IAM3D Payload Pickup Competition¶
Thesis
My team was tasked with designing and simulating a drone capable of completeing the IAM3D payload challenge. This challenge consisted of picking up a small 100g block of PLA and racing around an obstacle course in under 15 minutes. I was selected to be the CAD / hardware engineer due to my previous experience.
After a few technical reviews our team had reached our final component specs. We were using off the shelf ESCs, motors, and an electromagnet for pickup.
Design
I approached the design as I always do:
- Manufacturning method - Is it being 3D printed, injection molded, CNC
- Electromechanical access - All those wires need to lead to somewhere
- Ease of assembly / disassembly - Hard to reach places are even harder to screw bolts into
One stipulation of this challenge was: the more parts 3D printed parts on the drone, the higher the design score. Through a few design reviews the initial concept evolved into a compact drone that consisted of 20 3d printed parts. This design had two cameras, one in the front for racing views and one in the bottom for payload views.
Cross Section
Side View
Top View
Simulation
One of the main parts of our senior design was validation. Since we were not actually building or flying this drone, we were expected to validate our design and component choices using simulation. All simulations were ran in SolidWorks flow sim.
To ensure the batter had proper cooling I ran CFD. This was run assuming slowest flight speeds possible, as low as 2.25m/s. The results did show higher temperatures than expected around the 4S battery. This caused the team to switch from PLA to PETG for the battery standoff.
Battery Cooling
To ensure the landing legs could take a hard landing impact, FEA was run. Through some rough calculations, the force of a 15mph deceleration was found and applied evenly to all four feet. Given that plastics are hard to simulate, our factor of safety was lower than imagined at a 2. This is likely due to the complexity of printed plastics anistropic nature.
15mph Landing