An active disturbance rejection control design for the distillation process with input saturation via quantitative feedback theory

A two-stage Active Disturbance Rejection Control (ADRC) design procedure is presented for the output trajectory tracking control problem in Single Input Single Output (SISO) nonlinear systems. Aside from the given scalar system output, the plant is assumed to exhibit a second, physically measurable, internal scalar output variable. The system output is controlled in an ADRC manner from an implicit static, or dynamic, nonlinear feedback controller using, in general, a nonlinear differential expression of the internal output variable. A desired internal output trajectory is thus generated. The internal output variable, in turn, is controlled from the original input and forced to track the desired trajectory synthesized in the previous step by the auxiliary controller. Each ADRC controller design is based on a simplified model of the corresponding subsystem, usually relegating interaction variables and additive nonlinearities to be part of a local (total) disturbance input term. The control scheme is reduced to a set of linear ADRC controllers with, possibly, cancellation of nonlinear input gains which are assumed to be known. Two illustrative aerospace examples are presented where the proposed procedure is illustrated via digital computer simulations.

An active disturbance rejection control design with actuator rate limit compensation for the ALSTOM gasifier benchmark problem

This paper deals with the performance and robustness trade-offs of a class of time-delayed systems through traditional active disturbance rejection control (ADRC) and two modified structures applying Smith Predictor and estimate of time delay respectively. The integral absolute error (IAE) of disturbance rejection is investigated with the constraints of robustness in terms of the largest peaks of the sensitivity and complimentary sensitivity functions. Since the uncertainty in the knowledge of the time delay strongly influences the robustness of the controller, thus a robustness requirement in terms of delay margin (DM) is also used to perform the stability analysis and provide guidelines for parameters tuning.

In this paper, we propose a continuous finite-time-convergent active disturbance rejection control design scheme for a class of second order uncertain nonlinear systems. A continuous finite-time-convergent extended state observer is first developed to estimate the total disturbance which includes the nonlinear time-varying uncertain dynamics and the external disturbances. A continuous finite-time active disturbance rejection control design scheme is proposed by using saturation method. The key idea is using the estimate of the total disturbance to compensate the uncertainty such that the output tracks a given setpoint in finite time and stays at the setpoint afterwards, and all states of the closed-loop system remain uniformly bounded. By this dynamic compensation and saturation strategy, the finite-time stability of the error system is established under some weak restrictions on nonlinearities of the system. Experiments on a DC motor platform are carried out to illustrate the effectiveness of the proposed method.

The combination of Q-learning based tuning method and active disturbance rejection control for SISO systems with several practical factors

The intelligent motion control technology of Autonomous Underwater Vehicle (AUV) is the basis of long-distance voyage for AUV. The motion control capability in vertical plane is an important technical for AUV to complete multifarious missions. So, it is important and realistic significance to research on motion control in vertical plane of AUV. Motion control problem of AUV in vertical plane, especially depth control problems is researched based on active disturbance rejection control (ADRC) method in this paper. The kinetic and dynamic model in vertical plane of AUV is established and simplified. The active disturbance rejection controller design method is introduced. Detailed algorithms of each part for active disturbance rejection controller are discussed according to separability principle of ADRC. Based on ADRC, the depth controller is designed and applied in AUV. At last, simulation results indicate that the method is feasibility and effectiveness for AUV depth control.

This chapter deals with the active disturbance rejection control (ADRC) method to the lateral control of small air-to-ground missiles for helicopters. The main difficulties that arise in lateral control design of small missiles are related to the highly uncertain, nonlinear aerodynamic forces and force movements, thus it is difficult to obtain an accurate dynamic model. Besides, the huge variations of dynamic pressure make controller parameters, and are difficult to adapt to the whole flight envelope. To handle them, the design of the controller is based on ADRC, a nonlinear control design approach which is based on the extended state observer (ESO), and can estimate and compensate the uncertainty of the system, including structural errors, random, and other system errors. Six-degree freedom equations are established for the lateral channel, the equations are linearization with small disturbance theory, then the aerodynamic derivatives are obtained through wind tunnel test, the dynamic model is made and the aerodynamic features are analyzed. One-order ESO equations of lateral channel are deduced, the controller of the lateral channel which is based on the ESO is designed and parameters are adjusted, and finally, semi-physical simulations are made. Through the comparison with classical proportion integral differential (PID) controller, the controller based on ADRC has strong robustness and it could track control command rapidly and accurately.

This paper proposes a parameter tuning method of fractional-order active disturbance rejection controller (FOADRC) for permanent magnet synchronous motor (PMSM) servo system with frequency-domain analysis. In this method, a fractional-order proportional derivative (FOPD) and a fractional-order [proportional derivative] (FO[PD]) controllers design combining with active disturbance rejection control (ADRC) are proposed. A systematic parameter tuning scheme is presented, and a flat phase constraint is applied as a design specification, which guarantees the phase is flat around the gain crossover frequency point. The closed-loop system is robust to gain variations. The simulation results illustrate that the response of the PMSM servo system using FO[PD]-ADRC has a smaller overshoot, less tracking error, and better resistance to load disturbance than that using fractional-order proportional derivative ADRC (FOPD-ADRC).

In order to improve the scanning performance of an atomic force microscopy (AFM), advanced position control of the piezoelectric actuator along the z-axis should be carefully designed to enhance the control precision, speed and robustness. In this paper, active disturbance rejection controller (ADRC) is applied to replace the traditional Proportional-Integral-Derivative (PID) controller to improve the control performance of an AFM along its z-axis. Specifically, firstly we set up the transient profile generator to obtain the error signal more reasonably. Then, the tracking differentiator is designed to replace the traditional differentiator to reduce the noise amplification of output signals and realize fast tracking of input signals. Afterwards, we design an extended state observer to implement the state estimation. In this way, the entire ADRC is designed for the AFM in z-axis to improve the control speed, precision, as well as the robustness of the AFM system. Simulation results demonstrate the effectiveness of the proposed controller.

To address the challenges of accurately modeling the motion of deep-sea aquaculture vessels under the combined effects of dynamic disturbances from the external environment and coupled disturbances from the liquid levels within the aquaculture tanks, as well as the performance limitations of traditional Active Disturbance Rejection Control (ADRC), this study proposes an improved Active Disturbance Rejection Control strategy based on the ADRC structure, and applies it to the design of the controller for the dynamic positioning system of aquaculture vessels. Furthermore, to tackle the issues of numerous uncertain parameters and tuning difficulties inherent in ADRC, an Improved Whale Optimization Algorithm (IWOA) is introduced for parameter tuning. The optimization algorithm incorporates a chaotic optimization strategy and an improved adaptive inertia weight ω with nonlinear characteristics, which simplifies the complex process of constructing an adaptive function in the Grey Wolf Optimization (GWO) algorithm and addresses the slow global search speed and poor local optimization ability of the traditional Whale Optimization Algorithm (WOA). The final Simulink simulation results demonstrate that the ADRC controller designed with IWOA outperforms traditional WOA, GWO, and Genetic Algorithm-optimized ADRC controllers in terms of control effectiveness and disturbance rejection capability, improved the dynamic positioning control performance of aquaculture vessels.

This paper deals with multiple-input and multiple-output (MIMO) systems with time delays and in the presence of significant process uncertainties both internal and external. A predictive active disturbance rejection control (PADRC) design, combined with a decoupler, is proposed. The decoupler is designed to reduce the interaction among the loops based on the knowledge of process dynamics. The remaining interaction due to the imperfection of the decoupler, together with the internal and external uncertainties in the process, which could be quite significant, is then dealt with by an independent PADRC controller for each loop. The effectiveness of the proposed method is demonstrated in simulation studies using two well-known processes in chemical industry: the Wood and Berry system as well as the Vinante and Luyben system.

The parameter tuning optimization design is realized for an active disturbance rejection controller (ADRC) in combination with the improvement of the existing swarm intelligence algorithm. Taking the optimization design and application of ADRC as an example, this paper is focused on investigating the improvement of the hybrid algorithm composed of fish swarm algorithm and particle swarm optimization algorithm and its application in parameter tuning of ADRC. The main contents are as follows. First, the parameters that need to be tuned are determined based on the composition and principle of the ADRC. The module building technology of S-function is adopted to create the module library of ARDC in terms of the modular construction idea and a complete simulation example of ADRC is built in Simulink. Second, the parameters are improved according to the proposed hybrid algorithm composed of the artificial fish swarm algorithm and the standard particle swarm optimization algorithm, and the control performance is tested by the MATLAB simulation of the ADRC whose parameters are optimized by using the algorithm. Finally, the flight attitude control of the unmanned aerial vehicle (UAV) is taken as an application example, and the fixed-wing UAV is selected as the research object. Through the analysis of the experimental results, the effectiveness of the optimized design is verified for the ADRC in the attitude control of the UAV.

Nowadays, Dynamic Positioning (DP) is applied to various tasks such as subsea pipeline laying and the requirements for the positioning performance in marine operations are higher and higher. The main objective of this paper is to design a DP controller based on the Active Disturbance Rejection Control (ADRC) to solve the problems of long response time, large overshoot and low positioning accuracy in ship positioning. Firstly, the mathematical models of the ship and environmental disturbances are established. Secondly, the basic principle of ADRC is described. Meanwhile, stability analysis of the control system is introduced. Thirdly, ADRC is improved by the fal function filter and phase prediction method which solve the problem of dither and phase delay in tracking differentiators. Finally, simulations are carried out to verify the performance of the designed ADRC and the improved ADRC. Several simulation results show that the designed ADRC can realize the fixed-point control of the ship, which effectively solves the problems of long response time, overshoot and positioning accuracy, and compared with the traditional ADRC, the improved ADRC can reduce the error of straight track control, which indicates that ADRC can meet the requirements for the positioning performance and has a strong application value.

This paper investigates the design problem of the attitude controller for air-breathing supersonic vehicle subject to uncertainties and disturbances. Firstly, the longitudinal model is established for the attitude controller design which is devised as a strict feedback formulation, and a transformed tracking error is derived with the prescribed performance control technique such that it can limit the tracking error to a predefined region. Then, a novel linear active disturbance rejection control scheme is proposed for the attitude system to enhance the steady-state and transient-state performances by incorporating the transformed tracking error. On the basis of the Lyapunov stability theorem, the convergence and stability characteristics are both rigorously proved for the closed-loop system. Finally, extensive contrast simulations are conducted to demonstrate the effectiveness, robustness, and advantage of the proposed control strategy.

This paper presents an input prediction based active disturbance rejection control scheme for systems with time-delay. The new scheme is motivated by the principle of Smith-predictor and traditional active disturbance rejection control. In order to make the transitive relation between the virtual control input and actual output approach a pure inertial element, an input predictor is adopted. The approximate error forms part of total error as well as the internal uncertainties and external disturbances, which can be easily dealt by traditional active disturbance rejection controller. Numerical examples and simulations based on the fuel dynamics of a boiler turbine unit show the improvement of the new method.