The Inevitability of Failure from http://www.jameco.com/Jameco/workshop/MyStory/failure.html
By Hannah Moore
Majoring in engineering comes with the inevitability of failure – a lot of it! However failure allows us the opportunity to problem solve and learn from mistakes… and fail again.
Recently at The Ohio State University, my classmates and I were placed into teams and tasked to design and build an Advanced Energy Vehicle (AEV). We also needed to write the code necessary for the AEV to travel and perform specific tasks while minimizing input power and maximizing propulsion efficiency.
During the first few weeks of the project, we built a sample AEV and began to understand the coding language and the Arduino platform. The process was slow but it was a necessary first step.
Next, it was time to design our AEV. Before we realized, we had encountered our first bump in the road. Reflectance sensors needed to be placed by the wheels of the AEV and connected to the Arduino in order to determine the distance the vehicle had traveled. Our plan was to secure the sensors with zip ties but when it was time to attach the sensors they were nowhere to be found. They must have fallen out of our kit unnoticed! We had experienced our first fail, but it was also our first lesson learned.
Always double check the parts list before you begin a project!
We decided to use leftover twist ties from bags of supplies we found instead. We were relieved to discover this mishap and improvisation actually benefited us! We disassembled and reassembled the AEV often, switching the placement of the reflectance sensors each time. The twist ties could easily be undone and reused instead of the more permanent zip ties.
With a sample AEV finally built and a good foundation of code-writing knowledge, we began our first round of testing. We wrote code, uploaded to the Arduino, ran the AEV on the track and downloaded the resulting EEPROM data. We used the EEPROM data to manually convert it into physical parameters such as propulsion efficiency, kinetic energy, power, etc.
This was definitely not the most exciting part of the project. It consisted of calculation after calculation after calculation. We analyzed the data, improved the code, ran the AEV again, downloaded the data and repeated the whole cycle for days. A few days later we were informed that a data analysis program was available for our use. You mean that we spent the last few days doing calculations and analysis that could have been done by a computer in a matter of seconds?! Time is a precious resource in college. This was our second fail.
Learning from our frustrations of inefficiency, the team decided to completely redesign our AEV in order to see if it could decrease the input power needed and increase the efficiency of the propellers. Our new design hung down from the track with a vertical body rather than the horizontal body common to the design of most other groups. We liked the design but soon realized taking it from concept to reality would be our third failure.
Initially, the vertical body caused several balance issues. One side was heavier than the other, which caused the entire body to hang lopsided off of the suspended track. After numerous attempts to rearrange the pieces on the body and adding miscellaneous objects to function as counterweights, it was balanced – well, balanced enough to satisfy amateur engineers. We had our final design and had overcome each of the failures we had encountered thus far. Now it was time to focus on perfecting the code to control the AEV’s movement.
The AEV had to begin at one end of the track, travel to a gate, wait for it to open, then continue around the track, connect to a caboose, travel back to the gate, wait for it to reopen and finally return to its starting position.
Simple enough, right?
After days of writing code, testing, rewriting and retesting, our results were extremely inconsistent. Sometimes the vehicle wouldn’t make it halfway to the gate and other times it slammed into the closed gate. Determined not to fail again, we decided to test the reflectance sensors. We ran the test and the sensors failed. We had found our problem!
With a new set of reflectance sensors, we ran the test again. We were disappointed to discover the new sensors failed the test as well. More failing; what was wrong?
Double checking our methods, we soon realized that we had been testing the sensors incorrectly. Back to step one. It wasn’t the sensors after all.
The team then decided to change the code so that it was dependent on distance traveled by the AEV rather than the time traveled in order to increase consistency – and it did! Success! We tested the code multiple times and it ran flawlessly every single time.
The team was ready for our final run and evaluation. As we confidently approached the track, our professors complimented our creative design. Filled with pride that we had been able to overcome each failure we had encountered, we hung the AEV on the suspended track and flipped the switch to initiate movement. Everyone watched as our impressive AEV… choked.
Our AEV traveled along the track in a manner that hadn’t been observed since the code change. It stopped short of gates, slammed into them and didn’t connect to the caboose. We failed again and this time it really counted.
We didn’t let failure defeat us though. Although the AEV didn’t perform as we had hoped and didn’t meet all objectives of the project, our design resulted in a more efficient AEV. Our project had succeeded in that we had discovered how to increase the propulsion efficiency while keeping the input power low.
The project was an incredible learning experience. We faced several failures and overcame (most of) them with collaboration and problem solving skills. In the end, our AEV did not perform as expected but the project helped my team and I improve as engineers. I’m sure the next project will provide plenty of opportunity for failure… and improvement.
Hannah Moore finished her first year at The Ohio State University and was a summer intern at Jameco Electronics. Her love for math and science drove her to major in Electrical Engineering, which she is finding both challenging and fascinating.