Our task was to build a robot that could cross a gap between two tables without any human effort. We had to make the robot and develop the code in class with a certain time constraint.
Our idea for this project was to use rotating tires on either side of the EV3. The tires would be far enough apart that the back end wheels would push the front wheels off the table, and then when the front wheels touched the other table, they would be able to drag the back wheels over the space. Ultimately, our robot consisted of two motors and four tires: two tires in the back and two in the front.
One difficulty we had was trying to make the motors sturdy enough on the EV3 because if the motors weren’t attached well enough, the whole robot would have broken while trying to cross the gap. the weight of them over the gap would make it so the EV3 could not stay level and get over the second table. The EV3 itself was very heavy, so we had to make sure the motors had enough strength and stability to get across the gap without any issues. One way we tried to overcome this problem was by using lots of beams and support beams. These multiple beams were connected with small connectors to add to the stability. Also, we had to make sure that the front part was long enough so that the front wheels landed on the other table before the EV3 starts falling off the edge. By doing this, we were able to balance both ends of the EV3 so that when the EV3 did leave the table, the front and back wheels would have been able to balance the weight. In addition, to also make sure the front wheels were aligned high enough to get over and onto the table, we made sure that the wheels were the first thing that hit the table. We had the EV3 upside down so that the flat side with the screen would be the bottom and also allowed an easier transition from the gap onto the second table.
Furthermore, the front motor moved in such a way that the tires created a jumping action. This was created because the motors were already slightly off the table. Using gears we were able to have it so that during each rotation, the wheels only touched the table for a portion of the time. This resulted in enough forward force to propelled the whole robot forward while the two back wheels were off the table. With this motion we were able to have the robot fully cross the two tables. The back tires rotated normally just to drive the whole robot forward and initially off the table.
The code for this robot was very simple. We had the two motors spinning the same direction for 10 seconds. The front motor has a larger power to try and help it drag the back end of the robot over the gap when it finally crossed the table.
Our robot was able to pass the 6in, 13in, and 15in gap. WOOHOO GO US! YAYYYY! :)