We were really happy with the progress we made last week. This week was really putting the final touches on everything. I attached the reloading hopper to the back of the device along with the affixing the Jetson in the case. I also tuned the distance function of the launcher to match up with the distance that the CV system sends over.
I started testing more to gather data for the launcher metrics. These tests are the same as the ones we presented but I just want to make sure we have a sufficient pool of data to work with for our final report and poster.
Overall I’m proud of what we made. I think it was an interesting challenge and I’ve enjoyed getting this up and running.
This week JP and I did most of our work together in TechSpark. We went through 5-6 different versions of the loading mechanism for the launcher, starting from a ramp, and ending up with a small mechanism that uses a servo to push the ball into the spinning motors.
One thing that we noticed right away was that the long distance between the point the ball starts and the motors introduced a lot of inconsistency in both the direction and the power of the launch. We addressed this by moving the servo closer to the motors so we could precisely control the speed that the ball enters the motors as well.
The other big development of the week is I assembled the final launcher mechanism and placed it in the housing. There was a lot of troubleshooting we had to do to get the serial communication figured out between the nano and the arduino but we left techspark Friday in a really good place; we had the cup detection measure the distance to a cup we placed at an angle away from the robot, then it sent the angle and distance to the Arduino, which initiated the launch sequence, turning the launcher towards the cup, and shooting the ball at the correct distance to land in the cup.
Over the last two weeks we have made really amazing progress towards our final project. My main focus has been going through many iterations of the physical design, testing, and refining. The design for the launcher is fully made of parts to be laser cut so it is really easy to iterate on and quick to fabricate. The design we have landed on incorporates two plates to mount the motors. The second was necessary to mitigate the strong vibration that was introducing a lot of uncertainty in our shots. Another large change we made while iterating on our physical prototypes was the choice to angle the motors themselves, rather than have a ramp that would come after the straight motors. This made many aspects of the launcher much simpler, especially our loading mechanism. We found that having as little interference as possible after the ball leaves the wheels was the best way to increase consistency in our launches.
Test of our slide loading system:
Earlier test of just the launching mechanism:
With the aiming done, all we need to do to integrate the launcher with the aiming is to screw the base of the unit into the stepper motor shaft. Our immediate focus right now is to get our consistency higher. We are going to fabricate one last version of the launcher, along with a mount. As it stands, we have enough control to aim for the back of the formation vs the front, but not enough to distinguish between the individual rows. A lot of this is from the vibration and the fact that it isn’t yet secured in the housing and should be remedied in the final assembly. Even as it is now, we had a few of our friends toss balls at the same formation and they were about as accurate as our project, if not a little bit worse. It’s really exciting to see everything finally come together.
