Dec 31, 2007
Dec 27, 2007
Dec 26, 2007
We had a fabulous Christmas day yesterday - We started the day with the kids opening their presents... and watching the kids playing with the roller skates they got for Christmas and other cool toys while we stuffed ourselves with food and wine.
The highlight of the day was giving all the kids their own NXT for Christmas: I have had enough of having a single MINDSTORMS NXT in the house shared between four people - and decided it would increase the peace and harmony in the house if every child had their own NXT.
So for Xmas each of our children got one NXT, four NXT sensors each, and a selection of motors - including TECHNIC & PF XL motors, PF standard motors, remotes and power supplies.
To top it all, we decided to have a building competition , where everyone get an hour to dream up and build a machine (with or without the NXT) and fight each other.
To make it interesting, we piled up a room full of TECHNIC pieces they can use in addition to the box full of LEGO MINDSTORMS goodies and TECHNIC pieces they got for Christmas:
The building went really well. We had one hour of peace when the three kids were busy concentrating on buildng their best creations, whilst our 11 month old baby watched them from the rocking horse she got for Christmas.
At the end of the construction, we had the contest - we used the old Sumo ring we built two weeks ago for fighting. It was really etertaining to watch the contest. Our 12 year old boy won the first price after knocking the other two off the ring. Our 7 year girl won the fastest and cutest robot price for the four motor vehicle .. and our 14 year old boy got the most amusing and ingenious robot design price with his NXT based robotic caterpult with multiple motors and a pneumatic projectile launcher..
Why not share what you did for Christmas?
In the mean time, I like to wish you all a happy new year and a prosperous 2008.
Dec 24, 2007
Ho, ho, ho , merry Christmas to you all,
like Daniel said, on his site, he always knew that Santa should have been a robot…
Who else can bring gifts to all the kids, all over the world in just one night?
and a LEGO build full new year.
Dec 22, 2007
Thank you for your readership, your participation in discussions, comments, and the forum, and for encouragement. This blog has been an enjoyable way to meet more people who enjoy this hobby and continues to make my life more interesting. I've met some great people over the past 2 years and I'm looking forward to meeting some more.
Posts may be slow or non-existent over the next week or so - I do hope all the blog contributors take some time off and enjoy it with friends and family - I sure am!
See you in 2008!
Coverage the evening after the event http://www.kvue.com/video/lego-index.html?nvid=199957&shu=1
Coverage a few weeks before the event http://www.kvue.com/video/lego-index.html?nvid=198041&shu=1
Dec 21, 2007
Scores for each of 6 rounds can be viewed for the teams here along with those teams going to state at Georgia Tech in February.
Dec 19, 2007
At the FLL region final Rijnmond in Rotterdam (the Netherlands), I was asked to demonstrate the NXT and help out as a Mindstorms Doctor. (EHBMO) (the Dutch first aid) with an extra M for Mindstorms. During the competition I noticed a few things that I think are good for all to know:
1) Use an USB cable since Bluetooth does not always work. (two teams were glad I brought some spares)
2) Use the same configuration as you practice with at school. (one team had a different laptop)
3) Bring a spare IR tower and all the software. (firmware can cause headache)
4) Prepare if possible a second RCX, incase you lose the Firmware, just before the run.
5) Make sure your model is stable and does not fall apart just before the game.
6) Ask other teams, judges and referees for help, with technical problems, like lost firmware.
At our demonstration table we (Lotte and I) showed a large Wind turbine like the small vestas models in the Power Puzzle. the Kids loved the remote controlled models, like the Cranebot, the Bulldozer and a special 3G sensor from Mindsensors to control Marty (also form our book).
The overall winners were: team 29 GLRBOTS, form Grafisch Lyceum Rotterdam(dutch).
More Pictures are here
Dec 18, 2007
1. Table construction
The table I was a referee for (2 tables, actually) were not matched properly. One table was about 1/8 to 1/4" lower than the other and this caused the satellite to be angled lower on one side and higher on the other. There were quite a few teams that "missed" the trigger because there robot was designed for a perfectly horizontal surface and the trigger at a very specific height from the table's bottom. Obviously, this mismatch in table heights caused some headache, so I gave many teams the benefit of the doubt and awarded the points (and the satellite pointer) if I was able to determine they would have triggered it if the satellite had been at the correct angle (equal on both sides). The point here - inspect your table before you begin and let the referee know if you have any concerns.
2. Trays on table
We (all refs) did not allow trays to be set in the parking lot. This caused some controversy as any team that wished to use some sort of tray or box to have to hold it or sit it on the floor. Most teams just placed the correct pieces in the parking lot, but for some reason this ruling caused some irritation. If this is a key point to your team's success, discuss it with the refs before competition starts and find out the ruling. (As I understand it, trays are allowed but non-LEGO parts are NOT allowed to be set on the table - before everyone rushes in on this one, let's keep the comment to 1 or 2 AND only if you have an official answer and can provide a reference)
3. Sleep Timer
I had one or two robots turn themselves off during the waiting period before a match - this obviously caused the team problem when the match started because they thought the robot was turned on and ready to go. REMEMBER: either set your sleep timer to 30 minutes or 1 hour or off completely - you don't want to risk your robot turning off while you wait and then having to go through the power up while the clock is ticking.
Find out what your referee's position is on robot rescue. If the referee or a team member touches the robot outside of base, you lose a barrel as a penalty. Find out if the referee will allow the team member to reach for the robot or if the ref prefers to do it. Most refs will allow the team member to reach for their own robot if they say they are doing so - otherwise a request to the ref for a rescue might be required. Again, ask and know the procedure.
5. Sensors... again
Yes, I forgot that every NXT team is using the rotation sensor built into a motor. But when I was talking sensors, I was specifically referring to either the Ultrasonic or Light or Touch. I've said it before and I'll say it again, the Touch sensor makes a great "start" button and can replace the Orange Enter button on the front of the Brick. I saw MANY MANY teams reaching around to press the Orange button and not get their hands pulled away fast enough causing the robot to bump off course and forcing the team to grab and restart. If you've got a spare Touch sensor, mount it on top or to the side of your robot. In your program, you simply place a WAIT-TOUCH block (Orange block with the Hourglass and Touch Sensor symbols on it) and program it to wait until the Touch sensor is bumped (pressed and released)... then any remaining programming blocks in the program will begin to execute. This gives you time to pull your hand away without interfering with your robot's movement AND keeps you from having to reach around in an awkward position to push the Orange button.
Many teams asked about gears - they knew that gearing could give a robot more speed using certain gearing (and more power using other gearing options). This isn't the place to provide that information, but rest assured that there are plenty of places on the Internet that can show you how to use gearing with your NXT robot to give you either more speed or more pushing power.
7. Professional behavior
I cannot praise the teams I saw enough regarding their behavior at the competition. Teams were happy to be there and I saw ZERO trash-talking and/or negative comments from any teams. I think this was what made the event so successful - all the adults I spoke with that day were just smiling and laughing at how much fun the kids were having. I know it's a contest, but there was a team there that was high-fiving one another after completing ONLY the two missions they set out to complete. They weren't there to win but to show their parents/coach and everyone else that they were successful in making their robot do something over and over again. They chose to ignore the contest and focus on very specific obstacles that they decided to try and tackle. In the process, they learned some very important building and programming concepts and can apply those to future tasks.
I think my earlier post may have misled people into thinking there was no innovation in terms of robot building. Completely untrue. Whereas sensors were missing from 95% of the robots, there were some true engineering marvels seen that day in terms of construction and execution. I saw some solutions to certain missions that I honestly NEVER would have thought of but now I have some new tricks in my bag after observing them. It never ceases to amaze me how a team can come up with a solution that no one has ever considered. I would estimate that out of the 30 robots I saw that day, about 5-10 of them had an innovative mechanism or method for solving a mission.
9. Combination Missions
Someone emailed and asked about teams performing two or more missions at a time. Yes, this did happen, but not that often. When I saw it, it was mostly the robot starting out by doing the satellite mission and then turning left or right to do one additional mission. I did see 1 team during the entire day that attempted (successfully) 3 missions in one shot (won't tell you which ones to protect that team's strategy). Given the time limit on the missions, I do think that the winning teams at International this year are going to absolutely have to combine missions in order to reduce time at base. Time in base may be only 5 or 10 seconds, but do that 5 or 6 times and you've lost 1 minute of competition time. Think about it.
I believe that 90% of the teams I saw used some sort of attachment in one or more missions. By attachment, I'm talking about something easily and quickly removed at base in order to prep the robot for the next mission. There were a couple of robots that were completely stand-alone and required no additional work (they were larger in size, obviously). I even saw a few Tribots in the mix! Some teams get their kits late in the game and there is no reason to reinvent the wheel; if the Tribot works for you as a good base, go for it. It certainly is capable of holding and using attachments as the NXT-G software exercises demonstrate. Either way, the variety of attachments I saw was large - I saw cages, pincers, launchers, lances, etc. Keep in mind, though, that an attachment is only as good as it is structurally sound. If it's flimsy and comes apart easy in your hands, imagine what the satellite or house are going to do to it if they collide.
Dec 16, 2007
Anyway, here are my overall observations and opinions, none of which are based on scientific fact or any advanced statistical calculations - mainly just guessing and memory:
1. Mission most often attempted - Satellite
The surprising part about this mission wasn't that so many teams tried for it - it was the number of teams that tried and failed! Most teams lined it up using SET (standard eyeball trajectory) and I would estimate that 1 in 3 failed. Very surprising, isn't it? It takes 10-20 seconds of your time, so you should make sure you nail it every time.
2. Mission least often attempted - Car/Truck switch
Again, not surprising considering the work needed to get the points (two conditions must be met), but what was surprising was that the teams who did attempt it (maybe 1 out of every 10) got it to work.
3. Sensors hardly used at all
I saw a total of 30 teams come through my table, but none (ZERO) used sensors for any portion of the competion. Repeat - ZERO. With all the colors on the table, black lines, and angled lines, I thought for certain that at least 1 or 2 teams would use a Light sensor to help in some navigation... maybe the Ultrasonic to detect some of the Uranium or Corn items, but not a single one. Pre-programmed movement was the name of the game.
4. No jigs/templates
Once again, I saw no teams using any kind of template or jig device to line up their robots. A few teams did use the small colored lines that go around the inner edge of the base, but not in a way that I would consider as extremely accurate. For example, one team would line the wheels of its robot up with the left-most colored lines, but they didn't line the front of the robot up with any particular line - the result was that the movement they programmed kept missing the target (Corn) because the robot wasn't placed at the proper North-South starting position (N-S-E-W is written on the table, FYI). They had to run the same program 3 times and used trial and error to get the proper starting position. This should have been determined during testing.
5. Direction sheets
I saw 4 or 5 teams with a small "instruction manual" that they had written that had things on it such as the program name to select for a certain mission, the order they wished to run the missions, etc - one even had a "failover" selection in case one mission failed, they knew which missions NOT to run that might interfere with later missions. Very well thought out. I hadn't seen this before and was surprised. In the heat of the game, these teams were very methodical and didn't panic.
6. Wheel issues
Two teams consistently ran a mission that should have worked (oil rig) but a tire had not been checked before the competition and was either off the rim or not in alignment with the other wheel, causing the robot to rotate. Both times the teams grabbed their bot (penalty oil barrel) and ran it again, same result... grabbed the bot (another penalty) and went on to another mission. Check your tires! This is such an easy fix but can cause HUGE problems.
So many teams were stressed and reacting quickly to their robot. This caused many teams to reach and grab their robot (penalty) before it entered the base. One team grabbed the robot as it just entered the base and managed to rip off a large portion of a motor and attachment assembly - they wasted 30-40 seconds fixing it and missed out on 2 missions at least. Slow down - deep breaths... yes, time is ticking away, but hastiness caused too many mistakes for me to remember.
8. Program selection
I can't tell you how many teams wasted precious seconds trying to find the proper program for a mission or combination of missions. Cycling through the program files does take time. The best team I saw that managed this properly by having one teammate finding the program while the other handled adding/removing components. Good teamwork.
9. No RCX
30 teams - all using NXT. I didn't see a single RCX. Of the 10 teams I didn't see, there might have been... not sure.
10. False starts
A few teams were penalized because they pushed the start button before the competition countdown completed. We were very strict with this because so many teams were racing for the satellite and it had to be fair. Don't push your start button until the countdown hits zero.
I finished the biped about which I posted earlier. I added some sensors. The sound sensor was not used in this movie. With the ultrasonic sensor it avoids walls. The LED of the light sensor flashes if it turns, when it sees something. Altough it looks like it tips over, it is actually a pretty stable robot.
Brian "putting new spots on the Leopard" Davis
Dec 15, 2007
Though I haven't been to an official tournament, a scrimmage practice with 10 teams I recently attended had all NXT robots! And since most of these teams were new, I think the NXT is really causing people to start up teams.
I think this is one reason Scott Evans might have made it easier than claimed; he guessed that the release of the NXT would start many new teams, so making slightly simpler missions would make these new teams' first year smoother, while the complexity of other missions would still give (somewhat) a challenge to older teams.
And even though teams are scoring higher, I've noticed that robots are no longer as technical (? correct word?); many rely on dead-reckoning (even though teams like Jonathan's shows that this works just as well) and no longer use many or any sensors at all. In the days of the RCX, teams had to rely on sensors to get any accuracy at all. I think this is one area that the NXT can improve in.
So good luck to everyone, and I hope to see some of you at the World Festival in Atlanta!
Dec 14, 2007
Citing from the German FLL site:
Climate Connections - Building A Global Game Plan
The "winds of change are blowing" and with them comes FIRST LEGO League's 2008 Climate Connections Challenge! Join us as we explore why many experts believe the earth's climate is changing and how these changes impact you and our planet. The causes, contributions, and consequences are all interconnected and the experts are telling us to "think globally - act locally." People, resources, and local actions need to be united to establish a global game plan. Do FIRST LEGO League teams have what it takes to make these global Climate Connections?
Registration will start on 1st of March.
This is my last post before Xmas - and I hope you all have a safe and happy holidays. I will leave you with this excellent post on YouTube by OrganFairy from Denmark. Take it away Alpha Rex:
Dec 13, 2007
I noticed that teams scored significantly higher than last year, on average. Last year, the second highest score was a 298. This year, however, eleven teams got a 300 or higher! I've also heard of other states doing significanly better this year. It seems that, although the missions were intended to be harder, they've turned out to be easier. We'll probably be seeing quite a few perfect scores at the World Festival this year.
The other thing I noticed at the tournament is that the increased number of rules and complications seemed to be causing trouble with scoring. In our first round (when they got a perfect score), the referee scored at least half of the missions incorrectly!
You can read more about the tournament and see pictures and videos at http://www.teambuiltontherock.org/
Robot sumo is one of the fastest growing sports around. Now if you own a LEGO MINDSTORMS NXT, you can join in as well.
If you still don't feel the urge to get down to designing your own Sumo robot that is going to kick butt in the sumo ring against contestants all over the world, then this might help. This beginners Guide also has a video that walks you through getting your model ready for NXTLog in five simple steps.
Beginers Sumo Guide on LEGO web site.
If you checkout the five step video, you would notice a small clip of a Sumo robot in action with another robot. If you want to see the complete battle, check out this YouTube video:
And you still have a few days left if you have not started your Sumo robot. Good luck!
Basically the particle filter realizes that you won't have perfect odometery readings all the time, and so uses 3 ultrasonic sensors to 'correct' errors and stay on track.
"Localisation is the process of working out where you are, so localisation for a robot is having the robot work out where it is using the readings from its own sensors. Sounds easy, but it can be surprisingly challenging. The big problem stems from the fact that the robot's wheels have to slip to make the robot move (a fact of physics), so careful measurement of the motors' rotation sensors is not going to help you. Fitting streams of range readings from ultrasound or infrared sensors has problems with noise and error, too. So, over the last decade or so, roboticists have pretty well agreed that the best way to localise is to combine the all of robot's sensor readings over time using probability theory. Sounds challenging, but it can be surprisingly easy.
I've been using a probabilistic filter called a particle filter to localise a robot built around the NXT. The other name for this style of probabilistic localisation is Monte-Carlo Localisation, so called because it relies on finding the best odds from a series of seemingly random outcomes. All of the code is written in Robot-C and runs on-board the NXT in real time. This surprised me. Particle filters are supposed to be horribly computationally intensive with lots of floating point math, so surely you can't expect it to run on a LEGO brick ... but run it did."
He gives a great explanation of particle filters along with video of it in operation.
Source code in RobotC is provided for those that want to look under the hood.
Dec 12, 2007
Dean Takahashi, author of the Tech talk blog and father of a member of an American FLL all-girls team, the RoboChicks (nice name, almost as good as The Smiling Noodleheads mentioned there!), has published an article that I consider very worthwhile to read, as it shows the perspective from "inside" on the way a team and the associated persons experience a day of competition on an FLL event.
Check it out!
I'm aware of two new parts, but neither is directly related to the NXT.
Creator set 4995 will include a winch, powered by a pull-back motor. You can see it in this photo. The switch looks a lot like a touch sensor.
This is the sort of thing that one might use in a Great Ball Contraption, but I'm not sure that it will have a lot of robotics applications. Feel free to surprise me.
Brickset is showing a new Power Functions cable. It lists a 2007 release, but I haven't seen it for sale yet.
So, any rumors? Blurry photos smuggled out of the Denmark? Curious minds want to know.
Dec 11, 2007
Dec 10, 2007
Recently, I received a negative rating on amazon.com for my NXT-related book Advanced NXT: The da Vinci Inventions Book where the reader complained about the comprehensibility of some of the building instructions to him and his students.
Although a negative comment is something any author has to get along with, and although I do agree with him that some of those instructions have their weak points (as a result of the trade-off I was forced to make between the depth of detail and the volume of the book), I am nevertheless grieved that he never contacted me for support on that matter - in the book, I state on various occasions that every reader is welcome to contact me via my contact page and ask for help with points that are unclear to him/her, for other questions, suggestions or in general for any feedback to the book.
Like most authors of books, it is my desire that every reader should not get frustrated but make the best from the book, and hence I try to provide help or answers to any questions that I receive via the contact page (or any other channel) as soon as possible.
So I again encourage everyone of you who has bought the book but feels the need for help: please use that way of contacting me at your leisure.
Same goes for The LEGO(R) MINDSTORMS NXT Idea Book: me and my fellow authors are grateful for any hint, suggestion or question you have regarding it - you can use our forum for that (and some readers of the book have already done and received help there).
In general, that appeals to any (NXT) book around: most of the authors have spent a lot of their time, energy and heart on them and want to see their readers taking benefit of their efforts - and after all, you spent your money for a book, so why not use that option?
Dec 9, 2007
If you intend on entering the NXT SUMO contest, you still have more than a week to go. How good is your sumo robot?
One of the best thing you can do to see how well it will do in the ring, is to make a ring your self and see if your robot would last in the ring for five minutes with an inanimate object.
Building a ring is relatively easy: Click here for full instructions:
Dec 8, 2007
Because many of us would like to learn how to effectively use more of the parts in the NXT kit, I'm going to start by asking you, our readers and bloggers, to share how and when you would use this part---the TECHNIC Knob Wheel. If you include pictures (which I hope you will), please make them close-up shots.
Dec 7, 2007
A two legged walker has always been a robot on my to-do list. Inspired by Bruno Zarokian’s robot I created an NXT robot with the same functions. However, the mechanisms I used are different.
Right now it can walk and turn. A sensor to avoid walls will be added later. I hope to upload a video of it this week.
Dec 6, 2007
Desicritics.org, a blog run by Desis, has published a review of David J. Perdue's The Unofficial LEGO MINDSTORMS NXT Inventor's Guide. As a conclusion, they state that
"it's a book that makes you want to get off your chair and start building Lego inventions".Sounds rather positive, doesn't it?
All of you out there who have purchased that book: what is your attitude towards it?
Dec 5, 2007
Here's a freshly thrown video providing some idea of BenderBot's functionality and purpose.
BenderBot is a musical instrument which generates sound suitable for sampling and recording just as with any instrument. However, this instrument is like no other. You program and play it however you wish. The slate is clean (aside the sample programs and ideas) for you to create your own music. The bot can be set to run autonomously or can be operated manually. You program it as you wish. Viewers may notice (or knob-up your PC speakers until you do) the wild sound track segments near the start and end of the video. These segments are the results of a home recording studio production of BenderBot, an electric guitar, a sound processor pedal, and a Circuit Bent Texas Instruments Speak & Spell. These instruments were used to create sound samples that were then assembled into a nice track. Breaking it down further concerning BenderBot...with your PC and some freeware you can create a short sound sample, convert it for use in the NXT and NXT-G software, crank out some NXT sounds, record samples with your PC when you are jammin'out, mix'em around and produce your own 'noise'. What you see in the video is only a very tiny example of what can be produced using BenderBot. Different equipment combinations or a lone BenderBot can be used to achieve nice tracks. Grab a copy of the Idea Book and give BenderBot a spin!
Soon, I'll release a tutorial on creating NXT-G sound samples for NXT instruments and details for processing recordings towards song productions. I encourage readers to visit our forum section to discuss BenderBot and the other Idea Book Bots. A sound sample download section will soon be created to provide a few usable sound collections! Please, drop by and let us know how your NXTrument endeavors play out.
What kind of music will you create with your NXT instrument? Let us know!
Dec 4, 2007
This is a movie that I have created from my own photos. Unfortunately, the rechargable battery of my camera gave up rather soon, so the greatest part of the teams and of the event can not be seen there. :-(
Point Worth: 15 points.
Mission Location: The North-East (top right) corner of mat.
Estimated Difficulty Rating: 4/10
Time Length Rating: Medium
Unique Challenge Aspects: n/a
Wow, this mission is pretty straightfoward and simple: move the Uranium rings (I didn't know Uranium came in rings!) out of the farm for 15 points, though it might do a team good to bring them back to Base. The one trick to this might be the tricky placement of the Uranium rings in the corner, with the possible trap of getting stuck in the corner.
Built On The Rock won the Robot Performance award, and congratulations to the Robo Invaders (Champion's Award), Landroids (Robot Design), Gears (Teamwork), and Torn (Research Project), who will also be competing at NJ State on December 8th. We heard that the NJ Champion's award winner will be going to the World Festival in April (not all states are going), so it's going to be an exciting tournament!
Here are some pictures of the event:
Built On The Rock with the Robot Performance award. A couple of the old members and I aren't on the team this year, since we're older than 14.
The awards were shaped like puzzle pieces, with the Champion's award being a combination of the four others. The competition tables.
Team Gears had this wooden model of a robot displayed on their table... notice it doesn't have any gears. :-)The Landroids, a first-year team, doing a practice run... they were getting perfect scores in some of their practice runs, but unfortunately didn't get them on the official rounds.
Built On The Rock in their Teamwork interview.
You can also read about the event on our website: http://www.TeamBuiltOnTheRock.org
Dec 3, 2007
Dec 2, 2007
Dec 1, 2007
I just been playing with it - for me the most coolest addition is the PF Elements !!!
A quick look at the boxes included shows some new additions - the most notable ones are the LEGO Creator 4957 Ferris Wheel and the cool 4958 Monster Dino.
Thanks LEGO for listening. Now we can include PF motors in our NXT robotic models. It is a shame they still dont have the IR-Lnk though - you have to use a light sensor as a place holder until the IR-Link makes it to the pallette!
Why not try it and see if you like it?
Download it from here