Nonsmooth control based on finite-time disturbance estimator for the translational oscillator with a rotational actuator system with nonvanishing disturbances

2021 ◽  
pp. 095965182110561
Author(s):  
Xianqing Wu ◽  
Yijiang Zhao
Keyword(s):  
Theoretical Analysis ◽  
Finite Time ◽  
Control Performance ◽  
External Disturbances ◽  
Disturbance Estimation ◽  
Control Scheme ◽  
Uncertain Disturbances ◽  
Actuator System ◽  
Rotational Actuator ◽  
Disturbance Estimator

In this article, the stabilization and disturbance estimation of the translational oscillator with a rotational actuator with nonvanishing disturbances are considered. Different from existing methods, a disturbance estimator is designed to eliminate the effects of unexpected external disturbances. As far as we know, this article presents the first finite-time disturbance-estimator-based nonsmooth control scheme for the translational oscillator with a rotational actuator system. Specifically, first, a series of changes of coordinates is made for the model of the translational oscillator with a rotational actuator system. Then, a disturbance estimator is presented to estimate uncertain disturbances and a nonsmooth control scheme is designed to ensure the convergence of all the states. Furthermore, rigorous theoretical analysis is given. Finally, simulation tests are carried out and the obtained results demonstrate that the designed approach exhibits better control performance and stronger robustness than the existing methods.

scholarly journals Finite-Time Path Following Control of an Underactuated Marine Surface Vessel with Input and Output Constraints

2020 ◽  
Vol 10 (18) ◽  
pp. 6447
Author(s):  
Mingyu Fu ◽  
Lulu Wang
Keyword(s):  
Finite Time ◽  
Input Saturation ◽  
Path Following ◽  
Parametric Uncertainties ◽  
External Disturbances ◽  
Time Path ◽  
Path Following Control ◽  
Control Scheme ◽  
Marine Surface ◽  
Surface Vessel

This paper develops a finite-time path following control scheme for an underactuated marine surface vessel (MSV) with external disturbances, model parametric uncertainties, position constraint and input saturation. Initially, based on the time-varying barrier Lyapunov function (BLF), the finite-time line-of-sight (FT-LOS) guidance law is proposed to obtain the desired yaw angle and simultaneously constrain the position error of the underactuated MSV. Furthermore, the finite-time path following constraint controllers are designed to achieve tracking control in finite time. Additionally, considering the model parametric uncertainties and external disturbances, the finite-time disturbance observers are proposed to estimate the compound disturbance. For the sake of avoiding the input saturation and satisfying the requirements of finite-time convergence, the finite-time input saturation compensators were designed. The stability analysis shows that the proposed finite-time path following control scheme can strictly guarantee the constraint requirements of the position, and all error signals of the whole control system can converge into a small neighborhood around zero in finite time. Finally, comparative simulation results show the effectiveness and superiority of the proposed finite-time path following control scheme.

scholarly journals Finite-time trajectory control for a quadrotor aircraft using disturbance observer

2020 ◽  
Vol 17 (2) ◽  
pp. 172988142090384
Author(s):  
Zhaobi Chu ◽  
Songgang Zhou ◽  
Min Zhu ◽  
Hua Li
Keyword(s):  
Finite Time ◽  
External Disturbances ◽  
Trajectory Tracking Control ◽  
Loop Control ◽  
Finite Time Stability ◽  
Disturbance Estimation ◽  
Time Control ◽  
Quadrotor Aircraft ◽  
Closed Loop Control System ◽  
Loop Control System

In this article, we investigate the problem of finite-time trajectory tracking control for a quadrotor aircraft with unknown external disturbances. To improve convergence rate and disturbance rejection performance, a new composite controller is proposed by integrating finite-time control design and disturbance estimation attenuation technique. Explicit Lyapunov function is given to ensure the finite-time stability of the closed-loop control system. Numerical simulations also show the effectiveness of the proposed method.

scholarly journals RBFNN-Based Singularity-Free Terminal Sliding Mode Control for Uncertain Quadrotor UAVs

2021 ◽  
Vol 2021 ◽  
pp. 1-10 ◽  
Author(s):  
Meiling Tao ◽  
Xiongxiong He ◽  
Shuzong Xie ◽  
Qiang Chen
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Auxiliary Function ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Finite Time Convergence ◽  
Time Control ◽  
Control Scheme ◽  
Unknown Disturbances ◽  
Quadrotor Unmanned Aerial Vehicles

In this article, a singularity-free terminal sliding mode (SFTSM) control scheme based on the radial basis function neural network (RBFNN) is proposed for the quadrotor unmanned aerial vehicles (QUAVs) under the presence of inertia uncertainties and external disturbances. Firstly, a singularity-free terminal sliding mode surface (SFTSMS) is constructed to achieve the finite-time convergence without any piecewise continuous function. Then, the adaptive finite-time control is designed with an auxiliary function to avoid the singularity in the error-related inverse matrix. Moreover, the RBFNN and extended state observer (ESO) are introduced to estimate the unknown disturbances, respectively, such that prior knowledge on system model uncertainties is not required for designing attitude controllers. Finally, the attitude and angular velocity errors are finite-time uniformly ultimately bounded (FTUUB), and numerical simulations illustrated the satisfactory performance of the designed control scheme.

Continuous sliding mode control for the translational oscillator with a rotating actuator system

2022 ◽  
pp. 014233122110691
Author(s):  
Liqiang Wang ◽  
Xianqing Wu ◽  
Meizhen Lei
Keyword(s):  
Sliding Mode Control ◽  
Disturbance Rejection ◽  
Control Method ◽  
Sliding Mode ◽  
Control Performance ◽  
Mode Control ◽  
Stabilization Control ◽  
Control Scheme ◽  
Sliding Manifold ◽  
Actuator System

The stabilization and disturbance rejection of the translational oscillator with a rotating actuator (TORA) are considered in this paper. To deal with the control issues, a novel continuous sliding mode control method is designed for the TORA system. Compared with existing sliding mode control methods for the TORA system, the proposed method here is continuous. Specifically, first, a global diffeomorphism is introduced for the model of the TORA system. Then, an elaborate sliding manifold is constructed, and a continuous sliding mode control scheme is developed to ensure the convergence of the sliding manifold. Furthermore, rigorous theoretical analysis is given. Finally, simulation tests are carried out, and the obtained simulation results demonstrate that the proposed method exhibits superior stabilization control performance and strong robustness.

scholarly journals Finite-Time Stabilization Control for a Rigid Spacecraft under Parameter Uncertainties

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Aihua Zhang ◽  
Jianfei Ni ◽  
Xing Huo
Keyword(s):  
Finite Time ◽  
Parameter Uncertainties ◽  
External Disturbances ◽  
Attitude Stabilization ◽  
Stabilization Control ◽  
Time Control ◽  
Control Scheme ◽  
Lyapunov Stability Analysis ◽  
Homogeneous Method ◽  
Rigid Spacecraft

A novel finite-time control scheme is investigated for a rigid spacecraft in present of parameter uncertainties and external disturbances. Firstly, the spacecraft mathematical model is transformed into a cascading system by introducing an adaptive variable. Then a novel finite-time attitude stabilization control scheme for a rigid spacecraft is proposed based on the homogeneous method. Lyapunov stability analysis shows that the resulting closed-loop attitude system is proven to be stable in finite time without parameter uncertainties and asymptotically stable with parameter uncertainties. Finally, numerical simulation examples are also presented to demonstrate that the control strategy developed is feasible and effective for spacecraft attitude stabilization mission.

scholarly journals Terminal Sliding Mode Control with Unidirectional Auxiliary Surfaces for Hypersonic Vehicles Based on Adaptive Disturbance Observer

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Naibao He ◽  
Changsheng Jiang ◽  
Bin Jiang ◽  
Qian Gao
Keyword(s):  
Attitude Control ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Robust Adaptive Control ◽  
Hypersonic Vehicles ◽  
Control Performance ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Control Scheme ◽  
Observer Model

A novel flight control scheme is proposed using the terminal sliding mode technique, unidirectional auxiliary surfaces and the disturbance observer model. These proposed dynamic attitude control systems can improve control performance of hypersonic vehicles despite uncertainties and external disturbances. The terminal attractor is employed to improve the convergence rate associated with the critical damping characteristics problem noted in short-period motions of hypersonic vehicles. The proposed robust attitude control scheme uses a dynamic terminal sliding mode with unidirectional auxiliary surfaces. The nonlinear disturbance observer is designed to estimate system uncertainties and external disturbances. The output of the disturbance observer aids the robust adaptive control scheme and improves robust attitude control performance. Finally, simulation results are presented to illustrate the effectiveness of the proposed terminal sliding mode with unidirectional auxiliary surfaces.

Finite-time consensus of heterogeneous unknown nonlinear multi-agent systems with external disturbances via event-triggered control

2020 ◽  
pp. 107754632094834
Author(s):  
Mehdi Zamanian ◽  
Farzaneh Abdollahi ◽  
Seyyed Kamaleddin Yadavar Nikravesh
Keyword(s):  
Nonlinear Dynamics ◽  
Finite Time ◽  
Small Region ◽  
Multi Agent Systems ◽  
External Disturbances ◽  
Agent Systems ◽  
Control Scheme ◽  
Multi Agent ◽  
Unknown Nonlinear Dynamics ◽  
Event Triggered

This article investigates the practical finite-time consensus for a class of heterogeneous multi-agent systems composed of first-order and second-order agents with heterogeneous unknown nonlinear dynamics and external disturbances in an undirected communication topology. To reduce the system updates, we propose an event-triggered approach. By defining auxiliary states, an adaptive distributed event-triggered control is designed to achieve practical finite-time consensus. Unknown nonlinear dynamics for each agent are estimated using radial basis function neural network. The stability of the overall closed-loop system is studied through the Lyapunov criterion. It is proven that by applying the proposed control scheme, the local neighbor position error and the velocity error between any two agents converge to a small region in finite time. Furthermore, it is shown that the Zeno behavior is ruled out. Finally, applicability and effectiveness of the proposed control scheme is verified and validated by two examples.

Robust Control for Heave Compensator With the Use of Kalman Filter-Based Disturbances Estimator

2017 ◽  
Author(s):  
William H. Cuellar ◽  
Tassio Melo Linhares ◽  
Jose Oniram de A. Limaverde Filho ◽  
Jose A. R. Vargas ◽  
Eugenio Fortaleza
Keyword(s):  
Kalman Filter ◽  
Robust Control ◽  
Smooth Function ◽  
Control Design ◽  
Governing Equations ◽  
External Disturbances ◽  
Practical Applications ◽  
Backstepping Approach ◽  
Control Scheme ◽  
Disturbance Estimator

This paper presents a backstepping approach for an active heave compensator actuated by a double acting cylinder. For practical applications, is desired to stabilize the system around the equilibrium point when subjected to unknown external disturbances. Knowing the governing equations, a robust backstepping control design is proposed by introducing a well-defined smooth function and using a Nussbaum function together with a Kalman filter-based disturbance estimator. The efficiency of the proposed control scheme is demonstrated through numerical simulations and compared with related works.

Robust fault-tolerant flight control of quadrotor against faults in multiple motors

2021 ◽  
pp. 095441002199954
Author(s):  
Dinesh D Dhadekar ◽  
S E Talole
Keyword(s):  
Flight Control ◽  
Tracking Control ◽  
Fault Tolerant ◽  
External Disturbances ◽  
Detection And Identification ◽  
Attitude Tracking ◽  
Fault Detection And Identification ◽  
Attitude Tracking Control ◽  
Disturbance Estimator

In this article, position and attitude tracking control of the quadrotor subject to complex nonlinearities, input couplings, aerodynamic uncertainties, and external disturbances coupled with faults in multiple motors is investigated. A robustified nonlinear dynamic inversion (NDI)-based fault-tolerant control (FTC) scheme is proposed for the purpose. The proposed scheme is not only robust against aforementioned nonlinearities, disturbances, and uncertainties but also tolerant to unexpected occurrence of faults in multiple motors. The proposed scheme employs uncertainty and disturbance estimator (UDE) technique to robustify the NDI-based controller by providing estimate of the lumped disturbance, thereby enabling rejection of the same. In addition, the UDE also plays the role of fault detection and identification module. The effectiveness and benefits of the proposed design are confirmed through 6-DOF simulations and experimentation on a 3-DOF Hover platform.

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