This paper develops a novel Neural Network(NN)-based adaptive nonsingular practical predefined-time controller for the hypersonic morphing aircraft subject to actuator faults. Firstly, a novel Lyapunov criterion of pr...This paper develops a novel Neural Network(NN)-based adaptive nonsingular practical predefined-time controller for the hypersonic morphing aircraft subject to actuator faults. Firstly, a novel Lyapunov criterion of practical predefined-time stability is established. Following the proposed criterion, a tangent function based nonsingular predefined-time sliding manifold and the control strategy are developed. Secondly, the radial basis function NN with a low-complexity adaptation mechanism is incorporated into the controller to tackle the actuator faults and uncertainties. Thirdly, rigorous theoretical proof reveals that the attitude tracking errors can converge to a small region around the origin within a predefined time, while all signals in the closed-loop system remain bounded. Finally, numerical simulation results are presented to verify the effectiveness and improved performance of the proposed control scheme.展开更多
针对压电快反镜系统(Piezoelectric Fast Steering Mirror,PFSM)在跟踪过程中由自身压电磁滞和外界环境所引起的不确定干扰问题,文中提出了一种创新的预定时间自适应滑模控制器。此控制器使用障碍函数设计自适应律,并引入了预定时间的概...针对压电快反镜系统(Piezoelectric Fast Steering Mirror,PFSM)在跟踪过程中由自身压电磁滞和外界环境所引起的不确定干扰问题,文中提出了一种创新的预定时间自适应滑模控制器。此控制器使用障碍函数设计自适应律,并引入了预定时间的概念,以确保系统的响应更加灵活和高效。在保证控制系统状态的收敛时间小于预定时间上界的基础上,该控制策略还可通过障碍函数将滑模变量的收敛范围限制在一个微小的邻域内。文中利用Lyapunov稳定性理论证明了闭环控制系统的稳定性。最后,通过数值仿真验证了所设计控制器的有效性。结果表明:该控制器在提升PSFM性能、缩短跟踪时间以及提高精度方面具有显著优势。展开更多
In this paper,the singularity-free predefined-time fuzzy adaptive tracking control problem is studied for non-strict feedback(NSF)nonlinear systems considering mismatched external disturbances.An innovative practical ...In this paper,the singularity-free predefined-time fuzzy adaptive tracking control problem is studied for non-strict feedback(NSF)nonlinear systems considering mismatched external disturbances.An innovative practical predefined-time stability(PPTS)criterion is proposed to provide the theoretical basis for subsequent control design.Compared to the existing predefined-time stability(PTS)criterion,this criterion has a broader application range and can solve the control design issues of nonlinear systems with system uncertainties.Fuzzy logic systems(FLSs)are employed to identify unknown nonlinear functions.Based on the backstepping control technology,a singularity-free predefined-time control(PTC)design method is proposed,in which the hyperbolic tangent function is utilized to avoid the singular problem,and the nature of fuzzy basis function is adopted to resolve the algebraic loop problem.The PPTS of the closed-loop NSF nonlinear system is proven with the Lyapunov theory and the proposed PPTS criterion.Ultimately,the efficiency of the presented PTC design method is verified by several sets of simulations on a single link manipulator system.展开更多
In this paper, a command filter-based adaptive fuzzy predefined-time event-triggered tracking control problem is investigated for uncertain nonlinear systems with time-varying full-state constraints. By designing a sl...In this paper, a command filter-based adaptive fuzzy predefined-time event-triggered tracking control problem is investigated for uncertain nonlinear systems with time-varying full-state constraints. By designing a sliding mode differentiator, the inherent computational complexity problem within the predefined-time backstepping framework is solved. Different from the existing command filter-based finite-time and fixed-time control strategies that the convergence time of the filtering error is adjusted through the system initial value or numerous parameters, a novel command filtering error compensation method is presented,which tunes one control parameter to make the filtering error converge in the predefined time, thereby reducing the complexity of design and analysis of processing the filtering error. Then, an improved event-triggered mechanism(ETM) that builds upon the switching threshold strategy, in which an inverse cotangent function is designed to replace the residual term of the ETM,is proposed to gradually release the controller's dependence on the residual term with increasing time. Furthermore, a tan-type nonlinear mapping technique is applied to tackle the time-varying full-state constraints problem. By the predefined-time stability theory, all signals in the uncertain nonlinear systems exhibit predefined-time stability. Finally, the feasibility of the proposed algorithm is substantiated through two simulation results.展开更多
The system performance of grid-connected photovoltaic(PV)has a serious impact on the grid stability.To improve the control performance and shorten the convergence time,a predefined-time controller based on backsteppin...The system performance of grid-connected photovoltaic(PV)has a serious impact on the grid stability.To improve the control performance and shorten the convergence time,a predefined-time controller based on backstepping technology and dynamic surface control is formulated for the inverter in the grid-connected photovoltaic.The time-varying tuning functions are introduced into state-tracking errors to realize the predefined-time control effect.To address the“computational explosion problem”in the design process of backstepping control,dynamic surface control is adopted to avoid the analytical calculations of virtual control.The disturbances of the PV system are estimated and compensated by adaptive laws.The control parameters are chosen and the global stability of the closed-loop is ensured by Lyapunov conditions.Simulation results confirm the effectiveness of the proposed controller and ensure the predefined time control in the photovoltaic inverter.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 52233014, U2241215)。
文摘This paper develops a novel Neural Network(NN)-based adaptive nonsingular practical predefined-time controller for the hypersonic morphing aircraft subject to actuator faults. Firstly, a novel Lyapunov criterion of practical predefined-time stability is established. Following the proposed criterion, a tangent function based nonsingular predefined-time sliding manifold and the control strategy are developed. Secondly, the radial basis function NN with a low-complexity adaptation mechanism is incorporated into the controller to tackle the actuator faults and uncertainties. Thirdly, rigorous theoretical proof reveals that the attitude tracking errors can converge to a small region around the origin within a predefined time, while all signals in the closed-loop system remain bounded. Finally, numerical simulation results are presented to verify the effectiveness and improved performance of the proposed control scheme.
文摘针对压电快反镜系统(Piezoelectric Fast Steering Mirror,PFSM)在跟踪过程中由自身压电磁滞和外界环境所引起的不确定干扰问题,文中提出了一种创新的预定时间自适应滑模控制器。此控制器使用障碍函数设计自适应律,并引入了预定时间的概念,以确保系统的响应更加灵活和高效。在保证控制系统状态的收敛时间小于预定时间上界的基础上,该控制策略还可通过障碍函数将滑模变量的收敛范围限制在一个微小的邻域内。文中利用Lyapunov稳定性理论证明了闭环控制系统的稳定性。最后,通过数值仿真验证了所设计控制器的有效性。结果表明:该控制器在提升PSFM性能、缩短跟踪时间以及提高精度方面具有显著优势。
基金supported in part by the National Natural Science Foundation of China under Grant Nos.92267203,62373302,62333009,62176111,and 62333004in part by the Key-Area Research and Development Program of Guangdong Province under Grant No.2023B0303030001+2 种基金in part by the Program for Guangdong Introducing Innovative and Entrepreneurial Teams under Grant No.2019ZT08X214in part by the Natural Science Foundation of Shaanxi Province under Grant No.2024JC-YBQN-0663in part by Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University under Grant No.CX2023084。
文摘In this paper,the singularity-free predefined-time fuzzy adaptive tracking control problem is studied for non-strict feedback(NSF)nonlinear systems considering mismatched external disturbances.An innovative practical predefined-time stability(PPTS)criterion is proposed to provide the theoretical basis for subsequent control design.Compared to the existing predefined-time stability(PTS)criterion,this criterion has a broader application range and can solve the control design issues of nonlinear systems with system uncertainties.Fuzzy logic systems(FLSs)are employed to identify unknown nonlinear functions.Based on the backstepping control technology,a singularity-free predefined-time control(PTC)design method is proposed,in which the hyperbolic tangent function is utilized to avoid the singular problem,and the nature of fuzzy basis function is adopted to resolve the algebraic loop problem.The PPTS of the closed-loop NSF nonlinear system is proven with the Lyapunov theory and the proposed PPTS criterion.Ultimately,the efficiency of the presented PTC design method is verified by several sets of simulations on a single link manipulator system.
基金supported by the Revitalization of Liaoning Talents Program(Grant No.XLYC2203201)。
文摘In this paper, a command filter-based adaptive fuzzy predefined-time event-triggered tracking control problem is investigated for uncertain nonlinear systems with time-varying full-state constraints. By designing a sliding mode differentiator, the inherent computational complexity problem within the predefined-time backstepping framework is solved. Different from the existing command filter-based finite-time and fixed-time control strategies that the convergence time of the filtering error is adjusted through the system initial value or numerous parameters, a novel command filtering error compensation method is presented,which tunes one control parameter to make the filtering error converge in the predefined time, thereby reducing the complexity of design and analysis of processing the filtering error. Then, an improved event-triggered mechanism(ETM) that builds upon the switching threshold strategy, in which an inverse cotangent function is designed to replace the residual term of the ETM,is proposed to gradually release the controller's dependence on the residual term with increasing time. Furthermore, a tan-type nonlinear mapping technique is applied to tackle the time-varying full-state constraints problem. By the predefined-time stability theory, all signals in the uncertain nonlinear systems exhibit predefined-time stability. Finally, the feasibility of the proposed algorithm is substantiated through two simulation results.
基金supported by the State Grid Corporation of China Headquarters Science and Technology Project under Grant No.5400-202122573A-0-5-SF。
文摘The system performance of grid-connected photovoltaic(PV)has a serious impact on the grid stability.To improve the control performance and shorten the convergence time,a predefined-time controller based on backstepping technology and dynamic surface control is formulated for the inverter in the grid-connected photovoltaic.The time-varying tuning functions are introduced into state-tracking errors to realize the predefined-time control effect.To address the“computational explosion problem”in the design process of backstepping control,dynamic surface control is adopted to avoid the analytical calculations of virtual control.The disturbances of the PV system are estimated and compensated by adaptive laws.The control parameters are chosen and the global stability of the closed-loop is ensured by Lyapunov conditions.Simulation results confirm the effectiveness of the proposed controller and ensure the predefined time control in the photovoltaic inverter.
