Abdulsattar Abdullah Hamad¹, Ahmed S. Al-Obeidi², Enas H. Al-Taiy², Osamah Ibrahim Khalaf³, Dac-Nhuong Le^4,5,*

CMC-Computers, Materials & Continua, Vol.66, No.3, pp. 3311-3327, 2021, DOI:10.32604/cmc.2021.013395

Abstract Synchronization is one of the most important characteristics of dynamic systems. For this paper, the authors obtained results for the nonlinear systems controller for the custom Synchronization of two 4D systems. The findings have allowed authors to develop two analytical approaches using the second Lyapunov (Lyp) method and the Gardano method. Since the Gardano method does not involve the development of special positive Lyp functions, it is very efficient and convenient to achieve excessive system SYCR phenomena. Error is overcome by using Gardano and overcoming some problems in Lyp. Thus we get a great investigation into the convergence of error… More >

Guobao Zhang^a,b, Jing-Jing Xiong^a,b, Yongming Huang^a,b, Yong Lu^a,b,c, Ling Wang^a,b

Intelligent Automation & Soft Computing, Vol.24, No.3, pp. 541-551, 2018, DOI:10.31209/2018.100000021

Abstract This paper investigates the delay-dependent stability problem of recurrent neural networks with time-varying delay. A new and less conservative stability criterion is derived through constructing a new augmented Lyapunov-Krasovskii functional (LKF) and employing the linear matrix inequality method. A new augmented LKF that considers more information of the slope of neuron activation functions is developed for further reducing the conservatism of stability results. To deal with the derivative of the LKF, several commonly used techniques, including the integral inequality, reciprocally convex combination, and free-weighting matrix method, are applied. Moreover, it is found that the obtained stability criterion has a lower… More >

Muhammad Altaf Khan^1,*, Khanadan Khan², Mohammad A. Safi³, Mahmoud H. DarAssi⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 777-795, 2020, DOI:10.32604/cmes.2020.08208

Abstract The present paper investigates the theoretical analysis of the tuberculosis (TB) model in the discrete-time case. The model is parameterized by the TB infection cases in the Pakistani province of Khyber Pakhtunkhwa between 2002 and 2017. The model is parameterized and the basic reproduction number is obtained and it is found R₀ ¼ 1:5853. The stability analysis for the model is presented and it is shown that the discrete-time tuberculosis model is stable at the disease-free equilibrium whenever R₀ < 1 and further we establish the results for the endemic equilibria and prove that the model is globally asymptotically stable… More >

D. Vijeswaran^1,*, V. Manikandan²

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.3, pp. 801-813, 2019, DOI:10.32604/cmes.2019.07793

Abstract In a cyber-physical micro-grid system, wherein the control functions are executed through open communication channel, stability is an important issue owing to the factors related to the time-delay encountered in the data transfer. Transfer of feedback variable as discrete data packets in communication network invariably introduces inevitable time-delays in closed loop control systems. This delay, depending upon the network traffic condition, inherits a time-varying characteristic; nevertheless, it adversely impacts the system performance and stability. The load perturbations in a micro-grid system are considerably influenced by the presence of fluctuating power generators like wind and solar power. Since these non-conventional energy… More >

Felipe J. Torres^1,*, Gerardo V. Guerrero², Carlos D. García², Ricardo Zavala-Yoe³, Mario A. García¹, Adolfo R. López⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 609-630, 2019, DOI:10.32604/cmes.2019.07153

Abstract A complete modeling (including the actuator dynamics) of a robot manipulator that uses three-phase induction motors is presented in this paper. A control scheme is designed to synchronize robot manipulators actuated by induction motors under a masterslave scheme in the case where the joint velocity of the slave robots is estimated. All of the research on the synchronization of robot manipulators assumes the use of ideal actuators to drive the joints; for that reason, in this work, a three-phase induction motor is considered to be a direct-drive actuator for each joint. An entire model of the mated system is obtained… More >

V. Venkatachalam^{1, *}, D. Prabhakaran¹

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.3, pp. 321-334, 2018, DOI:10.3970/cmes.2018.114.321

Abstract This paper presents, using Lyapunov-Krasovskii functional technique combined with reciprocal convex lemma is considered for a networked control temperature control system with additive time-varying-delays. In the stability analysis, a new LK functional is assumed, and take the time-derivative of the (LK) functional, using reciprocal convex combination technique was employed to obtain less conservative stability criteria. Finally, the proposed stability analysis culminates into a stability criterion in the LMI (linear matrix inequalities) framework. The results obtained are in accordance with the theoretically obtained in the temperature control system and they are closer to the standard benchmark temperature-control system. More >

Yonghong Zhang^1,*, Yunfei Deng¹, Yunping Liu¹, Lihua Wang¹

CMC-Computers, Materials & Continua, Vol.59, No.3, pp. 833-851, 2019, DOI:10.32604/cmc.2019.04078

Abstract In the transition mode of quad tilt wing-unmanned aerial vehicle (QTW-UAV), the system stability of UAV will change with the tilt angle changes, which will cause serious head drop down. Meanwhile, with the complex air flow and other disturbances, the system is prone to side bias, frying, stall and other kinetic stability problems, hence the system stability analysis has become an urgent problem to be solved. To solve the stability problem, we need the quantitative criteria of system stability and effective tool of stability analysis, and can improve the stability of the motion control by optimizing the structural parameters of… More >

Junjun Jiang¹, Congqing Wang^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.1, pp. 105-121, 2019, DOI:10.32604/cmes.2019.06277

Abstract Aircraft skin health concerns whether the aircraft can fly safely. In this paper, an improved mechanical structure of the aircraft skin inspection robot was introduced. Considering that the aircraft skin surface is a curved environment, we assume that the curved environment is equivalent to an inclined plane with a change in inclination. Based on this assumption, the Cartesian dynamics model of the robot is established using the Lagrange method. In order to control the robot’s movement position accurately, a position backstepping control scheme for the aircraft skin inspection robot was presented. According to the dynamic model and taking into account… More >

S. Rugonyi, K. J. Bathe¹

CMES-Computer Modeling in Engineering & Sciences, Vol.2, No.2, pp. 195-212, 2001, DOI:10.3970/cmes.2001.002.195

Abstract The solution of fluid flows, modeled using the Navier-Stokes or Euler equations, fully coupled with structures/solids is considered. Simultaneous and partitioned solution procedures, used in the solution of the coupled equations, are briefly discussed, and advantages and disadvantages of their use are mentioned. In addition, a simplified stability analysis of the interface equations is presented, and unconditional stability for certain choices of time integration schemes is shown. Furthermore, the long-term dynamic stability of fluid-structure interaction systems is assessed by the use of Lyapunov characteristic exponents, which allow differentiating between a chaotic and a regular system behavior. Some state-of-the-art numerical solutions… More >

Muhammad Shoaib Arif¹, Mairaj Bibi², Adnan Jhangir³

CMC-Computers, Materials & Continua, Vol.54, No.2, pp. 181-195, 2018, DOI:10.3970/cmc.2018.054.181

Abstract This communique is opted to study the approximate solution of the Algebraic Lyapunov equation on the manifold of positive-definite Hermitian matrices. We choose the geodesic distance between -AHX - XA and P as the cost function, and put forward the Extended Hamiltonian algorithm (EHA) and Natural gradient algorithm (NGA) for the solution. Finally, several numerical experiments give you an idea about the effectiveness of the proposed algorithms. We also show the comparison between these two algorithms EHA and NGA. Obtained results are provided and analyzed graphically. We also conclude that the extended Hamiltonian algorithm has better convergence speed than the… More >