An Adaptive Fault-Tolerant Sliding Mode Control Allocation Scheme for Multirotor Helicopter Subject to Simultaneous Actuator Faults

Abstract

This paper proposes a novel adaptive sliding mode based control allocation scheme for accommodating simultaneous actuator faults. The proposed control scheme includes two separate control modules with virtual control part and control allocation part, respectively. As a lowlevel control module, the control allocation/re-allocation scheme is used to distribute/redistribute virtual control signals among the available actuators under fault-free or faulty cases, respectively. In the case of simultaneous actuator faults, the control allocation and re-allocation module may fail to meet the required virtual control signal which will degrade the overall system stability. The proposed online adaptive scheme can seamlessly adjust the control gains for the high-level sliding mode control module and reconfigure the distribution of control signals to eliminate the effect of the virtual control error and maintain stability of the closed-loop system. In addition, with the help of the boundary layer for constructing the adaptation law, the overestimation of control gains is avoided, and the adaptation ceases once the sliding variable is within the boundary layer. A significant feature of this study is that the stability of the closed-loop system is guaranteed theoretically in the presence of simultaneous actuator faults. The effectiveness of the proposed control scheme is demonstrated by experimental results based on a modified unmanned multirotor helicopter under both single and simultaneous actuator faults conditions with comparison to a conventional sliding mode controller and a linear quadratic regulator scheme.

Adaptive Fault-Tolerant Sliding-Mode Control for High-Speed Trains With Actuator Faults and Uncertainties

“…The sliding-mode control has been used extensively to deal with fault-tolerant control (see, e.g. [21]- [22], [25]- [27]). However, the uncertainty existing in the input distribution matrix are rarely considered in the existing work, and specifically, the associate result for high-speed train has not been available.…”

“…There are many results about the fault-tolerant sliding-mode control design (see for example [21]- [22], [25]- [27]). However, the considered faults are always assumed to have known bounds or more information of faults, except the contributions mentioned in Remark 4.…”

“…As the position/speed tracking is the main task for trains to guarantee the on-time schedule, the adaptive technique is pertinent to high-speed trains with unknown faults. Moreover, the results about the adaptive fault-tolerant sliding-mode control are rare, although there are some works for the aircrafts [21], [22]. This paper is focused on the fault-tolerant control problem for the longitudinal dynamical model of high-speed trains with traction system actuator faults and uncertainties.…”

Intelligent trajectory tracking of an aircraft in the presence of internal and external disturbances

“…Fault‐tolerant flight control (FTC) schemes have been studied extensively in the literature . The dynamic model of an aircraft changes significantly after the fault occurrence, which leads to reduced effectiveness of the controllers that are designed based on a nominal model and in some cases the closed‐loop system becomes unstable after the fault occurrence.…”

Nonlinear Fault-Tolerant Trajectory Tracking Control of a Quadrotor UAV

“…It is easy to implement and can deal with nonlinear part of dynamic systems, satisfactorily. In addition, due to the robustness of the SMC, it can be used satisfactorily to maintain the closed-loop performance in the presence of model uncertainties and external disturbances [2].…”