Semi-Autonomous Non-singular Terminal Sliding Mode Control of a Micro Aerial Robot for Outdoor Wall Climbing Operation

In this work, a non-singular terminal mode sliding mode controller is developed for output tracking with unmodeled dynamics, parameter uncertainty, and constrained disturbances, allowing the micro aerial robot to climb the wall. In order to successfully eliminate chattering in control action, it is recommended to use a modified power rate reaching law. Using Lyapunov’s criterion, we demonstrate stability over finite intervals of time. The effectiveness of the suggested control for trajectory tracking and wall climbing under conditions of parametric uncertainty and disturbances is shown via simulation. The suggested controller is compared to conventional sliding mode techniques to validate the claimed decrease in chattering. The suggested control strategy for free-flight and wall-climbing operations in GPS-denied outdoor settings is validated by real-time trials with a modified Crazyflie nano-quadcopter.