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

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.

Author(s):  
Pournami Padmalatha ◽  
Susy Thomas

In this paper, a variable structure control law is proposed for discrete time sliding mode control so as to reduce both reaching time and quasi sliding mode band reduction. This new law is composed of two different sliding variable dynamics; one to achieve fast reaching and the other to counter its effect on widening the quasi sliding mode band. This is accomplished<br />by introducing a boundary layer around the sliding surface about which the transformation of the sliding variable dynamics takes place. This provides the flexibility to choose the initial dynamics in such a way as to speed up the reaching phase and then at the boundary transform this dynamics to one that reduces the quasi sliding mode band. Thus, the law effectively<br />coalesces the advantageous traits of hitherto proposed reaching laws that succeed in either the reduction of reaching phase or the elimination of quasi sliding mode band. The effectiveness of the proposed reaching law is validated through simulations.<br /><br />


Author(s):  
J. A. Tenreiro Machado

This paper studies fractional order variable structure control algorithms. For that purpose the fractional order of the sliding mode is varied and its effect upon the system performance is evaluated. The test bed is constituted by a simple mechanical manipulator. Both the system response and the control effort are analysed. The results show that the fractional order provides an extra method for adjusting the closed loop system response.


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