Ibrahim M. Mehedi^1,2,*, Mohd Heidir Mohd Shah¹ , Soon Xin Ng³ , Abdulah Jeza Aljohani^1,2, Mohammed El-Hajjar³, Muhammad Moinuddin^1,2

CMC-Computers, Materials & Continua, Vol.70, No.3, pp. 4691-4705, 2022, DOI:10.32604/cmc.2022.020954

Abstract

This paper presents the design and implementation of Adaptive Generalized Dynamic Inversion (AGDI) to track the position of a Linear Flexible Joint Cart (LFJC) system along with vibration suppression of the flexible joint. The proposed AGDI control law will be comprised of two control elements. The baseline (continuous) control law is based on principle of conventional GDI approach and is established by prescribing the constraint dynamics of controlled state variables that reflect the control objectives. The control law is realized by inverting the prescribed dynamics using dynamically scaled Moore-Penrose generalized inversion. To boost the robust attributes against system nonlinearities, parametric… More >

Ali Murtaza¹, Muhammad Usman Qadir¹, Muhammad Awais Khan¹, Izhar ul Haq^1,*, Kamran Shah¹, Nizar Akhtar²

Intelligent Automation & Soft Computing, Vol.31, No.3, pp. 1887-1899, 2022, DOI:10.32604/iasc.2022.020006

Abstract Transfemoral prostheses have evolved from mechanical devices to microprocessor-based, electronically controlled knee joints, allowing amputees to regain control of their limbs. For improved amputee experience at varying ambulation rates, these devices provide controlled damping throughout the swing and stance phases of the gait cycle. Commercially available microprocessor-based prosthetic knee (MPK) joints use linear controllers, heuristic-based methods, and finite state machine based algorithms to track the refence gait cycle. However, since the amputee experiences a variety of non-linearities during ambulation, such as uneven terrains, walking backwards and climbing stairs, therefore, traditional controllers produces error, abnormal movements, unstable control system and require… More >

Yanzan Han^1,*, Hang Zhou¹, Zengfang Shi¹, Shuang Liang²

Computer Systems Science and Engineering, Vol.40, No.3, pp. 1099-1108, 2022, DOI:10.32604/csse.2022.017741

Abstract Urban rail trains have undergone rapid development in recent years due to their punctuality, high capacity and energy efficiency. Urban trains require frequent start/stop operations and are, therefore, prone to high energy losses. As trains have high inertia, the energy that can be recovered from braking comes in short bursts of high power. To effectively recover such braking energy, an onboard supercapacitor system based on a radial basis function neural network-based sliding mode control system is proposed, which provides robust adaptive performance. The supercapacitor energy storage system is connected to a bidirectional DC/DC converter to provide traction energy or absorb… More >

Abdelatif Oussar^1,*, Abdelmoumen Ferrag¹, Mohamed Guiatni¹, Mustapha Hamerlain²

Intelligent Automation & Soft Computing, Vol.29, No.2, pp. 467-495, 2021, DOI:10.32604/iasc.2021.01000

Abstract This paper presents the design of a robust architecture for the tracking of an unmanned ground vehicle (UGV) by an unmanned aerial vehicle (UAV). To enhance the robustness of the ground vehicle in the face of external disturbances and handle the non-linearities due to inputs saturation, an integral sliding mode controller was designed for the task of trajectory tracking. Stabilization of the aerial vehicle is achieved using an integral-backstepping solution. Estimation of the relative position between the two agents was solved using two approaches: the first solution (optimal) is based on a Kalman filter (KF) the second solution (robust) uses… More >

Rabii Fessi¹, Hegazy Rezk^2,3,*, Soufiene Bouallègue^1,4

CMC-Computers, Materials & Continua, Vol.68, No.2, pp. 2265-2282, 2021, DOI:10.32604/cmc.2021.017237

Abstract The research on Unmanned Aerial Vehicles (UAV) has intensified considerably thanks to the recent growth in the fields of advanced automatic control, artificial intelligence, and miniaturization. In this paper, a Grey Wolf Optimization (GWO) algorithm is proposed and successfully applied to tune all effective parameters of Fast Terminal Sliding Mode (FTSM) controllers for a quadrotor UAV. A full control scheme is first established to deal with the coupled and underactuated dynamics of the drone. Controllers for altitude, attitude, and position dynamics become separately designed and tuned. To work around the repetitive and time-consuming trial-error-based procedures, all FTSM controllers’ parameters for… More >

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 >

D. Menaga¹, M. Premkumar², R. Sowmya^1,*, S. Narasimman³

Energy Engineering, Vol.117, No.6, pp. 481-495, 2020, DOI:10.32604/EE.2020.013282

Abstract The proposed controller accompanies with different sliding surfaces. To understand maximum power point extraction as opposed to nonlinear uncertainties and unknown disturbance of a grid-connected photovoltaic system to various control inputs (u_d, u_q) is designed. To extract maximum power from a solar array and maintain unity power flow in a grid by controlling the voltage across the dclink capacitor (V_pvdc) and reactive current (i_q). A multiple input-output with multiple uncertainty constraints have considered designing proposed sliding mode controllers to validated their robustness performance. An innovative controller verifies uncertain inputs, constant and changes in irradiances, and temperature of the photo-voltaic system.… More >

Qidan Zhu^a, Zhibo Yang^a,*

Computer Systems Science and Engineering, Vol.34, No.4, pp. 179-189, 2019, DOI:10.32604/csse.2019.34.179

Abstract The approach power compensator system (APCS) plays a role in the automatic carrier landing system (ACLS), and the performance of the APCS is affected by the carrier air-wake in the final-approach . In this paper, the importance of the APCS is verified through the analysis of the signal flow chart of the ACLS. Hence, it is necessary to suppress the carrier air-wake in order to improve the anti-interference ability. The adaptive sliding mode control (ASMC) not only has better dynamic tracking performance compared to the nonlinear mode, but also can efficiently resist the disturbance caused by the carrier air-wake. The… More >

Qiping Chen^*, Haoyu Sun, Ning Wang, Zhi Niu, Rui Wan

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 513-524, 2020, DOI:10.32604/fdmp.2020.09375

Abstract The possibility to enhance the stability and robustness of electrohydraulic brake (EHB) systems is considered a subject of great importance in the automotive field. In such a context, the present study focuses on an actuator with a four-way sliding valve and a hydraulic cylinder. A 4-order nonlinear mathematical model is introduced accordingly. Through the linearization of the feedback law of the high order EHB model, a sliding mode control method is proposed for the hydraulic pressure. The hydraulic pressure tracking controls are simulated and analyzed by MATLAB/Simulink soft considering separately different conditions, i.e., a sine wave, a square wave and… More >

Ji Liang¹, Zhihuan Chen^2,*, Xiaohui Yuan^1,3,*, Binqiao Zhang³, Yanbin Yuan⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 603-629, 2020, DOI:10.32604/cmes.2020.09328

Abstract Terminal sliding mode controller method is introduced to enhance the regulation performance of the hydraulic turbine governing system (HTGS). For the purpose of describing the characteristics of controlled system and deducing the control rule, a nonlinear mathematic model of hydraulic turbine governing system with bifurcated penstocks (HTGSBF) under control input saturation is established, and the input/output state linearization feedback approach is used to obtain the relationship between turbine speed and controller output. To address the control input saturation problem, an adaptive assistant system is designed to compensate for controller truncation. Numerical simulations have been conducted under fixed point stabilization and… More >