Zhenshuai Wan^1,2,*, Longwang Yue², Yanfeng Wang², Pu Zhao²

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1047-1065, 2024, DOI:10.32604/cmes.2024.053773 - 27 September 2024

Abstract Hydraulic actuators are highly nonlinear when they are subjected to different types of model uncertainties and dynamic disturbances. These unfavorable factors adversely affect the control performance of the hydraulic actuator. Although various control methods have been employed to improve the tracking precision of the dynamic system, optimizing and adjusting control gain to mitigate the hydraulic actuator model uncertainties remains elusive. This study presents an adaptive back-stepping sliding mode controller (ABSMC) to enhance the trajectory tracking precision, where the virtual control law is constructed to replace the position error. The adaptive control theory is introduced in More >

A. Jegatheesh^1,*, M. Germin Nisha², N. Kopperundevi³

Intelligent Automation & Soft Computing, Vol.36, No.1, pp. 745-760, 2023, DOI:10.32604/iasc.2023.028011 - 29 September 2022

Abstract Interacting The highest storage capacity of a circular tank makes it popular in process industries. Because of the varying surface area of the cross-sections of the tank, this two-tank level system has nonlinear characteristics. Controlling the flow rate of liquid is one of the most difficult challenges in the production process. This proposed effort is critical in preventing time delays and errors by managing the fluid level. Several scholars have explored and explored ways to reduce the problem of nonlinearity, but their techniques have not yielded better results. Different types of controllers with various techniques… 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 - 09 October 2021

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,… 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 - 16 June 2021

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) 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 - 13 April 2021

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,… 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 - 01 May 2020

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… More >

Zhe Sun¹, Yunrui Bi², Songle Chen¹, Bing Hu¹, Feng Xiang³, Yawen Ling¹, Zhixin Sun^{1, ∗}

CMC-Computers, Materials & Continua, Vol.61, No.1, pp. 119-128, 2019, DOI:10.32604/cmc.2019.05274

Abstract For enhancing the control effectiveness, we firstly design a fuzzy logic based sliding mode controller (FSMC) for nonlinear crane systems. On basis of overhead crane dynamic characteristic, the sliding mode function with regard to trolley position and payload angle. Additionally, in order to eliminate the chattering problem of sliding mode control, the fuzzy logic theory is adopted to soften the control performance. Moreover, aiming at the FSMC parameter setting problem, a DE algorithm based optimization scheme is proposed for enhancing the control performance. Finally, by implementing the computer simulation, the DE based FSMC can effectively More >

Rooh ul Amin¹, Irum Inayat², Li Aijun¹, Shahaboddin Shamshirband^3,4,*, Timon Rabczuk⁵

CMC-Computers, Materials & Continua, Vol.57, No.3, pp. 365-388, 2018, DOI:10.32604/cmc.2018.03757

Abstract A bio-inspired global finite time control using global fast-terminal sliding mode controller and radial basis function network is presented in this article, to address the attitude tracking control problem of the three degree-of-freedom four-rotor hover system. The proposed controller provides convergence of system states in a pre-determined finite time and estimates the unmodeled dynamics of the four-rotor system. Dynamic model of the four-rotor system is derived with Newton’s force equations. The unknown dynamics of four-rotor systems are estimated using Radial basis function. The bio-inspired global fast terminal sliding mode controller is proposed to provide chattering… More >