Robustness Of Sliding Mode Research Articles

Speed Control for PMSM with Fast-Terminal Super-Twisting Sliding Mode Controller via Extended State Disturbance Observer

Since robustness is only maintained on the sliding-mode surface, sliding mode control is inherently non-globally stable. Therefore, reducing the time to reach the sliding mode is crucial for enhancing sliding mode robustness. To improve the performance of conventional super-twisting reaching law (CSTRL) further, we propose a fast-terminal super-twisting reaching law (FTSTRL) designed to improve the quality of sliding mode control. This approach incorporates a terminal term and an exponential term with the CSTRL to ensure rapid convergence. The effectiveness of the designed FTSTRL is validated by comparing it to the CSTRL and a new sliding mode reaching law, demonstrating its superior performance. Finally, integrated square error (ISE), integrated time square error (ITSE), integrated absolute error (IAE), and integrated time absolute error (ITAE) are employed for detailed comparative and quantitative analyses of the simulation results.

Speed Control for PMSM with Fast Variable-Speed Sliding Mode Control via High-Gain Disturbance Observer

Since robustness only exists on the sliding mode/surface, sliding mode control is non-globally stable. Therefore, shortening the time to reach the sliding mode is an important method of improving sliding mode robustness. However, there is an inherent contradiction between rapidity and overshoot. Therefore, ensuring rapid convergence without overshoot is a worthwhile research problem. Consequently, this paper proposes a design for a fast variable speed reaching law (FVSRL) to improve the quality of sliding mode control. The constructed approach rate is based on a variable speed term, an exponential term, and a fast term, ensuring rapid convergence without overshoot. At the same time, a high-gain disturbance observer is employed for feedforward compensation. Finally, the designed reaching law is validated by comparing it with conventional exponential approach rates and a new sliding mode reaching law, demonstrating its superior performance. Detailed comparative and quantitative analyses of the simulation results using the conventional exponential reaching law, the new sliding mode reaching law, and the FVSRL are performed, utilizing metrics such as integrated square error, integral time square error, integrated absolute error, and integral time absolute error.

Sliding Mode Robust Active Disturbance Rejection Control for Single-Link Flexible Arm with Large Payload Variations

This paper proposes a novel robust control scheme for tip trajectory tracking of a lightweight flexible single-link arm. The developed control scheme deals with the influence of tip payload changes and disturbances during the working process of the flexible arm, thus realizing the accurate tracking for the tip reference trajectory. The robust control scheme is composed of an inner loop and an outer loop. The inner loop adopts the traditional PD control, and an active disturbance rejection control (ADRC) with a sliding mode (SM) compensation is designed in the outer loop. Moreover, the sliding mode compensation is mainly used to cope with the disturbance estimation error from the extended state observer (ESO), by which the insensitivity to tip payload variations and strong disturbance resistance is achieved. Finally, some numerical simulations are performed to support the theoretical analysis. The results show that the system is more robust to the tip mass variations of the arm and more resistant to the external torque after adding the sliding mode robustness term to the ADRC.

주기성 부하를 갖는 DC모터 속도제어 시스템의 SMC와 PI제어의 강인성 비교

주기성 부하를 갖는 DC모터 속도제어 시스템의 SMC와 PI제어의 강인성 비교

Sliding Mode Robustness Control Strategy for Shearer Height Adjusting System

This paper firstly established mathematical model of height adjusting hydro cylinder of the shearer, as well as the state space equation of the shearer height adjusting system. Secondly we designed a shearer automatic height adjusting controller adopting the sliding mode robustness control strategy. The height adjusting controller includes the sliding mode surface switching function based on Ackermann formula, as well as sliding mode control function with the improved butterworth filter. Then simulation of the height adjustment controller shows that the sliding mode robustness control solves buffeting of typical controller, and achieves automatic control for the rolling drum of the shearer. DOI : http://dx.doi.org/10.11591/telkomnika.v12i2.3734

Rotor position control for induction machines using diametrical inversion of stator voltage

To accurately solve the speed or rotor position control problem of an induction motor (IM), the key has been a proper design of a torque controller included in a cascaded control structure. The IM dynamic behaviour presents a nonlinear coupling between the flux and the torque and so the decoupling has been the first task, as in field-oriented control and direct torque control, where some feedback signals are obtained using observers. A recent IM command action, the diametrical inversion, whose implementation is easy and gives good results, uses the sliding mode. A mechanical first order switching function determines the successive application of IM stator voltage diametrical inversions. A torque controller is not needed, the sliding mode robustness eliminates the decoupling problem, and the fast inversion of the electromagnetic torque allows a rotor positioning faster than a torque controlled second order system. Some simulation and experimental results show the position responses and exhibit the system robustness to external disturbances and winding resistance variations with temperature.