microcontroller, motors, wheels, and parts to build the frame.  We would be scored on how many objects we picked up, the weight of the vehicle, and the team’s presentation performance.

Since we didn’t really aim to win the competition, the team ended up being super chill through the entire competition.  One of the officials said to us, “Your team is the least stressful team we’ve seen!”  We made so many lame/funny/stupid jokes during the competition and had such great laughs.  Throughout the entire competition, I was probably super sleepy, and found no time to rest at all.  Despite the fact that we didn’t aim to win, we still tried hard in the competition.

Our strategy was simple: KISS.  Keep It Simple Stupid.  We realized that in the 5 hours we were given to design it, we did not have time to make anything complex.  It made the most sense.

The biggest design issue was the question of how the vehicle was going to know how to return back to its starting location after it leaves.  The only sensors we were given were buttons that would be pressed when the vehicle ran into an object.  None of these sensors would help us achieve this.  We thought of making the robot do a 180 degree turn, but this was difficult since we didn’t really have a way of measuring how many degrees the vehicle had turned.  We tried to time it, but the time it took to turn varied depending on how heavy the cargo was.  One of my teammates came up with the terrific idea of not rotating at all.  The vehicle would drive straight, pick up and then go in reverse back to the starting location.  We would then orient the vehicle in another direction to pick up the next object (we were allowed to do this since teams are allowed to touch their vehicle when it is in the starting location).

Going with this strategy, the vehicle would drive in a straight line toward the target object.  A sensor placed in the front of the object would be activated when the vehicle hit the object.  This would signal a cage to come down and enclose the object.  Then the vehicle would go in reverse back to its starting location.  The cage was simply a “fence” that was initially raised and then lowered to enclose the object.

After a lot of testing, we were quite confident that ours was going to work.  While doing all of this testing and designing, one of my group members made the PowerPoint presentation.  It basically talked about how the device worked and our design strategy.

The only preparation for the presentation that we had was just 5 minutes of telling who would present which slide.  When it came time for us to present, we looked at the slide and pretty much made up what we were going to say on the spot.  Because of this, our presentation seemed quite natural.  The fact that we all worked on the project allowed us to all know what we were talking about, so we didn’t stutter a lot.  I figure we did okay on the presentations.  Nothing spectacular.

After the presentations, each team took turns demonstrating their device.  There were a few designs that were definitely innovative, ambitious, and simple.  Among these, there was one that lowered a large arm onto the ground and sweep in a 360 to catch all the objects and return them all home at the same time.  It was a interesting design, but there was no way for the robot could do a perfect 360, since it was impossible to get the timing for it right and the power the motors gave would not be enough to move the entire load.  There was also a design that relied on randomly searching the entire field for an object and then moving around the perimeter of the field to return home.  This was the most ambitious design, but it didn’t work out because its random searching didn’t find any objects to grab.  Another team relied on the same principle as ours but were heavier.

As each team demonstrated their vehicle, it became apparent that our team had a big chance of winning.  We were very confident that we would get at at least one object, and our vehicle was the lightest one.  The team with the lightest vehicle would score the most points in terms of weight.  But for object retrieval, no team retrieved more than one object.  It was either one or zero.  If our vehicle grabbed even one object, we would be in first place for vehicle performance.  When it became our team’s turn to demo, our vehicle worked exactly the way we wanted it to.  We grabbed one.  We went on the grab another, but due to us failing to aim the vehicle properly, we failed to grab a second.  But it didn’t matter, we were in the lead in points.  Since no team grabbed more than one, we placed first in terms of vehicle performance.  We had a chance to win.

After the officials calculated the totals of all the scores, my team placed first out of twelve teams!  The best part about this is that even though we did zero preparation, we came out on top because we executed our design strategy better than the other teams.  We made use of the testing time to make sure our project actually worked.  It seemed like a lot of the projects weren’t tested that thoroughly, but that might have to do with the intense time pressure and a complex design.  The lack of pressure to win allowed us to perform so much better.

The configuration that I used was that I had my computer connected to an XBee USB Explorer via USB.  On the other end was an Arduino Duemilanove powered by six 1.2 V NiMH batteries, and this microcontroller powered the XBee using its 5 V pin.  I compiled and downloaded the program at the bottom of the article to my Arduino and I tested it using the Serial Monitor that comes with the Arduino IDE.

Even though the test program is simple, it shows that a wireless link can be made between the computer and the microcontroller, meaning that the microcontroller can process computer input to do even more crazy things.

Link: http://forums.trossenrobotics.com/tutorials/how-to-diy-128/xbee-basics-3259/

The section about the robot factor is basically about DC motor selection.  All it does is do a power balance between the energy provided by the motor and the energy required to move the vehicle at a particular speed an acceleration.

http://www.societyofrobots.com/mechanics_dynamics.shtml