Final Design and Code

Final Design and Sales Pitch

See the final AEV Design, Sales Pitch, and Code used for the final performance test

Final AEV Design SolidWorks Model

Strengths of Final AEV Design

Pictured above is the team’s final AEV design. This design completing the final performance test under budget with a power consumption of 215.3 joules over 42 seconds. The team believes that the passengers using the AEV must be able to complete their trip in a efficient and safe manner, while being able to afford transport on the AEV. Without any of these criteria being satisfied, the passengers will be unable to reach their destinations. Based on these criteria, the team believes that their AEV design superior to any other design in the class due to its high power and time efficiency, stability, consistency, and cheap cost of production. For these reason, Group L’s AEV design is the right choice for Advanced Energy Vehicle project.

Efficiency

The team AEV was highly efficient, both in joules and time. The team AEV required only 215.3 joules over 42 seconds, as seen below, to complete the final performance test once optimized, and this is one of the biggest strengths of the team’s AEV design. Due to the high level of precision using the power braking method, the team was able to allow the AEV to travel at high speeds, with a high level of precision. This allowed the team to travel at motorspeeds of over 60% both with and without the caboose, making the AEV the fastest to complete the final performance test. The team was also able to utilize coasting since the AEV traveled at high speeds, allowing the AEV to be highly power efficient. Due to the coasting between the loading zones and the gate, the AEV was able to use only 215.3 joules for the final performance test, causing it to have the most efficient joule used/second of any AEV in the class. This high level of efficiency is a leading factor that Group L’s AEV design is the most effective design in the class.

Final Performance Test: Power vs. Time

Stability

The final AEV was also highly stable. Due to its centered arm, and downward facing wing two motor setup, the team AEV was able to have a high level of stability on the track. Because of this, the AEV’s weight was evenly distributed between both wheels, allowing for easy acceleration and braking. Between all testing, the AEV wheels never slipped off the track, and the AEV was always able start from rest with low power consumption. The team believes that without the center arm design, other AEV’s will be unable to be as efficient as Group L’s design.

Consistency

The team also believes that Group L’s design is superior due to its high level of consistency when braking at the gate and loading zones. While many other AEV designs struggled for consistency between tests, Group L’s final design was highly precise and consistent when braking due to its use of coasting and power braking, making it superior to other AEV designs. When testing, the team’s design never failed when braking at the gate or loading zone. The team believes this is due to the use of power braking. The team found that utilizing power braking was a highly consistent method, with an average braking distance of 4 inches, when compared to 63 inches when using the coasting method, see aR&D Coasting vs. Power Braking. Because of this, the team utilized power braking in their final design, allowing the AEV to be consistent from trial to trial, as the power braking method provided a far more consistent braking distance when compared to other AEV designs. The team believes this is the component of the final design that separates it from other team AEV designs.

Cost of Production and Use

The team found that a minimalist design was not only more efficient, but also more cost effective. Since the final AEV design only utilized a base, two wing shapes, two motors, and reflectance sensors, the team’s final design was cost effective when compared to other designs. With a final cost of $165,195 the team believes this design is cost effective when compared to more advanced designs. By choosing to use power braking instead of a servo motor, and only the bare minimum base and arm shapes, the team was able to save approximately $50,000 when compared to more complex designs. This low cost design saves not only Watts Scientific valuable funds, but also the passengers using the AEV, as a cheaper cost to build an AEV will allow for cheaper prices for travel. In addition to being cost effective, the team found that the minimalist lightweight design was a cause for the high level efficiency mentioned above. When paired with the high level efficiency, Group L’s AEV design is both efficient and cost effective, making it the superior option for any AEV project. Below is the total cost of the team AEV including capital costs and costs for performance testing. Based on the table below, it can be seen how cost effective the team AEV design is, as even with safety and accuracy penalties, the team was able to finish on budget.

Final Performance Test Costs for Group L

 

Final Performance Test Code

//Power braking
//Accelerates both motors to 40% power over 2 seconds
reverse(4);
// Runs both motors at 40% power for 4 seconds
motorSpeed(4,63);
goFor(2);
brake(4);
goToAbsolutePosition(276.0);
//reverse motors
reverse(4);
//Runs both motors at 30% power for 1 seconds
motorSpeed(4,90);
goFor(0.5);
//Brakes both motors
brake(4);
motorSpeed(4,0);
goFor(7);
reverse(4);
// end of performance 1. Runs both motors at 40% power for 4 seconds
motorSpeed(4,60);
goFor(2);
brake(4);
goToAbsolutePosition(560.0);
//reverse motors
reverse(4);
//Runs both motors at 30% power for 1 seconds
motorSpeed(4,72);
goFor(0.5);
//Brakes both motors
brake(4);
//AEV at rest for 7.5 seconds in loading zone
goFor(7.5);
//all motors at 60% power for 4 seconds
motorSpeed(4,68);
goFor(2.6);
brake(4);
goToAbsolutePosition(393.0);
//gate on return run
reverse(4);
//run all motors at 87% power for 1 second to power brake
motorSpeed(4,90);
goFor(1);
brake(4);
//AEV rests at gate for 8.75 seconds so gate can open properly
goFor(9.75);
//run all motors at 55% power for 4.25 seconds
reverse(4);
motorSpeed(4,65);
goFor(2.25);
brake(4);
goFor(2.65);
//power braking for starting point
reverse(4);
motorSpeed(4,88.5);
goFor(1);
brake(4);