High Performance Regulator for Fractional Order Systems: A Soft Variable Structure Control Approach

2014 ◽  
Vol 17 (4) ◽  
pp. 1342-1346 ◽  
Author(s):  
Shyam Kamal ◽  
Bijnan Bandyopadhyay
Keyword(s):  
Fractional Order ◽  
High Performance ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Fractional Order Systems ◽  
Control Approach ◽  
Structure Control

Study on Active Suspension with Variable Structure Control Based on the Fractional Order Exponential Reaching Law

2017 ◽  
Vol 872 ◽  
pp. 337-345
Author(s):  
Yan Dong Chen
Keyword(s):  
Fractional Order ◽  
Reference Model ◽  
Sliding Mode ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Active Suspension ◽  
Mode Switching ◽  
Structure Control ◽  
Reaching Law ◽  
Exponential Reaching Law

Based on the dynamic model of 1/4 vehicle suspension, an active control system is designed using the fractional order exponential reaching law of model following variable structure control strategy. An active suspension with linear quadratic optimal control is used as the reference model. The sliding mode switching surface parameters is designed by pole placement method to ensure the stability of the system. At the same time, combined with the index reaching law proposed by Professor Gao Wei Bing and the definition and properties of fractional index, constructs a similar fractional order exponent reaching law to improve the dynamic quality of sliding mode motion. And in MATLAB, system modeling and controller design are implemented. By setting up experiments, the different suspensions are compared. The results show that compared with the passive suspension, the performance of the vehicle can be improved better, and the performance of the tracking reference model has good tracking performance. Moreover, compared with the integral exponential reaching law, the chattering can be more effectively weakened. Finally, before and after the change of vehicle parameters in the simulation, the results show that the system has good robustness.

Variable Structure Control of an Underactuated Air Spindle Testbed

2004 ◽  
Author(s):  
Hashem Ashrafiuon
Keyword(s):  
Attitude Control ◽  
Degrees Of Freedom ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Vertical Axis ◽  
Lyapunov Theory ◽  
Control Approach ◽  
Structure Control ◽  
Sliding Surfaces ◽  
Air Spindle

A robust control algorithm is developed for attitude control of an air spindle testbed based on variable structure control. The variable structure control approach is formulated for underactuated systems with actuated accelerations as control inputs. First order sliding surfaces are defined per actuated degrees of freedom as a linear combination of the tracking position and velocity errors of both actuated and unactuated coordinates. The controller law is determined based on Lyapunov theory and is shown to be asymptotically stable for the tiled air spindle axis where gravitational effects are included but only marginally stable for the vertical axis. Multiple step sliding surfaces are proposed to achieve asymptotic stability in the latter case. Simulations of the controller performance verify its effectiveness and accuracy.

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