Event-Trigger-Based Adaptive Barrier Function Higher-Order Global Sliding Mode Control Technique for Quadrotor UAVs

This article proposes an event-triggered control technique based on an adaptive barrier function higher-order global sliding mode control (SMC) for a class of quadrotor unmanned aerial vehicles subject to model uncertainties and unknown external disturbances. The event-triggered control technique is considered to increase the sampling interval of the control signal updates, and at the same time, maintain the stability and increase the overall efficiency of the controlled system. Lyapunov's stability theory is considered to derive the adaptive continuous barrier function so as to completely eliminate the chattering phenomenon typically associated with SMC. The designed control law is smooth and continuous, and the system's states converge to a predetermined bound around the switching surface at a finite time. The effectiveness of the suggested control method is assessed using a simulation study in MATLAB-Simulink environment and considering a comparison analysis with other prevalent approaches. The proposed control scheme can also be used for finite-time fault-tolerant control of various types of quadrotors, such as infrared obstacle-avoidance quadrotors subject to time-delay and input saturation.