Robust adaptive backstepping fast terminal sliding mode controller for uncertain quadrotor UAV

This paper proposes a novel composite integrated guidance and control (IGC) law for missile intercepting against unknown maneuvering target with multiple uncertainties and control constraint. First, by using back-stepping technique, the proposed IGC law design is separated into guidance loop and control loop. The unknown target maneuvers and variations of aerodynamics parameters in guidance and control loop are viewed as uncertainties, which are estimated and compensated by designed model-assisted reduced-order extended state observer (ESO). Second, based on the principle of active disturbance rejection control (ADRC), enhanced feedback linearization (FL) based control law is implemented for the IGC model using the estimates generated by reduced-order ESO. In addition, performance analysis and comparisons between ESO and reduced-order ESO are examined. Nonlinear tracking differentiator is employed to construct the derivative of virtual control command in the control loop. Third, the closed-loop stability for the considered system is established. Finally, the effectiveness of the proposed IGC law in enhanced interception performance such as smooth interception course, improved robustness against multiple uncertainties as well as reduced control consumption during initial phase are demonstrated through simulations.

Back-stepping active disturbance rejection control design for integrated missile guidance and control system via reduced-order ESO.

The Active Disturbance Rejection Control (ADRC) prefers the cascaded integral system for a convenient design or better control effect and takes it as a typical form. However, the state variables of practical system do not necessarily have a cascaded integral relationship. Therefore, this paper proposes an algebraic substitution method and its structure, which can convert a noncascaded integral system of PID control into a cascaded integral form. The adjusting parameters of the ADRC controller are also demonstrated. Meanwhile, a numerical example and the oscillation control of a flexible arm are demonstrated to show the conversion, controller design, and control effect. The converted system is proved to be more suitable for a direct ADRC control. In addition, for the numerical example, its control effect for the converted system is compared with a PID controller under different disturbances. The result shows that the converted system can achieve a better control effect under the ADRC than that of a PID. The theory is a guide before practice. This converting method not only solves the ADRC control problem of some noncascaded integral systems in theory and simulation but also expands the application scope of the ADRC method.

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An ADRC Method for Noncascaded Integral Systems Based on Algebraic Substitution Method and Its Structure

In industrial environments, over several decades, Automated Guided Vehicles (AGVs) and Autonomous Mobile Robots (AMRs) have served to improve efficiencies of intralogistics and material handling tasks. However, for system integrators, the choice and effective deployment of improved, suitable and reliable communication and control technologies for these unmanned vehicles remains a very challenging task. Specifics of communication for AGVs and AMRs imposes stringent performance requirements on latency and reliability of communication links which many existing wireless technologies struggle to satisfy. In this paper, a review of latest AGVs and AMRs research results in the past decade is presented. The review encompasses results from different past and present research domains of AGVs. In addition, performance requirements of communication networks in terms of their latencies and reliabilities when they are deployed for AGVs and AMRs coordination, control and fleet management in smart manufacturing environments are discussed. Integration challenges and limitations of present state-of-the-art AGV and AMR technologies when those technologies are used for facilitating AGV-based smart manufacturing and factory of the future applications are also thoroughly discussed. The paper also present a thorough discussion of areas in need of further research regarding the application of 5G networks for AGVs and AMRs fleet management in smart manufacturing environments. In addition, novel integration ideas by which tactile Internet, 5G network slicing and virtual reality applications can be used to facilitate AGV and AMR based factory of the future (FoF) and smart manufacturing applications were motivated.

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A Review of Recent Advances in Automated Guided Vehicle Technologies: Integration Challenges and Research Areas for 5G-Based Smart Manufacturing Applications

A fractional order adaptive backstepping control scheme is presented for an incommensurate fractional order systems in the presence of input saturation. In order to compensate the saturation, the necessary signals are generated by constructing a fractional order auxiliary system. Besides the nonlinear functions and unknown parameters of systems, the uncertainties, especially the unknown control input coefficient, are emphasized here. The adoption of fractional order parameters update law and nonlinear feedback has added more degree of freedom to controllers, which leads to a larger range of application. The frequency distributed model is introduced so that the indirect Lyapunov method is available in the procedure of controller design. All the differential signals, used for the control and estimation, are obtained through fractional order tracking differentiator. Compared with previous methods, the backstepping method is first adopted to solve the saturation problem of incommensurate order systems with nonlinearities and uncertainties, which achieves stabilization and tracking. To highlight the effectiveness of the proposed controller, simulation examples are demonstrated at last.

Adaptive backstepping control for fractional order systems with input saturation

Stabilization of a class of nonlinear systems with actuator saturation via active disturbance rejection control

In this technical note, the active disturbance rejection control (ADRC) is generalized to uncertain nonaffine-in-control nonlinear systems. The proposed controller incorporates both an extended state observer (ESO) as well as a dynamic inversion. The ESO is designed to estimate system state and total uncertainty, which includes the uncertain internal dynamics and the external disturbance, and is nonaffine-in-control. Based on the output of the ESO, the dynamic inversion is used to deal with the nonaffine-in-control problem. The proposed control has a multi-time-scale structure, in which the ESO is the fastest time scale; the dynamic inversion is the second; and the considered nonlinear system is the slowest. The practical convergence of the resulting closed-loop system is obtained. An example is presented to illustrate the efficiency of the proposed method.

Active Disturbance Rejection Control for Uncertain Nonaffine-in-Control Nonlinear Systems

Active disturbance rejection control for uncertain time-delay nonlinear systems

Backstepping design of missile guidance and control based on adaptive fuzzy sliding mode control

Summary
A novel anti-windup design method is provided for a class of uncertain nonlinear systems subject to actuator saturation and external disturbance. The controller considered incorporates both an active disturbance rejection controller as well as an anti-windup compensator. The dynamical uncertainties and external disturbance are treated as an extended state of the plant, and then estimate it using an extended state observer and compensate for it in the control action, in real time. The anti-windup compensator produces a signal based on the difference between the controller output and the saturated actuator output, and then augment the signal to the control to deal with the windup phenomenon caused by actuator saturation. We first show that, with the application of the proposed controller, the considered nonlinear system is asymptotically stable in a region including the origin. Then, in the case that the controller in linear form, we establish a linear matrix inequality-based framework to compute the extended state observer gain and the anti-windup compensation gain that maximize the estimate of the domain of attraction of the resulting closed-loop system. The effectiveness of the proposed method is illustrated by a numerical example. Copyright © 2016 John Wiley & Sons, Ltd.

Maopeng Ran

Papers

Stabilization of a class of nonlinear systems with actuator saturation via active disturbance rejection control

Active Disturbance Rejection Control for Uncertain Nonaffine-in-Control Nonlinear Systems

Active disturbance rejection control for uncertain time-delay nonlinear systems

Backstepping design of missile guidance and control based on adaptive fuzzy sliding mode control

Anti-windup design for uncertain nonlinear systems subject to actuator saturation and external disturbance