scholarly journals Robust Full Tracking Control Design of Disturbed Quadrotor UAVs with Unknown Dynamics

Aerospace ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 115 ◽  
Author(s):  
Nabil Nafia ◽  
Abdeljalil El Kari ◽  
Hassan Ayad ◽  
Mostafa Mjahed

In this study, we develop a rigorous tracking control approach for quadrotor unmanned aerial vehicles (UAVs) with unknown dynamics, unknown physical parameters, and subject to unknown and unpredictable disturbances. In order to better estimate the unknown functions, seven interval type-2-adaptive fuzzy systems (IT2-AFSs) and five adaptive systems are designed. Then, a new IT2 adaptive fuzzy reaching sliding mode system (IT2-AFRSMS) which generates an optimal smooth adaptive fuzzy reaching sliding mode control law (AFRSMCL) using IT2-AFSs is introduced. The AFRSMCL is designed a way that ensures that its gains are efficiently estimated. Thus, the global proposed control law can effectively achieve the predetermined performances of the tracking control while simultaneously avoiding the chattering phenomenon, despite the approximation errors and all disturbances acting on the quadrotor dynamics. The adaptation laws are designed by utilizing the stability analysis of Lyapunov. A simulation example is used to validate the robustness and effectiveness of the proposed method of control. The obtained results confirm the results of the mathematical analysis in guaranteeing the tracking convergence and stability of the closed loop dynamics despite the unknown dynamics, unknown disturbances, and unknown physical parameters of the controlled system.

2014 ◽  
Vol 1016 ◽  
pp. 649-654
Author(s):  
Ya Feng Niu ◽  
Yong Ming Gao

This paper discusses the cooperative control for formation keeping of fractionated spacecraft, which is a new concept in recent years. For system of second-order differential equations of formation flying dynamics, knowledge of graph and consensus theory is introduced in study. By means of the idea of sliding mode control, we design a tracking control law for time-varying desired signal. Via exchanging error information among modules, the control law can make errors synchronized up to zero to achieve tracking. Relative velocity information between modules is not needed in this control law, which will efficiently reduce the requirements for relative navigation between modules. Then we prove the stability of the control system. Finally numerical simulation results show the effectiveness of the control law. By configuring the control parameters reasonably, we can achieve high degree of control accuracy.


Author(s):  
Hongzhuang Wu ◽  
Songyong Liu ◽  
Cheng Cheng ◽  
Changlong Du

This work proposes a novel observer based direct adaptive fuzzy second-order-like sliding mode control (SMC) method for a certain class of high order unknown nonlinear dynamical systems with unmeasurable states. An observer is firstly developed to estimate the tracking error vector directly, and the stability of the observer is analyzed based on Meyer-Kalman-Yakubovich (MKY) lemma. Based on the observer, the equivalent control law is approximated by a double-input single-output fuzzy logic system (FLS), in which the observation of the sliding surface and its derivative are applied as the inputs. In addition, an adaptive switching control law is added to mitigate the system chattering and improve the stability of the system. The free parameters of the controller are adjusted online by the adaptive laws that are derived from the Lyapunov stability analysis. Finally, the convergence of the overall closed-loop system is demonstrated, and the simulation examples illustrate the efficacy of the proposed control method.


2020 ◽  
Vol 12 (11) ◽  
pp. 168781402097523
Author(s):  
Moussa Labbadi ◽  
Yassine El Houm ◽  
Ahmed Abbou ◽  
Mohamed Cherkaoui

The present paper proposes an adaptive global nonlinear sliding mode controller (AGNSMC) for the tracking problem of a quadrotor subjected to external disturbances. In order to eliminate the reaching phase and to guarantee the sliding mode of the quadrotor states in the initial time, a novel control law is developed. The upper bounds of disturbances affected the quadrotor dynamics are rejected based on adaptive laws for the both attitude and position subsystem. The tracking performance is enhanced by using the suggested controller. The stability of quadrotor is guaranteed and the global sliding mode surfaces converge to origin values in a finite time. To show the robustness of the proposed control approach against the external disturbances, simulation results are presented and compared with the results of the super-twisting-integral sliding mode controller.


Robotics ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 40 ◽  
Author(s):  
Nabil Nafia ◽  
Abdeljalil El Kari ◽  
Hassan Ayad ◽  
Mostafa Mjahed

This paper develops a new robust tracking control design for n-link robot manipulators with dynamic uncertainties, and unknown disturbances. The procedure is conducted by designing two adaptive interval type-2 fuzzy logic systems (AIT2-FLSs) to better approximate the parametric uncertainties on the system nominal. Then, in order to achieve the best tracking control performance and to enhance the system robustness against approximation errors and unknown disturbances, a new control algorithm, which uses a new synthesized AIT2 fuzzy sliding mode control (AIT2-FSMC) law, has been proposed. To deal with the chattering phenomenon without deteriorating the system robustness, the AIT2-FSMC has been designed so as to generate three adaptive control laws that provide the optimal gains value of the global control law. The adaptation laws have been designed in the sense of the Lyapunov stability theorem. Mathematical proof shows that the closed loop control system is globally asymptotically stable. Finally, a 2-link robot manipulator is used as case study to illustrate the effectiveness of the proposed control approach.


Author(s):  
Nasim Ullah ◽  
Irfan Sami ◽  
Wang Shaoping ◽  
Hamid Mukhtar ◽  
Xingjian Wang ◽  
...  

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.


Author(s):  
Yohan Díaz-Méndez ◽  
Leandro Diniz de Jesus ◽  
Marcelo Santiago de Sousa ◽  
Sebastião Simões Cunha ◽  
Alexandre Brandão Ramos

Sliding mode control (SMC) is a widely used control law for quadrotor regulation and tracking control problems. The purpose of this article is to solve the tracking problem of quadrotors using a relatively novel nonlinear control law based on SMC that makes use of a conditional integrator. It is demonstrated by a motivation example that the proposed control law can improve the transient response and chattering shortcomings of the previous approaches of similar SMC based controllers. The adopted Newton–Euler model of quadrotor dynamics and controller design is treated separately in two subsystems: attitude and position control loops. The stability of the control technique is demonstrated by Lyapunov’s analysis and the effectiveness and performance of the proposed method are compared with a similar integral law, also based on SMC, and validated by tracking control problems using numerical simulations. Simulations were developed in the presence of external disturbances in order to evaluate the controller robustness. The effectiveness of the proposed controller was verified by performance indexes, demonstrating less accumulated tracking errors and control activity and improvement in the transient response and disturbance rejection when compared to a conventional integrator sliding mode controller.


Author(s):  
Tsung-Chih Lin ◽  
Yu-Chen Lin ◽  
Majid Moradi Zirkohi ◽  
Hsi-Chun Huang

In this paper, a novel direct adaptive fuzzy moving sliding mode proportional integral (PI) tracking control of a three-dimensional (3D) overhead crane which is modeled by five highly nonlinear second-order ordinary differential equations is proposed. The fast and robust position regulation and antiswing control can be achieved based on the proposed approach. Due to universal approximation theorem, fuzzy control provides nonlinear controller, i.e., fuzzy logic controllers, to perform the unknown nonlinear control actions. Simultaneously, in order to achieve fast and robust regulation and to enhance robustness in the presence of disturbance and parameter variations, moving sliding mode control (SMC) is introduced to tradeoff between reaching phase and sliding phase. Hence, the sliding surface is moved by changing the magnitude of the slope by adaptive law and varying the intercept by tuning algorithm. Simulations performed using a scaled 3D mathematical model of the crane confirm that the proposed control scheme can keep the horizontal position of the payload invariable and suppress the swing of the payload effectively during the hoisting or lowing process.


Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7454
Author(s):  
Yunsheng Fan ◽  
Bowen Liu ◽  
Guofeng Wang ◽  
Dongdong Mu

This paper focuses on an issue involving robust adaptive path following for the uncertain underactuated unmanned surface vehicle with time-varying large sideslips angle and actuator saturation. An improved line-of-sight guidance law based on a reduced-order extended state observer is proposed to address the large sideslip angle that occurs in practical navigation. Next, the finite-time disturbances observer is designed by considering the perturbations parameter of the model and the unknown disturbances of the external environment as the lumped disturbances. Then, an adaptive term is introduced into Fast Non-singular Terminal Sliding Mode Control to design the path following controllers. Finally, considering the saturation of actuator, an auxiliary dynamic system is introduced. By selecting the appropriate design parameters, all the signals of the whole path following a closed-loop system can be ultimately bounded. Real-time control of path following can be achieved by transferring data from shipborne sensors such as GPS, combined inertial guidance and anemoclinograph to the Fast Non-singular Terminal Sliding Mode controller. Two examples as comparisons were carried out to demonstrate the validity of the proposed control approach.


2020 ◽  
Vol 10 (11) ◽  
pp. 3719
Author(s):  
Ran Jiao ◽  
Wusheng Chou ◽  
Yongfeng Rong ◽  
Mingjie Dong

Aerial operation with unmanned aerial vehicle (UAV) manipulator is a promising field for future applications. However, the quadrotor UAV manipulator usually suffers from several disturbances, such as external wind and model uncertainties, when conducting aerial tasks, which will seriously influence the stability of the whole system. In this paper, we address the problem of high-precision attitude control for quadrotor manipulator which is equipped with a 2-degree-of-freedom (DOF) robotic arm under disturbances. We propose a new sliding-mode extended state observer (SMESO) to estimate the lumped disturbance and build a backstepping attitude controller to attenuate its influence. First, we use the saturation function to replace discontinuous sign function of traditional SMESO to alleviate the estimation chattering problem. Second, by innovatively introducing super-twisting algorithm and fuzzy logic rules used for adaptively updating the observer switching gains, the fuzzy adaptive saturation super-twisting extended state observer (FASTESO) is constructed. Finally, in order to further reduce the impact of sensor noise, we invite a tracking differentiator (TD) incorporated into FASTESO. The proposed control approach is validated with effectiveness in several simulations and experiments in which we try to fly UAV under varied external disturbances.


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