scholarly journals Robustness control for nonlinear systems based on homogeneous prescribed sliding mode control

2021 ◽  
Vol 4 (2) ◽  
pp. 1019-1035
Author(s):  
PHU XUAN DO ◽  
HUNG QUOC NGUYEN
Keyword(s):  
Energy Consumption ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Control Function ◽  
Linear Matrix ◽  
Sliding Surface ◽  
Seat Suspension ◽  
Mode Control ◽  
Input Control ◽  
Severe Disturbance

This paper presents a new homogeneous control using dual sliding mode control, and robustness control using linear matrix inequality (LMI) constraints. The controller is applied for the severe disturbance. A sliding surface function, which relates to an exponential function and itself t-norm, is applied to save the energy consumption of the control system. The constraints related LMI are proposed with the matrices and vectors of the systems following the chosen matrices in control the energy for control. Solution of the constraints is also presented with new approach to save the time of calculation. In addition, the proof for the proposed controller is also presented by using the candidate Lyapunov function. In the input control function, the t-norm type is embedded to improve its performance in control disturbance. Besides of the t-norm, the modified sliding surface in the input control is also improve the energy for controlling. The combination of these robustness control elements would bring a new view for the design of control. The advantages of the controller are demonstrated via computer simulation for a seat suspension system. A magneto-rheological fluid seat suspension with its random disturbances is used. To prove the flexibility of the controller, the proposed approach is compared with an existing controller. The compared control has the same structure as shown in the proposed model. However, its design has a disadvantage in control the severe disturbance. The comparison between two controls is a clear view of distinct improvement. The results of simulations show that the controller provides better performance and stability of the system. The stability is also analyzed through the variation of the input control and power spectral density related energy consumption.

scholarly journals Adaptive Neural Network Sliding Mode Control for Nonlinear Singular Fractional Order Systems with Mismatched Uncertainties

2020 ◽  
Vol 4 (4) ◽  
pp. 50
Author(s):  
Xuefeng Zhang ◽  
Wenkai Huang
Keyword(s):  
Neural Network ◽  
Sliding Mode Control ◽  
Fractional Order ◽  
Sliding Mode ◽  
Rbf Neural Network ◽  
Linear Matrix ◽  
Fractional Order Systems ◽  
Sliding Surface ◽  
Mode Control ◽  
Necessary And Sufficient

This paper focuses on the sliding mode control (SMC) problem for a class of uncertain singular fractional order systems (SFOSs). The uncertainties occur in both state and derivative matrices. A radial basis function (RBF) neural network strategy was utilized to estimate the nonlinear terms of SFOSs. Firstly, by expanding the dimension of the SFOS, a novel sliding surface was constructed. A necessary and sufficient condition was given to ensure the admissibility of the SFOS while the system state moves on the sliding surface. The obtained results are linear matrix inequalities (LMIs), which are more general than the existing research. Then, the adaptive control law based on the RBF neural network was organized to guarantee that the SFOS reaches the sliding surface in a finite time. Finally, a simulation example is proposed to verify the validity of the designed procedures.

Modified Sliding Mode Control for Mismatched Uncertain Systems with Unknown Disturbances

2016 ◽  
Vol 829 ◽  
pp. 123-127
Author(s):  
Van Van Huynh ◽  
Thao Phuong Thi Nguyen
Keyword(s):  
Sliding Mode Control ◽  
Uncertain Systems ◽  
Sliding Mode ◽  
Existence Condition ◽  
Adaptive Sliding Mode Control ◽  
Linear Matrix ◽  
Control Law ◽  
Sliding Surface ◽  
Mode Control ◽  
System States

In this paper, a new sliding mode control law is developed for a class of mismatched uncertain systems with more general exogenous disturbances. First, we derive a new existence condition of linear sliding surface in terms of strict linear matrix inequalities such that the reduce-order sliding mode dynamics is is asymptotically stable. Second, we propose an adaptive sliding mode control law such that the system states reach the sliding surface in finite time and stay on its thereafter. Final, a numerical example is used to demonstrate the efficacy of the proposed method.

Finite-time H∞ sliding mode control of uncertain T-S fuzzy system with time-varying delay based on observer

2021 ◽  
Vol 40 (1) ◽  
pp. 983-999
Author(s):  
Huan Li ◽  
Pengyi Tang ◽  
Yuechao Ma
Keyword(s):  
Sliding Mode Control ◽  
Finite Time ◽  
Sliding Mode ◽  
Linear Matrix ◽  
Time Interval ◽  
Sliding Mode Controller ◽  
Time Varying ◽  
Sliding Surface ◽  
State Estimator ◽  
Mode Control

In this paper, a class of observer-based sliding mode controller is designed, and the finite-time H∞ control problem of uncertain T-S fuzzy systems with time-varying is studied. Firstly, an integral-type sliding surface function with time-delay is devised based on the state estimator, and sufficient criteria of finite-time bounded and finite-time H∞ bounded can be obtained for the T-S systems. Moreover, the proposed sliding mode control law is integrated to ensure the dynamics of controlled system into the sliding surface in a finite-time interval. Then, according to the linear matrix inequalities (LMIs), the desired gain matrices of fuzzy sliding mode controller and state estimator are derived. Finally, effectiveness gives some illustrative examples may be used to display the value of the current proposed method as well as a significant improvement.

scholarly journals Sliding Mode Control of the Vehicle Speed System Based on LMIs

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Hong-Liang Gao ◽  
Hong-Cong Zhang ◽  
Xiao-Ling Li
Keyword(s):  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Control Function ◽  
Linear Matrix ◽  
Vehicle Speed ◽  
Tracking Accuracy ◽  
Nonlinear Characteristics ◽  
State Observation ◽  
Mode Control

Due to the nonlinear characteristics of the vehicle speed system, its stability is difficult to control. This paper analyzes the stability and traceability of the vehicle speed system under nonlinear characteristics. A sliding mode control method of the nonlinear system state observation based on linear matrix inequalities (LMIs) is proposed. In the proposed control method, Lyapunov function is used as the control function to track the position and speed of the vehicle speed system in real time. In the design process of the controller, the successive scaling method (SSM) is designed to improve the tracking accuracy. The simulation results demonstrate that the sliding mode control can effectively track the position of the vehicle speed system, which has better stability and traceability for the nonlinear vehicle speed system.

scholarly journals Sliding Mode Control for Multiagent System with Time-Delay and Uncertainties: An LMI Approach

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Pengfei Guo ◽  
Jie Zhang ◽  
Ming Lyu ◽  
Yuming Bo
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Linear Matrix ◽  
Sliding Surface ◽  
Simple Method ◽  
Mode Control ◽  
Feedback Control Method ◽  
System With Time Delay

This paper considers the sliding mode control of multiagent systems (MAS) with time-delay and uncertainties in terms of linear matrix inequality (LMI). By constructing virtual feedback control method, the design of control system is simplified for time-delay independent system without uncertainties. For a class of uncertain systems with single time-delay, the essence of SMC design is analyzed in order to acquire a simple method for designing sliding surface. In terms of multiple timedelay system with uncertainties, a sufficient condition for sliding surface with independent time-delay is acquired, while control law is also designed to ensure the robust stability of closed-loop system. Finally, the effectiveness of conclusion is demonstrated by simulation results.

Sliding Mode Control Based on Novel Nonlinear Sliding Surface for a Class of Time-Varying Delay Systems

2014 ◽  
Vol 615 ◽  
pp. 375-381
Author(s):  
Qi Feng Ren ◽  
Cun Che Gao ◽  
Shu Hui Bi
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Sufficient Conditions ◽  
Delay Systems ◽  
Linear Matrix ◽  
Time Varying ◽  
Sliding Surface ◽  
Time Varying Delay ◽  
Mode Control ◽  
Varying Delay

The sliding mode control (SMC) design is discussed for a class of time-varying delay systems which is delay-range-dependent and rate-range-dependent. A novel time-varying nonlinear sliding surface is employed. The choice of nonlinear sliding surface is to change the state matrix of sliding mode system, which can combine the advantages of different conventional linear sliding surfaces. Thus the better transient qualities of system states, i.e., quicker response and smaller overshoot, can be achieved. The sufficient conditions ensuring the asymptotic stability of sliding mode are derived in terms of linear matrix inequalities. The algorithms deciding unknown parameters of the nonlinear sliding surface and the corresponding sliding mode controller are also presented. Finally, A numerical example is given to illustrate the effectiveness of the result here.

Neural Adaptive Sliding Mode Control for a Class of Nonlinear Neutral Delay Systems

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Yugang Niu ◽  
James Lam ◽  
Xingyu Wang ◽  
Daniel W. C. Ho
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Delay System ◽  
Delay Systems ◽  
Adaptive Sliding Mode Control ◽  
Linear Matrix ◽  
Sliding Surface ◽  
Neutral Delay ◽  
Neutral Delay Systems ◽  
Mode Control

This paper is concerned with the problem of sliding mode control (SMC) for a class of neutral delay systems with unknown nonlinear uncertainties that may not satisfy the norm-bounded condition. A SMC scheme based on neural-network approximation is proposed for the uncertain neutral delay system. By means of linear matrix inequality (LMI) approach, a sufficient condition is given such that the resultant closed-loop system is guaranteed to be stable, and the states asymptotically converge to zero. When the LMI is feasible, the designs of both the sliding surface and the sliding mode control law can be easily obtained via convex optimization. It is shown that the state trajectories are driven toward the specified sliding surface that depends on the current states as well as the delayed states. Finally, a simulation result is given to illustrate the effectiveness of the proposed method.

scholarly journals Discrete-Time Sliding-Mode Control of Uncertain Systems with Time-Varying Delays via Descriptor Approach

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
Maode Yan ◽  
Aryan Saadat Mehr ◽  
Yang Shi
Keyword(s):  
Sliding Mode Control ◽  
Discrete Time ◽  
Sliding Mode ◽  
Existence Condition ◽  
Linear Matrix ◽  
Time Varying ◽  
Sliding Surface ◽  
Mode Control ◽  
Descriptor Approach ◽  
Delay Dependent

This paper considers the problem of robust discrete-time sliding-mode control (DT-SMC) design for a class of uncertain linear systems with time-varying delays. By applying a descriptor model transformation and Moon's inequality for bounding cross terms, a delay-dependent sufficient condition for the existence of stable sliding surface is given in terms of linear matrix inequalities (LMIs). Based on this existence condition, the synthesized sliding mode controller can guarantee the sliding-mode reaching condition of the specified discrete-time sliding surface for all admissible uncertainties and time-varying delays. An illustrative example verifies the effectiveness of the proposed method.

scholarly journals New Time-Varying Sliding Surface for Switching Type Quasi-Sliding Mode Control

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3811
Author(s):  
Katarzyna Adamiak ◽  
Andrzej Bartoszewicz
Keyword(s):  
Sliding Mode Control ◽  
Continuous Time ◽  
Sliding Mode ◽  
Representative Point ◽  
Time Varying ◽  
Sliding Surface ◽  
External Disturbances ◽  
Mode Control ◽  
Switching Type ◽  
Time Systems

This study considers the problem of energetical efficiency in switching type sliding mode control of discrete-time systems. The aim of this work is to reduce the quasi-sliding mode band-width and, as follows, the necessary control input, through an application of a new type of time-varying sliding hyperplane in quasi-sliding mode control of sampled time systems. Although time-varying sliding hyperplanes are well known to provide insensitivity to matched external disturbances and uncertainties of the model in the whole range of motion for continuous-time systems, their application in the discrete-time case has never been studied in detail. Therefore, this paper proposes a sliding surface, which crosses the system’s representative point at the initial step and then shifts in the state space according to the pre-generated demand profile of the sliding variable. Next, a controller for a real perturbed plant is designed so that it drives the system’s representative point to its reference position on the sliding plane in each step. Therefore, the impact of external disturbances on the system’s trajectory is minimized, which leads to a reduction of the necessary control effort. Moreover, thanks to a new reaching law applied in the reference profile generator, the sliding surface shift in each step is strictly limited and a switching type of motion occurs. Finally, under the assumption of boundedness and smoothness of continuous-time disturbance, a compensation scheme is added. It is proved that this control strategy reduces the quasi-sliding mode band-width from O(T) to O(T3) order from the very beginning of the regulation process. Moreover, it is shown that the maximum state variable errors become of O(T3) order as well. These achievements directly reduce the energy consumption in the closed-loop system, which is nowadays one of the crucial factors in control engineering.

Robust sliding mode control for a class of underactuated systems with mismatched uncertainties

2009 ◽  
Vol 223 (6) ◽  
pp. 785-795 ◽  
Author(s):  
D W Qian ◽  
X J Liu ◽  
J Q Yi
Keyword(s):  
Robust Control ◽  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Underactuated Systems ◽  
Sliding Surface ◽  
Nominal System ◽  
Sliding Surfaces ◽  
Mode Control ◽  
Mismatched Uncertainties

Based on the sliding mode control methodology, this paper presents a robust control strategy for underactuated systems with mismatched uncertainties. The system consists of a nominal system and the mismatched uncertainties. Since the nominal system can be considered to be made up of several subsystems, a hierarchical structure for the sliding surfaces is designed. This is achieved by taking the sliding surface of one of the subsystems as the first-layer sliding surface and using this sliding surface and the sliding surface of another subsystem to construct the second-layer sliding surface. This process continues till the sliding surfaces of all the subsystems are included. A lumped sliding mode compensator is designed at the last-layer sliding surface. The asymptotic stability of all of the layer sliding surfaces and the sliding surface of each subsystem is proven. Simulation results show the validity of this robust control method through stabilization control of a system consisting of two inverted pendulums and mismatched uncertainties.

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