UAV Auto-Route & Angle Correction

Autonomous UAV Flight Controller
Sep- Dec 2024
4 Months Development
Project praised by the department

Project Overview

This project introduces a low-power PID-based control framework for fixed-wing UAV stabilization and trajectory correction. Instead of relying on thrust-vectoring or high-RPM motors, the system employs aerodynamic control surfaces (ailerons, elevator, rudder) actuated by servos, guided by real-time IMU feedback. Implemented on an STM32 microcontroller with a custom PCB shield, the design achieves energy-efficient orientation control using minimal sensors.

A key innovation lies in its bounded flap-angle correction strategy, which applies proportional surface deflections across error ranges, saturating only at extremes. This pragmatic approach ensures robust stabilization with low computational load, making it particularly suited for long-endurance, resource-constrained UAVs.

Originally built as a demonstration prototype, this work evolved into a research paper titled “IMU-Fused PID Control Framework for Autonomous UAV Stabilization and Trajectory Correction.”

Project Gallery

UAV - Autonomous Navigation Table Test
Custom Flight Controller PCB Design v1.0
Simulated PID results
UAV Prototype Visualization
Block Diagram

Technical Specifications

Microchip

Core Controller:

STM32F446RE

32-bit ARM Cortex-M4 microcontroller running real-time PID loops for stable flight control

IMU

Sensor Suite:

ArduIMU v3

9-DOF IMU providing fused orientation data via UART for precise attitude measurement

Servo

Actuation:

Standard RC Servos

Controlling ailerons, elevator, and rudder for accurate maneuvering and stability

Microchip

Custom Hardware:

In-house PCB Shield

Handles power regulation, IO hub functions, and noise-free routing for clean signal transmission

Microchip

Firmware:

STM32CubeIDE

Modular firmware with dedicated PID loops for each axis, ensuring responsive flight control

Results & Validation

  • Successfully corrected large initial disturbances (Roll: 72°, Pitch: 23°, Yaw: 41°) back to level orientation (0°) in simulations.
  • Ground test-bench validation confirmed smooth servo actuation proportional to pitch/roll/yaw deviations with negligible overshoot.
  • Correction speed hierarchy: Roll stabilized fastest, followed by Pitch, with Yaw converging slowest due to lower control authority.
  • System demonstrated low-latency, real-time response using STM32 with IMU feedback loop.
  • Achieved stabilization with lower power consumption compared to thrust-vectoring approach, making it suitable for endurance UAVs.