scholarly journals Robust nonsingular sliding mode control of the maglev train system: case study

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Kammogne Soup Tewa Alain ◽  
Kenmogne Fabien ◽  
Siewe Siewe Martin ◽  
Fotsin Hilaire Bertrand

AbstractThis paper deals with a new approach to explore the precise dynamic response of the maglev system train and its control. Magnetic-suspension systems are characterized by high nonlinearity and open-loop instability which are the core components of maglev vehicles. Firstly, we use the electromagnetics and mechanics laws to derive the mathematical expressions of the proposed maglev system. Analytical investigation and theoretical calculation show that for the specific values of the control system parameters, the maglev system train can be significantly improved. It points out that the inherent nonlinearity, the inner coupling, misalignments between the sensors and actuators, and external disturbances are the main issues that should be considered for maglev engineering. Secondly, a control strategy based on the precise model of a nonsing ular robust sliding mode control is designed to reduce the upper bound of both the uncertainty and interference of the sliding mode controller. This approach presents an added value compared to the new sliding control methods in terms of overshoot and speed of convergence which is designed to control the vertical position of the proposed system. By using rigorous mathematical transformation associated with the adaptation laws in the frequency domain, a sufficient condition is drawn for the stability of the dynamical error based on the Lyapunov theory. This allows us a great possibility for interpreting the operation of the maglev train system. Numerical results are presented to show the effectiveness of our proposed control scheme.

Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2424
Author(s):  
Yong Yang ◽  
Yunbing Yan ◽  
Xiaowei Xu

It is difficult to model and determine the parameters of the steer-by-wire (SBW) system accurately, and the perturbation is variable with complex and changeable tire–road conditions. In order to improve the control performance of the vehicle SBW system, an adaptive fast super-twisting sliding mode control (AFST-SMC) scheme with time-delay estimation (TDE) is proposed. The proposed scheme uses TDE to acquire the lumped dynamics in a simple way and establishes a practical model-free structure. Then, a fractional order (FO) sliding mode surface and a fast super-twisting sliding mode control structure were designed on the basic super-twisting sliding mode to ensure fast convergence and high control accuracy. Since the uncertain boundary information of the actual system is unknown, a novel adaptive algorithm is proposed to regulate the control gain based on the control errors. Theoretical analysis concerning system stability is given based on the Lyapunov theory. Finally, the effectiveness of the method is verified through comparative experiments. The results show that the proposed TDE-AFST-FOSMC control scheme has the advantages of model-free, fast response and high accuracy.


Author(s):  
Cheng Cheng ◽  
Songyong Liu ◽  
Hongzhuang Wu

This paper proposes an observer-based sliding mode control method for electro-hydraulic servo systems with uncertain nonlinearities, external disturbances, and immeasurable states. The mathematical model is built based on the principle of electro-hydraulic servo systems. Owing to its highly robustness and finite time properties, the sliding mode observer is chosen and designed to estimate the velocity and the equivalent pressure online only using the position feedback. Then, in order to tackle the chattering problem of conventional sliding mode control and increase the control accuracy, a novel second-order sliding mode control scheme is proposed based on the fractional-order proportional–integral–derivative sliding surface and the state observer. The stability of the overall system is proved by Lyapunov theory. Finally, the detailed simulations are conducted, which include the comparative analysis of control performance with other methods and the study of observation performance.


Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2990
Author(s):  
Yang ◽  
Liao

Since the zero initial conditions of the boost converter are far from the target equilibrium point, the overshoot of the input current and the output voltage will cause energy loss during the start-up process when the converter adopts the commonly used small-signal model design control method. This paper presents a sliding mode control strategy that combines two switching surfaces. One switching surface based on the large-signal model is employed for the start-up to minimize inrush current and voltage overshoot. The stability of this strategy is verified by Lyapunov theory and simulation. Once the converter reaches the steady-state, the other switching surface with PI compensation of voltage error is employed to improve the robustness. The latter switching surface, which is adopted to regulate the voltage, can not only suppress the perturbation of input voltage and load, but also achieve a better dynamic process and a zero steady-state error. Furthermore, the discrete sliding mode controller is implemented by digital signal processor (DSP). Finally, the results of simulation, experiment and theoretical analysis are consistent.


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.


2018 ◽  
Vol 41 (4) ◽  
pp. 1068-1078 ◽  
Author(s):  
Lu Liu ◽  
Shihong Ding ◽  
Li Ma ◽  
Haibin Sun

In this paper, a novel discontinuous second-order sliding mode control approach has been developed to handle sliding mode dynamics with a nonvanishing mismatched disturbance by using Lyapunov theory and a finite-time disturbance observer. Firstly, the finite-time disturbance observer is designed to estimate the nonvanishing mismatched disturbance. Secondly, a virtual controller has been constructed based on the estimated value such that the sliding variable can be stabilized to zero in a finite time. Then, the real discontinuous controller is designed to guarantee that the virtual controller can be well tracked in a finite time. Lyapunov analysis also verifies the finite-time stability of the closed-loop sliding mode control system. The developed discontinuous second-order sliding mode control method possesses two appealing features including strong robustness with respect to the matched and mismatched nonvanishing disturbances, and relaxation on the constant upper bound of uncertainties widely used in a conventional second-order sliding mode. Finally, an academic example is illustrated to verify the effectiveness of the proposed method.


2011 ◽  
Vol 14 (4) ◽  
pp. 92-105
Author(s):  
Hai Thanh Nguyen ◽  
Nghia Hoai Duong ◽  
Chuyen Quang Lam

The adaptive sliding mode control for civil structures using Magnetorheological (MR) dampers is proposed for reducing the vibration of the building in this paper. Firstly, the indirect sliding mode control of the structures using these MR dampers is designed. Therefore, in order to solve the nonlinear problem generated by the indirect control, an adaptive law for sliding mode control (SMC) is applied to take into account the controller robustness. Secondly, the adaptive SMC is calculated for the stability of the system based on the Lyapunov theory. Finally, simulation results are shown to demonstrate the effectiveness of the proposed controller.


2020 ◽  
Vol 31 (1) ◽  
pp. 68-76

We constitute a control system for overhead crane with simultaneous motion of trolley and payload hoist to destinations and suppression of payload swing. Controller core made by sliding mode control (SMC) assures the robustness. This control structure is inflexible since using fixed gains. For overcoming this weakness, we integrate variable fractional-order derivative into SMC that leads to an adaptive system with adjustable parameters. We use Mittag–Leffler stability, an enhanced version of Lyapunov theory, to analyze the convergence of closed-loop system. Applying the controller to a practical crane shows the efficiency of proposed control approach. The controller works well and keeps the output responses consistent despite the large variation of crane parameters.


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