Tuesday, February 13, 2018

B2B - Lab: Tracks vs. Tracks...

I volunteer at quite a few FLL (FIRST LEGO Lague) tournaments and I noticed that very few teams use tracks on their robots, mostly rookie teams. So the Brics~2~Bots Engineers decided to test tracks on the field mat with various combinations of small rubber studs (Boost & Technic kits) and large red rubber studs (which were available when the EV3 was first launched). 


Our test robot was simple. An NXT with EV3 motors. Programmed with EV3 software.


 First, Brandon made a test program for the vehicle to move first backward then forward, turn left and then turn right. It used the programming block Move Tank at a power of 50 for 2 rotations, then repeated the sequence with a power of 75. There was a WAIT of 1 second between actions.  The program was set up to see if the robot could start & stop at the same spot; this would indicate the precision & consistency of the robot's movements. Observations of the robot's performance were recorded.

Tracks without studs.
Bumpy with slippage. Turns not consistent. Robot out of control!
Tracks w/small rubber studs on the outer edge or inner edge of the tracks.

Somewhat slow moving even at 75. Slightly bumpy on the FLL field mat & smooth surfaces. Seems to have consistent turns. Placement of studs is better on the outer edge of the tracks. To start and stop at the same spot it is off by 1-1.5 inches forward.
Tracks w/small rubber studs alternating inside & out positions.
Visibly less bumpy, but with consistent turns. To start and stop at the same spot it is off by .5-1 inches forward.
Tracks with 2 small rubber studs per track.
Appears to be a bit less bumpy than a single stud per track. Consistent turns. To start and stop at the same spot it is off by .5-1 inches forward.
Tracks w/large rubber studs on alternating tracks track.

It is bumpy at 50 power and very bumpy at 75 power. To start and stop at the same spot it is off by
1 inch forward and .5 to the left.
Tracks w/large rubber studs on every track.
Less bumpy that alternating tracks, but still rather bumpy. Consistent turns. To start and stop at the same spot was almost perfect.

Each time the robot stopped there was a rocking motion. This might be cause for concern traveling a longer distance than 2 rotations might cause inconsistent results.

It has a better grip on rough surfaces & is good for crawling over a low obstacle.


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