Robotics Activity

Team: Lauren, Gianna, Zhongfan

For our first lab exercise, our team was instructed to build a basic two-motor NXT car.  In the next lab exercise, our team was to use the car that we built the week before.

We launched the VI wheel rotation straight program on the LABVIEW software and with the help from our professor, we learned how the program works to measure the distance that the wheels on our car were traveling and the speed at which the car travels.

Using a ruler, we measured the diameter of the wheel and computed the circumference of the wheel in meters and recorded that distance (.172m).

Then we ran the program and recorded the wheel rotations, the time it took for the wheels to turn, and the distance the car moved from both the program and what we measured ourselves.

From there compared our results and changed the power levels of the motors (75, 50, 25).

Our Measurements (m)
	75	50	25
1st	0.52	0.35	0.13
2nd	0.54	0.345	0.12
3rd	0.53	0.345	0.12
Computer Measurements (cm)
	75	50	25
1st	0.465	0.295	0.106
2nd	0.477	0.293	0.102
3rd	0.473	0.298	0.108
% Error
	75	50	25	Average
1st	11.2	17.1	24
2nd	12.4	16.3	20.1
3rd	11.4	14.6	15.4
Average	11.7	16	19.83	15.8

Our results show that the amount of power we gave our car inversely affected the distance that the car traveled. This experiment gave us a hands on experience with the relationship of power and distance.

I feel that our high error percentage is rather high. This error could be because of the direction that the robot seemed to repeatedly move instead of a constant straight line and this affected the distance that we recorded. In addition, we may have not simply read the ruler as accurately as we could have which would cause a difference in our results and the program results.

Below are actual pictures from our team experience: