Our final performance test took 57.07 seconds to complete and used 244.083 Joules of energy. The final cost was $623,069.47, significantly exceeding our budget of $500,000. Despite the expense of the system, we still believe that our AEV has many strengths compared to others.
First, the low power percentage used in our code aids in the extension of the battery life. As the battery weakens over time, the motors function deteriorates, leading to potentially dangerous inconsistencies between runs. Our code prevents the battery voltage from dropping very much between runs. Our AEV can perform many more runs before needing a battery charge or replacement, and is therefore safer than a less efficient AEV. This is supported by the battery testing activity, which showed that the voltage of the battery progressively decreased as additional runs are completed. It was qualitatively observed later during testing that the AEV’s performance severely declined as a large amount of runs had been completed. All of these deficiencies are minimized by our AEV’s low motor power code. The first performance test used a version of the code that utilized higher motor power than the final code. This would have decreased the battery’s voltage more quicly and led to an increase in maintenance required and inconsistencies after completing many runs. These reasons, coupled with a decrease in energy usage, was why a lower powered code was used following the completion of performance test two.
The low motor power code also has a direct correlation to the speed of the AEV. While many groups focused on completing the final performance test quickly, we focused on keeping the runs consistent if slow. In addition to the decreased need for battery-related maintenance, our AEV is also one of the safest. The slow speed of the AEV is more conducive to the passengers’ well being, which is especially important considering that the AEV will be used by many for transportation to work and other important places. Despite the lack of cost efficiency demonstrated by our AEV, it is extremely important that all passengers are transported to their destinations safely and comfortably. In this, our AEV excels. In the unlikely case of a crash or severely malfunction, the effects would be much less severe for an AEV travelling at a slower speed. We believe that some faster-moving AEVs would not meet the safety requirements of the people of Linden.
The use of air braking instead of Servo motor braking may not be as efficient, but we still believe that not using the Servo motor has benefits. Servo motor braking often requires the use of outside tools to aid in the braking. Many of these tools added to the cost of building the AEV and will likely add additional maintenance costs in the future. We believe that the maintenance of this type of system will more than offset the cost reduction incurred by its greater efficiency. Our AEV’s lower maintenance requirements will result in lower costs over time. Although the starting cost of our vehicle is high and well over the budget, we believe our model makes up for all of that by keeping maintenance costs very low.
One final strength of our AEV is its low cost of assembly. The majority of our final cost comes from the final performance test due to energy use and the longer duration of the trip. The assembly of the AEV cost only $163,180. We believe that our prototype is efficient and cost effective, but changes to our code or other cheap additions to our AEV could have further decreased the energy usage by a large amount. An increase in testing time could have fixed the efficiency issues, but we believe that the design we use is the correct starting point to allowing our project to become the most efficient prototype out there.