Chattering free adaptive multivariable sliding mode controller for systems with matched and mismatched uncertainty

Area of Science:

• Control Systems Engineering
• Aerospace Engineering
• Robotics

Background:

• Multi-input multi-output (MIMO) systems are prevalent in various engineering applications, including aerospace and robotics.
• These systems often face challenges due to matched and mismatched uncertainties, impacting stability and performance.
• Conventional sliding mode controllers (SMCs) can suffer from chattering, a high-frequency oscillation that degrades system performance.

Purpose of the Study:

• To propose a novel chattering-free adaptive sliding mode controller (SMC) for stabilizing uncertain multi-input multi-output (MIMO) systems.
• To address both matched and mismatched uncertainties in the control design.
• To validate the controller's effectiveness using a realistic simulation of a vertical take-off and landing (VTOL) aircraft.

Main Methods:

• A proportional plus integral (PI) sliding surface is designed to ensure system stability.
• An adaptive gain tuning mechanism is incorporated to prevent overestimation and mitigate chattering.
• The proposed controller is applied to a mathematical model of a VTOL aircraft system for simulation.

Main Results:

• The adaptive SMC effectively stabilized the MIMO system despite the presence of matched and mismatched uncertainties.
• Chattering phenomenon was significantly reduced compared to traditional SMCs.
• Simulation results demonstrated robust performance and accurate trajectory tracking for the VTOL aircraft.

Conclusions:

• The proposed chattering-free adaptive SMC offers a robust solution for stabilizing uncertain MIMO systems.
• The adaptive gain tuning is crucial for preventing overestimation and enhancing control performance.
• The VTOL aircraft simulation confirms the practical applicability and effectiveness of the developed control strategy.