Fault-tolerant control of second-order systems based on augmented improved extended state observer and non-singular high-order fast terminal sliding mode

Abstract

In this article, a fault-tolerant control method based on augmented improved extended state observer and non-singular high-order fast terminal sliding mode is proposed for a class of second-order systems with actuator faults. First, the initial peak of the traditional extended state observer is avoided by improving the structure of the observer. Second, the total disturbance and its change trend are observed simultaneously, so as to better realize the compensation of total disturbance. The convergence of the observer is proved theoretically. In addition, by designing non-singular high-order fast terminal sliding mode surface, the sliding mode variable converges rapidly during the whole process to improve the algorithm’s rapidity. Finally, the chattering of control signal caused by sliding mode control is greatly reduced using high-order sliding mode technology, and the stability of the whole closed-loop system is proved by Lyapunov criterion. The comparative experimental results on the fault-tolerant control platform of the quadrotor unmanned aerial vehicle demonstrate the effectiveness and superiority of the proposed observer and controller.

Research on speed sensorless control strategy of permanent magnet synchronous motor based on fuzzy super-twisting sliding mode observer

“…EKF 15 , 16 matrix has a large amount of calculation, high complexity, poor real-time performance, and large delay. MRAS 17 , 18 requires accurate model feedback parameters and cannot be used in large speed ranges; among them, SMO 19 – 24 is simpler than other methods. SMO has low requirements for the accuracy of the system model, is insensitive to parameter changes and external interference, and has strong robustness.…”

Novel robust approach–based dynamic global terminal synergetic tracking control for uncertain second-order systems: Wind turbine system and power converter applications

“…Although these mechanisms significantly enhance the convergence speed, the chattering effects still persist. On the other side, various types of SMCs with nonlinear surfaces have been studied 22,23 to guarantee the tracking errors of systems. The terminal sliding mode scheme is commonly used for this purpose, but it suffers from slow convergence speed and singularity issues.…”