Fault-Tolerant Control of Quadcopter UAVs Using Robust Adaptive Sliding Mode Approach

Abstract

In this paper, a fault-tolerant control method is proposed for quadcopter unmanned aerial vehicles (UAV) to account for system uncertainties and actuator faults. A mathematical model of the quadcopter UAV is first introduced when faults occur in actuators. A normal adaptive sliding mode control (NASMC) approach is proposed as a baseline controller to handle the chattering problem and system uncertainties, which does not require information of the upper bound. To improve the performance of the NASMC scheme, radial basis function neural networks are combined with an adaptive scheme to make a quick compensation in presence of system uncertainties and actuator faults. The Lyapunov theory is applied to verify the stability of the proposed methods. The effectiveness of modified ASMC algorithm is compared with that of NASMC using numerical examples under different faulty conditions.

Fault Diagnosis and Fault-Tolerant Control Scheme for Quadcopter UAVs with a Total Loss of Actuator

“…We choose the PID controller for translational movements because in a commercial quadcopter the position controller has a lower response than attitude controller. Moreover, when the attitude controller is robust to uncertainties and actuator faults, the performance of position controller will be enhanced as well [27]. The fault-tolerant controller is designed in Section 3.4 to reconfigure the allocation matrix of quadcopter to handle the complete actuator failure (fault estimation value is larger than threshold value).…”

“…The suggested FD scheme can estimate the magnitude of actuator faults over time and in the presence of disturbances of which the upper bound is unknown, which is modified from [25,26]. The FTC scheme contains two controllers: (1) an adaptive sliding mode controller is designed from a previous study [27], as long as the fault magnitude remains below a certain threshold, and (2) a fault-tolerant controller based on the reconfiguration technique, which is designed to compensate actuator faults above this threshold. Unlike previous studies, the proposed method aims to integrate FD and FTC scheme into the single unit with the goal to handle total loss of actuator.…”

Quadcopter Adaptive Trajectory Tracking Control: A New Approach via Backstepping Technique

“…It is undeniable that the conventional proportional-integral-derivative (PID) control is still widely used in a variety of many applications all over the world because it is uncomplicated to be applied and acceptably meet given requirements in many studies [7][8][9][10][11][12][13][14][15]. The authors [16][17][18][19] presented the use of a multi-loop control scheme (i.e., inner-loop and outer-loop) to control quadcopters in specific applications. Several authors improved a modified PID approach to design control laws based on nonlinear mathematical models to achieve a position tracking [20,21].…”

“…In horizontal flow, the virtual input r 1 is calculated by combining tracking error ξ and the time-derivative of reference in (23). At the next stage, by using the matrix A(U 1 , ψ) (19), r 1 , and the horizontal velocities, virtual control r 2 (26) is obtained to become the input of the aforementioned box [1]. After finding virtual control r 3 (31), the proposed adaptive law in the mentioned box [2] (41) and (42) cooperatives with r 3 and angular rateq to obtain the intermediate control law (40).…”

A Novel Filter Extracted Equivalent Control Based Fixed Frequency Sliding Mode Approach for Power Electronic Converters

“…Disturbance rejection, order reduction and capability to handle systems with un-modeled dynamics are the key properties of Sliding Mode Control (SMC) that make it a good choice to control non-linear systems with perturbations. The system under SMC becomes invariant to parametric changes and its performance is completely robust against matched disturbances [1][2][3][4]. Due to these properties, SMC finds a wide range of applications in motor control, PWM drives, power electronics, robotics, micro-grids and automotive control [5][6][7][8][9][10][11][12].…”