In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated...In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV constraint.The boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to constrain the body line-of-sight(BLOS)in IEGC system to fit a circular FOV.Then,the nonlinear adaptive controller is designed to estimate the changing aerodynamic parameters.The generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking accuracy.Furthermore,the command filters are used to solve the"differential expansion"problem during the backstepping design.The Lyapunov theory is used to prove the stability of the overall closed-loop IEGC system.Finally,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.展开更多
This paper investigates the heading tracking problem of surface vehicles with unknown model parameters.Based on finite/fixed-time control theories and in the context of command filtered control,two novel adaptive cont...This paper investigates the heading tracking problem of surface vehicles with unknown model parameters.Based on finite/fixed-time control theories and in the context of command filtered control,two novel adaptive control laws are developed by which the vehicle can track the desired heading within settling time with all signals of the closed-loop system are uniformly bounded.The effectiveness and performance of the schemes are demonstrated by simulations and comparison studies.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
An adaptive command filter control strategy was proposed to realize the asymptotic tracking of the roll speed,which successfully suppressed torsional vibration for the main drive system of the rolling mill with nonlin...An adaptive command filter control strategy was proposed to realize the asymptotic tracking of the roll speed,which successfully suppressed torsional vibration for the main drive system of the rolling mill with nonlinear friction,nonlinear damping,current harmonic,time-varying stiffness and unknown disturbance.A finite time predetermined performance method was proposed,so that the speed tracking error of the main transmission system was always constrained in the performance function and converged to its minimum boundary within the specified time.Based on the adaptive estimation of harmonic amplitude,the torque control law of the motor was obtained by using the filter backstepping method,which prevented the torsional vibration of the system caused by the input fluctuation and avoided the complexity explosion of the controller design,and the stability of the closed-loop system was strictly proved by the Lyapunov theory.The actual numerical simulation verified the effectiveness of the proposed control strategy.展开更多
Morphing unmanned aerial vehicle(UAV) can manipulate its shape for excellent flight performance under different conditions.The most research of the morphing UAV focuses on modeling. However, the issues including nonli...Morphing unmanned aerial vehicle(UAV) can manipulate its shape for excellent flight performance under different conditions.The most research of the morphing UAV focuses on modeling. However, the issues including nonlinear characteristics, strong couplings, and mismatched disturbances are inevitable, which can lead to a great challenge in controller design. In this paper,a composite anti-disturbance controller is developed for morphing UAV to achieve enhanced flight performance under multiple sources of disturbances. In the inner loop, a nonlinear disturbance observer(DO) is constructed to estimate the inertial forces and moment;while in the outer loop, the command filtered backstepping(CFBS) method is adopted to guarantee the stability of the closed-loop system. The system outputs can promptly track reference signals in the morphing process of the UAV. The novelty is that the disturbance estimations are added into the control laws to compensate the mismatched disturbances. When comparing to the previous methods, the control scheme presented in this study can significantly improve the performance of anti-disturbance.Finally, the effectiveness of the proposed method is illustrated by numerical simulations.展开更多
文摘In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV constraint.The boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to constrain the body line-of-sight(BLOS)in IEGC system to fit a circular FOV.Then,the nonlinear adaptive controller is designed to estimate the changing aerodynamic parameters.The generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking accuracy.Furthermore,the command filters are used to solve the"differential expansion"problem during the backstepping design.The Lyapunov theory is used to prove the stability of the overall closed-loop IEGC system.Finally,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.
基金supported by the National Natural Science Foundation of China(U1808205)the Fundamental Research Funds for the Central Universities(N2023011)+1 种基金the Youth Foundation of Hebei Educational Committee(QN2020522)the Natural Science Foundation of Hebei Province(F2020501018)。
文摘This paper investigates the heading tracking problem of surface vehicles with unknown model parameters.Based on finite/fixed-time control theories and in the context of command filtered control,two novel adaptive control laws are developed by which the vehicle can track the desired heading within settling time with all signals of the closed-loop system are uniformly bounded.The effectiveness and performance of the schemes are demonstrated by simulations and comparison studies.
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This work was supported by the Natural Science Foundation of China(Grant No.U20A20187).
文摘An adaptive command filter control strategy was proposed to realize the asymptotic tracking of the roll speed,which successfully suppressed torsional vibration for the main drive system of the rolling mill with nonlinear friction,nonlinear damping,current harmonic,time-varying stiffness and unknown disturbance.A finite time predetermined performance method was proposed,so that the speed tracking error of the main transmission system was always constrained in the performance function and converged to its minimum boundary within the specified time.Based on the adaptive estimation of harmonic amplitude,the torque control law of the motor was obtained by using the filter backstepping method,which prevented the torsional vibration of the system caused by the input fluctuation and avoided the complexity explosion of the controller design,and the stability of the closed-loop system was strictly proved by the Lyapunov theory.The actual numerical simulation verified the effectiveness of the proposed control strategy.
文摘Morphing unmanned aerial vehicle(UAV) can manipulate its shape for excellent flight performance under different conditions.The most research of the morphing UAV focuses on modeling. However, the issues including nonlinear characteristics, strong couplings, and mismatched disturbances are inevitable, which can lead to a great challenge in controller design. In this paper,a composite anti-disturbance controller is developed for morphing UAV to achieve enhanced flight performance under multiple sources of disturbances. In the inner loop, a nonlinear disturbance observer(DO) is constructed to estimate the inertial forces and moment;while in the outer loop, the command filtered backstepping(CFBS) method is adopted to guarantee the stability of the closed-loop system. The system outputs can promptly track reference signals in the morphing process of the UAV. The novelty is that the disturbance estimations are added into the control laws to compensate the mismatched disturbances. When comparing to the previous methods, the control scheme presented in this study can significantly improve the performance of anti-disturbance.Finally, the effectiveness of the proposed method is illustrated by numerical simulations.
