Autopilot System for Agricultural Quadcopters with Aerial Imaging

This paper presents a GPS-guided autopilot system for agricultural quadcopters, enabling precise aerial monitoring of rice fields. The system uses a Texas Instruments Stellaris EK-LM4F120XL microcontroller, Naza-M Lite flight controller, and 5-megapixel Raspberry Pi NoIR camera to capture near-infrared imagery. A ground station with MATLAB-based software supports real-time GPS tracking, route visualization, and flight command transmission via a 433 MHz CC1101 RF module. The quadcopter operates in autopilot mode, following GPS-defined checkpoints with an average error of 0.5 meters, or manual mode via a handheld controller. Data transmission uses a serial protocol at 115,200 baud with headers, XOR-encoded coordinates, and checksums. A flowchart details the flight process with error correction and image capture at designated points. Aerial images are processed using NDVI to assess plant health through spectral reflectance. Experimental results confirm high positional accuracy. Future work includes pest detection, yield estimation, and improved flight stability. Developed by Can Tho University and Can Tho RC Club, the system shows promise for scalable agricultural monitoring, though further refinement is needed for reliability.