Some of the comments/discussions going on in the previous post got me thinking a little more and, of course, I realized after posting it that there were some things missing. So, apologies in advance for another long post, here goes:
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.
4. Rescue
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.
6. Gears
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.
8. Ingenuity
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.
10. Attachments
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.
Jim
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.
4. Rescue
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.
6. Gears
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.
8. Ingenuity
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.
10. Attachments
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.
Jim