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2022 ◽  
Vol 12 (2) ◽  
pp. 893
Author(s):  
Lan Li ◽  
Yi Jiang ◽  
Xiaowei Yang ◽  
Jianyong Yao

Uncertainties and disturbances widely exist in electrohydraulic lifting mechanisms of launcher systems, which may worsen the rapid-erection tracking accuracy and even make the system unstable. To deal with the issue, an asymptotic tracking control framework is developed for electrohydraulic lifting mechanisms of launcher systems. Firstly, the dynamic equations and state-space forms of the electrohydraulic lifting mechanism are modeled. Based on the system model, a nonlinear rapid-erection robust controller is constructed to achieve the improvement of the system control performance, in which a nonlinear feedback term is employed to remove the effects of uncertainties and disturbances on tracking performance. Compared to the existing results, the asymptotic tracking stability of the closed-loop system can be assured based on the Lyapunov theory analysis. In the end, the simulation example of an actual electrohydraulic lifting mechanism of the launcher system is done to validate the effectiveness with the proposed controller.


2022 ◽  
Vol 40 ◽  
pp. 1-11
Author(s):  
Meraj Ali Khan

This paper studies the contact CR-warped product submanifolds of a generalized Sasakian space form admitting a nearly cosymplectic structure. Some inequalities for the existence of these types of warped product submanifolds are established, the obtained inequalities generalize the results that have acquired in \cite{atceken14}. Moreover, we also estimate another inequality for the second fundamental form in the expressions of the warping function, this inequality also generalizes the inequalities that have obtained in \cite{ghefari19}. In addition, we also explore the equality cases.


Author(s):  
Arpan Sardar ◽  
Avijit Sarkar

In this paper, we characterize Ricci–Yamabe solitons and gradient Ricci–Yamabe solitons on 3-dimensional generalized Sasakian space forms with quasi Sasakian metric. Furthermore, we study [Formula: see text]-Ricci–Yamabe solitons and gradient [Formula: see text]-Ricci–Yamabe solitons on 3-dimensional generalized Sasakian space forms with quasi Sasakian metric. Finally, we construct an example to verify a result of our paper.


2021 ◽  
Vol 79 ◽  
pp. 101831
Author(s):  
Wagner Oliveira Costa-Filho
Keyword(s):  

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yanlin Li ◽  
Ali H. Alkhaldi ◽  
Akram Ali

In this study, we develop a general inequality for warped product semi-slant submanifolds of type M n = N T n 1 × f N ϑ n 2 in a nearly Kaehler manifold and generalized complex space forms using the Gauss equation instead of the Codazzi equation. There are several applications that can be developed from this. It is also described how to classify warped product semi-slant submanifolds that satisfy the equality cases of inequalities (determined using boundary conditions). Several results for connected, compact warped product semi-slant submanifolds of nearly Kaehler manifolds are obtained, and they are derived in the context of the Hamiltonian, Dirichlet energy function, gradient Ricci curvature, and nonzero eigenvalue of the Laplacian of the warping functions.


Author(s):  
Denis Fabricio Sousa De Sá ◽  
João Viana Fonseca Neto

To improve the performance of a thermal plant based on Peltier cell actuators, an online parametric estimation via artificial neural networks and adaptive controller is presented. The control actions  are based on adaptive digital controller and an adaptive quadratic linear regulator approaches. The Artificial neural networks topology is based on ARX and NARX models, and its training algorithms, such as accelerated backpropagation and recursive least square. The Control strategies are design-oriented to adaptive digital PID controller and quadratic linear regulator framework. The proposal is evaluated on  temperature control of an object that is inside of a chamber.


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