Decentralized Variable Structure Control for Uncertain Large-Scale Time-Delayed Systems: A New Approach

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Cunchen Gao ◽  
Lin Zhao
Keyword(s):  
Large Scale ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Auxiliary Function ◽  
Interconnected System ◽  
Delayed Systems ◽  
Switching Surface ◽  
Structure Control ◽  
Inequality Technique ◽  
The Stability

In this paper, a novel decentralized variable structure control (DVSC) scheme is proposed for a class of large-scale time-delayed systems (LSSs) with mismatched interconnections and uncertainties. New invariance conditions are derived such that each subsystem in the switching surface is completely invariant to both delay interconnections and uncertainties. It also shows that the stability of each closed-loop subsystem is guaranteed. By constructing auxiliary function and applying matrix norm inequality technique, the developed DVSC law for the interconnected system is realized independently through the delay terms. Moreover, the chattering around the switching surface can be reduced by the proposed design approach. Illustrative example is given to verify the validity of the developed controller.

Enhanced Grey Variable Structure Control Methodology of Parallel-Connected DC-AC Inverters for Ultra-Precision Machining

2015 ◽  
Vol 661 ◽  
pp. 29-35
Author(s):  
En Chih Chang ◽  
Hung Liang Cheng ◽  
Chien Hsuan Chang ◽  
Jin Wei Liu ◽  
Chih Hsien Chuang ◽  
...  
Keyword(s):  
Output Voltage ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Precision Machining ◽  
Structure Control ◽  
Highly Nonlinear ◽  
Ultra Precision ◽  
The Stability ◽  
Control Methodology ◽  
Voltage Harmonics

This paper develops an enhanced grey variable structure controlled DC-AC inverter in parallel, and is suitable for the application of ultra-precision machining (UPM). The enhanced grey variable structure control methodology consists of a nonlinear sliding function (NSF) and a grey model, GM(2,1). The NSF has finite system-state convergence time, and thus the AC output voltage regulation and balanced current-sharing among the parallel modules can be achieved. However, once the loading of the UPM is a highly nonlinear condition, the chatter still exists in NSF. The chatter may cause heat losses and high voltage harmonics in parallel-connected DC-AC inverter output, and thus deteriorates the stability and reliability of the UPM. To eliminate the chatter, the control gains of the NSF can be adjusted by the use of the GM(2,1) under system uncertainty bounds are overestimated. With the enhanced methodology, the parallel-connected DC-AC inverter yields a high-quality AC output voltage with low voltage harmonics and fast dynamic response under highly nonlinear loading, thus achieving the stability and reliability of the UPM. Experimental results are performed to demonstrate the enhanced methodology.

Tracking Design of an Omni-Direction Autonomous Ground Vehicle by Hierarchical Enhancement Using Fuzzy Second-Order Variable Structure Control

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Chih-Lyang Hwang ◽  
Yunta Lee
Keyword(s):  
Tracking Error ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Second Order ◽  
Hierarchical Architecture ◽  
Switching Surface ◽  
Ground Vehicle ◽  
Structure Control ◽  
Linear Dynamic ◽  
Order Variable

Owing to the hierarchical architecture of the derived model of the omni-direction autonomous ground vehicle (OD-AGV), the virtual desired trajectory (VDT) is first designed by the first switching surface, which is set as the linear dynamic pose error of the OD-AGV. In sequence, the trajectory tracking control (TTC) is designed by the second switching surface, which is the linear dynamic tracking error of the VDT. To deal with nonlinear time-varying uncertainties including system disturbance and different ground conditions, enhanced fuzzy second-order variable structure control (EF2VSC) is designed into both VDT and TTC. Finally, the experiments for tracking the circular trajectories with different curvatures, traveling velocities, and poses of the OD-AGV are presented to validate the effectiveness and robustness of the proposed hierarchical enhancement using fuzzy second-order variable structure control (HEF2VSC).

scholarly journals A Local Controller for Discrete-Time Large-Scale System by Using Integral Variable Structure Control

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
C. H. Chai ◽  
Johari H. S. Osman
Keyword(s):  
Discrete Time ◽  
Large Scale ◽  
Variable Structure Control ◽  
Variable Structure ◽  
System Stability ◽  
Large Scale System ◽  
Structure Control ◽  
Time Integral ◽  
Unmatched Uncertainty ◽  
Local Controller

A new local controller for discrete-time integral variable structure control of a large-scale system with matched and unmatched uncertainty is presented. The local controller is able to bring the large-scale system into stability by using only the states feedback from individual subsystem itself. A new theorem is established and proved that the controller is able to handle the effect of interconnection for the large-scale system with matched and unmatched uncertainty, and the system stability is ensured. The controller is able to control the system to achieve the quasi-sliding surface and remains on it. The results showed a fast convergence to the desired value and the attenuation of disturbance is achieved.

Sign in / Sign up

Export Citation Format

Share Document