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Your search keyword '"Wu, Shizhen"' showing total 11 results
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11 results on '"Wu, Shizhen"'

1. Enhanced-Coupling Based Nonlinear Control for Aerial Transportation Systems with Variable-Length Cable

Author

Yu, Hai, Wu, Shizhen, Liang, Xiao, Fang, Yongchun, Han, Jianda, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Yan, Liang, editor, and Deng, Yimin, editor

Published
2023
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4. Geometric Maneuvering for Underactuated VTOL Vehicles

Author

Wu, Shizhen, Liang, Xiao, Fang, Yongchun, and He, Wei

Abstract

The geometric maneuvering problem for underactuated vertical takeoff and landing vehicles is considered in this article. First, driven by the demands in this study, the input-to-state stability (ISS) theory is extended to the closed set case with input restriction considered. Then, the inner-outer loop hierarchical paradigm, originally proposed for tracking, is modified for the maneuvering problem, based on which the maneuvering problem is formulated as a closed set stabilization problem. Then, a novel singularity-free outer-loop maneuvering control law is proposed, whose ISS property is proved under the above extended ISS theory framework. Then, the geometric maneuvering controller is designed for thrust and torque inputs by combining such outer-loop control law with the existing attitude controller, and the interconnected closed-loop system is proved to be uniformly asymptotically stable. Real-time flight experimental results are presented to illustrate the efficacy of the proposed controller.

Published
2024
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10. Adaptive Sliding-Mode Disturbance Observer-Based Nonlinear Control for Unmanned Dual-Arm Aerial Manipulator Subject to State Constraints

Author

Liu, Bingbing, Yu, Hai, Wu, Shizhen, Liang, Xiao, and Fang, Yongchun

Abstract

The unmanned dual-arm aerial manipulator system is composed of a multirotor unmanned aerial vehicle (UAV) and two manipulators. Compared to a single manipulator, dual-arm always provides greater flexibility and versatility in both goods delivery and complex task execution. However, the practical application of the system is limited due to nonlinearities and complex dynamic coupling behavior between the multirotor and the manipulator, as well as the one between the inner and outer loop of the multirotor. In this paper, a holistic model of the dual-arm aerial manipulator system is first derived with complete model information. Subsequently, an adaptive sliding-mode disturbance observer (ASMDO) is proposed to handle external disturbances and unmeasurable disturbances caught by unmeasurable angular velocity and acceleration of the manipulators. Moreover, for safety concerns and transient performance requirements, the state constraints should be guaranteed. To this end, an auxiliary term composed of constrained variable signals is introduced. Then, the performance of the designed method is proven by rigorous analysis. Finally, the proposed method is validated through two sets of simulation tests.

Published
2023
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11. Myricetin alleviates H2O2-induced senescence and apoptosis in rat nucleus pulposus-derived mesenchymal stem cells.

Author

Xie T, Pan R, Huang W, Dong S, Wu S, and Ye Y

Subjects
Rats, Animals, Rats, Sprague-Dawley, Hydrogen Peroxide pharmacology, Reactive Oxygen Species, Sirtuin 1, Apoptosis, Culture Media, Flavonoids pharmacology, Nucleus Pulposus, Mesenchymal Stem Cells
Abstract

Introduction: Transplantation of mesenchymal stem cells (MSCs) has been reported to be a novel promising target for the regeneration of degenerated intervertebral discs (IVDs). However, the culture and survival limitations of MSCs remain challenging for MSC-based biological therapy. Myricetin, a common natural flavonoid, has been suggested to possess antiaging and antioxidant abilities. Therefore, we investigated the biological function of myricetin, and its related mechanisms involving cell senescence in intervertebral disc degeneration (IDD)., Material and Methods: The nucleus pulposus-derived mesenchymal stem cells (NPMSCs) were isolated from 4-month-old Sprague-Dawley (SD) rats and identified by examining surface markers and multipotent differentiation. Rat NPMSCs were cultured in an MSC culture medium or culture medium with different concentrations of H2O2. Myricetin or the combination of myricetin and EX527 were added to the culture medium to investigate the effects of myricetin. Cell viability was evaluated by cell counting kit-8 assays (CCK-8). The apoptosis rate was determined using Annexin V/PI dual staining. The mitochondrial membrane potential (MMP) was analyzed by a fluorescence microscope after JC-1 staining. The cell senescence was determined by SA-β-Gal staining. MitoSOX green was used to selectively estimate mitochondrial reactive oxygen species (ROS) Apoptosis-associated proteins (Bax, Bcl2, and cleaved caspase-3), senescence markers (p16, p21, and p53), and SIRT1/PGC-1α signaling pathway-related proteins (SIRT1 and PGC-1α) were evaluated by western blotting., Results: The cells isolated from nucleus pulposus (NP) tissues met the criteria for MSCs. Myricetin showed no cytotoxicity up to a concentration of 100 μM in rat NPMSCs cultured for 24 h. Myricetin pretreatment exhibited protective effects against H₂O₂-induced apoptosis. Myricetin could also alleviate H₂O₂-induced mitochondrial dysfunctions of increased mitochondrial ROS production and reduced MMP. Moreover, myricetin pretreatment delayed rat NPMSC senescence, as evidenced by decreased exppression of senescence indicators. Pretreatment of NPMSCs with 10 μM EX527, a selective inhibitor of SIRT1, prior to exposure to 100 μM H2O2, reversed the inhibitory effects of myricetin on cell apoptosis., Conclusions: Myricetin could affect the SIRT1/PGC-1α pathway to protect mitochondrial functions and alleviate cell senescence in H₂O₂-treated NPMSCs.

Published
2023
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