Atlas Stones Challenge - Day 4

Last class was the first trial day. We finished the general construction portion of the challenge, so we continued to work on coding. By the end of that class, our robot was able to lift and bring back one mass (50 grams); one third of the programming was completed. However, towards the last twenty-minutes, while running the track, the robot would make small, quick, jerking motions during turns. We knew that the distance of the wheels from the NXT Brick may have been causing a large amount of friction, but we were unsure if it was the cause of the jerking as well. For next class, we may rethink wheel placement and swivel size. We will definitely continue working towards a completed, efficient coding.

Atlas Stones Challenge - Day 3

Final robot design

Here is a picture of the final robot. As previously mentioned, my partner coded as I built, so we were able to test the robot as soon as it was completed. Something different I tried in terms of the winch was having it stretch from opposite ends of the robot. This would balance the mass distribution. I also added a 200 gram mass on the side of the winch and motor to counter the weight of the masses it'd be lifting. Based on some test trials, the robot's systems are running well and strongly. For the next class, we plan on trying to complete the programming. Maybe we will even be able to run our first trial.

Atlas Stones Challenge - Day 2

Robot by the end of Day 2

By the time I returned to class, my partner and I decided we would divide the work necessary to complete the challenge. I would be in charge of the design and construction of the robot while my partner would be in charge of the coding and actions of the robot; the coding in this challenge was much more difficult than before. I was able to complete the entire base of the robot within one class period. We decided that the foundation would be low to the ground to prevent it from tipping as we added upwards. Next class I plan finishing the rest of the body, mainly the winch.

Atlas Stones Challenge - Day 1

For the first day of the Atlas Stones Challenge, I was ill and had to miss class. Typically before the actual construction, we are supposed to evaluate the situation/challenge and brainstorm potential design ideas based on the requirements. Below is a Google Document describing the functions, systems, and integration of our robot. This was completed by my partner George Gikas when I was absent.

Transfer the Load with Winch Challenge - Day 5

Today was the final trial of the challenge. My partner and I had completed the initial requirements last class, so this time, we focused on gaining bonus points. Any team that lifted more than one mass would receive those points. Previously, our robot did not complete more than one cycle due to uneven weight distribution; the robot was top heavy. 

Below is a video of our robot completing two cycles of the challenge. It lifted a total of 400g (200g per mass). 

Final Thoughts 

I had more fun in this challenge than the first one; however, it was a lot more difficult. The robot was different than all the one's we created before, especially since it was not car-based. This time, we had to apply our knowledge of gear ratios in order for the robot to properly function, and we had to conduct multiple calculations.

Performance: As previously mentioned, our robot completed all requirements in order to receive full credit. Throughout the building process, we directed our focus to weight distribution and stability. We added counterweights to various places, allowing the mass to be lifted steadily. If we were to do this challenge again, we would more closely focus on the string that lifted the mass; it kept on slipping, limiting our robot to completing only two cycles.

Improvement and Learning: Thanks to this challenge, I am proud to say that I now understand the concept of "torque", for it is something I never understood before. To put it as my partner did, we also learned a lot about patience; taking apart and rebuilding practically defined our Winch Challenge experience. Because this trial was more successful than the last, I hope that my robot-building skills continue to increase as I move onto the next challenge. 

Transfer the Load with Winch Challenge - Day 4

Last class we completed the challenge! My partner and I fixed the sliding string by adding a second axle where it could loop over. We added a metal Lego hook to the end of the string to allow the string to smoothly return down. We also used the rubber Lego wheels as weights and balances. We noticed that each time we ran the program, the top motor would lean extremely far forward. Originally there were three support axles where it connected to, but we were able to find a location to insert a fourth one, greatly improving its stability. In order to receive full credit for the challenge, we needed to lift one mass up to the table, have the robot change directions while holding the mass, deposit it on a wooden block, and return to the ground. Bonus points would be awarded if the robot could lift multiple masses. We were very close to completing another cycle, but unfortunately it lifted the mass just short of the necessary height. Next class we still have another trial. By that time, we will try to enforce the robot even more, and hopefully receive extra credit.

Transfer the Load with Winch Challenge - Day 3

Design by the end of class

Last class was the first trial day. We were able to successfully balance our robot's systems by using what we learned from the previous unit. In the beginning of the challenge, each team was given two 100 gram masses to help with balancing mass distribution. We connected two long axles opposite to the end where the 200 gram mass was being lifted, and we hung the two 100 gram ones at the far end of the axles. Doing this greatly steadied our robot. As for programming, we were able to find decent power combinations to accommodate our gear ratio. With these two portions completed, our robot was practically set to complete the required actions; however, when put into motion, the string used to lift the mass kept on sliding out of place. Trying to prevent the string from slipping took up  most of our time. Unfortunately, due to lack  we missed our first trial opportunity. Hopefully next class we will be able to test our design.

Final code