Adaptive Disturbance Rejection Control Research Articles

Aircraft system modeling under turbulence conditions and aircraft adaptive turbulence compensation

An adaptive disturbance rejection control scheme is developed for solving the wind turbulence compensation problem. The turbulence wind studied in this paper is based on the mutual switch of several dominant wind directions. The linear models of aircraft under wind turbulence with different dominant directions are given. An adaptive controller is designed based on the model reference adaptive control when the aircraft encounters the wind turbulence in different dominant directions. Desired closed-loop system stabilization and output tracking have been proven. A simulation study on aircraft compensation has been presented to verify the effectiveness of our designed method.

Current Driver Design for Electromagnetic Coil Using Adaptive Active Disturbance Rejection Control

An adaptive active disturbance rejection controller is used in the current driver design of the electromagnetic coil. Extended state observer of the 1st-order system is adopted for disturbance observation of ADRC. The supervised recursive least squares method is proposed for real-time parameters estimation, in which the excitation signal variance is used to trigger the parameter estimator. The experimental results demonstrate that ADRC combined with real-time parameter estimation simplifies the parameter tuning and improves the parameter adaptive ability.

Hybrid State Constraint Adaptive Disturbance Rejection Controller for a Mobile Worm Bio-Inspired Robot

This study presents the design of a hybrid active disturbance rejection controller (H-ADRC) which regulates the gait cycle of a worm bio-inspired robotic device (WBRD). The WBRD is designed as a full actuated six rigid link robotic manipulator. The controller considers the state restrictions in the device articulations; this means the maximum and minimum angular ranges, to avoid any possible damage to the structure. The controller uses an active compensation method to estimate the unknown dynamics of the WBRD by means of an extended state observer. The sequence of movements for the gait cycle of a WBRD is represented as a class of hybrid system by alternative reference frameworks placed at the first and the last link. The stability analysis employs a class of Hybrid Barrier Lyapunov Function to ensure the fulfillment of the angular restrictions in the robotic device. The proposed controller is evaluated using a numerical simulation system based on the virtual version of the WBRD. Moreover, experimental results confirmed that the H-ADRC may endorse the realization of the proposed gait cycle despite the presence of perturbations and modeling uncertainties. The H-ADRC is compared against a proportional derivative (PD) controller and a proportional-integral-derivative (PID) controller. The H-ADRC shows a superior performance as a consequence of the estimation provided by the homogeneous extended state observer.

An Adaptive Disturbance Rejection Controller for Artificial Pancreas

Artificial pancreas (AP) systems are designed to automate glucose management for patients with type 1 diabetes. In this work, we propose an adaptive disturbance rejection control approach for AP systems to achieve safe and effective glucose regulation. The controller is built within the framework of active disturbance rejection control, but incorporates safety operation constraints, and glucose- and velocity-dependent parameter adaptation modules for the key control parameters. In silico performance comparison between the proposed controller and an adaptive zone model predictive controller (MPC) (Shi, Dassau, and Doyle III, 2019a) is conducted on the 10-adult cohort of the FDA-accepted UVA/Padova T1DM simulator. For both announced and unannounced meals, the controller achieves comparable glucose regulation performance in terms of mean glucose (134.9 mg/dL vs. 135.4 mg/dL, p < 0.001; 149.7 mg/dL vs. 151.7 mg/dL, p < 0.001, respectively) and percentage time in [70, 180] mg/dL (93.8% vs. 92.4%, p < 0.001; 76.0% vs. 72.4%, p < 0.001, respectively) without increasing the risk of hypoglycemia. The results indicate the feasibility of achieving comparable glucose regulation performance through a non-optimization control law for AP systems.

Multi‐functional grid‐connected inverter with enhanced disturbance rejection capability

Apart from the basic renewable generation function, the multi-functional grid-connected inverter (MFGCI) derived from traditional grid-connected inverter could provide ancillary power quality enhancement functions for the interfaced grid. However, with multiple functions integrated into one control system, the control scheme of MFGCI would become inevitably more complicated and vulnerable to the disturbance in distribution networks. Here, a control scheme of MFGCI for rejecting both the steady-state and dynamic-state disturbance is designed. The proposed control scheme includes an inner loop controller and an improved reference current generation algorithm, which constitutes an overall MFGCI control scheme. To reject the steady-state disturbance which would distort the output current of MFGCI, the inner loop controller by combining the linear adaptive disturbance rejection controller (LADRC) and repetitive controller (RC) is designed. While for the dynamic-state disturbance which would amplify the output current of MFGCI or even destroy the stability of the system, an improved reference current generation algorithm with enhanced dynamic disturbance rejection capability is proposed. The proposed MFGCI could provide overall improvements in both dynamic- and steady-state disturbance rejection capability. Finally, some experiments are conducted to verify the superiority of the proposed MFGCI.

Robust Control based on ADRC and DOBC for Small-Scale Helicopter

Abstract This paper introduces and compares two robust control techniques estimating disturbances for small-scale unmanned helicopters: adaptive disturbance rejection control (ADRC) and disturbance observer based control (DOBC). The six-degree-of-freedom dynamics model of the unmanned helicopter includes modeling errors and uncertainties that degrade control performance. Furthermore, the external disturbance and complex internal coupling seriously affect the control stability of the small unmanned aerial vehicle (UAV), but this is difficult to be considered in advance for controller design. For this reason, ADRC and DOBC are designed using a minimum nominal model to compensate for internal uncertainties and external disturbances. Simulation results based on slalom maneuvers show that the proposed controller successfully compensates for disturbance and provides excellent performance compared to the case of using only the PID controller. Other than to unmanned helicopters, it is applicable to most dynamic systems that can be approximated as a double integrator system.

Adaptive rejection of unmatched input disturbances for output tracking using a control separation LQ method

SummaryIn this paper, an adaptive disturbance rejection scheme is developed for output tracking of multivariable nonminimum‐phase systems in the presence of uncertain unmatched input disturbances. Using a new cost function, a control separation–based LQ control framework is established for desired disturbance rejection and output tracking. The finite‐time and infinite‐time control separation–based LQ solutions are derived in an explicit composite controller structure, which has enhanced disturbance compensation and output tracking properties, as compared with a traditional LQ solution. An adaptive parameter update algorithm is used for estimation of uncertain disturbances, based on which an adaptive control separation–based LQ control solution is developed for plants in the presence of uncertain disturbances. Simulation results are presented to verify the desired adaptive disturbance rejection control system performance.

自适应线性自抗扰控制器的设计

自适应线性自抗扰控制器的设计

Adaptive Disturbance Rejection Control for Automatic Carrier Landing System

An adaptive disturbance rejection algorithm is proposed for carrier landing system in the final-approach. The carrier-based aircraft dynamics and the linearized longitudinal model under turbulence conditions in the final-approach are analyzed. A stable adaptive control scheme is developed based on LDU decomposition of the high-frequency gain matrix, which ensures closed-loop stability and asymptotic output tracking. Finally, simulation studies of a linearized longitudinal-directional dynamics model are conducted to demonstrate the performance of the adaptive scheme.

An adaptive disturbance rejection control scheme for multivariable nonlinear systems

ABSTRACTAn adaptive disturbance rejection control scheme is developed for uncertain multi-input multi-output nonlinear systems in the presence of unmatched input disturbances. The nominal output rejection scheme is first developed, for which the relative degree characterisation of the control and disturbance system models from multivariable nonlinear systems is specified as a key design condition for this disturbance output rejection design. The adaptive disturbance rejection control design is then completed by deriving an error model in terms of parameter errors and tracking error, and constructing adaptive parameter-updated laws and adaptive parameter projection algorithms. All closed-loop signals are guaranteed to be bounded and the plant output tracks a given reference output asymptotically despite the uncertainties of system and disturbance parameters. The developed adaptive disturbance rejection scheme is applied to turbulence compensation for aircraft fight control. Simulation results from a benchmark aircraft model verify the desired system performance.

Direct adaptive control for individual blade pitch control of wind turbines for load reduction

In this article, a theory of adaptive disturbance rejection control is used to design an individual blade pitch controller to reduce the loading in a utility-scale wind turbine. The goal of the adaptive disturbance rejection control is to regulate the blade pitch angle individually to reduce the asymmetrical loading in blade due to vertical wind shear and also to reject the unnecessary disturbance introduced by the wind turbulence. The applicability of the theory is illustrated by implementing the controller in the National Renewable Energy Laboratory’s 5-MW nonlinear, high-fidelity wind turbine model and simulating it in MATLAB/Simulink.

Adaptive disturbance rejection control for compartmental systems with application to intraoperative anesthesia influenced by hemorrhage and hemodilution effects

AbstractCompartmental system models involve dynamic states whose values are nonnegative. These models are widespread in biological and physiological sciences and play a key role in understanding these processes. In this paper, we develop a direct adaptive disturbance rejection control framework for compartmental dynamical systems with exogenous bounded disturbances. The proposed framework is Lyapunov based and guarantees partial asymptotic stability of the closed‐loop system, that is, asymptotic stability with respect to part of the closed‐loop system states associated with the plant dynamics. The remainder of the states associated with the adaptive controller gains are shown to be Lyapunov stable. In the case of bounded energy ℒ︁2 disturbances, the proposed approach guarantees a nonexpansivity constraint on the closed‐loop input–output map between the plant disturbances and performance variables. Finally, a numerical example involving the infusion of the anesthetic drug propofol for maintaining a desired constant level of depth of anesthesia for surgery in the face of continuing hemorrhage and hemodilution is provided. Copyright © 2008 John Wiley &amp; Sons, Ltd.

Visual Tracking of a Maneuvering Target

This paper presents an acceleration-command generation and its implementation for an aerial vehicle in the problem of visual target tracking, when the target is free to make any maneuver with arbitrary but otherwise bounded acceleration. The acceleration command is generated by an adaptive disturbance rejection control algorithm that uses only visual information about the target, obtained by a monocular camera mounted on the aerial vehicle. This information consists of the maximal image size in pixels and the pixel coordinates of the image centroid in the image plane. The acceleration command is translated into forward velocity and attitude angle commands, which are afterward used to obtain actual control surface deflections for the aerial vehicle. Simulations of a full nonlinear model verify the theoretical statements.

Adaptive Disturbance Rejection Controller for Visual Tracking of a Maneuvering Target

This paper presents an adaptive disturbance rejection control architecture for a flying vehicle to track a maneuvering target using a monocular camera as a visual sensor. Viewing the target’s velocity as a time-varying disturbance, the change in magnitude of which has a bounded integral, a guidance law is derived that guarantees asymptotic tracking of the target in the presence of measurement noise and an intelligent excitation signal in the reference input. Implementation of the guidance law is done via conventional adaptive block backstepping. Simulations illustrate the benefits of the method.

Suppression of Persistent Rotor Vibrations Using Adaptive Techniques

Recent work in the area of adaptive control has seen the development of techniques for the adaptive rejection of persistent disturbances for structural systems. They have been implemented and tested for large-scale structural systems, with promising results, but have not been widely applied to smaller-scale systems and devices. Rotor systems are subject to a variety of persistent disturbances (for example, due to mass imbalance, blade-pass effects) that occur at the rotor running speed or multiples of the running speed. The frequencies of such disturbance forces are generally known, but their magnitudes tend to vary over time. Adaptive techniques to counter the effects of such disturbances would appear to be a promising strategy in this regard. In order to assess the effectiveness of adaptive disturbance rejection for rotor applications and identify issues associated with implementation, an adaptive disturbance rejection control is developed, implemented, and tested for a magnetic-bearing-supported rotor system. Some conclusions and insights concerning the application of this method to rotor system vibration suppression are presented and discussed.

Adaptive output rejection of unmatched input disturbances

To adaptively reject the effect of certain unmatched input disturbances on the output of a linear time-invariant system, a transfer function matching condition is needed. A lemma which presents a novel basic property of linear systems is derived to characterize system conditions for such transfer function matching. An adaptive disturbance rejection control scheme is developed for such systems with uncertain dynamics parameters and disturbance parameters. This adaptive control technique is applicable to control of systems with actuator failures whose failure values, failure time instants, and failure patterns are unknown. A solution is presented to this adaptive actuator failure compensation problem, which ensures closed-loop stability and asymptotic output tracking, in the presence of any up to m−1 uncertain failures of the total m actuators. Desired adaptive system performance is verified by simulation results.