Stabilization and Tracking of a Quadrotor Using Modified Sigmoid Sliding Mode Control

Area of Science:

• Robotics and Control Systems
• Aerospace Engineering

Background:

• Quadrotor systems present challenges due to underactuation, nonlinearity, and coupled dynamics.
• Existing control methods struggle with achieving robust stabilization and precise tracking under disturbances.

Purpose of the Study:

• To propose a modified sigmoid sliding mode control (MS-SMC) for stabilizing and tracking nonlinear quadrotor systems.
• To enhance quadrotor performance by introducing a novel nonlinear sliding surface and control strategy.

Main Methods:

• Development of a modified sigmoid sliding surface for faster initial value convergence.
• Implementation of a double-loop control architecture (position outer loop, attitude inner loop).
• Utilization of Lyapunov functions to guarantee closed-loop system stability for each subsystem.

Main Results:

• The proposed MS-SMC demonstrated superior stabilization and tracking performance compared to conventional sliding mode control (CSMC) and back-stepping sliding mode control (BS-SMC).
• Effective handling of model uncertainties and external disturbances was confirmed through simulations.
• The modified sigmoid function facilitated quicker system equilibrium.

Conclusions:

• The MS-SMC approach offers a robust and effective solution for controlling complex quadrotor dynamics.
• This method provides improved performance and resilience against uncertainties and disturbances in quadrotor applications.