Zhenshuai Wan^*, Yu Fu, Chong Liu, Longwang Yue

Intelligent Automation & Soft Computing, Vol.36, No.3, pp. 3565-3581, 2023, DOI:10.32604/iasc.2023.036601

Abstract Hydraulic servo system plays an important role in industrial fields due to the advantages of high response, small size-to-power ratio and large driving force. However, inherent nonlinear behaviors and modeling uncertainties are the main obstacles for hydraulic servo system to achieve high tracking performance. To deal with these difficulties, this paper presents a backstepping sliding mode controller to improve the dynamic tracking performance and anti-interference ability. For this purpose, the nonlinear dynamic model is firstly established, where the nonlinear behaviors and modeling uncertainties are lumped as one term. Then, the extended state observer is introduced to estimate the lumped disturbance.… More >

Muhammad Riaz¹, Masooma Raza Hashmi¹, Dragan Pamucar², Yuming Chu^3,4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.3, pp. 1125-1164, 2021, DOI:10.32604/cmes.2021.013699

Abstract The existing concepts of picture fuzzy sets (PFS), spherical fuzzy sets (SFSs), T-spherical fuzzy sets (T-SFSs) and neutrosophic sets (NSs) have numerous applications in decision-making problems, but they have various strict limitations for their satisfaction, dissatisfaction, abstain or refusal grades. To relax these strict constraints, we introduce the concept of spherical linear Diophantine fuzzy sets (SLDFSs) with the inclusion of reference or control parameters. A SLDFS with parameterizations process is very helpful for modeling uncertainties in the multi-criteria decision making (MCDM) process. SLDFSs can classify a physical system with the help of reference parameters. We discuss various real-life applications of… More >