Constrained Model Predictive Control

This paper focuses on the practical output tracking control for a category of high-order uncertain nonlinear systems with full-state constraints. A high-order tan-type barrier Lyapunov function (BLF) is constructed to handle the full-state constraints of the control systems. By the BLF and combining a backstepping design technique, an adding a power integrator, and a fuzzy control, the proposed approach can control high-order uncertain nonlinear system with full-state constraints. A novel controller is designed to ensure that the tracking errors approach to an arbitrarily small neighborhood of zero, and the constraints on system states are not violated. The numerical example demonstrates effectiveness of the proposed control method.

Adaptive Fuzzy Control With High-Order Barrier Lyapunov Functions for High-Order Uncertain Nonlinear Systems With Full-State Constraints

A constructive method is presented to design controllers that force the output of nonlinear systems in a strict feedback form to track a bounded and sufficiently smooth reference trajectory asymptotically. Under a suitable condition on the initial output tracking error, the proposed controllers guarantee the output tracking error within a symmetric or an asymmetric pre-specified limit range, and boundedness of all signals of the closed-loop system. A transformation is introduced to take care of the output tracking error constraint. Smooth and/or p-times differentiable step functions are proposed and incorporated in the output tracking error transformation to overcome difficulties due to the asymmetric limit range on the output tracking error. As a result, there are no switchings in the proposed controllers despite the asymmetric limit range. The proposed control design is then applied to design a tracking controller for active magnetic bearings as an illustrating application.

Control of Nonlinear Systems with Output Tracking Error Constraints

This paper investigates event-triggered finite-time tracking control problem for full state constraints nonlinear systems with uncertain parameters. Considering a class of full state constraints nonlinear systems, a new finite-time barrier Lyapunov function (FTBLF) is constructed, and it is utilized to achieve finite-time tracking control while each state constraints are not violated. Further, to reduce communication resource burden, a time-varying threshold event-triggered mechanism is proposed. Meanwhile, by integrating prescribed exponential function into FTBLF, the transient performance can be guaranteed and free from influences of event-triggered control input. Finally, on the basic of backstepping design, an event-triggered adaptive finite-time tracking control method is developed. The proposed method guarantees that tracking error tends to a small adjustable set and its trajectory is within specified bound, while full state constraints are never violated. Two examples are given to demonstrate the control effect.

Event-triggered adaptive finite-time tracking control for full state constraints nonlinear systems with parameter uncertainties and given transient performance

Output-feedback control strategies of lower-triangular nonlinear nonholonomic systems in any prescribed finite time

This article concentrates on an adaptive backstepping control design of time-delay strict-feedback uncertain nonlinear systems subject to full state constraints. The tan-type barrier Lyapunov functions (tBLFs) and Lyapunov-Krasovskii function are united together, which successfully get over the difficulties of system design in which the first function is involved to ensure full state constraints satisfaction and the second is established to eliminate the effect of delayed states. By employing a new control scheme, asymptotic tracking performance is arrived, and all the states remain in the desirable regions for all the system running time. Meanwhile, the boundedness of all signals of the closed-loop system is guaranteed. The performance of the control scheme is illustrated through a class of single degree of freedom (1-DOF) time-delay electrostatic microactuator systems.

Asymptotic tracking control for time-delay nonlinear systems with parametric uncertainties and full state constraints.

In this paper, we investigate the tracking control problem for a class of strict-feedback nonlinear systems with parametric uncertainties and time-varying asymmetric full-state constraints. By intr...

TABLF-based adaptive control for uncertain nonlinear systems with time-varying asymmetric full-state constraints

Global robust output tracking control for a class of uncertain cascaded nonlinear systems

In this paper, the problem of global stabilization control via partial-state feedback is addressed for a class of uncertain nonholonomic systems with the disturbed virtual control directions. The investigated nonholonomic system has the input-to-state stable (ISS) dynamic uncertainties. The small gain theorem and the changing supply function technique are employed to derive a global stabilization controller. Additionally, we develop a switching control strategy in order to get around the smooth stabilization burden associated with nonholonomic systems. The simulation results illustrate the efficacy of the presented algorithm.

Partial-state Feedback Stabilization for a Class of Generalized Nonholonomic Systems with ISS Dynamic Uncertainties

This article considers the global robust output regulation problem via output feedback for a class of cascaded nonlinear systems with input-to-state stable inverse dynamics. The system uncertainties depend not only on the measured output but also all the unmeasurable states. By introducing an internal model, the output regulation problem is converted into a stabilisation problem for an appropriately augmented system. The designed dynamic controller could achieve the global asymptotic tracking control for a class of time-varying reference signals for the system output while keeping all other closed-loop signals bounded. It is of interest to note that the developed control approach can be applied to the speed tracking control of the fan speed control system. The simulation results demonstrate its effectiveness.

Yan Zhao

Papers

Asymptotic tracking control for time-delay nonlinear systems with parametric uncertainties and full state constraints.

TABLF-based adaptive control for uncertain nonlinear systems with time-varying asymmetric full-state constraints

Global robust output tracking control for a class of uncertain cascaded nonlinear systems

Partial-state Feedback Stabilization for a Class of Generalized Nonholonomic Systems with ISS Dynamic Uncertainties

Global robust output regulation control for cascaded nonlinear systems using the internal model principle