Progress Report 1.) The motor ran with only one minor noticeable defect. As the turbines began to turn there was some sticking between the blades and the rotor for motor one. However, once motor two became active this issue was resolved speeding up and slowing down appropriately with the percent of power programmed for both motors.
Progress Report 2.) In this lab, the commands are not instantaneously expressed. This delay can cause error in the AEV’s performance. For example, if the motor speed is changed in the middle of the run, it takes time for the AEV to implement the command which causes extra time not accounted for between the speed change.
Reflectance Sensors and Built AEV:
The reflectance sensors measures position using marks. The AEV may not consistently travel the same distance within the same time interval, so measuring the AEV’s movement through position allows for greater accuracy.
Progress Report 3.) In the Power vs Time graph, the places where the code (CSS1) changed percent power is evident. From 0-3 seconds, the AEV was coded to accelerate to 25% power, in this case 3.0 Watts, and sustain that power for one second. The plot shows this was completed successfully. Next, the code called for a power drop to 20%, in this case 2.5 Watts, sustaining that power for two seconds. The motors were then coded to reverse and return to 25% power for two seconds. This time, however, 25% power was around 5.0 Watts, an issue that will need to be fixed. Lastly, the motors were coded to brake, as shown by the termination of all power. From the graph, there is some delay and inconsistency in the implementation of the code. It was made evident that using power as a guide for the AEV motion will be inconsistent unless further improvements are made.
During the trial run, our AEV’a movement was not smooth. The Power vs Distance graph showed that. In between power switches, the AEV went through periods of near stand still. Some idleness is inevitable because the code cannot be implemented instantaneously; however, it would be beneficial to reduce the idleness as much as possible. This could be done by coding as few power changes as possible.
Progress Report 4-5.)
Madison’s Sketch:
Madison’s design used the L shaped arm with the battery and controller attached to the bottom platform and the motors attached to the back. Her design utilized a braking arm that was above the AEV. This would improve the accuracy of the AEV braking.
Pros: Madison’s design improved the inaccurate braking of the AEV.
Cons: Madison’s design was not energy efficient.
Jacob’s Sketch:
Jacob’s design had two platforms coming off the arm with a motor off each. This would improve distribution of the motors’ force.
Pros: Jacob’s design improved the motor force distribution.
Cons: Jacob’s design had too much mass.
Adam’s Sketch:
The goal of Adam’s design was to evenly distribute the mass of the AEV to create better balance and to relocate the motors so their force was more towards the center of mass. He used the T-shaped arm for the best balance and put the AEV controller on one side of the arm and the battery on the other side. Adam moved the controller and battery forward to balance the weight of the motors on the back of the AEV.
Pros: Adam’s design improved balance, force distribution of the motors, and energy efficiency.
Cons: A new platform would need to be 3D printed.
Lauren’s Sketch:
Lauren’s design utilized the T-shaped arm. She chose to put the AEV body in the center of the leg to balance the vehicle. Lauren stacked the motors to more evenly disperse their power. She also tried to eliminate extra plastic on the frame in hopes of making the AEV lighter. In addition to the parts in the kit, Lauren’s design would require three 3D printed attachments (the piece where the control system was placed, the battery holder, and the motor holder on the back). The pointed dome would be cardboard for modeling purposes. The dome was designed to increase the safety of passengers, an important aspect of the MCR.
Pros: Lauren’s design highlighted balance, mass reduction, and safety.
Cons: 3D printing three parts would be expensive.
Screening Table:
AEV Sample Design Madison Lauren Adam Jacob
Mass +’+’+’+ +’+’+’+ +’+’+’+ +’+’+’+
balance 0’0’0’0 +’0’0’+ +’+’+’+ 0’0’0′-
durability +’0′-‘0 0’0’+’0 0’0’0’+ -‘0’-‘0
energy efficiency +’+’+’0 +’+’+’0 +’+’+’0 +’+’+’0
safety 0’0’0’0 +’+’+’0 0’0’+’0 +’0’0’0
Totals
+’ 4 7 5 4
0′ 7 5 7 6
-‘ 1 0 0 2
Scoring Table:
AEV Sample Design/% weight Madison Lauren Adam Jacob
Mass/25% 3 2.5 3.75 3
balance /25% 3 4 4 3
durability/15% 2.5 2.5 2.5 2.5
energy efficiency/20% 2.5 2.5 3.75 2.5
safety/15% 1.25 2.5 1.5 1.25
Total score 2.5625 2.875 3.2875 2.5625
Conclusion: Adam and Lauren’s AEV concepts will be carried forward in the design cycle.
Team G’s First Prototype Sketch:
