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Paper details
Number 3 - September 2015
Volume 25 - 2015
Design of passive fault-tolerant controllers of a quadrotor based on sliding mode theory
Abdel-Razzak Merheb, Hassan Noura, François Bateman
Abstract
In this paper, sliding mode control is used to develop two passive fault tolerant controllers for an AscTec Pelican UAV
quadrotor. In the first approach, a regular sliding mode controller (SMC) augmented with an integrator uses the robustness
property of variable structure control to tolerate partial actuator faults. The second approach is a cascaded sliding mode
controller with an inner and outer SMC loops. In this configuration, faults are tolerated in the fast inner loop controlling
the velocity system. Tuning the controllers to find the optimal values of the sliding mode controller gains is made using the
ecological systems algorithm (ESA), a biologically inspired stochastic search algorithm based on the natural equilibrium of
animal species. The controllers are tested using SIMULINK in the presence of two different types of actuator faults, partial
loss of motor power affecting all the motors at once, and partial loss of motor speed. Results of the quadrotor following a
continuous path demonstrated the effectiveness of the controllers, which are able to tolerate a significant number of actuator
faults despite the lack of hardware redundancy in the quadrotor system. Tuning the controller using a faulty system improves
further its ability to afford more severe faults. Simulation results show that passive schemes reserve their important role in
fault tolerant control and are complementary to active techniques.
Keywords
quadrotor UAV control, fault tolerant control, sliding mode control, cascaded SMC, bio-inspired gain tuning