Robust Attitude Control for Quadrotors Based on Parameter Optimization of a Nonlinear Disturbance Observer

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Shatadal Mishra ◽  
Todd Rakstad ◽  
Wenlong Zhang
Keyword(s):  
Flight Control ◽  
Attitude Control ◽  
Disturbance Rejection ◽  
Disturbance Observer ◽  
Control Unit ◽  
Nonlinear Disturbance Observer ◽  
Wave Disturbances ◽  
Active Disturbance Rejection ◽  
Exogenous Disturbances ◽  
Nonlinear Disturbance

This paper presents a nonlinear disturbance observer (NDOB) for active disturbance rejection in the attitude control loop for quadrotors. An optimization framework is developed for tuning the parameter in the NDOB structure, which includes the infinity-norm minimization of the weighted sum of noise-to-output transfer function and load disturbance sensitivity function. Subsequently, the minimization generates an optimal value of the parameter based on the tradeoff between disturbance rejection and noise propagation in the system. The proposed structure is implemented on PIXHAWK, a real-time embedded flight control unit. Simulation tests are carried out on a custom built, high-fidelity simulator providing physically accurate simulations. Furthermore, experimental flight tests are conducted to demonstrate the performance of the proposed approach. The system is injected with step, sinusoidal, and square wave disturbances, and the corresponding system tracking performance is recorded. Experimental results show that the proposed algorithm attenuates the disturbances better compared to just a baseline controller implementation. The proposed algorithm is computationally cheap, an active disturbance rejection technique and robust to exogenous disturbances.

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>

Disturbance observer based dynamic surface flight control for an uncertain aircraft

2017 ◽  
Vol 232 (4) ◽  
pp. 729-744 ◽  
Author(s):  
Jianjun Ma ◽  
Peng Li ◽  
Zhiqiang Zheng
Keyword(s):  
Flight Control ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Tracking Error ◽  
Small Neighborhood ◽  
Dynamic Surface ◽  
Nonlinear Disturbance Observer ◽  
Actuator Dynamics ◽  
Highly Nonlinear ◽  
Nonlinear Disturbance

To handle the flight control problem of an uncertain aircraft with highly nonlinear characteristics, internal uncertainties and external disturbances, an adaptive dynamic surface controller based on nonlinear disturbance observer is designed in this paper. A novel nonhomogeneous nonlinear disturbance observer is designed to approximate the uncertainties and disturbances, which can exactly estimate the disturbances in finite time. Dynamic surface control is utilized to avoid the explosion of complexity in traditional backstepping design. Through Lyapunov synthesis, the closed-loop control system is demonstrated to be semi-globally uniformly ultimately bounded and the tracking error converges to a small neighborhood of origin. Besides, actuator dynamics are taken into account, and the controller for actuator dynamics with consideration of limitation is developed based on sliding-mode control theory. The effectiveness of the proposed control is shown by simulation experiments.

scholarly journals Bounded Attitude Control with Active Disturbance Rejection Capabilities for Multirotor UAVs

2021 ◽  
Vol 11 (13) ◽  
pp. 5960
Author(s):  
José Fermi Guerrero-Castellanos ◽  
Sylvain Durand ◽  
German Ardul Munoz-Hernandez ◽  
Nicolas Marchand ◽  
Lorenzo L. González Romeo ◽  
...  
Keyword(s):  
Attitude Control ◽  
Disturbance Rejection ◽  
Tracking Control ◽  
Closed Loop ◽  
Control Law ◽  
Active Disturbance Rejection ◽  
Attitude Tracking ◽  
Exogenous Disturbances ◽  
Attitude Tracking Control ◽  
The Stability

This paper addresses an attitude tracking control design applied to multirotor unmanned aerial vehicles (UAVs) based on an ADRC approach. The proposed technique groups the endogenous and exogenous disturbances into a total disturbance, and then this is estimated online via an extended state observer (ESO). Further, a quaternion-based feedback is developed, which is assisted by a feedforward term obtained via the ESO to relieve the total disturbance actively. The control law is bounded; consequently, it takes into account the maximum capabilities of the actuators to reject the disturbances. The stability is analyzed in the ISS framework, guaranteeing that the closed loop (controller-ESO-UAV) is robustly stable. The simulation results allow validation of the theoretical features.

Anti-disturbance control based on nonlinear disturbance observer for a class of stochastic systems

2018 ◽  
Vol 41 (6) ◽  
pp. 1665-1675 ◽  
Author(s):  
Lewei Dong ◽  
Xinjiang Wei ◽  
Huifeng Zhang
Keyword(s):  
Disturbance Observer ◽  
Stochastic Systems ◽  
Disturbance Attenuation ◽  
Nonlinear Disturbance Observer ◽  
Disturbance Dynamics ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Nonlinear Disturbance ◽  
Linear Disturbance ◽  
State Responses

In engineering, there exist lots of nonlinear disturbance dynamics, which can be described by nonlinear exogenous systems. The current stochastic linear disturbance observer is conservative and is not applicable for nonlinear disturbance dynamics. This paper studies a class of stochastic systems with multiple disturbances, including white noise and disturbances modelled by a nonlinear exogenous system. To estimate the disturbance with nonlinear dynamics, a stochastic nonlinear disturbance observer is proposed. Based on the observer, a nonlinear disturbance observer-based disturbance attenuation control (NDOBDAC) scheme is constructed such that the composite closed-loop system is asymptotically mean-square bounded. According to the simulation example, the state responses of the system diverge in the absence of control, but it tends to be [Formula: see text] under NDOBDAC, which demonstrates the effectiveness of the proposed scheme. In addition, the anti-disturbance control accuracy of NDOBDAC approximately improves [Formula: see text] times compared with [Formula: see text] control and active disturbance rejection control (ADRC). The simulation results demonstrate the feasibility and effectiveness of the proposed scheme.

scholarly journals Robust Predictive Functional Control for Flight Vehicles Based on Nonlinear Disturbance Observer

2015 ◽  
Vol 2015 ◽  
pp. 1-16
Author(s):  
Yinhui Zhang ◽  
Huabo Yang ◽  
Zhenyu Jiang ◽  
Fan Hu ◽  
Weihua Zhang
Keyword(s):  
Flight Control ◽  
Disturbance Observer ◽  
Linear Structure ◽  
Flight Vehicle ◽  
Nonlinear Disturbance Observer ◽  
Flight Vehicles ◽  
Predictive Functional Control ◽  
State Dependent ◽  
Functional Control ◽  
Nonlinear Disturbance

A novel robust predictive functional control based on nonlinear disturbance observer is investigated in order to address the control system design for flight vehicles with significant uncertainties, external disturbances, and measurement noise. Firstly, the nonlinear longitudinal dynamics of the flight vehicle are transformed into linear-like state-space equations with state-dependent coefficient matrices. And then the lumped disturbances are considered in the linear structure predictive model of the predictive functional control to increase the precision of the predictive output and resolve the intractable mismatched disturbance problem. As the lumped disturbances cannot be derived or measured directly, the nonlinear disturbance observer is applied to estimate the lumped disturbances, which are then introduced to the predictive functional control to replace the unknown actual lumped disturbances. Consequently, the robust predictive functional control for the flight vehicle is proposed. Compared with the existing designs, the effectiveness and robustness of the proposed flight control are illustrated and validated in various simulation conditions.

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