Controlling Fluctuated Chaotic Power Systems With Compensation of Input Saturation: Application to Electric Direct Current Machines

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Mohammad Pourmahmood Aghababa

It is shown that brushless direct current (DC) motors (BLDCMs), which have found many useful applications in motion control areas, display chaotic behaviors. To avoid undesirable inherent oscillations of such DC motors, a control strategy should be adopted in the applications. So, the control problem of applied chaotic power systems is taken into account in this paper. Some important aspects of the design and implementation are considered to reach a suitable controller for the applications. In this regard, it is assumed that the system is fluctuated by unknown uncertainties and environmental noises. Additionally, a part of the system dynamics is supposed to be unknown in advance and the effects of nonlinear input saturation are fully taken into account. Then, a one input nonsmooth adaptive sliding mode controller is realized to handle the aforementioned issues. The proposed controller does not require any knowledge about the bounds of the system uncertainties and external fluctuations as well as about the parameters of the input saturation. The finite time convergence and robustness of the driven control scheme are mathematically proved and numerically illustrated using matlab simulations for DC motors.

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Dan-xu Zhang ◽  
Yang-wang Fang ◽  
Peng-fei Yang ◽  
You-li Wu ◽  
Tong-xin Liu

This paper proposed a finite time convergence global sliding mode control scheme for the second-order multiple models control system. Firstly, the global sliding surface without reaching law for a single model control system is designed and the tracking error finite time convergence and global stability are proved. Secondly, we generalize the above scheme to the second-order multimodel control system and obtain the global sliding mode control law. Then, the convergent and stable performances of the closed-loop control system with multimodel controllers are proved. Finally, a simulation example shows that the proposed control scheme is more effective and useful compared with the traditional sliding mode control scheme.


Author(s):  
Samaneh Mohammadpour ◽  
Tahereh Binazadeh

This paper considers the robust synchronization of chaotic systems in the presence of nonsymmetric input saturation constraints. The synchronization happens between two nonlinear master and slave systems in the face of model uncertainties and external disturbances. A new adaptive sliding mode controller is designed in a way that the robust synchronization occurs. In this regard, a theorem is proposed, and according to the Lyapunov approach the adaptation laws are derived, and it is proved that the synchronization error converges to zero despite of the uncertain terms in master and slave systems and nonsymmetric input saturation constraints. Finally, the proposed method is applied on chaotic gyro systems to show its applicability. Computer simulations verify the theoretical results and also show the effective performance of the proposed controller.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Wenguang Zhang ◽  
Wenjun Yi

The finite-time attitude tracking control for gliding-guided projectile with unmatched and matched disturbance is investigated. An adaptive variable observer is used to provide estimation for the unmeasured state which contains unmatched disturbance. Then, an improved adaptive twisting sliding mode algorithm is proposed to compensate for the matched disturbance dynamically with better transient quality. Finally, a proof of the finite-time convergence of the closed-loop system under the disturbance observer and the adaptive twisting sliding mode-based controller is derived using the Lyapunov technique. This attitude tracking control scheme does not require any information on the bounds of uncertainties. Simulation results demonstrate that the proposed method which is able to acquire the minimum possible values of the control gains guaranteeing the finite-time convergence performs well in chattering attenuation and tracking precision.


2018 ◽  
Vol 41 (2) ◽  
pp. 405-416 ◽  
Author(s):  
Haitao Chen ◽  
Shenmin Song ◽  
Xuehui Li

This paper studies the finite time spacecraft attitude tracking control problem, while considering modeling uncertainty, external disturbances and control input saturation. A novel integral terminal sliding mode surface (ITSMS) is designed by combining the fast terminal sliding mode surface (FTSMS) with a low pass filter to achieve a fast finite time convergence rate for the control system, without input singularity. An auxiliary signal is used to compensate for the effects of actuator saturation. The basic controller is first formulated based on the ITSMS, fast-TSM-type reaching law and auxiliary system, in the presence of an external disturbance and input saturation. Then, an adaptive control procedure is introduced, which simultaneously handles modeling uncertainty and external disturbance, thereby creating an adaptive attitude tracking controller. The proposed controller provides a fast finite time convergence rate for the control system, based on the newly designed ITSMS, while simultaneously compensating for modeling uncertainty, external disturbances and input saturation, without restricting the parameter selection process nor requiring repeated differentiation of nonlinear functions. Finally, digital simulation results are presented and demonstrate the effectiveness of the proposed controllers.


Author(s):  
Y. Wan

Abstract In this paper, a new control scheme is proposed to achieve stability for a single-machine infinite-bus power system. A power system model simultaneously considering input saturation and time-varying uncertainties is presented. A sufficient condition for the system convergence is given and based on this result, a switching excitation control law with auxiliary system is designed. The stability analysis and simulation results all show that the developed controller is effective.


2018 ◽  
Vol 41 (4) ◽  
pp. 975-989 ◽  
Author(s):  
Ziquan Yu ◽  
Youmin Zhang ◽  
Yaohong Qu

In this paper, a prescribed performance-based distributed neural adaptive fault-tolerant cooperative control (FTCC) scheme is proposed for multiple unmanned aerial vehicles (multi-UAVs). A distributed sliding-mode observer (SMO) technique is first utilized to estimate the leader UAV’s reference. Then, by transforming the tracking errors of follower UAVs with respect to the estimated references into a new set, a distributed neural adaptive FTCC protocol is developed based on the combination of dynamic surface control (DSC) and minimal learning parameters of neural network (MLPNN). Moreover, auxiliary dynamic systems are exploited to deal with input saturation. Furthermore, the proposed control scheme can guarantee that all signals of the closed-loop system are bounded, and tracking errors of follower UAVs with respect to the estimated references are confined within the prescribed bounds. Finally, comparative simulation results are presented to illustrate the effectiveness of the proposed distributed neural adaptive FTCC scheme.


2021 ◽  
Vol 2021 ◽  
pp. 1-10 ◽  
Author(s):  
Meiling Tao ◽  
Xiongxiong He ◽  
Shuzong Xie ◽  
Qiang Chen

In this article, a singularity-free terminal sliding mode (SFTSM) control scheme based on the radial basis function neural network (RBFNN) is proposed for the quadrotor unmanned aerial vehicles (QUAVs) under the presence of inertia uncertainties and external disturbances. Firstly, a singularity-free terminal sliding mode surface (SFTSMS) is constructed to achieve the finite-time convergence without any piecewise continuous function. Then, the adaptive finite-time control is designed with an auxiliary function to avoid the singularity in the error-related inverse matrix. Moreover, the RBFNN and extended state observer (ESO) are introduced to estimate the unknown disturbances, respectively, such that prior knowledge on system model uncertainties is not required for designing attitude controllers. Finally, the attitude and angular velocity errors are finite-time uniformly ultimately bounded (FTUUB), and numerical simulations illustrated the satisfactory performance of the designed control scheme.


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