Nonlinear Robust Control of a New Reconfigurable Unmanned Aerial Vehicle

Abstract

In this paper, a nonlinear robust Fast Terminal Sliding Mode Controller (FTSMC) is designed to control and stabilize a new reconfigurable Unmanned Aerial Vehicle (UAV) in the presence of uncertain and variable parameters. The studied UAV is an over-actuated system due the number of actuator control inputs. It can modify the length and the angles between its four arms in different ways, which result an important variation in its Center of Gravity (CoG), inertia, and control matrix. The proposed FTSMC offers many advantages such as, reaching the desired states in a finite-time unlike the conventional sliding mode, robustness vis-a-vis uncertain and unknown parameters, fast convergence towards the sliding surface, high accuracy and reducing the chattering phenomena. Furthermore, the closed-loop stability of the this UAV is ensured by the Lyapunov theory. The eight actuators used to rotate and extend the UAV arms are controlled by simple Proportional Integral Derivative (PID) controllers. Lastly, the robustness and efficiency of the proposed controller are evaluated through a flight scenario, where the UAV geometric parameters are variable over time.

Adaptive integral backstepping control of a reconfigurable quadrotor with variable parameters’ estimation

“…In this section, we will introduce the dynamic model, which incorporates all the geometric changes of the reconfigurable quadrotor shape. This model is developed to extend first our previous research works, 26,30,31 second to ameliorate the models existing in the literature, and third to use it later in the control loop.…”

Sliding Mode Controller Based on the Sliding Mode Observer for a QBall 2+ Quadcopter with Experimental Validation

“…Moreover, they have a simple mechanical design, a small size and a low cost [1,2,3,4,5,6,7]. Quadrotors are widely exploited in military and civilian missions such as, search and rescue, mapping, protection of sensitive points, and infrastructure inspection [8,9,10,11,12]. The QBall 2 quadcopter is an innovative platform intended for scientific research to fly indoor using Optitrack Flex-3 cameras [13].…”

Adaptive Attitude Control for Foldable Quadrotors

“…Also, not accounting for any modeling uncertainties, such as inertia or aerodynamics, can further deteriorate the tracking performance. In this context, robust controllers have been explored to obtain the desired tracking performance by considering bounded model uncertainties [4]- [7]. The uncertainty bounds for these systems are generally held constant across the various configurations, and may lead to chattering in the control inputs [8].…”