scholarly journals Study on spacecraft formation capture control method based on disturbance observer

2021 ◽  
Vol 39 (5) ◽  
pp. 1012-1021
Author(s):  
Xiaolong WANG ◽  
Chong SUN ◽  
Qun FANG ◽  
Qi LI ◽  
Shuo SONG
Keyword(s):  
Collision Avoidance ◽  
Disturbance Observer ◽  
Control Method ◽  
Avoidance Performance ◽  
Capture Process ◽  
Spacecraft Formation ◽  
Control Scheme ◽  
Close Range ◽  
The Stability ◽  
Compound Disturbance

In the presence of compound disturbances, a multi-spacecraft cooperative collision avoidance capture control method based on disturbance observer was proposed, which can solve the problem of low speed rolling non-cooperative target close-range capture in space. Firstly, a relative motion model of attitude and orbit coupling is established. Secondly, the disturbance observer is used to estimate and cancel the compound disturbance in the capture process. At the same time, the hyperquadric surfaces are used to describe the shape of space non-cooperative targets and capture spacecraft to establish a composite artificial potential field, and a robust control law with collision avoidance function is also designed. Finally, the stability of the controlled system is proved by using Lyapunov function, and the collision avoidance performance of the system is analyzed. Numerical simulations are carried out to evaluate the effectiveness of the proposed control scheme.

scholarly journals Robust Synchronization Control of Uncertain Fractional-Order Chaotic Systems via Disturbance Observer

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Kaijuan Xue ◽  
Yongbing Huangfu
Keyword(s):  
Fractional Order ◽  
Disturbance Observer ◽  
Chaotic Systems ◽  
Control Method ◽  
Observer Design ◽  
Synchronization Error ◽  
Synchronization Control ◽  
Compact Set ◽  
Control Scheme ◽  
Unknown Disturbances

This paper studies the synchronization of two different fractional-order chaotic systems through the fractional-order control method, which can ensure that the synchronization error converges to a sufficiently small compact set. Afterwards, the disturbance observer of the synchronization control scheme based on adaptive parameters is designed to predict unknown disturbances. The Lyapunov function method is used to verify the appropriateness of the disturbance observer design and the convergence of the synchronization error, and then the feasibility of the control scheme is obtained. Finally, our simulation studies verify and clarify the proposed method.

Integrated Modified Repetitive Control With Disturbance Observer of Piezoelectric Nanopositioning Stages for High-Speed and Precision Motion

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Zhao Feng ◽  
Jie Ling ◽  
Min Ming ◽  
Xiaohui Xiao
Keyword(s):  
Disturbance Observer ◽  
High Speed ◽  
External Disturbance ◽  
Repetitive Control ◽  
Optimization Procedure ◽  
Tracking Performance ◽  
Hysteresis Nonlinearity ◽  
Control Scheme ◽  
The Stability ◽  
Precision Motion

The tracking performance of piezoelectric nanopositioning stages is vital in many applications, such as scanning probe microscopes (SPMs). Although modified repetitive control (MRC) can improve tracking performance for commonly used periodic reference input, it is sensitive to unexpected disturbances that deteriorate tracking precision, especially for high-speed motion. In order to achieve high-speed and precision motion, in this paper, a new composite control scheme by integrating MRC with disturbance observer (DOB) is developed. To simplify controller implementation, the hysteresis nonlinearity is treated as external disturbance and the proposed method is designed in frequency domain. The stability and robust stability are analyzed, and an optimization procedure to calculate the controller parameters is employed to enhance the performance to the maximum extent. To validate the effectiveness of the proposed method, comparative experiments are performed on a piezoelectric nanopositioning stage. Experimental results indicate that the hysteresis is suppressed effectively and the proposed method achieves high-speed and precision tracking with triangular waves references up to 25 Hz and improves the disturbance rejection ability with disturbances under different frequencies and robustness to model uncertainty through comparing with feedback controllers and MRC, respectively.

Zero Phase Robust Control of XY Table Linear Servo System

2013 ◽  
Vol 419 ◽  
pp. 713-717
Author(s):  
Xi Mei Zhao ◽  
Ming Ming Jiang ◽  
Hong Yi Li ◽  
Hao Liu
Keyword(s):  
Disturbance Observer ◽  
Position Control ◽  
Control Method ◽  
Phase Error ◽  
Tracking Error ◽  
Servo System ◽  
Direct Drive ◽  
Tracking Accuracy ◽  
Control Scheme ◽  
Zero Phase

For direct drive XY table servo system, position control is designed. Considering the error which is caused by the disturbance of the system, friction factor and so on. The control method combing the zero phase error tracking controller (ZPETC) with the disturbance observer (DOB) is adopted. The system tracking error is reduced by adopting ZPETC, and through influences of disturbance to the system is diminished by the disturbance observer. Thus the tracking accuracy and robustness of the system are improved. Simulation results show that this control scheme is effective. It can obviously improve the accuracy of the system.

scholarly journals A Theoretical Concept of Decoupled Current Control Scheme for Grid-Connected Inverter with L-C-L Filter

2021 ◽  
Vol 11 (14) ◽  
pp. 6256
Author(s):  
Mohamad Amin Ghasemi ◽  
Seyed Fariborz Zarei ◽  
Saeed Peyghami ◽  
Frede Blaabjerg
Keyword(s):  
Control Method ◽  
Controller Design ◽  
Current Control ◽  
System Stability ◽  
State Equations ◽  
Lcl Filter ◽  
Control Scheme ◽  
Grid Connected Inverter ◽  
The Stability ◽  
Grid Side

This paper proposes a nonlinear decoupled current control scheme for a grid-connected inverter with LCL filter. Decoupling the active and reactive current control channels is one of the main demands in the control of inverters. For inverters with an L filter, the decoupling can be achieved by a proper feed-forward of grid voltages. However, the coupling of channels is a complex issue for converters with LCL filters. The resonance mode of the LCL filter may cause instability, which adds more complexity to the analysis. In this paper, state equations of the system are provided, which highlight the coupling between active and reactive currents injected into the grid. Accordingly, a non-linear control scheme is proposed which effectively decouples the channels and dampens the resonant modes of the LCL filter. The stability of the proposed control method is verified by the Lyapunov criterion. Independency of the system stability to the grid-impedance is another feature of the proposed approach. Moreover, only grid-side currents are needed for implementation of the proposed scheme, avoiding the need for additional current sensors for the output capacitor and grid-side inductor. For accurate modelling of the inverter, the computation and PWM sampling delays are included in the controller design. Finally, various case studies are provided that verify the performance of the proposed approach and the stability of the system.

Task-space asymptotic tracking control of robots using a direct adaptive Taylor series controller

2018 ◽  
Vol 24 (23) ◽  
pp. 5570-5584 ◽  
Author(s):  
Seyed Mohammad Ahmadi ◽  
Mohammad Mehdi Fateh
Keyword(s):  
Taylor Series ◽  
Control Method ◽  
Tracking Error ◽  
Time Derivative ◽  
Approximation Error ◽  
Task Space ◽  
Control Approach ◽  
Control Scheme ◽  
Asymptotic Tracking ◽  
The Stability

This paper presents a robust task-space control approach using a direct adaptive Taylor series controller for electrically driven robot manipulators. In an adaptive Taylor series control scheme, the parameters of controller are directly tuned in order to reduce the task-space tracking error in the presence of structured and unstructured uncertainty. Also, the upper bound of approximation error is estimated to form a robustifying term and the asymptotic convergence of task-space tracking error and its time derivative is proven based on the stability analysis. Simulation results are included to verify the effectiveness of the proposed control method.

Collision-avoidance steering control for autonomous vehicles using neural network-based adaptive integral terminal sliding mode

2020 ◽  
Vol 39 (3) ◽  
pp. 4689-4702
Author(s):  
Zhe Sun ◽  
Jiayang Zou ◽  
Defeng He ◽  
Zhihong Man ◽  
Jinchuan Zheng
Keyword(s):  
Neural Network ◽  
Control System ◽  
Collision Avoidance ◽  
Sliding Mode ◽  
Autonomous Vehicle ◽  
Kinematic Model ◽  
Avoidance Performance ◽  
Steering Control ◽  
Terminal Sliding Mode ◽  
Control Scheme

Due to the complex driving conditions confronted by an autonomous vehicle, it is significant for the vehicle to possess a robust control system to achieve effective collision-avoidance performance. This paper proposes a neural network-based adaptive integral terminal sliding mode (NNAITSM) control scheme for the collision-avoidance steering control of an autonomous vehicle. In order to describe the vehicle’s lateral dynamics and path tracking characteristics, a two-degrees-of-freedom (2DOF) dynamic model and a kinematic model are adopted. Then, an NNAITSM controller is designed, where a radial basis function neural network (RBFNN) scheme is utilized to online approximate the optimal upper bound of lumped system uncertainties such that prior knowledge about the uncertainties is not required. The stability of the control system is proved via Lyapunov, and the selection guideline of control parameters is provided. Last, Matlab-Carsim co-simulations are executed to test the performance of the designed controller under different road conditions and vehicle velocities. Simulation results show that compared with conventional sliding mode (CSM) and nonsingular terminal sliding mode (NTSM) control, the proposed NNAITSM control scheme owns evident superiority in not only higher tracking precision but also stronger robustness against various road surfaces and vehicle velocities.

Opto-electronic platform tracking control of multi-rotor unmanned aerial vehicles based on composite disturbance compensation

2019 ◽  
Vol 233 (12) ◽  
pp. 4410-4420 ◽  
Author(s):  
Rijun Wang ◽  
Yue Bai ◽  
Zhiqiang Zeng ◽  
Junyuan Wang ◽  
Wenhua Du ◽  
...  
Keyword(s):  
Disturbance Observer ◽  
Adaptive Fuzzy Control ◽  
Tracking Performance ◽  
Velocity Signal ◽  
Control Precision ◽  
Control Scheme ◽  
Vehicle Systems ◽  
Aerial Vehicle ◽  
Series Of Experiments ◽  
The Stability

Airborne opto-electronic platforms are very important in unmanned aerial vehicle systems. The stability and tracking performance of airborne opto-electronic platforms are easily affected by disturbance factors, making compensating for those disturbances a very prominent issue. In this paper, compared to the traditional disturbance observer, an improved velocity signal based disturbance observer (IVDOB) is particularly designed to compensate for the disturbance. Then its capability, robustness, and stability are discussed. For improving the stabilization accuracy and tracking performance of airborne opto-electronic platforms, the universal approximation property of fuzzy systems is used to compensate the disturbance further and an adaptive fuzzy control system based on IVDOBs is proposed. To validate the scheme, a series of experiments were carried out. The results show that the proposed control scheme can achieve reliable control precision and satisfy the requirements of airborne opto-electronic platform tasks.

A Novel Trajectory Tracking Control Method for a Nonholonomic Mobile Robot with System Uncertainties and Disturbances

2013 ◽  
Vol 823 ◽  
pp. 193-198
Author(s):  
Run Zhou Zhao ◽  
Xi Zheng Zhang ◽  
Cai Hong Shi ◽  
Wei Chen
Keyword(s):  
Trajectory Tracking ◽  
Control Method ◽  
Hybrid Control ◽  
Kinematic Model ◽  
Network Dynamic ◽  
Trajectory Tracking Control ◽  
Dynamic Controller ◽  
Control Scheme ◽  
System Uncertainties ◽  
The Stability

This paper focuses on the trajectory tracking problem of mobile robots with system uncertainties and disturbances. With the integration of a kinematic controller and a dynamic controller, a hybrid control method is presented. Firstly, an adaptive kinematic controller is proposed through the kinematic model and backstepping method. Secondly, a neural network dynamic controller is proposed, with the consideration of system uncertainties and disturbances. The stability of the proposed control scheme is verified via the Lyapunov method and Barbalat lemma. Finally, results of circular trajectory simulation have illustrated the effectiveness of the present control scheme.

scholarly journals Disturbance Compensation Based Finite-Time Tracking Control of Rigid Manipulator

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Mohamed Elamin Sahabi ◽  
Guipu Li ◽  
Xiangyu Wang ◽  
Shihua Li
Keyword(s):  
Finite Time ◽  
Tracking Control ◽  
Disturbance Observer ◽  
Control Method ◽  
Disturbance Compensation ◽  
Adding A Power Integrator ◽  
Time Simulation ◽  
Control Scheme ◽  
Mismatched Disturbances ◽  
Power Integrator

The finite-time tracking control problem of rigid manipulator system with mismatched disturbances is investigated via a composite control method. The proposed composite controller is based on finite-time disturbance observer and adding a power integrator technique. First, a finite-time disturbance observer is designed which guarantees that the disturbances can be estimated in a finite time. Then, a composite controller is developed based on adding a power integrator approach and the estimates of the disturbances. Under the proposed composite controller, the manipulator position can track the desired position in a finite time. Simulation results show the effectiveness of the proposed control scheme.

scholarly journals A new approach on the modelling, chaos control and synchronization of a fractional biological oscillator

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Ali Saleh Alshomrani ◽  
Malik Zaka Ullah ◽  
Dumitru Baleanu
Keyword(s):  
Chaos Control ◽  
Control Method ◽  
Phase Portraits ◽  
New Approach ◽  
Control Scheme ◽  
Biological Oscillator ◽  
The Stability ◽  
Control And Synchronization ◽  
And Control ◽  
Active Control Method

AbstractThis research aims to discuss and control the chaotic behaviour of an autonomous fractional biological oscillator. Indeed, the concept of fractional calculus is used to include memory in the modelling formulation. In addition, we take into account a new auxiliary parameter in order to keep away from dimensional mismatching. Further, we explore the chaotic attractors of the considered model through its corresponding phase-portraits. Additionally, the stability and equilibrium point of the system are studied and investigated. Next, we design a feedback control scheme for the purpose of chaos control and stabilization. Afterwards, we introduce an efficient active control method to achieve synchronization between two chaotic fractional biological oscillators. The efficiency of the proposed stabilizing and synchronizing controllers is verified via theoretical analysis as well as simulations and numerical experiments.

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