An integral sliding mode fault tolerant control for a class of non-linear Lipschitz systems

This paper proposes an active fault-tolerant control (FTC) strategy for a class of non-linear Lipschitz systems. The proposed FTC approach employs the integral sliding mode control (ISMC) technique due to its inherent capability of dealing with system uncertainties. First, under the nominal fault-free condition, the linear matrix inequality technique is introduced to design the primary controller for the non-linear Lipschitz system. To accommodate the actuator faults/failures, the ISMC law is combined with a control allocation scheme that distributes the control signals to the redundant actuators. A non-linear octorotor system is then used as a test bench to validate the tolerance performance of the proposed FTC strategy. In particular, the proposed FTC strategy is applied for the inner-loop control, while in the outer loop, a fractional-order control approach is used to achieve the precise longitude and latitude control. Finally, various simulations are performed to justify the effectiveness of the proposed control scheme.