In an experiment to measure distance in relation to velocity my partner and I used a Lego NXT Robot car that we built the week prior in SCI 184.
These were the instructions:
1. Launch the VI wheel_rotation_straight.vi
2. Study (with the instructor) the VI to understand how it works to measure the distance the wheels travel, and the speed at which the car travels.
3. With a ruler measure the diameter of the wheel and compute the circumference of the wheel in meters (circumference= p*diameter). Record that distance in the front panel of the VI.
4. Run the VI and record:
a. The wheel rotation (in degrees and in number of turns). How are the degrees that the wheel rotated related to the number of turns of the wheel?
b. The time it took for the wheels to turn (in seconds and milliseconds). How are seconds related to milliseconds?
c. The distance the car moved. How is the distance related to the number of turns
5. Measure the distance with a ruler and compare your results with that of the VI. What could account for the discrepancies?
6. Repeat (5) for two other power levels of the motors (keep both motors at the same power level though).
The Results:
When running the test my partner and I realized that the power on the wheels affected how straight it ran across the desk. Therefore we applied more power to the weaker wheel in hopes that it straighten the course of the robot. Fortunately this had some affect but still veered off at an angle at longer distances . We tested the robot at three different time spans of one, two, and three seconds. After calculating the velocity error at 14%-16% and distance error at 7%-9% are observation was that our time was not concussive for accurate testing . Had we had given the robot a longer run time it would have had smaller margins. Another variable in the high margin of error was the power applied to the wheel one wheel turned at an angle and caused our measurements to be less than precise.