Xuena Zhao

In this article, we propose an adaptive neural network event-triggered control (ETC) to suppress the vibration of a high-rise building under uncertainty. This neural network efficiently handles unmodeled components in the system and approximates unknown nonlinear functions. An ETC mechanism with a relative threshold strategy is introduced, balancing the control effectiveness of the active mass damper (AMD) and extending operational lifespan. The ultimate boundedness of the system is verified using the Lyapunov direct method, ensuring convergence of vibration displacement and acceleration toward zero. The efficacy of this control scheme is demonstrated through detailed numerical simulations and experimental analyses.

Unsteady aerodynamics because of wing motion and underactuated caused by bionic driving mode are among the most notable challenges to accurate dynamic modeling and flight control for flapping-wing aircraft (FWAs). In this paper, we establish a comprehensive 6-degree-of-freedom (DoF) dynamic model to describe the multi-mode motion of a falcon-like FWA. The unsteady vortex lattice method (UVLM) is used to compute the time-varying aerodynamic forces on the main wing, accounting for the effects of flexible deformations and lateral dynamics. Based on a series of wind tunnel experiments, a data-driven model for the V-tail is developed using an artificial neural network (ANN) to capture the relationship between ruddervators’ deflections and aerodynamic forces. A simulation environment, constructed on the foundation of aerodynamic modeling and dynamic analysis, is validated with both open-loop and closed-loop flight data. The virtual system allows for rapid verification and optimization of the model and control parameters, which can enhance the flexibility and reliability of the development process of FWAs. Note to Practitioners—This work addresses the challenges of modeling and controlling FWAs, which are known for their exceptional agility but also pose significant difficulties due to unsteady aerodynamics and underactuated mechanisms. We develop a 6-DoF dynamic model and simulation environment for a falcon-like FWA, capturing multi-mode motion. Unlike dynamic models constrained to small perturbations around stable operating points, our approach provides a more comprehensive description of FWA dynamics across diverse flight modes. Validated with real flight data, this virtual environment is proven to be reliable and capable of supporting advanced control methods such as reinforcement learning and model predictive control. It offers a platform for optimizing FWA design and control, enhancing flexibility and reliability in practical applications while paving the way for further improvements in complex flight scenarios.

In the context of increasingly networked control systems, this article concentrates on the noncollocated control issue of input and output quantization for industrial processes governed by semilinear parabolic partial differential equation (PDE) systems. Both the control and measurement signals are quantized and transmitted through the network, which causes signal errors and reduces the stability and robustness of the system. A Luenberger-type PDE observer is developed to overcome the control difficulty of quantized measurement feedback signals and noncollocated pointwise sensors. Based on the observed value, a feedback controller is proposed, which undergoes quantization and operates on the distributed actuators within the domain. By employing the Lyapunov direct method, it is demonstrated that the observer can accurately track the system state with exponential precision, and the closed-loop system is exponentially converged. The well-posedness analysis of the closed-loop system is discussed via the $C_{0}$-semigroup method. The performance of the developed control strategy is validated through simulation examples.

Aiming at the windproof and seismic problems of a high-rise building with large flexible structures, this article introduces a boundary control technology for a high-rise building with active mass damper (AMD) under input and output constraints. Hamilton's principle is used to establish an infinite-dimensional distributed parameter system model of a high-rise building with AMD. Based on the partial differential equations model, a boundary control law with input and output constraints is proposed, where the bounded input constraints are handled by a smooth hyperbolic tangent function and the output constraints are dealt with by a barrier Lyapunov function. It is proved that the vibration is well suppressed by the controller, and the input and output constraints are not violated. Numerical simulations and experiments are used to verify the effectiveness of the control performance.

In this article, an adaptive event-triggered boundary control scheme is proposed for a flexible single-link manipulator (FSLM) system with communication constraints. The hysteresis quantizer with unknown parameters is applied to the control input, which brings a negative effect on the control performance. To reduce the communication burden, we take into account a relative threshold event-triggered mechanism. An adaptive strategy is adopted to compensate for the quantization error and evaluate the unknown parameters. In terms of the Lyapunov direct method, the angle tracking error and the vibration displacement of the FSLM are proved to exponentially converge to the neighborhood of zero. Furthermore, the performance of the developed control algorithm is presented by numerical simulations and experiments.

In this article, we consider the time-varying trajectory tracking boundary control problem for the flexible rotation beam subject to distributed disturbance. A partial differential equation model for the flexible rotation beam system with the coupling of angle and vibration displacement is established by Hamilton principle. By introducing a servo system generated by the reference signal, a boundary controller is proposed to track the desired time-varying trajectory, which is different from the fixed angular position in most existing work. A Lyapunov-based stability analysis is presented to demonstrate that the tracking error system between the servo system and the original system is uniformly ultimately bounded. Based on the infinite dimensional operator theory, it is proved that the closed-loop system is well posed and all signals remain bounded. Numerical simulations verify the correctness of the theory and the effectiveness of the control strategy. And the experiments based on the Quanser platform demonstrate the same result as well.

In this study, we propose an adaptive fuzzy event-triggered control scheme for an autonomous aerial refueling hose system involving uncertainty, an event-triggered mechanism, and actuator failures. The unknown nonlinear function is approximated using the designed fuzzy logic systems. Through introduction of the adaptive compensation scheme, the problem of an infinite number of actuator failures, including partial and complete failures, is solved. In addition, the event-triggered control strategy is designed to achieve vibration suppression while decreasing the communication burden between the controllers and actuators. The stability of the closed-loop system is demonstrated via the Lyapunov direct method. Finally, simulation examples are presented to confirm the validity of the proposed control scheme.

This article focuses on flexible single-link manipulators (FSLMs) under boundary control and in-domain control. The actuators of the system include the dc motor at the end of the joint and $m$ piezoelectric controllers installed at the flexible link, which is regarded as an Euler–Bernoulli beam. The problem of the infinite number of actuator failures, including the partial loss of the effectiveness and total loss of effectiveness, is solved by the adaptive compensation method. By introducing the relative threshold strategy, the event-triggered control (ETC) scheme is proposed to achieve angle regulation and vibration suppression while reducing the communication burden between the controllers and the actuators. The Lyapunov direct method is utilized to prove that the system is uniformly ultimately bounded and both the angular tracking error and elastic displacement converge to a neighborhood of zero. Numerical simulation results are provided to demonstrate the effectiveness of the proposed control law.

This article focuses on a two-dimensional flexible two-link manipulator that moves in a plane. The two links are simplified into Euler–Bernoulli beams and the coupled partial differential equation-ordinary differential equation dynamic model is established via Hamiltonian's principle. Two torque controllers acting on two motors, respectively, are designed for the simultaneous angular position control of two motors and suppression of the elastic vibrations of the links. The Lyapunov direct method and extended LaSalle invariance principle are used to prove the asymptotic stability of the system. In addition, numerical simulations illustrate the correctness and reasonability of the theoretical proof for the stability analysis and boundary control design, and the experimental verification on the platform of the Quanser laboratory also reaches the same conclusion.