scholarly journals Synthesis of modal controller with compensation of external disturbance for the object with parametric uncertainty on the criterion of maximum robustness

2014 ◽  
Vol 2 (21) ◽  
pp. 157 ◽  
Author(s):  
Gennadi Ivanovich Lozgachev ◽  
Mikhail Mikhailovich Bezryadin
Keyword(s):  
External Disturbance ◽  
Parametric Uncertainty ◽  
Modal Controller

scholarly journals A composite controller based on nonlinear H_∞ and nonlinear disturbance observer for attitude stabilization of a flying robot

2021 ◽  
Vol 22 (1) ◽  
pp. 270
Author(s):  
Vahid Razmavar ◽  
Heidar Ali Talebi ◽  
Farzaneh Abdollahi
Keyword(s):  
Attitude Control ◽  
Disturbance Observer ◽  
External Disturbance ◽  
Parametric Uncertainty ◽  
Control Technique ◽  
Robust Controller ◽  
Nonlinear Disturbance Observer ◽  
Control Scheme ◽  
Nonlinear Disturbance ◽  
Flying Robot

<span>In this article a novel composite control technique is introduced. We added a nonlinear disturbance observer to a nonlinear H_∞ control to form this composite controller. The quadrotor kinematics and dynamics is formulated using euler angles and parameters. After that, this nonlinear robust controller is developed for this flying robot attitude control for the outdoor conditions. Because under these conditions the flying robot, experiences both external disturbance and parametric uncertainty. Stability analysis is also presented to show the global asymptotical stability using a Lyapunov function. The simulation results showed that the suggested composite controller had a better performance in comparison with a nonlinear H_∞ control scheme.</span>

Sliding mode control for non-linear systems with global invariance

1997 ◽  
Vol 211 (1) ◽  
pp. 75-82 ◽  
Author(s):  
C-L Chen ◽  
W-Y Lin
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
External Disturbance ◽  
Parametric Uncertainty ◽  
Invariance Property ◽  
Control Law ◽  
Continuous Control ◽  
Mode Control ◽  
Non Linear Systems ◽  
The Cost

In the conventional sliding mode control, a discontinuous control signal is applied to achieve the sliding condition. This control makes the system invariant to parametric uncertainty and external disturbance, but also causes chattering. Modified approaches are introduced to eliminate chattering at the cost of the invariance property or accuracy. This paper describes the use of the concept of extended systems, such that a continuous control is obtained using a sliding mode control design scheme. A sliding surface is assigned so that the sliding mode motion will occur while the proposed control law is applied. This results in a system with global invariance.

scholarly journals Design of H∞Control and Simplified Instrument Fault Detection on DC Motor

2020 ◽  
Author(s):  
Lintang Erlangga ◽  
Bagas Budhi Permana ◽  
Ulynnuha Setiyadi ◽  
Samiadji Herdjunanto ◽  
Sujoko Sumaryono
Keyword(s):  
Fault Detection ◽  
Detection Method ◽  
External Disturbance ◽  
Parametric Uncertainty ◽  
Sensor Fault ◽  
Closed Loop System ◽  
Structured Singular Value ◽  
Robust Control Design ◽  
And Performance ◽  
Performance Uncertainty

In the presence of uncertainty, a closed-loop system must be able to maintain its stability and performance. Uncertainty can be categorized into two meanings, disturbance from external systems and perturbation in a dynamical system. In this paper, we will present a robust control design by considering a disturbance from external factors, and analyze its robustness using Structured Singular Value respect to parametric uncertainty and external disturbance. Beside that, every control system has their own region to operate, outside that region a performance degradation will occur, and led into unstability. One factor to that catastrophic is a fault in instrument reading, to anticipate it, this paper also implement Simplified Instrument Fault Detection method to detect a sensor fault in order to give an alarm for further action.

Robust Intelligent Fault-Tolerant Based Finite-Time Attitude Control for Quadrotor UAV Without Angular Velocity Measurements

2021 ◽  
Author(s):  
Kang Liu ◽  
Rujing Wang
Keyword(s):  
Angular Velocity ◽  
Finite Time ◽  
Attitude Control ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
External Disturbance ◽  
Input Saturation ◽  
Parametric Uncertainty ◽  
Accurate Information ◽  
Terminal Sliding Mode

Abstract This study considers the problem of finitetime attitude control for quadrotor unmanned aerial vehicles (UAVs) subject to parametric uncertainties, external disturbances, input saturation, and actuator faults. Under the strong approximation of radial basis function neural networks (RBFNN), an adaptive finitetime NN observer is first presented to obtain the accurate information of unavailable angular velocity. More importantly, an adaptive mechanism to adjust the output gain of the fuzzy logic system (FLS) is developed to avoid the selection of larger control gains, and can even work well without the prior information on the bound of the lumped disturbance. Based on the nonsingular fast terminal sliding mode manifold, a novel switching control law is designed by incorporating the adaptive FLS and fast continuous controller in order to remove the undesired chattering phenomenon and solve the negative effects induced from the parametric uncertainty, external disturbance, and actuator fault. To deal with the input saturation, an auxiliary system is constructed. The rigorous theoretical analysis is given to prove that all the signals in the closed-loop system are uniformly bounded, and tracking errors converge into bounded neighborhoods near the origin in finite time. Moreover, the issue of selecting control parameters is analyzed in detail. Last but not least, the comparative simulation results show the validity and feasibility of the proposed control framework.

Robust Control for the Relay ICPT System Under External Disturbance and Parametric Uncertainty

2017 ◽  
Vol 25 (6) ◽  
pp. 2168-2175 ◽  
Author(s):  
Chenyang Xia ◽  
Wei Wang ◽  
Guoping Chen ◽  
Xiaojie Wu ◽  
Shijie Zhou ◽  
...  
Keyword(s):  
Robust Control ◽  
External Disturbance ◽  
Parametric Uncertainty

scholarly journals Attitude-constrained reorientation control for spacecraft based on extended state observer

2018 ◽  
Vol 10 (8) ◽  
pp. 168781401879452 ◽  
Author(s):  
Yu Cheng ◽  
Dong Ye ◽  
Zhaowei Sun
Keyword(s):  
Actuator Saturation ◽  
Estimation Error ◽  
External Disturbance ◽  
Parametric Uncertainty ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Finite Time Stability ◽  
Backstepping Controller ◽  
The Difference

This article investigates the spacecraft attitude reorientation control problem in the presence of attitude constraint, actuator saturation, parametric uncertainty, and external disturbance. First, a nonlinear tracking law based on a strictly convex potential function is proposed to generate the virtual control angular velocity which has only one global minimum. Then, utilizing the auxiliary system governed by the difference between the upper bound of actuator torque and the untreated command torque, a novel backstepping controller is presented, which is able to satisfy the constraint of actuator saturation and guarantee the stability of control system. In addition, an extended state observer with the uniformly ultimately bounded estimation error and finite-time stability is put forward to realize the real-time compensation of the compound disturbance consisting of parametric uncertainty and external disturbance. Therefore, it enhances the robustness and improves the accuracy of the extended state observer–based backstepping controller. Finally, simulation results validate the effectiveness and reliability of the proposed schemes.

Control and disturbances compensation in underactuated robotic systems using the derivative-free nonlinear Kalman filter

Robotica ◽  
2015 ◽  
Vol 35 (3) ◽  
pp. 687-711 ◽  
Author(s):  
Gerasimos G. Rigatos
Keyword(s):  
Kalman Filter ◽  
External Disturbance ◽  
Parametric Uncertainty ◽  
Robotic Manipulator ◽  
Robotic Systems ◽  
Differential Flatness Theory ◽  
Closed Chain ◽  
Control Scheme ◽  
Derivative Free ◽  
Nonlinear Kalman Filter

SUMMARYThe Derivative-free nonlinear Kalman Filter is used for developing a robust controller which can be applied to underactuated MIMO robotic systems. The control problem for underactuated robots is non-trivial and becomes further complicated if the robot is subjected to model uncertainties and external disturbances. Using differential flatness theory it is shown that the model of a closed-chain 2-DOF robotic manipulator can be transformed to linear canonical form. For the linearized equivalent of the robotic system it is shown that a state feedback controller can be designed. Since certain elements of the state vector of the linearized system cannot be measured directly, it is proposed to estimate them with the use of a novel filtering method, the so-called Derivative-free nonlinear Kalman Filter. Moreover, by redesigning the Kalman Filter as a disturbance observer, it is shown that one can estimate simultaneously external disturbance terms that affect the robotic model or disturbance terms which are associated with parametric uncertainty. The efficiency of the proposed Kalman Filter-based control scheme is tested in the case of a 2-DOF planar robotic manipulator that has the structure of a closed-chain mechanism.

scholarly journals Design of H∞Control and Simplified Instrument Fault Detection on DC Motor

2020 ◽  
Author(s):  
Lintang Erlangga ◽  
Bagas Budhi Permana ◽  
Ulynnuha Setiyadi ◽  
Samiadji Herdjunanto ◽  
Sujoko Sumaryono
Keyword(s):  
Fault Detection ◽  
Detection Method ◽  
External Disturbance ◽  
Parametric Uncertainty ◽  
Sensor Fault ◽  
Closed Loop System ◽  
Structured Singular Value ◽  
Robust Control Design ◽  
And Performance ◽  
Performance Uncertainty

In the presence of uncertainty, a closed-loop system must be able to maintain its stability and performance. Uncertainty can be categorized into two meanings, disturbance from external systems and perturbation in a dynamical system. In this paper, we will present a robust control design by considering a disturbance from external factors, and analyze its robustness using Structured Singular Value respect to parametric uncertainty and external disturbance. Beside that, every control system has their own region to operate, outside that region a performance degradation will occur, and led into unstability. One factor to that catastrophic is a fault in instrument reading, to anticipate it, this paper also implement Simplified Instrument Fault Detection method to detect a sensor fault in order to give an alarm for further action.

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