scholarly journals An Approach to Robust Control of the Hopf Bifurcation

2011 ◽  
Vol 2011 ◽  
pp. 1-21 ◽  
Author(s):  
Giacomo Innocenti ◽  
Roberto Genesio ◽  
Alberto Tesi

The paper illustrates a novel approach to modify the Hopf bifurcation nature via a nonlinear state feedback control, which leaves the equilibrium properties unchanged. This result is achieved by recurring to linear and nonlinear transformations, which lead the system to locally assume the ordinary differential equation representation. Third-order models are considered, since they can be seen as proper representatives of a larger class of systems. The explicit relationship between the control input and the Hopf bifurcation nature is obtained via a frequency approach, that does not need the computation of the center manifold.

Author(s):  
Yuan Yao ◽  
Yapeng Yan ◽  
Zhike Hu ◽  
Kang Chen

We put forward the motor active flexible suspension and investigate its dynamic effects on the high-speed train bogie. The linear and nonlinear hunting stability are analyzed using a simplified eight degrees-of-freedom bogie dynamics with partial state feedback control. The active control can improve the function of dynamic vibration absorber of the motor flexible suspension in a wide frequency range, thus increasing the hunting stability of the bogie at high speed. Three different feedback state configurations are compared and the corresponding optimal motor suspension parameters are analyzed with the multi-objective optimal method. In addition, the existence of the time delay in the control system and its impact on the bogie hunting stability are also investigated. The results show that the three control cases can effectively improve the system stability, and the optimal motor suspension parameters in different cases are different. The direct state feedback control can reduce corresponding feed state's vibration amplitude. Suppressing the frame's vibration can significantly improve the running stability of bogie. However, suppressing the motor's displacement and velocity feedback are equivalent to increasing the motor lateral natural vibration frequency and damping, separately. The time delay over 10 ms in control system reduces significantly the system stability. At last, the effect of preset value for getting control gains on the system linear and nonlinear critical speed is studied.


2017 ◽  
Vol 29 (3) ◽  
pp. 591-601
Author(s):  
Ryota Hayashi ◽  
◽  
Genki Matsuyama ◽  
Hisanori Amano ◽  
Hitomu Saiki ◽  
...  

[abstFig src='/00290003/14.jpg' width='300' text='Amphibian vehicle maneuvering simulator' ] This study proposes a maneuvering support system for an amphibian vehicle by applying a nonlinear state feedback control law for vehicle trajectory control. We consider that the vehicle should not drift sideways for good driving performance. To derive a nonlinear state feedback control law, we have defined ‘Maneuvering Trajectory’ as an additional reference trajectory that is generated by the driver’s maneuver. We have constructed a Lyapunov-like function for the trajectory control system. In this paper, we construct a vehicle-maneuvering simulator and set a clockwise circular reference trajectory. The efficiency of the proposed maneuvering support system is shown in the maneuvering simulations. We consider the case where the propulsive forces of the vehicle have limited influence on maneuverability. A new warning display system is proposed so that the driver can recognize if his or her maneuver is not suitable. Then, we examine the feasibility of the proposed warning display system through several simulations.


2017 ◽  
Vol 62 (5) ◽  
pp. 2450-2456 ◽  
Author(s):  
Azita Dabiri ◽  
Balazs Kulcsar ◽  
Hakan Koroglu

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