Design, Development, And Flight Testing Of A Pixhawk-Based Quadcopter Uav For Search And Rescue Operations Using Mission Planner Ground Control Station

Unmanned aerial vehicles (UAVs) have emerged as indispensable assets in search and rescue (SAR) operations, offering rapid deployment, real-time aerial reconnaissance, and significantly reduced risk to human personnel in hostile or inaccessible environments. This paper presents the comprehensive design, systematic hardware integration, firmware configuration, and extensive field evaluation of a quadcopter UAV specifically engineered for SAR missions. The flight controller is built on the Pixhawk 4 autopilot platform running the ArduCopter firmware stack, configured and monitored through the Mission Planner ground control station (GCS). A 500 mm glass-fiber S500 frame serves as the mechanical backbone, housing four 1000 KV brushless motors, 30 A electronic speed controllers (ESCs), and 10-inch carbon-fiber propellers selected through aerodynamic thrust analysis to achieve a maximum total thrust of 3920 g-yielding a thrust-to-weight ratio of 2.48 at maximum take-off weight. Dynamic modeling of the quadrotor is derived from Newton-Euler rigid-body mechanics, and a cascaded proportional-integral-derivative (PID) control architecture is tuned iteratively using Mission Planner's real-time parameter editor and AutoTune routines. The UAV integrates an RTK-capable GPS module, a 4K imaging payload mounted on a vibration-damped gimbal, a 915 MHz telemetry link, and an NVIDIA Jetson Nano companion computer for on-board image processing. A structured flight-test campaign comprising hover stability, waypoint navigation, wind-rejection, return-to-launch, and endurance trials was conducted across twelve flight sessions totaling 9.4 hours of airtime. Results demonstrate a positional hold accuracy of ±0.74 m, a maximum endurance of 18.9 minutes under SAR payload, and successful autonomous waypoint missions at altitudes up to 118.4 m above ground level. The paper contributes a fully documented, replicable, and cost-effective UAV development methodology applicable to academic research institutions and small SAR organizations operating under constrained budgets.