Robust control for hypersonic vehicles with parametric and unstructured uncertainties

Author(s):  
Hao Liu ◽  
Deyuan Liu ◽  
Jianxiang Xi ◽  
Yao Yu

A robust flight controller is proposed for the longitudinal model of generic hypersonic vehicles, whose dynamics involves nonlinearities, parameter uncertainties, and unstructured uncertainties. The proposed longitudinal controller is developed based on the standard [Formula: see text] theory and the robust compensating approach. The robust compensating approach is introduced to reduce the influences of multiple uncertainties and nonlinearities on the closed-loop control system. Compared to the [Formula: see text] control theory, these influences in the whole frequency range can be restrained. Theoretical analysis and numerical simulation results are presented to illustrate the tracking performance properties of the designed robust control approach.

Author(s):  
Xuhuan Xie ◽  
Shanbin Li ◽  
Bugong Xu ◽  
Qinxue Li

This paper addresses the problem of resilient adaptive event-triggered control (AETC) for networked stochastic control systems (NSCSs) in the presence of the external disturbance and the energy-constrained, nonperiodic denial-of-service (DoS) attacks. A novel adaptive event-triggered scheme (AETS) that considers the effect of the energy-constrained, nonperiodic DoS attacks on the communication network is proposed to reduce the usage of system resources and adapt the variation of the plant state, and the model of closed-loop control system is established in the framework of time-delay systems and switched systems. Then, based on the Lyapunov stability theory, the stability criterion and the co-design algorithm are derived, which are used to ensure that the closed-loop control system is stochastically exponentially stable (SES) with an [Formula: see text] disturbance attenuation performance and to implement the co-design of state-feedback controller and proposed AETS, respectively. Unlike the network-based [Formula: see text] control approach for NSCSs in the existing literature, the resilient adaptive event-triggered network-based [Formula: see text] control approach proposed in this paper not only can considerably save the usage of system resources, but also can be resilient towards the energy-constrained, nonperiodic DoS attacks. Finally, a resilient AETC for the F16 aircraft system shows the effectiveness and superiority of proposed strategy.


2011 ◽  
Vol 219-220 ◽  
pp. 3-7
Author(s):  
Ning Zhang ◽  
Rong Hua Liu

An expert control system based on transient response patterns and expert system techniques is proposed in this paper. Depending on the features of the closed-loop control system determines the control decision and adjusts the parameters of the controller. The proposed method requires minimal proper information about the controlled plant and, with the linear re-excitation learning method, the system is kept satisfying the performance criterion.


2017 ◽  
Vol 3 (2) ◽  
pp. 363-366
Author(s):  
Tobias Steege ◽  
Mathias Busek ◽  
Stefan Grünzner ◽  
Andrés Fabían Lasagni ◽  
Frank Sonntag

AbstractTo improve cell vitality, sufficient oxygen supply is an important factor. A deficiency in oxygen is called Hypoxia and can influence for example tumor growth or inflammatory processes. Hypoxia assays are usually performed with the help of animal or static human cell culture models. The main disadvantage of these methods is that the results are hardly transferable to the human physiology. Microfluidic 3D cell cultivation systems for perfused hypoxia assays may overcome this issue since they can mimic the in-vivo situation in the human body much better. Such a Hypoxia-on-a-Chip system was recently developed. The chip system consists of several individually laser-structured layers which are bonded using a hot press or chemical treatment. Oxygen sensing spots are integrated into the system which can be monitored continuously with an optical sensor by means of fluorescence lifetime detection.Hereby presented is the developed hard- and software requiered to control the oxygen content within this microfluidic system. This system forms a closed-loop control system which is parameterized and evaluated.


2013 ◽  
Vol 321-324 ◽  
pp. 917-920
Author(s):  
Guang Ya Liu ◽  
Xiao Song Li

Three-phase voltage source PWM rectifier generally adopts double closed loop control system. According to the high frequency characteristic of three-phase voltage source PWM rectifier, this paper put forward the setting method of current inner ring regulator and voltage outer ring regulator PI parameter. Finally, it is verified by simulation.


2015 ◽  
Vol 1084 ◽  
pp. 636-641
Author(s):  
Valeriy F. Dyadik ◽  
Nikolay S. Krinitsyn ◽  
Vyacheslav A. Rudnev

The article is devoted to the adaptation of the controller parameters during its operation as a part of a control loop. The possibility to identify the parameters of the controlled plant model in the closed control loop has been proved by a computer simulation. The described active identification method is based on the response processing of the closed loop control system to standard actions. The developed algorithm has been applied to determine the model parameters of the flaming fluorination reactor used for the production of uranium hexafluoride. Designed identification method improves the quality of the product and the efficiency of the entire production.


Author(s):  
Bahram Yaghooti ◽  
Ali Siahi Shadbad ◽  
Kaveh Safavi ◽  
Hassan Salarieh

In this article, an adaptive nonlinear controller is designed to synchronize two uncertain fractional-order chaotic systems using fractional-order sliding mode control. The controller structure and adaptation laws are chosen such that asymptotic stability of the closed-loop control system is guaranteed. The adaptation laws are being calculated from a proper sliding surface using the Lyapunov stability theory. This method guarantees the closed-loop control system robustness against the system uncertainties and external disturbances. Eventually, the presented method is used to synchronize two fractional-order gyro and Duffing systems, and the numerical simulation results demonstrate the effectiveness of this method.


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