Article
Engineering, Marine
Jian Xu, Xing Wang, Ping Liu, Qiaoyu Duan
Summary: This paper proposes an adaptive proportional-integral sliding mode-based fault tolerant control method for autonomous underwater vehicles (AUVs) to address control issues in the presence of dynamic uncertainties and thruster failures. By using radial basis function neural network and an adaptive approach to evaluate dynamics uncertainty, and conducting theoretical analysis and mathematical proof based on Lyapunov stability analysis to ensure convergence of tracking errors to zero. Experimental results demonstrate that the method can achieve system stability and good control performance even in the case of thruster failure.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Marine
Xing Wang, Jian Xu, Ping Liu
Summary: This article proposes an adaptive non-singular integral terminal sliding mode-based fault tolerant control method for autonomous underwater vehicles. The method shows unique superiority in convergence rate and overcomes the singularity problem effectively. It uses radial basis function neural network and adaptive technique to estimate the dynamics uncertainty.
Article
Automation & Control Systems
Cheng Zhu, Bing Huang, Bin Zhou, Yumin Su, Enhua Zhang
Summary: This paper presents a model-parameter-free control strategy for the trajectory tracking problem of autonomous underwater vehicles, using two control architectures to achieve desired trajectories with improved system reliability under actuator failures. The proposed controllers leverage sliding mode control technology and adaptive algorithms to handle nonlinear dynamics of underwater vehicles, demonstrating validity through theoretical analysis and numerical simulations.
Article
Computer Science, Artificial Intelligence
Zhongcai Zhang, Yuqiang Wu
Summary: This article discusses the trajectory tracking control for an autonomous underwater vehicle (AUV) with model uncertainties and output constraints, using tan-type barrier Lyapunov function and adaptive fuzzy control. State feedback and output feedback tracking controllers are proposed, achieving desired output constraints and bounded closed-loop system signals through analysis. Simulations confirm the validity and feasibility of the designed control strategies.
IEEE TRANSACTIONS ON FUZZY SYSTEMS
(2021)
Article
Computer Science, Information Systems
Quang Van Vu, Tuan Anh Dinh, Thien Van Nguyen, Hoang Viet Tran, Hai Xuan Le, Hung Van Pham, Thai Dinh Kim, Linh Nguyen
Summary: This study proposes a hierarchical sliding mode control technique and neural networks for an adaptive learning mechanism to efficiently control an autonomous underwater vehicle. The uncertainties in the system caused by external disturbances can affect the control system, but the stability of the AUV system is theoretically guaranteed by the proposed approach.
Article
Multidisciplinary Sciences
Shun An, Longjin Wang, Yan He, Jianping Yuan
Summary: This study proposed an adaptive backstepping sliding mode control scheme for autonomous underwater vehicles, effectively addressing the impact of dynamic uncertainty, external disturbance, and quantization error on control. By combining backstepping control technique and sliding mode control method, the control strategy demonstrated improved robustness of the closed-loop system through the use of an adaptive law to estimate total uncertainties in real time.
ADVANCED THEORY AND SIMULATIONS
(2022)
Article
Automation & Control Systems
Alejandra Hernandez-Sanchez, Olga Andrianova, Alexander Poznyak, Isaac Chairez
Summary: The paper introduces a state feedback and robust controller design for regulating the tridimensional movement of autonomous underwater mobile crafts (AUMCs) using Averaged Sub-Gradient Integral Sliding Mode Realisation (ASGISMR). This design successfully handles tracking error and enables AUMCs to maintain continuous movement underwater.
INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE
(2021)
Article
Computer Science, Artificial Intelligence
Rupam Gupta Roy, Dibyendu Ghoshal
Summary: The article utilizes Gray Wolf optimization combined with second-order sliding mode control for AUV yaw angle control, aiming to reduce errors and enhance performance compared to existing approaches. Simulation results show improvement in steady-state response, error analysis, yaw angle analysis, and controller response.
Article
Engineering, Marine
Yan Yan, Xiangtao Zhao, Shuanghe Yu, Chaoli Wang
Summary: This paper presents a method that combines neural networks and sliding mode control for trajectory tracking of autonomous surface vehicles. By integrating robust control parameters with approximation errors, accurate estimation and constraint of model uncertainties and external disturbances are successfully achieved.
Article
Automation & Control Systems
Jian Xu, Yunfei Cui, Zheping Yan, Fei Huang, Xue Du, Di Wu
Summary: This paper investigates the target tracking control problem for an underactuated autonomous underwater vehicle (AUV) in the presence of actuator faults and external disturbances based on event-triggered mechanism. The five degrees-of-freedom kinematic and dynamic models are constructed using the backstepping method as the major control framework. Radial basis function neural network (RBFNN) and adaptive control method are utilized to estimate and compensate for uncertain information and actuator faults. The effectiveness and reasonableness of the designed tracking controllers are illustrated through comparative simulations.
JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS
(2023)
Article
Mathematics
Jiajian Liang, Wenkai Huang, Fobao Zhou, Jiaqiao Liang, Guojian Lin, Endong Xiao, Hongquan Li, Xiaolin Zhang
Summary: This paper proposes a double-loop proportional-integral-differential neural network sliding mode control method to eliminate the influence of nonlinear disturbances on the trajectory tracking of autonomous underwater vehicles. Experimental results demonstrate its strong anti-jamming ability and tracking performance.
Article
Automation & Control Systems
Dong Qu, Wen-Bo Xie, Guan-Qun Chen, Bing Yang, Yan Peng
Summary: This article introduces an observer-controller structure for nonlinear systems with external disturbances, uncertainties, and performance constraints. By utilizing a sliding mode observer, an integral barrier Lyapunov function, an equivalent output injection technique, and backstepping technique, the proposed approach is able to limit the signals and tracking error in the closed-loop system, ensuring stability and performance.
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2023)
Article
Engineering, Marine
Tao Chen, Xingru Qu, Zhao Zhang, Xiao Liang
Summary: This article presents a distributed cooperative path-maneuvering control approach for multiple autonomous underwater vehicles, using boustrophedon motions and trigonometric functions to generate parameterized paths, employing distributed maneuvering control laws for accuracy, and developing consensus protocols through graph theory to maintain formation configurations.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Marine
Dongbo Hou, Wei Cao, Wenjun Wang, Yiguo Li, Cong Wang
Summary: This paper addresses the issue of position tracking control of autonomous underwater gliders in the presence of model uncertainties and external disturbances. An adaptive control system based on filtered backstepping is proposed, utilizing neural networks and sliding mode control to enhance robustness. Lyapunov stability theory is employed to demonstrate boundedness of all signals and convergence of tracking errors to a neighborhood of zero. The presented controller offers practical implementation without requiring knowledge of glider parameters and external environmental disturbances. Simulation results verify the effectiveness and robustness of the proposed control system.
Article
Engineering, Marine
Amir Naderolasli, Khoshnam Shojaei, Abbas Chatraei
Summary: A new controller design based on dynamic surface control (DSC) method is proposed for the constrained platoon formation control of underactuated autonomous underwater vehicles (AUVs). The controller takes into account model uncertainties and limited field-of-view (FOV) constraints. An asymmetric barrier Lyapunov function (BLF) is used to prevent violations of FOV constraints for both line-of-sight range and orientation angles. The proposed controller has advantages over existing works in terms of enforcing desired values for range and orientation angles, avoiding collisions between vehicles, improving tracking error convergence rate, and enhancing transient performance.
Article
Microbiology
Ayesha Ahmed Chaudhri, Mahnoor Nadeem, Asim ur Rahman, Tayyaba Alam, Wasim Sajjad, Fariha Hasan, Malik Badshah, Samiullah Khan, Fazal Rehman, Aamer Ali Shah
CURRENT MICROBIOLOGY
(2020)
Article
Oncology
Sadia Nazir, Kamran Tahir, Rabia Irshad, Qudrat Ullah Khan, Shafiullah Khan, Ismat Ullah Khan, Asif Nawaz, Fazal Rehman
Summary: This study synthesized ZnO/Pd-MCM-41 nanostructural materials with antibacterial properties, exhibiting efficient light inhibition activity against E. coli, P. aeruginosa, and S. aureus. The nanostructures also showed high antioxidant activity by stabilizing 99% DPPH at very low concentrations.
PHOTODIAGNOSIS AND PHOTODYNAMIC THERAPY
(2021)
Article
Health Care Sciences & Services
Faran Emmanuel, Ahsan Ahmad, Tahira Reza, Khurram Shahzad, Fazal Ur Rehman, Muhammad Malik, Raza Zaidi, Alizeh Faran, Usman Bashir, Farhan Aslam, Assad Hafeez, James Blanchard
Summary: The COVID-19 containment and lockdown policies have had significant impacts on the utilization of reproductive, maternal, newborn, and child health (RMNCH) services in Pakistan. The utilization of RMNCH care declined during both the first and second wave of the pandemic, with the greatest reduction seen in children under 5 years old receiving treatment for pneumonia. Although service utilization increased from June to September, the second wave of COVID-19 led to another decrease. Priority actions to reinstate routine services include continued provision of family planning services, uninterrupted immunization campaigns, and routine maternal and child services.
EASTERN MEDITERRANEAN HEALTH JOURNAL
(2022)
Article
Thermodynamics
Khalil Ur Rehman, A. U. Khan, Fazal Rehman, Wasfi Shatanawi
Summary: The thermal case study focuses on inspecting heat transfer aspects for radial stagnation point flow. A linear twisting cylinder is assumed for the heated viscous nanofluid, and the arrangement between torsionally rotating cylinders and radial stagnation point flow is investigated. The study articulates three possible parameters: the dimensionless torsion rate sigma, the volume fraction of nanoparticles phi, and the Wangs Reynolds number R. Numerical results of the governing flow field equations are obtained using the BVP-Midrch routine integrated with the Maple software. It is found that the axial wall stress is weakly dependent on sigma, weakly dependent on phi, and strongly dependent on R. The azimuthal wall stress is strongly dependent on R and shows a decreasing behavior, linearly increasing with sigma at the starting value of zero. The temperature gradient exhibits slight variation during positive iteration in torsional rate, and the heat flux at the surface has a direct relation to the volume fraction of nanoparticles.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Physics, Multidisciplinary
Fazal Ur Rehman, Manzar Zahra, Ali H. Reshak, Iqra Qayyum, Aoun Raza, Zeshan Zada, Shafqat Zada, Muhammad M. Ramli
Summary: Organic solar cells (OSCs) are gaining attention in the field of photovoltaics due to their flexibility and environmental-friendliness. However, their energy conversion efficiency is lower than that of conventional solar cells, so improving their effectiveness is crucial. Researchers have developed ZnO-integrated PVA nanocomposite films to enhance the performance efficiency of OSCs.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Remote Sensing
Ahmad Mahmood, Fazal Ur Rehman, Aamer Iqbal Bhatti
Summary: This paper discusses the challenge of achieving maximum gliding range in aero gliding vehicles and proposes a non-uniform control vector parameterization approach to achieve stable gliding flight while maximizing the gliding range. Simulation results show that the proposed approach outperforms traditional methods, with a maximum gliding range of 121.278 km and a maximum horizontal range of 120.856 km.
Article
Materials Science, Multidisciplinary
Zeshan Zada, Junaid Khan, Abdul Ahad Khan, Ali H. Reshak, Dania Ali, Fazal Ur Rehman, Inayat Urrahman, Muhammad Saqib, Muhammad Irfan, Muhammad M. Ramli
Summary: In this study, the detailed properties of the rare-Earth based XMn2Si2 (X=Dy, Er) compounds were investigated using the FP-LAPW method with GGA+U in the ferromagnetic phase. The results show that the ferromagnetic phase is the most suitable for these compounds, as supported by previous experimental findings. The compounds exhibit metallic behavior with hybridization between the Dy/Er-f and Mn-d states in the valence band and the Si-p state in the conduction band. The rare-Earth based DyMn2Si2 compound shows stronger ferromagnetic behavior patterns compared to ErMn2Si2. Additionally, ErMn2Si2 demonstrates high ZT values in the high-temperature region, making it a potential contender for high-temperature applications in waste heat management.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2023)
Article
Cardiac & Cardiovascular Systems
Abdul Baqi, Fazal Ur Rehman, Pirbhat Shams Memon, Syed Furrukh Omair
Summary: Elevated levels of cardiac troponin I are significantly associated with length of stay and in-hospital mortality in dengue-infected patients. Atrial fibrillation, diabetes mellitus, hypertension, low serum bicarbonate, high serum creatinine, and any abnormality on echocardiography are associated with adverse outcomes in dengue-infected patients.
Article
Chemistry, Physical
Fazal Ur Rehman, Manzar Zahra, Iqra Qayyum, Aoun Raza, Amir Waseem
Summary: ZnO nanoparticles and Cu-modified ZnO nano composites were successfully prepared using a hydrothermal approach with an aqueous methanolic solution as the reaction solvent. The synthesized materials showed nano-sized structures, confirmed by XRD patterns and FT-IR results. The optical properties of the materials were improved with increasing concentration of Cu metal on ZnO surface, as indicated by UV visible spectroscopy analysis. SEM analysis revealed the spherical morphology of the synthesized nano composites, while EDX graph confirmed the elemental composition of Zn, O, and Cu. The photo catalytic activity of the materials was optimized under sunlight, as observed during the degradation of Tartrazine Yellow Azo Dye.
IRANIAN JOURNAL OF CATALYSIS
(2022)
Article
Automation & Control Systems
Waseem Abbasi, Fazal Ur Rehman, Ibrahim Shah, Arshad Rauf
INTERNATIONAL JOURNAL OF ROBOTICS & AUTOMATION
(2019)
Proceedings Paper
Psychology, Multidisciplinary
Fazal Ur Rehman, Rosman Bin Md Yusoff, Farwida Javed, Shafie Bin Mohamed Zabri, Fadillah Binti Ismail, Mohammad Saeed Shahbaz, Altaf Hussain
AIMC 2017 - ASIA INTERNATIONAL MULTIDISCIPLINARY CONFERENCE
(2018)
Article
Automation & Control Systems
Sami Ud Din, Fazal Ur Rehman, Qudrat Khan
CONTROL ENGINEERING AND APPLIED INFORMATICS
(2018)
Proceedings Paper
Engineering, Electrical & Electronic
Waseem Abbasi, Fazal Ur Rehman, Ibrahim Shah
2017 AEIT INTERNATIONAL ANNUAL CONFERENCE
(2017)
Proceedings Paper
Computer Science, Interdisciplinary Applications
Muhammad Sarfraz, Fazal Ur Rehman
2017 13TH INTERNATIONAL CONFERENCE ON EMERGING TECHNOLOGIES (ICET 2017)
(2017)
Proceedings Paper
Computer Science, Interdisciplinary Applications
Waseem Abbasi, Ibrahim Shah, Fazal Ur Rehman, Sami Ud Din
2017 13TH INTERNATIONAL CONFERENCE ON EMERGING TECHNOLOGIES (ICET 2017)
(2017)
