For this project, we intend to create a mechanism that automates the planting process. Our requirements for this proposal included creating a linkage system that will dig out dirt, insert a seed into the hole, and push the soil back over the hole. Our initial design also proposed a method of watering the soil after the seed drop, but we did not follow through with this design in our prototypes. Furthermore, this motion will be performed by two tools, whose motion will be coupled, with the primary actions of each tool timed to happen in a certain order. One tool will dig out a hole for the seed, and then push the dirt back into place. The other tool will drop a seed into the hole after the hole is dug and before it’s covered back up. We also intend for there to be a feature that moves the entire structure holding the tools over by a small distance so that the process can be repeated on a new patch of soil. Our final prototype includes the addition of wheels to our mechanism, as recommended by judges on the prototype demonstration day.
Our mechanism was designed into two main components: a prismatic joint and a linkage system. The prismatic joint allows our entire system to move in the x-direction. On top of the prismatic joint will be a wall in the y-direction that is fixed on the plate. This fixed wall will hold the first link in our linkage system. This linkage system has 5 links, one of which is connected to the shovel head. By using MotionGen, we were able to see that this system does allow our shovel head to fully rotate and change in height to shovel dirt. Not included in the drawing: on top of one of the links is a closed tube that holds the seed and water. We hope to this design in a way that when that link reaches a certain angle, it will slightly shift a circular closed plate inside the tube that will allow the water and seed to come out.
Initial Sketch
Linkage System in MotionGen: From MotionGen, we are able to determine that think linkage system has two degrees of freedom.