Rebecca
MorettaMechanical Engineer

In this group project I was in charge of the mechanical design and assembly, as well as electrical design and sensor integration. I chose a robotic arm for its versatility and familiarity, modelling the design after palletizing arms used in industrial applications.

We began by outlining what the arm needed to accomplish, and I iterated several designs in SolidWorks. Once we settled on a final design, we simulated the arm's kinematics in MATLAB. For the electronics, I prototyped on a breadboard, then moved the finalized circuit to a perforated board for a clean build with no loose wires — choosing it over a manufactured PCB so shipping time wouldn't eat into testing.

During testing, the PETG gearboxes kept skipping due to the material's low rigidity. Reprinting them in PLA solved the problem, and I added a counterweight to help the arm carry its own weight.

I began by training an object detection model on about 40 images of white lines, yellow lines, red lines, and rubber ducks.

I then assembled the robot on a 3D-printed PETG base with four DC motors, four wheels, a Radxa Rock 5C board, a 12V battery, two DC motor drivers, and a PID board. After mapping each motor to the keyboard, I wrote a Python script that follows the midpoint between the lane lines using the detection model, then tuned the PID controls to improve the accuracy and speed of the robot's movement.

I began by designing a control heat sink with rectangular fins in an in-line array, then a second with the same fin shape and length in a staggered array. From there I continued designing heat sinks with varying fin cross-sectional geometry and fin lengths.

Every design was run through a SolidWorks thermal simulation with an applied convection, and the results were compared side by side.