Study on Sliding Mode Control in Bidirectional DC/DC Converter Based on State Space Averaging Method

2014 ◽  
Vol 678 ◽  
pp. 399-405
Author(s):  
Yan Mei

Bidirectional DC/DC converter is used for the battery charging and discharging. The sliding mode controller based on state space averaging algorithm is used for controlling bidirectional DC/DC converter. Two kinds of working modes, buck mode and boost mode, have been analyzed and three kinds of working states which are consisted by two working modes have been deeply discussed, and the automatic switch logic diagram when battery charging and discharging through the bidirectional DC/DC converter has been presented. Situation of system based on S1, S2 conducting alternately has been studied, and the simulations were also presented. According to the results, the characteristics of good stability and transient can be confirmed.

Author(s):  
Imen Saidi ◽  
Asma Hammami

Introduction: In this paper, a robust sliding mode controller is developed to control an orthosis used for rehabilitation of lower limb. Materials and Methods: The orthosis is defined as a mechanical device intended to physically assist a human subject for the realization of his movements. It should be adapted to the human morphology, interacting in harmony with its movements, and providing the necessary efforts along the limbs to which it is attached. Results: The application of the sliding mode control to the Shank-orthosis system shows satisfactory dynamic response and tracking performances. Conclusion: In fact, position tracking and speed tracking errors are very small. The sliding mode controller effectively absorbs disturbance and parametric variations, hence the efficiency and robustness of our applied control.


2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Dilan Chen ◽  
Weidong Zhang

This paper is concerned with the sliding mode control for uncertain stochastic neutral systems with multiple delays. A switching surface is adopted first. Then, by means of linear matrix inequalities (LMIs), a sufficient condition is derived to ensure the global stochastic stability of the stochastic system in the sliding mode for all admissible uncertainties. The synthesized sliding mode controller guarantees the existence of the sliding mode.


Author(s):  
Jinwei Sun ◽  
JingYu Cong ◽  
Liang Gu ◽  
Mingming Dong

As the possibility of faults in active suspension actuators are higher and more severe compared to other components, this study presents a fault-tolerant control approach based on the second-order sliding mode control method. The aim of the controller is to improve riding comfort, guarantee handling stability, and provide adequate suspension stroke in the presence of disturbances and actuator faults. A nonlinear full-vehicle suspension system and hydraulic actuator with nonlinear characteristics are adopted for accurate control. Firstly, a nonlinear sliding manifold based on a nonsingular fast terminal sliding mode controller is introduced to suppress the sprung mass heave, pitch, and roll motions arising from road disturbances. Secondly, a second-order sliding mode-based super twisting controller is utilized to track the desired forces generated by the nonsingular fast terminal sliding mode controller with actuator faults and uncertainties. The controllers are robust against disturbances, uncertainties, and faults. Moreover, the stability of the super twisting controller is proved by the strong Lyapunov functions. Finally, numerical simulations are performed to demonstrate the effectiveness of the controller. Four different conditions, random road profile, bump road excitation, single-wheel bump excitation, and partial faults are considered. The main contributions of this study are: (1) combination of the above algorithms to deal with actuator faults and improve active suspension performance; (2) the controller proposed in this study has a simple structure. Simulation results indicate that the nonsingular fast terminal sliding mode super twisting controller can guarantee the performance of the closed-loop system under both faulty and healthy conditions.


2000 ◽  
Author(s):  
J. Choi ◽  
C. W. de Silva ◽  
V. J. Modi ◽  
A. K. Misra

Abstract This paper focuses a robust and knowledge-based control approach for multi-link robot manipulator systems. Based on the concepts of sliding-mode control and fuzzy logic control (FLC), a fuzzy sliding-mode controller has been developed in previous work. This controller possesses good robustness properties of sliding-mode control and the flexibility and ‘intelligent’ capabilities of knowledge-based control through the use of fuzzy logic. This paper presents experimental studies with fuzzy sliding-mode control as well as conventional sliding-mode control. The results show that the tracking error is guaranteed to converge to a specification in the presence of uncertainties. The performance of the fuzzy sliding-mode controller is found to be somewhat better than that of the conventional sliding-mode controller.


2007 ◽  
Vol 18-19 ◽  
pp. 79-86
Author(s):  
A.S. Kadalla ◽  
M.I. Onogu

The problem of precise control of the air – gap of magnetic levitation vehicles is considered in this paper. A sliding mode controller is designed for the levitation control task. Robustness of the controller was investigated using computer simulations. The results show that the controller is robust to parameter variations of up to ±13% and can tolerate disturbances up to ±400N/Kg.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Lin Chang ◽  
Yingjie Yu ◽  
Tingrui Liu

Flutter is an important form of wind turbine blade failure. Based on damping analysis, synthetically considering aeroelastic vibration instability of the blade and using the parameter fitting method, the aeroelastic flutter model of the pretwisted blade is built, with the simulation and emulation of flap and lead-lag directions flutter of the 2D dangerous cross section realized. Through the construction of two controllers, modular combinatorial sliding mode controller and sliding mode controller based on LMI for parameterized design suppress blade aeroelastic flutter. The results show that a better control effect can be achieved on the premise of the design of the precise parameters of the controller: the proposed sliding mode control algorithm based on LMI can effectively act on the aeroelastic system of the blade, significantly reduce the vibration frequency, and make the aeroelastic system converge to an acceptable static difference in a short time, which proves the effectiveness of sliding mode control in suppressing high-frequency vibration under high wind speed.


2020 ◽  
Vol 26 (17-18) ◽  
pp. 1425-1434 ◽  
Author(s):  
Sunhua Huang ◽  
Jie Wang

In this study, a fractional-order sliding mode controller is effectively proposed to stabilize a nonlinear power system in a fixed time. State trajectories of a nonlinear power system show nonlinear behaviors on the angle and frequency of the generator, phase angle, and magnitude of the load voltage, which would seriously affect the safe and stable operation of the power grid. Therefore, fractional calculus is applied to design a fractional-order sliding mode controller which can effectively suppress the inherent chattering phenomenon in sliding mode control to make the nonlinear power system converge to the equilibrium point in a fixed time based on the fixed-time stability theory. Compared with the finite-time control method, the convergence time of the proposed fixed-time fractional-order sliding mode controller is not dependent on the initial conditions and can be exactly evaluated, thus overcoming the shortcomings of the finite-time control method. Finally, superior performances of the fractional-order sliding mode controller are effectively verified by comparing with the existing finite-time control methods and integral order sliding mode control through numerical simulations.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Xing Fang ◽  
Fei Liu

A novel full-order terminal sliding-mode controller (FOTSMC) based on the finite-time disturbance observer (FTDO) is proposed for the “JIAOLONG” manned submersible with lumped disturbances. First, a finite-time disturbance observer (FTDO) is developed to estimate the lumped disturbances including the external disturbances and model uncertainties. Second, a full-order terminal sliding-mode surface is designed for the manned submersible, whose sliding-mode motion behaves as full-order dynamics rather than reduced-order dynamics in conventional sliding-mode control systems. Then, a continuous sliding-mode control law is developed to avoid chattering phenomenon, as well as to drive the system outputs to the desired reference trajectory in finite time. Furthermore, the closed-loop system stability analysis is given by Lyapunov theory. Finally, the simulation results demonstrate the satisfactory tracking performance and excellent disturbance rejection capability of the proposed finite-time disturbance observer based full-order terminal sliding-mode control (FTDO-FOTSMC) method.


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