Xiuyu He

Vibration Control of an Industrial Moving Strip in the Presence of Input Deadzone

This paper investigates the boundary control design and the stability analysis for an axially moving strip system under the external time-varying disturbances. Based on the infinite dimensional dynamical model, the active control strategies are acted on the boundary of the system to deal with the problems of vibration suppression and nonlinear deadzone input characteristic. In addition, a disturbance observer is constructed to handle the bounded and uncertain boundary disturbance. With the proposed boundary control laws, the states of the moving strip system are proven to converge to a neighbourhood of the equilibrium points, namely, the stability of the moving strip system can be guaranteed. Through comparing the simulation results, the effectiveness of the boundary control law is verified.

Boundary Vibration Control of Variable Length Crane Systems in Two-Dimensional Space With Output Constraints

A variable length crane system under the external disturbances and constraints is studied in the two-dimensional space. The dynamical analysis of the cable system considers the variable length, variable tension, variable speed, and the coupled vibrations of the cable in longitudinal-transverse directions. Considering output constraint problems, boundary control algorithms with output signal barriers are designed and acted on the boundary of the cable to reduce the coupled vibrations of the flexible crane cable, and to ensure the stability of the system in theory. Effectiveness and performance of the proposed control schemes are depicted via several simulation examples.

PDE Model-Based Boundary Control Design for a Flexible Robotic Manipulator With Input Backlash

This brief considers the control design problem for a flexible robotic manipulator. Our control strategies are to: 1) move the manipulator to the certain desired angle; 2) suppress the vibration at the neighborhood of the desired angle; and 3) handle the backlash nonlinearity existing in the practical system. Based on the infinite-dimensional dynamic model, a boundary controller with input backlash is designed to achieve the control aims. An output feedback method is adopted to represent a controller to handle the feedback signals that are not able to be measured directly. The effectiveness of the designed controllers and the stability of the system are demonstrated by theoretical analysis, numerical simulations, and physical experiments.

Robust adaptive vibration control for an uncertain flexible Timoshenko robotic manipulator with input and output constraints

ABSTRACT The problems of the constraints and the vibration suppression are investigated for the flexible Timoshenko robotic manipulator in this paper. Robust adaptive boundary control laws with the disturbance observes are designed to guarantee the convergence of the feedback flexible Timoshenko robotic manipulator system with the uncertain parameters and the states are proven to be uniform bounded. In addition, the proposed boundary controls are verified to be effectiveness by the numeral experiments.

Modeling and vibration control of flexible wings with output constraint

In this paper, we present modeling and vibration control with boundary output constraint. By using the Hamiltons principle, the dynamics of the flexible wings are represented by partial differential equations (PDEs) and several ordinary differential equations (ODEs). Based on the Lyapunovs direct method, model-based barrier control is developed to control the vibrations of the flexible wings under the boundary output constraint. To achieve the constraint violation, a novel barrier Lyapunov function is employed for the control design and stability analysis. The vibration suppress is well achieved without violation of constraint.

Boundary control of flexible aircraft wings for vibration suppression

ABSTRACT In this paper, we propose a boundary control strategy for vibration suppression of two flexible wings. As a basic approach, Hamiltons principle is used to ascertain the system dynamic model, which includes governing equations – four partial differential equations and boundary conditions – several ordinary differential equations. Considering the coupled bending and torsional deformations of flexible wings, boundary control force and torque act on the fuselage to regulate unexpected deformations of flexible wings. Then, we present the stability analysis of the closed-loop system through Lyapunovs direct method. Simulations are carried out by using finite difference method. The simulation experimental results illustrate the significant effect of the developed control strategies.

Three-Dimensional Vibrations Control Design for a Single Point Mooring Line System with Input Saturation

This paper presents a boundary control design for a single point mooring line system with input saturation in three-dimensional (3D) space. The system is described by some partial differential equations (PDEs) and ordinary differential equations (ODEs). The control strategy proposed in this paper at the tip payload of the mooring line and the control design uses Lyapunov’s direct method (LDM) to ensure the stability of the system. In order to compensate the input saturation, we propose an auxiliary system. With the proposed boundary control, the mooring system’s uniform boundedness under the effect of external environment is obtained. The presented boundary control is implementable with feasible equipment because all information in the system can be gained and calculated through various sensors or by applying a backward difference algorithm. Simulation results are provided to prove that the controller is effective in regulating the vibration of the system.

A Boundary Control Method for Suppressing Flexible Wings Vibration of the FMAV

In this paper, we propose a boundary control strategy for vibration suppression of two flexible wings and a rigid body. As a basic approach, Hamilton’s principle is used to ascertain the system dynamic model, which includes governing equations and boundary conditions. Considering the coupled bending and torsional deformations of flexible wings, boundary control force and torque act on the rigid body to regulate unexpected deformations of flexible wings that caused by air flow. Then, we present stability analysis of the closed-loop system through Lyapunov’s direct method. Simulations are carried out by using finite difference method. The results illustrate the significant effect of the developed control strategies.

Boundary control design for a flexible robotic manipulator modeled as a Timoshenko beam

The dynamical model and the stability analysis of the flexible robotic manipulator system described with the Timoshenko beam are investigated in this paper. The vibration of the manipulator is suppressed under the external disturbance, the rotation of the Timoshenko beams cross-section is reduced and the desired angular position is traced with the designed boundary control laws. In addition, the states of the closed-loop system are proven to be exponentially convergent. The numeral simulation is given to verity the effectiveness of the designed control.

Boundary control based on an infinite dimensional system of a marine riser with constraint

In this paper, the constrained problem of the joint angles for a flexible marine riser is investigated. The riser system is described by partial differential equations (PDEs) - ordinary differential equations (ODEs), which avoid the spillover effect. Boundary control based on the integral-barrier Lyapunov function (IBLF) is achieved by three actuators equipped at the top boundary of the riser. Under the time-varying disturbances, the designed control can suppress vibration of the riser and ensure joint angles in the constrained range. The stability is proved under the designed control laws. Numerical simulations are given to illustrate the effectiveness of the designed control laws.