The Challenge
The Robofest Minefield Navigation Challenge required a swarm of micro aerial vehicles under 500g to autonomously map and mark safe corridors through a simulated minefield. We needed a custom flight architecture from scratch that could handle pathfinding and thermal detection. My role on the team focused on the mechanical engineering, custom payload design, structural optimization, and vibration isolation of the drone chassis.
Technical Deep Dive
Chassis Structural Optimization (FEA)
Static Structural Analysis: I engineered a lightweight Quad-X frame in SolidWorks, then performed structural Finite Element Analysis (FEA) in ANSYS. By simulating maximum thrust loads (up to 3.2 kg of static thrust at full throttle) on the motor mounts, I identified high-stress concentration zones at the arm roots. I iteratively optimized the rib layouts and wall thickness to maximize bending stiffness, reducing predicted deformation by 40% while keeping the frame weight strictly under the competition limits.
Vibration Modal Analysis: To prevent motor high-frequency vibrations from interfering with the flight controller sensors, I carried out a modal simulation in ANSYS to map the structural resonances of the 3D-printed chassis. By identifying the natural frequencies of the drone frame, I designed custom vibration-isolated silicone damping mounts for the avionics deck, shifting the frame’s resonant peaks away from the 100-300 Hz motor operating frequencies.
Payload Mechanisms & Marker Integration
Custom Payload Mounts: I designed and 3D-printed vibration-isolated mounts for the MLX90640 thermal arrays. I also engineered a lightweight, servo-driven liquid dispenser mechanism utilizing an SG90 micro servo. I relied on rapid FDM 3D printing iterations to refine the mechanism clearances and ensure reliable paint marking of safe pathways.
Avionics Integration: I designed a custom KiCad carrier PCB to integrate the Teensy 4.0/4.1 flight controller and the sensor suite (MPU-6050, optical flow, and barometer) directly onto the 3D-printed chassis deck.
Results
- Weight Optimization: I successfully integrated complex computing, sensing, and mechanical dispenser payloads while keeping the master drone at 469g and scout drones at 397g, well under the 500g limit.
- Structural Integrity: The FEA-validated chassis withstood landing impacts and high-acceleration flight maneuvers without cracking, proving the effectiveness of the optimized rib geometry.
- Competition Success: The synergy between my hardware designs and the team’s swarm software stack secured us a finalist position and a ₹2 lakh prize at Robofest Gujarat 5.0.