Nour Ben Ammar¹, Hegazy Rezk^2,3,*, Soufiene Bouallègue^1,4

CMC-Computers, Materials & Continua, Vol.67, No.3, pp. 4081-4100, 2021, DOI:10.32604/cmc.2021.015681

Abstract This work presents a memetic Shuffled Frog Leaping Algorithm (SFLA) based tuning approach of an Integral Sliding Mode Controller (ISMC) for a quadrotor type of Unmanned Aerial Vehicles (UAV). Based on the Newton–Euler formalism, a nonlinear dynamic model of the studied quadrotor is firstly established for control design purposes. Since the main parameters of the ISMC design are the gains of the sliding surfaces and signum functions of the switching control law, which are usually selected by repetitive and time-consuming trials-errors based procedures, a constrained optimization problem is formulated for the systematically tuning of these unknown variables. Under time-domain operating… More >

Lingzhi Yu¹, Yunqing Gu^1,*, Jiegang Mou¹, Denghao Wu¹, Zhenfu Chen², Yun Ren³

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 1007-1018, 2020, DOI:10.32604/fdmp.2020.09509

Abstract In order to improve the performances of a cycloid gerotor pump, the variations of the radial force induced by different rotating speeds and outlet pressures are analyzed numerically. Using the numerical simulations as a basis, an improved oil inlet and outlet groove structure is proposed. The results show that the radial force decreases with the decrease of the outlet pressure and of the rotor speed. Compared with the original model, the large-end oil inlet line and pressure line of the new oil groove are claw-shaped. This configuration can effectively weaken the pressure changes inside the gerotor pump and reduce accordingly… More >

Jungang Jia^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 919-933, 2020, DOI:10.32604/fdmp.2020.09566

Abstract To solve the problem of temperature rise caused by the high power density of high-speed permanent magnet synchronous traction motors, the temperature rise of various components in the motor is analyzed by coupling the equivalent thermal circuit method and computational fluid dynamics. Also, a cooling strategy is proposed to solve the problem of temperature rise, which is expected to prolong the service life of these devices. First, the theoretical bases of the approaches used to study heat transfer and fluid mechanics are discussed, then the fluid flow for the considered motor is analyzed, and the equivalent thermal circuit method is… More >

Ivan Paulo Canal^1,*, Manuel Martin Pérez Reimbold², Maurício de Campos²

CMES-Computer Modeling in Engineering & Sciences, Vol.125, No.1, pp. 65-75, 2020, DOI:10.32604/cmes.2020.010741

Abstract An aircraft quadrotor is a complex control system that allows for great flexibility in flight. Controlling multirotor aerial systems such as quadrotors is complex because the variables involved are not always available, known, and accurate. The inclusion of payload changes the dynamic characteristics of the aircraft, making it necessary to adapt the control system for this situation. Among the various control methods that have been investigated, proportional-integralderivative (PID) control offers good results and simplicity of application; however, achieving stability and high performance is challenging, with the most critical task being tuning the controller gains. The Ziegler–Nichols (ZN) theory was used… More >

Pi-Yun Chen, Guan-Yu Chen^*

Intelligent Automation & Soft Computing, Vol.26, No.3, pp. 489-500, 2020, DOI:10.32604/iasc.2020.013925

Abstract The objective of this paper is to design a new Quadrotor Autonomous Following System, and the main three contents are as follows: Object tracking, quadrotor attitude determination and the controller. The image tracking portion performs object detection and keeps tracking by way of the Tracking-Learning-Detection (TLD), and gets the information of the target motion estimation positions. The attitude determination of the Quadrotor has adopted the Inertial Navigation System and sensors of the accelerometer, gyroscope and electronic compass, etc. for retrieving the information. The Kalman filter is also utilized for estimating the current values in order to reduce external interference, improve… More >

M. A. Kamel^a, M. A. Abido^b, Moustafa Elshafei^c

Intelligent Automation & Soft Computing, Vol.24, No.4, pp. 795-805, 2018, DOI:10.1080/10798587.2017.1342414

Abstract Directional Steering System (DSS) has been established for well drilling in the oilfield in order to accomplish high reservoir productivity and to improve accessibility of oil reservoirs in complex locations. In this paper, a novel feedback linearization controller to cancel the nonlinear dynamics of a DSS is proposed. The proposed controller design problem is formulated as an optimization problem for optimal settings of the controller feedback gains. Gravitational Search Algorithm (GSA) is developed to search for optimal settings of the proposed controller. The objective function considered is to minimize the tracking error and drilling efforts. In this study, the DSS… More >

Jilin Zhang^1,4,5, Xuechao Liu^1,5, Jian Wan^2,1,5, Yongjian Ren^1,5, Binglin Xu^1,5, Jianfan He^1,5, Yuchen Fan^1,5, Li Zhou^1,5, Zhenguo Wei⁶, Juncong Zhang⁶, Jue Wang³

Intelligent Automation & Soft Computing, Vol.25, No.3, pp. 527-546, 2019, DOI:10.31209/2019.100000109

Abstract A numerical optimization algorithm for unsteady flows of rotor based on web service is proposed. Space discretization uses the finite volume method, time discretization uses the implicit dual-time steps method, and turbulence model uses the Spalart–Allmaras (S–A) model. In order to efficiently use the computing resources of the cluster, a service-oriented service computing architecture is used in a parallel computing service program. In order to realize the load balance of hybrid grid partition, the grid is partitioned by Metis Library. Meanwhile, data communication based on Message Passing Interface (MPI) technology guarantees the consistency of convergence between parallel algorithm and serial… More >

Rana Javed Masood¹, DaoBo Wang¹, Zain Anwar Ali², Muhammad Anwar²

Intelligent Automation & Soft Computing, Vol.25, No.2, pp. 295-304, 2019, DOI:10.31209/2018.100000009

Abstract In this article, adaptive hybrid control scheme is proposed for controlling the position of a coaxial tri-rotor unmanned aerial system (UAS) in the presence of input saturation and external wind disturbance. The adaptive hybrid controller consists of model reference adaptive control with integral feedback (MRACI) and proportional integral derivative (PID) controller. The adaptive controller deals with the flight dynamics uncertainties and PID controller is used for tuning the gains of MRACI whereas the stability of system is verified by Lyapunov stability criterion. The integrator improves the order of the system thereby improving the convergence rate by rejecting the noise and… More >

Nan Wu^1,#, Kuan Lu^1,2,#,*, Yulin Jin^2,3,*, Haopeng Zhang¹, Yushu Chen²

Sound & Vibration, Vol.54, No.2, pp. 113-125, 2020, DOI:10.32604/sv.2020.09783

Abstract Two different order reduction methods of the deterministic and stochastic systems are discussed in this paper. First, the transient proper orthogonal decomposition (T-POD) method is introduced based on the high-dimensional nonlinear dynamic system. The optimal order reduction conditions of the T-POD method are provided by analyzing the rotor-bearing system with pedestal looseness fault at both ends. The efficiency of the T-POD method is verified via comparing with the results of the original system. Second, the polynomial dimensional decomposition (PDD) method is applied to the 2 DOFs spring system considering the uncertain stiffness to study the amplitude-frequency response. The numerical results… More >

C. Mapelli¹, A. Manes^1,2, M. Giglio¹, D. Mombelli¹

Structural Durability & Health Monitoring, Vol.9, No.2, pp. 181-199, 2013, DOI:10.32604/sdhm.2013.009.181

Abstract The definition of a complex operative scenario like ballistic damage, that introduces large strains and failure, is a current challenge in the design of critical mechanical components. Aerospace, automotive and manufacturing industries have recently increased their interest in numerical simulations with the long term aim to make these approaches not only reliable enough to reproduce the experimental results but also to provide a trustworthy and effective tool for design. To achieve this aim, the knowledge and calibration of material behaviour is required. Starting from a previous characterization of the constitutive law and ductile failure criterion of Al 6061-T6 aluminium alloy,… More >