scholarly journals Neural observer-based path following control for underactuated unmanned surface vessels with input saturation and time-varying disturbance

2019 ◽  
Vol 16 (5) ◽  
pp. 172988141987807
Author(s):  
Lei Wan ◽  
Jiangfeng Zeng ◽  
Yueming Li ◽  
Hongde Qin ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Disturbance Observer ◽  
External Disturbance ◽  
Input Saturation ◽  
Path Following ◽  
Dynamic Surface Control ◽  
Dynamic Surface ◽  
Surface Control ◽  
Surface Vessels ◽  
Path Following Control ◽  
Control Scheme

In this study, a new neural observer-based dynamic surface control scheme is proposed for the path following of underactuated unmanned surface vessels in the presence of input saturation and time-varying external disturbance. The dynamic surface control technique is augmented by a robust adaptive radial basis function neural network and a nonlinear neural disturbance observer. Radial basis function neural network is employed to deal with system uncertainties, and the nonlinear neural disturbance observer is developed to compensate for the unknown compound disturbance that contains the input saturation approximation error and the external disturbance. Moreover, the stringent known boundary requirement of the unknown disturbance constraint is eliminated with the proposed nonlinear neural disturbance observer. Meanwhile, to deal with the non-smooth saturation nonlinearity, a new parametric hyperbolic tangent function approximation model with arbitrary prescribed precision is constructed, which results in the transient performance improvement for the path following control system. Stability analysis shows that all the signals in the closed-loop system are guaranteed to be ultimately bounded. Comparative simulation results further demonstrate the effectiveness of the proposed control scheme.

Robust Constrained Trajectory Tracking Control for Quadrotor Unmanned Aerial Vehicle Based on Disturbance Observers

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Bing Zhu ◽  
Mou Chen ◽  
Tao Li
Keyword(s):  
Control System ◽  
Attitude Control ◽  
Position Control ◽  
External Disturbance ◽  
Input Saturation ◽  
Dynamic Surface Control ◽  
Trajectory Tracking Control ◽  
Dynamic Surface ◽  
Control Scheme ◽  
Aerial Vehicle

Abstract In this paper, a trajectory tracking control scheme for a quadrotor unmanned aerial vehicle (UAV) under unknown external disturbance and input saturation is developed. This scheme includes the position control system and attitude control one, in which the attitude control system is further divided into the fast loop for angular velocity and the slow one for attitude angle based on time-scale separation principle. Then, an input constrained dynamic surface control scheme combined with a disturbance observer is designed to achieve the total thrust, desired roll, and pitch angle in the position control system. For the coupled attitude system, a dynamic surface control scheme together with generalized model predictive controller (GMPC) is proposed to tackle both the fast loop system and the slow one. Since the unknown external disturbance and input saturation are considered, a sliding mode disturbance observer (SMDO) is further designed to achieve the strong robustness. Finally, some simulation results are presented to show robustness and effectiveness of our proposed tracking scheme.

Prescribed performance-based distributed fault-tolerant cooperative control for multi-UAVs

2018 ◽  
Vol 41 (4) ◽  
pp. 975-989 ◽  
Author(s):  
Ziquan Yu ◽  
Youmin Zhang ◽  
Yaohong Qu
Keyword(s):  
Cooperative Control ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Input Saturation ◽  
Dynamic Surface Control ◽  
Tracking Errors ◽  
Dynamic Surface ◽  
Prescribed Performance ◽  
Surface Control ◽  
Control Scheme

In this paper, a prescribed performance-based distributed neural adaptive fault-tolerant cooperative control (FTCC) scheme is proposed for multiple unmanned aerial vehicles (multi-UAVs). A distributed sliding-mode observer (SMO) technique is first utilized to estimate the leader UAV’s reference. Then, by transforming the tracking errors of follower UAVs with respect to the estimated references into a new set, a distributed neural adaptive FTCC protocol is developed based on the combination of dynamic surface control (DSC) and minimal learning parameters of neural network (MLPNN). Moreover, auxiliary dynamic systems are exploited to deal with input saturation. Furthermore, the proposed control scheme can guarantee that all signals of the closed-loop system are bounded, and tracking errors of follower UAVs with respect to the estimated references are confined within the prescribed bounds. Finally, comparative simulation results are presented to illustrate the effectiveness of the proposed distributed neural adaptive FTCC scheme.

scholarly journals Robust composite neural dynamic surface control for the path following of unmanned marine surface vessels with unknown disturbances

2018 ◽  
Vol 15 (4) ◽  
pp. 172988141878664 ◽  
Author(s):  
Jiangfeng Zeng ◽  
Lei Wan ◽  
Yueming Li ◽  
Ziyang Zhang ◽  
Yufei Xu ◽  
...  
Keyword(s):  
Neural Network ◽  
Path Following ◽  
Dynamic Surface Control ◽  
Prediction Errors ◽  
Tracking Accuracy ◽  
Tracking Errors ◽  
Dynamic Surface ◽  
Surface Control ◽  
Surface Vessels ◽  
Marine Surface

This article presents a robust composite neural-based dynamic surface control design for the path following of unmanned marine surface vessels in the presence of nonlinearly parameterized uncertainties and unknown time-varying disturbances. Compared with the existing neural network-based dynamic surface control methods where only the tracking errors are commonly used for the neural network weight updating, the proposed scheme employs both the tracking errors and the prediction errors to construct the adaption law. Therefore, faster identification of the system dynamics and improved tracking accuracy are achieved. In particular, an outstanding advantage of the proposed neural network structure is simplicity. No matter how many neural network nodes are utilized, only one adaptive parameter that needs to be tuned online, which effectively reduces the computational burden and facilitates to implement the proposed controller in practice. The uniformly ultimate boundedness stability of the closed-loop system is established via Lyapunov analysis. Comparison studies are presented to demonstrate the effectiveness of the proposed composite neural-based dynamic surface control architecture.

Attitude and height tracking control of unmanned helicopters with disturbances via disturbance observer-based composite dynamic surface control

2021 ◽  
pp. 014233122110232
Author(s):  
Xiangyu Wang ◽  
Ling Han ◽  
Jiyu Liu
Keyword(s):  
Tracking Control ◽  
Disturbance Observer ◽  
Control Design ◽  
Dynamic Surface Control ◽  
Control Technique ◽  
Tracking Errors ◽  
Dynamic Surface ◽  
Surface Control ◽  
Control Scheme ◽  
Tracking Controller

In this paper, the attitude and height tracking control problem is studied for unmanned helicopters with disturbances. To solve the problem, a composite control scheme is proposed based on the combination of dynamic surface control and disturbance observer-based control techniques. The control design includes two parts. In the first part, some nonlinear disturbance observers are designed to accurately estimate the helicopter’s disturbances in different channels. In the second part, based on the disturbance estimates and dynamic surface control technique, a composite dynamic surface tracking controller is designed. Under the proposed composite controller, the attitude and height tracking errors are uniformly ultimately bounded and they can be regulated to be very small by selecting proper controller parameters. For one thing, the proposed control scheme avoids “explosion of terms”, which generally exists in conventional backstepping control and provides a simpler control design. For another thing, without sacrificing the nominal control performances, the anti-disturbance ability of the closed-loop helicopter system is enhanced by using disturbance observers and feedforward compensations. Numerical simulations demonstrate the effectiveness and advantages of the proposed composite tracking controller.

Path Following Control of Underactuated Marine Vessels via Dynamic Surface Control Technique

2008 ◽  
Author(s):  
So-Ryeok Oh ◽  
Jing Sun ◽  
Zhen Li
Keyword(s):  
Design Method ◽  
Direct Method ◽  
Design Procedure ◽  
Path Following ◽  
Dynamic Surface Control ◽  
Control Technique ◽  
Dynamic Surface ◽  
Surface Control ◽  
Path Following Control ◽  
Marine Vessels

This paper considers the path following problem of underactuated marine vessels whose control imposes a challenging problem due to its under-actuated nature. The recently developed Dynamic Surface Control (DSC) design method is applied to overcome the problem of explosion of terms associated with the backstepping design procedure. We show that the exponential stability of the resulting closed loop dynamics can be proved using Lyapunov direct method. The feasibility of the proposed Dynamic Surface Controller is evaluated analytically and verified through computer simulations and experiments.

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