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

• Published in: IEEE transactions on industrial electronics (1982) Vol. 65; no. 5; pp. 4227 - 4236
• Main Authors: Wang, Ban, Zhang, Youmin
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Actuators; Adaptation; Adaptive control; Adaptive sliding mode control (SMC); Boundary layer stability; Closed loop systems; control allocation (CA)/reallocation; Control stability; Control systems; Fault tolerance; Fault tolerant systems; fault-tolerant control (FTC); Faults; hardware redundancy; Helicopters; Linear quadratic regulator; multirotor helicopter; On-line systems; Resource management; Rotors; simultaneous actuator faults; Sliding mode control; Systems stability; Unmanned aerial vehicles; Unmanned helicopters
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2017.2772153

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 low-level control module, the control allocation/reallocation scheme is used to distribute/redistribute virtual control signals among the available actuators under fault-free or faulty conditions, respectively. In the case of simultaneous actuator faults, the control allocation and reallocation 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 the 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.