In anticipation for Meet 1, we continued to fine-tune our autonomous and get more driver practice in. We are definitely making progress with Emilio getting used to the new drive-train on the robot, and having a better aim for the hook during end game. Since we could not strafe because we were not using Mecanum wheels, Emilio had to learn to line up the hook with the lander using our drive train every time. Therefore, we knew he needed to practice a lot and decided that we would allow Emilio to practice whenever we were not working on it.
We successfully finished the driver practice with some tuning on the mechanical parts and the program. From all the brainstorming we did throughout the past few weeks, we are confident for the robot will succeed the process of harvesting and scoring minerals in the depot in Meet 1.
After Andrew wired our meet 1 robot, we began to test how it cleared the crater and harvested the minerals using the sponge. We constructed the robot from wood. The zip-tie harvester was made by aligning 14 zip ties on a metal part. We covered the zip ties in surgical tubing to ensure more grip on the minerals and duck taped them to each other to make sure that the harvester was stiff enough to actually lift the minerals against gravity. Lastly, we added a sponge near the bottom because it was the best material to grip the minerals from the bottom since zip ties were not yet strong enough to start the harvesting cycle.
We were surprised out how violent the harvester worked but it was able to actually take the minerals and deposit them into our sorter. We also placed our pixy cam above the harvester and considered it the front. The hanger is behind the harvester for easier excess to the lander when the game was done. We decided to place this all above the drivetrain that we created from the compliant wheels.
Currently, we are making improvements on the robot and searching a replacement for the sponge.
We also discussed what we wanted the path of the autonomous and made a quick outline.
Today we worked on the harvester of the meet 1 version of our robot. We managed to create more traction on the zip ties by making them stiffer. After struggling with creating an efficient zip tie harvester we decided on trying out a sponge for the intake. We got inspiration from a past robot of ours that had the same idea. We also decided on having this robot ready to go by meet 1 which is one week from today.
Our robot is made out of plywood which was cut into parts for the robot such as the harvester, both outer walls including the back, the inner walls and the ceiling to secure all main power sources. We designed our robot to pick up and push minerals into the depot, at end game, the hook mechanism gets into action with the support of the Spiral elevator mechanism pushing the hook up by spiral rod spinning clockwise and counterclockwise allowing the robot to lift itself up and down.
We also created an outline for our robot placing the subsystems where we believed they would best work with each other. The harvester would grab the minerals and the depositor’s design ensured that only two would fit in there. This is another example of when we used a mechanical solution to a problem. Lastly, we placed the hook behind the harvester to ensure the easiest access to the lander at endgame.
Today we finally started to work on the first wooden robot of the season. We started by adding a motor for the harvester. After a lot of trail and error Emilio was able to make a functional chain and add zip ties to the harvester. Although the harvester does not currently work, we were one step closer to completing it.
Today we had our first competition of the season. Although it did not go as we hoped, we learned of many problems and many solutions that we may need to address. We found that our autonomous occasionally would stop working when the linear actuator would not reach its full height. We also lost 2 matches because of a loose set screw in the actuator.
We decided that from now on we must make a pre-match checklist to use in each of our competitions before each match in order to have the robot working to its full capacity every match. However, our hanger contraption worked very well and allowed us to score many points. Therefore, we decided to keep this design for our next version of our robot.
Today we improved the programming and worked on the pixy cam for the robot so that it can detect on gold and silvers minerals during our autonomous period. We were trying to understand the pixy cam and get used to using it. We found many things we like about the pixy cam but we also found that it is difficult to use. After much trial and error, we realized it was reliable but not the best solution to our problem.
Today we made progress with programming and prototyping, and we’re trying to get our robot in order. We prototyped a six-wheeled drive center drive train and tested to see if got over the crater. After many tests, we found various issues that are shown in the picture below. After the testing was finished we concluded that it wasn’t the best drive train for this year’s challenge.
Conclusion: This chassis get stuck on the crater. Moreover, the gears will grind up the crater and it will certainly be declared illegal. Therefore we must not use it.
Today we began to work on the autonomous for meet 0. Having a functional autonomous will score us at least 45 points every match. Besides that we worked on more prototyping and creating models for our designs.
After weeks of going over designs, we presented our ideas to Mr. Feldman and Mr. Zarzaca. Our tabletop review is an essential part of the design process that was introduced to us by JPL’s very own Mr. Feldman. This serves as an opportunity to receive constructive criticism from professional engineers who use their experience to judge and improve our mechanism’s design.
Here are the strategy notes and sketches that were recorded by Troy
We started off by explaining the game to our judges so they could get an understanding of the problem we have to overcome. We then covered our game strategy and the reasons why we decided on approaching the game that way. Next, we explained our mechanisms and how they follow our game strategy. We started off by explaining the smaller more simpler mechanisms such as the hook on a linear actuator and the team marker on a magnet. We also explained the main scoring mechanisms to them. We explained what we intended to go inside the crater with a zip tie harvester. However, Mr. Feldman and Mr. Ray first pointed out that having a harvester that can pick up both silver and gold minerals might have trouble going over the crater rim because of the low clearance required to pick up cubes. We elucidated the problem which it had not been something we had considered and asked for their input. On that occasion, we came up with the design of having either spring loaded or a complaint ramp at the bottom of the harvester.
A distinct look on the harvester strategy plans
Additionally, we proposed our idea for a lander scorer. We first proposed our idea that consisted off one arm that would essentially fling the mineral into the lander. Mr. Feldman and Mr. Ray both found that it did not properly sort the two minerals and would most likely result in a very inaccurate method of scoring. We then showed them our idea for a sorter. They loved the idea. The only problem was on how to get the sorter up to the corner of the lander. We explained our idea for an arm with a servo that keeps the sorter leveled and then dumps the minerals up top. Although they were fond of the idea, Mr. Feldman and Mr. Ray came up with the idea of a linkage that would perform all the necessary movements for the scorer. Mr. Feldman even offered to give us a linkage encyclopedia to find the proper linkage to use. We decided that if we are capable of making the proper linkage, this would be the route we would take for our scorer.