Search

Global sampled‐data stabilization for a class of nonlinear continuous system with input delay has been investigated directly in the discrete‐time domain due to challenges confronted in dealing with infinite‐dimensional system under input delay. Memorized state feedback controllers and output feedback controllers based on dynamic extension of state space have been constructed within the framework of co‐design between sampling period and scaling gain. Upon this compensation scheme, global sampled‐data stabilization a class of nonlinear system has been successfully realized no matter the input delay is smaller than the sampling period or not. Compared with memory‐less sampled‐data controllers, not only sampled‐data stabilization under large input delay has been realized but also transient performance of closed‐loop system has been further improved. Simulation results under different input delays and sampling periods have illustrated the effectiveness of results obtained. [ABSTRACT FROM AUTHOR]

Summary: This paper proposes some novel compensating strategies in output feedback controller design for a class of nonlinear uncertain system. With Euler approximation introduced for unmeasured state and coordinate transformation constructed for continuous system, sampled‐data stabilization under arbitrary sampling period is firstly realized for linear system using compensation between sampling period and scaling gain. Then global sampled‐data stabilization for a class of nonlinear system is studied using linear feedback domination of Lyapunov functions. Extension of obtained results to three‐dimensional system or systems under general assumptions are also presented. With the compensation schemes proposed in controller design, the sufficiently small sampling period or approximating step previously imposed is not required any more. The proposed controllers can be easily implemented using output measurements sampled at the current step and delayed output measurements sampled at the previous step without constructing state observers which has been illustrated by the numerical studies. [ABSTRACT FROM AUTHOR]

The sampled-data stabilization of a fractional continuous linear system under arbitrary sampling periods was first investigated in this paper wherein novel co-designed sampled-data controllers were constructed based on the compensation of scaling gains. With the help of fractional difference approximation, sufficient and necessary conditions for global asymptotic stability were first presented in the discrete-time domain, and then co-designed sampled-data controllers were constructed with only the "newest" or "oldest" state information available for controller design. Due to the compensation scheme between scaling gains and sampling periods, much more flexibility on selecting different sampling periods was provided in the sampled-data stabilization of the fractional continuous linear system which is significantly preferred for digital implementation. Numerical studies are also presented to illustrate the effectiveness of our co-designed sampled-data controllers under different sampling periods. [ABSTRACT FROM AUTHOR]

ABSTRACT This article investigates the distributed adaptive multi‐lane fusion control for two‐dimensional (2‐D) plane vehicle platoons with variable distance constraints, input hysteresis, and angle sensor faults. Variable distance constraints occur within a limited time interval (VDCOLT), which limits vehicle spacing within a variable range during preset time intervals while keeping the vehicle spacing unconstrained at other times. Combined with a transformed error function, a new shifting function is introduced to convert the constrained spacing error variables into the unconstrained variables while keeping the unconstrained variable unchanged. Designing the position controller ensures that the distance satisfies VDCOLT and reduces the adverse effects caused by unknown signs of input hysteresis by using a Nussbaum function. Moreover, a new angle controller based on the hyperbolic tangent function is designed to solve the problem of angle sensor faults. Furthermore, the stability of the vehicle platoon is achieved through the backstepping control and sliding‐mode control methods. Finally, a numerical simulation is provided to verify the proposed techniques. [ABSTRACT FROM AUTHOR]

Sampled‐data output consensus problem has been firstly considered within co‐design framework where control gains and sampling periods are incorporated together. In construction of co‐designed controllers, we firstly introduce a scaled coordinate transformation for the original system in the continuous‐time domain. Then design of sampled‐data controllers with absolute/relative damping and stability analysis of closed‐loop system have been conducted directly in discrete‐time domain. Main novelty of the co‐design method lies in that the sampling period can be arbitrarily large due to the compensation of control gains. Compared with previous work on sampled‐data consensus protocols, conservatism on allowable sampling periods has been greatly relaxed and more flexibility has been provided for digital implementation of the obtained sampled‐data controllers. Simulation studies with different sampling periods are also provided to illustrate the effectiveness of the co‐designed sampled‐data output controllers. [ABSTRACT FROM AUTHOR]

This paper employs the direct method to design sampled-data state/output feedback controller for a class of uncertain nonlinear systems under a general linear growth condition. Both state feedback controller and observer are constructed directly in the discrete-time domain for the difference-integral systems equivalent to the continuous-time systems. To dominate the influence of the uncertain nonlinearities, a co-design process is used to determine the sampling period and scaling gain together. Compared to the emulation method, the direct co-design method can handle a broader class of nonlinear systems and has more flexibility in choosing the sampling period that is less restrictive for digital implementation. [ABSTRACT FROM AUTHOR]