On January 29 during class time we ran an experiment by using lego robots and a computer program that allowed us to change features of the robot; the time that the robot would move, and the amount of power that each engine that powered the robots wheels were given. The goal of our experiment was to see when changing the power setting but leaving the same amount of travel time; what the difference would be in velocity, and distance (meters).
Before actually driving the little robot around, we need to find the circumference of the robots wheel. By finding this measurement, we would be able to know how many rotations the wheel would go through during each of its travels. We found the the wheels circumference was .1758 meters. After finding this information we then used the computer program to input the amount of power given to each engine, the circumference of the wheel and the amount of time the robot would drive. Time was the constant variable in our experiment meaning it remained at 2 second throughout the entire trial run. The only variable we alternated was the power. We would do three runs for each power setting we would use in order to double check our data and make sure that each run was accurate. In total we went through nine trial runs and three different power settings for the engine (each engine would always have the same amount of power). When doing the runs it was very simple; we would enter the power setting, line up the bot evenly with the beginning of a ruler, and then we would simply hit a start button on the computer that would run the bots for the set time. After the bot finished rolling we would measure its progress write it down in our data table and repeat. The program actually did the math for us and gave us the velocity of the bot and the distance. We would still compare the distance the computer got with the distance we could see using the naked eye to search for fault in the program.
In the end we were able to find all of the variables we were in need of. For example; when you run a bot for 2 seconds with a power in both engines of 50 watts. The bot will travel 32.9 cm which is then converted into meters which turns out to be 0.3297 m. Then you get a velocity of 0.1653 m/sec. The rest of our data is shown below in the table we created using a google spreadsheet.
Time | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
Power | 50 | 50 | 50 | 40 | 40 | 40 | 35 | 35 | 35 |
Circumference | 0.1758 | 0.1758 | 0.1758 | 0.1758 | 0.1758 | 0.1758 | 0.1758 | 0.1758 | 0.1758 |
Distance(m) | 0.3297 | 0.33067 | 0.33021 | 0.25448 | 0.25106 | 0.2512 | 0.2076 | 0.2115 | 0.2051 |
(cm) | 32.9 | 33.07 | 32.8 | 25.4 | 24 | 24.1 | 20.5 | 21.2 | 20.3 |
Velocity | 0.1653 | 0.1651 | 0.1651 | 0.12724 | 0.12553 | 0.12553 | 0.1037 | 0.10574 | 0.10257 |