Discrete-Time Sliding Mode Control for Nonlinear Systems With Unmatched Uncertainties and Uncertain Control Vector

1997 ◽  
Vol 119 (3) ◽  
pp. 503-512 ◽  
Author(s):  
E. A. Misawa
Keyword(s):  
Boundary Layer ◽  
Sliding Mode Control ◽  
Discrete Time ◽  
Sliding Mode ◽  
Control Technique ◽  
Control Vector ◽  
Smooth Functions ◽  
Mode Control ◽  
Modeling Errors ◽  
Unmatched Uncertainties

This paper presents a technique for control system design that provides robust stability in the presence of bounded modeling errors. The proposed method is a discrete-time version of a well known sliding mode control technique with saturation functions that generates the boundary layer without requiring either matched uncertainties or smooth functions. It is shown that the boundary layer can be made attractive and that the boundary layer thickness is bounded under mild coditions. It is also shown that asymptotic stability can be guaranteed if the available model is assumed to be perfect. An example is used to illustrate the proposed design technique.

scholarly journals Sliding Mode Control for Active Suspension System with Data Acquisition Delay

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Uiliam Nelson L. T. Alves ◽  
José Paulo F. Garcia ◽  
Marcelo C. M. Teixeira ◽  
Saulo C. Garcia ◽  
Fernando B. Rodrigues
Keyword(s):  
Sliding Mode Control ◽  
Discrete Time ◽  
Control Strategy ◽  
Continuous Time ◽  
Sliding Mode ◽  
Experimental Tests ◽  
Active Suspension ◽  
Suspension System ◽  
Control Technique ◽  
Mode Control

This paper addresses the problem of control of an active suspension system accomplished using a computer. Delay in the states due to the acquisition and transmission of data from sensors to the controller is taken into account. The proposed control strategy uses state predictors along with sliding mode control technique. Two approaches are made: a continuous-time and a discrete-time control. The proposed designs, continuous-time and discrete-time, are applied to the active suspension module simulator from Quanser. Results from computer simulations and experimental tests are analyzed to show the effectiveness of the proposed control strategy.

Boundary Layer Eigenvalues in SISO Discrete-Time Sliding Mode Control with Observer

2006 ◽  
Vol 128 (3) ◽  
pp. 729-730
Author(s):  
Hanz Richter ◽  
Eduardo A. Misawa
Keyword(s):  
Boundary Layer ◽  
Sliding Mode Control ◽  
Discrete Time ◽  
Sliding Mode ◽  
Tracking Error ◽  
System Matrix ◽  
Mode Control ◽  
Sliding Manifold ◽  
Error Dynamics ◽  
Linear State

A result that allows us to specify the sliding manifold in observer-based discrete-time sliding mode control is presented. Selection of coefficients is done by analyzing the tracking error dynamics inside the boundary layer, where the closed-loop system has a linear state feedback configuration, rather than assuming that ideal sliding occurs. The result facilitates assignment of eigenvalues for the system matrix which defines such linear dynamics.

Quantitative Feedback Theory (QFT) for Chattering Reduction and Improved Tracking in Sliding Mode Control (SMC)

2003 ◽  
Vol 125 (4) ◽  
pp. 665-669 ◽  
Author(s):  
E. Z. Taha, ◽  
G. S. Happawana, ◽  
Y. Hurmuzlu
Keyword(s):  
Boundary Layer ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Control Technique ◽  
System Response ◽  
Quantitative Feedback Theory ◽  
Major Drawback ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Mode Control

Sliding mode control (SMC) is a robust control technique with chattering as a major drawback. Chattering is undesirable because it can excite unmodeled high-frequency dynamics of the system. One way to reduce chattering is to introduce a boundary layer around the sliding surface while keeping the boundary layer attractive. Introduction of the boundary layer, however, causes the system response to oscillate around the sliding manifold. These oscillations, in turn, may lead to undesirable tracking errors. In this paper, we propose a quantitative feedback theory (QFT) controller (a low pass filter) to minimize the oscillations within the boundary layer and considerably improve the tracking response. We also provide an example to demonstrate the key features of the proposed method.

scholarly journals Control of Chaos in a Single Machine Infinite Bus Power System Using the Discrete Sliding Mode Control Technique

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Mohamed Zribi ◽  
Muthana T. Alrifai ◽  
Nejib Smaoui
Keyword(s):  
Sliding Mode Control ◽  
Power System ◽  
Discrete Time ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Control Technique ◽  
Reaching Law ◽  
Mode Control ◽  
Control Scheme ◽  
Simulation Results

Under certain conditions, power systems may exhibit chaotic behaviors which are harmful and undesirable. In this paper, the discrete time sliding mode control technique is used to control a chaotic power system. The objective of the control is to eliminate the chaotic oscillations and to bring order to the power system. Two discrete time sliding mode control (DSMC) schemes are proposed for a fourth order discrete time chaotic power system. The first DSMC control scheme is based on the well-known exponential reaching law. The second DSMC control scheme is based on the recently developed double power reaching law. It is shown that the states of the controlled system converge to their desired values. Simulation results are presented for different values of the gains of the controllers as well as for different initial conditions. These results indicate that both control schemes work well. However, the simulation results show that the second control scheme gave better results since it was able to greatly reduce the chattering problem.

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