FRC Robotics Prototypes

Yesterday we spent six hours at robotics working on prototypes for our new robot. I spent my time on the kicker team working to build a kicker where we could vary the force and therefore the distance that it kicked a soccer ball. We managed to kick 34 feet! This involved a lot of physics, so much so that we had to borrow a force sensor from Doc. (Thanks Doc!) Our robot kicker is a "foot" attached to a "leg" with holes in it with rubber tubing strung through it. When we tighten the rubber tubes and then pull the foot back, the potential energy in the foot is great, so that when we released the foot it sprung forward and kicked the ball. After we got this prototype working, our coach asked us to find out how much force we needed to apply for each distance the ball was kicked (for later programming use I believe). So we borrowed a force sensor and attached it to the tubing. We had already figured out that the more strands of tube we used, the more force, and therefore the further the ball traveled. This means that force and displacement are directly related, therefore the spring constant equation applied (Force = K x displacement). So with the force sensor attached, our kicker team kicked the ball using the four different amounts of tubing, measured the distance the ball traveled and the force of the tube, then collected the data for the spring constant.

We also discovered that the robot kicks with projectile motion, and we kicked the ball over a 18(ish) inch obstacle that was 25 feet away. If we say that the ball went about 1.5 meters in the air after each kick then we can use kinematics (deltaY=Vvi T+.5Ay T^2) to find that it takes .55 seconds to reach the ground 34 feet (10.36 meters)away. Therefore we can use (X=ViT) to find that the initial velocity of the ball is 18.8 meters/seconds.