- Performance of the electric motors: The first motor appeared to work as intended. At high and low speeds, there appeared to be little to no resistance when starting or stopping the propeller. The second motor appeared to have issues spinning the propeller and would stop, start, and falter frequently. However, when spinning the propeller at high speeds, the motor had no issues and appeared to work as intended.
- Discuss how the commands may limit the success of the AEV: In steps 3, 4, and 5 of the algorithm, the AEV is reversed and then braked without specifying a certain distance for the AEV to travel. As a result, the distance traveled at the specified energy level may be different from battery to battery, which result in inconsistencies when testing the AEV with a separate battery. In addition, since a distance is not specified for the AEV to brake, the AEV will take differing amounts of time to stop based on the battery used.
- Upload a photo of the sensors:
- Describe the function of the reflective sensors & their importance: The reflective sensors record how fast the wheels are rotating by recording the number of times a non-reflective material passes over the sensor. Each time this happens, this is referred to as a “mark” [1]. As a result, by counting the marks and converting the distance between these marks into inches, the AEV knows how far it has traveled. Therefore, these sensors are important because they are able to communicate with the arduino about how far the AEV has traveled. This allows the team to be able to program the arduino to have the AEV travel specified distances.
- Graphs and Code depicting Energy vs. Time and Energy vs. Distance:
In the graph relating power to time, the power output by the AEV gradually increases to around seven Watts in about three seconds. During this time, the AEV is accelerating to 25% power, which is consistent with the consistent increase in power output. After three seconds, the motors reduce to 25% power, which is consistent with the decrease in power output to four watts after three and half seconds. In turn, the AEV then reduces to 20% power, which results in a sharp power output decrease at four seconds. Next, the AEV reverses its motors, which results in a power spike as the AEV switches direction. After this switch, the AEV again runs at 25% power for two seconds, which results in output power of six Watts.In the graph relating distance to power, the power spikes when the AEV moves. At this moment, the AEV begins powering its motors and moving, which is consistent with the power spike. The power output remains around seven Watts as the AEV accelerates and begins moving forward. After travelling less than a tenth of a meter, the motors stop accelerating and operate at 25% power, which results in a consistent power output between a tenth and five-tenths of a meter. Next, after travelling five-tenths of a meter, the motors decrease power consumption and operate at 20% power until reaching 1.5 meters. At 1.5 meters, the motors reverse, which results in a spike in power output. Finally, the motors return to operating at 25% power and remain at 25% power from around 1.75 meters to 2.5 meters, where the AEV brakes and power consumption ends.
Matlab Code used to plot graphs:
% Convert the table of data to an array.
data = table2array(performanceanalysis1);
% Extract the power output, distance, and time from the array.
power = data(:, 7);
distance = data(:, 4);
time = data(:, 1);
% Name and output the graph relating distance and power consumption.
distanceGraph = figure;
plot(distance, power);
title(‘Power Output through Distance Traversed’);
xlabel(‘Distance (Meters)’);
ylabel(‘Power Output (Watts)’);
% Name and output the graph relating time and powerconsumption.
timeGraph = figure;
plot(time, power);
ylabel(‘Power Output (Watts)’);
xlabel(‘Time (Seconds)’);
title(‘Power Distribution over the Time of the Run’);
ExportFigure(timeGraph, distanceGraph);
Source:
[1] Ohio State Fundamentals of Engineering Program, “Preliminary R&D Lab Manual.” [Course documentation]. Available: carmen.osu.edu for ENGR 1182. [Accessed Jan. 19, 2019].