scholarly journals BLSTM-Based Adaptive Finite-Time Output-Constrained Control for a Class of AUSs with Dynamic Disturbances and Actuator Faults

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Shiyi Huang ◽  
Lulu Rong ◽  
Xiaofei Chang ◽  
Zheng Wang ◽  
Zhaohui Yuan ◽  
...  
Keyword(s):  
Finite Time ◽  
Short Term Memory ◽  
Control Structure ◽  
Control Law ◽  
Tracking Errors ◽  
Time Control ◽  
Learning Speed ◽  
Output Constraints ◽  
Adaptive Laws ◽  
Adaptive Control Algorithm

In this paper, a BLSTM-based adaptive finite-time control structure has been constructed for a class of aerospace unmanned systems (AUSs). Firstly, a novel neural network structure possessing both the time memory characteristics and high learning speed, broad long short-term memory (BLSTM) network, has been constructed. Secondly, several nonlinear functions are utilized to transform the tracking errors into a novel state vector to guarantee the output constraints of the AUSs. Thirdly, the fractional-order control law and the corresponding adaptive laws are designed, and as a result, the adaptive finite-time control scheme has been formed. Moreover, to handle the uncertainties and the faulty elevator outputs, an inequality of the multivariable systems is utilized. Consequently, by fusing the output of the BLSTM, the transformation of the tracking errors, and the adaptive finite-time control law, a novel BLSTM-based intelligent adaptive finite-time control structure has been established for the AUSs under output constraints. The simulation results show that the proposed BLSTM-based adaptive control algorithm can achieve favorable control results for the AUSs with multiple uncertainties.

Finite-time control of uncertain time-varying systems in p-normal form

2020 ◽  
Author(s):  
Kanya Rattanamongkhonkun ◽  
Radom Pongvuthithum ◽  
Chulin Likasiri
Keyword(s):  
Normal Form ◽  
Finite Time ◽  
Control Law ◽  
Time Varying ◽  
Time Control ◽  
Special Cases ◽  
Time Varying Systems ◽  
A Chain ◽  
Uncertain Time ◽  
Power Integrator

Abstract This paper addresses a finite-time regulation problem for time-varying nonlinear systems in p-normal form. This class of time-varying systems includes a well-known lower-triangular system and a chain of power integrator systems as special cases. No growth condition on time-varying uncertainties is imposed. The control law can guarantee that all closed-loop trajectories are bounded and well defined. Furthermore, all states converge to zero in finite time.

A New Finite Time Control Solution for Robotic Manipulators Based on Nonsingular Fast Terminal Sliding Variables and the Adaptive Super-Twisting Scheme

2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Vo Anh Tuan ◽  
Hee-Jun Kang
Keyword(s):  
Finite Time ◽  
Control Method ◽  
Sliding Mode ◽  
Robotic Manipulators ◽  
Control Law ◽  
Continuous Control ◽  
Terminal Sliding Mode ◽  
Finite Time Convergence ◽  
Position Errors ◽  
Time Control

In this study, a new finite time control method is suggested for robotic manipulators based on nonsingular fast terminal sliding variables and the adaptive super-twisting method. First, to avoid the singularity drawback and achieve the finite time convergence of positional errors with a fast transient response rate, nonsingular fast terminal sliding variables are constructed in the position errors' state space. Next, adaptive tuning laws based on the super-twisting scheme are presented for the switching control law of terminal sliding mode control (TSMC) so that a continuous control law is extended to reject the effects of chattering behavior. Finally, a new finite time control method ensures that sliding motion will take place, regardless of the effects of the perturbations and uncertainties on the robot system. Accordingly, the stabilization and robustness of the suggested control system can be guaranteed with high-precision performance. The robustness issue and the finite time convergence of the suggested system are totally confirmed by the Lyapunov stability principle. In simulation studies, the experimental results exhibit the effectiveness and viability of our proposed scheme for joint position tracking control of a 3DOF PUMA560 robot.

scholarly journals Positiveness and Observer-Based Finite-Time Control for a Class of Markov Jump Systems with Some Complex Environment Parameters

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Chengcheng Ren ◽  
Shuping He
Keyword(s):  
Finite Time ◽  
Disturbance Attenuation ◽  
Linear Matrix ◽  
Control Law ◽  
Complex Environment ◽  
Markov Jump ◽  
Markov Jump Systems ◽  
Time Control ◽  
Jump Systems ◽  
Environment Parameters

An observer-based finite-time L2-L∞ control law is devised for a class of positive Markov jump systems in a complex environment. The complex environment parameters include bounded uncertainties, unknown nonlinearities, and external disturbances. The objective is to devise an appropriate observer-based control law that makes the corresponding augment error dynamic Markov jump systems be positive and finite-time stabilizable and satisfy the given L2-L∞ disturbance attenuation index. A sufficient condition is initially established on the existence of the observer-based finite-time controller by using proper stochastic Lyapunov-Krasovskii functional. The design criteria are presented by means of linear matrix inequalities. Finally, the feasibility and validity of the main results can be illustrated through a numerical example.

Distributed finite-time tracking for multiple uncertain mechanical systems with dead-zone input and external disturbances

2019 ◽  
Vol 41 (15) ◽  
pp. 4450-4461 ◽  
Author(s):  
Jihong Jia ◽  
Xia Xie ◽  
Zhikai Zhang ◽  
Guangren Duan
Keyword(s):  
Finite Time ◽  
Dead Zone ◽  
Mechanical Systems ◽  
Small Neighborhood ◽  
Consensus Protocol ◽  
Tracking Errors ◽  
External Disturbances ◽  
Adding A Power Integrator ◽  
Adaptive Laws ◽  
Power Integrator

This paper addresses the distributed finite-time tracking problem for multiple uncertain mechanical systems with dead-zone input and external disturbances. An observer-based adaptive finite-time consensus protocol is designed, which consists of two steps. Firstly, distributed observers are developed such that all the mechanical systems can obtain the leader’s state in finite settling time. Then, based on backstepping method and adding a power integrator technique, the finite-time consensus protocol and appropriate adaptive laws are designed to track the estimated leader’s state. Rigorous proofs show that the tracking errors between each mechanical system and the leader can converge to a small neighborhood of origin in finite time despite the presence of dead-zone nonlinearity and external disturbances. Finally, simulation example is provided to demonstrate the effectiveness of the proposed scheme.

scholarly journals Disturbance Observer-Based Input-Output Finite-Time Control of a Class of Nonlinear Systems

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Leipo Liu ◽  
Xiaona Song ◽  
Zhumu Fu ◽  
Shuzhong Song
Keyword(s):  
Nonlinear Systems ◽  
Finite Time ◽  
Disturbance Observer ◽  
Sufficient Conditions ◽  
State Feedback Control ◽  
Linear Matrix ◽  
Control Law ◽  
Input Output ◽  
Classical State ◽  
Time Control

This paper is concerned with disturbance observer-based input-output finite-time control of a class of nonlinear systems with one-sided Lipschitz condition, as well as multiple disturbances. Firstly, a disturbance observer is constructed to estimate the disturbance generated by an exogenous system. Secondly, by integrating the estimation of disturbance with a classical state feedback control law, a composite control law is designed and sufficient conditions for input-output finite-time stability (IO-FTS) of the closed-loop system are attained. Such conditions can be converted into linear matrix inequalities (LMIs). Finally, two examples are given to show the effectiveness of the proposed method.

scholarly journals A continuous integral terminal sliding mode control approach for a class of uncertain nonlinear systems

2019 ◽  
Vol 52 (5-6) ◽  
pp. 720-728
Author(s):  
Huawei Niu ◽  
Qixun Lan ◽  
Yamei Liu ◽  
Huafeng Xu
Keyword(s):  
Nonlinear Systems ◽  
Sliding Mode Control ◽  
Finite Time ◽  
Sliding Mode ◽  
Control Law ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Control Approach ◽  
Mode Control ◽  
Time Control

In this article, the continuous integral terminal sliding mode control problem for a class of uncertain nonlinear systems is investigated. First of all, based on homogeneous system theory, a global finite-time control law with simple structure is proposed for a chain of integrators. Then, inspired by the proposed finite-time control law, a novel integral terminal sliding mode surface is designed, based on which an integral terminal sliding mode control law is constructed for a class of higher order nonlinear systems subject disturbances. Furthermore, a finite-time disturbance observer-based integral terminal sliding mode control law is proposed, and strict theoretical analysis shows that the composite integral terminal sliding mode control approach can eliminate chattering completely without losing disturbance attenuation ability and performance robustness of integral terminal sliding mode control. Simulation examples are given to illustrate the simplicity of the new design approach and effectiveness.

Adaptive finite-time consensus for multiple mechanical systems with unknown backlash nonlinearity and uncertain dynamics

2020 ◽  
pp. 014233122095296
Author(s):  
Jiabo Ren ◽  
Baofang Wang ◽  
Mingjie Cai
Keyword(s):  
Finite Time ◽  
External Disturbance ◽  
Mechanical Systems ◽  
Small Region ◽  
Control Technique ◽  
Position Errors ◽  
Time Control ◽  
Uncertain Dynamics ◽  
Adaptive Laws ◽  
Backlash Nonlinearity

This paper studies the problem of finite-time consensus (FTC) for uncertain multiple mechanical systems with unknown backlash nonlinearity and external disturbance. Combining finite-time control technique and graph theory, a distributed adaptive FTC protocol is proposed. Radial basis function neural networks are employed to approximate the unknown functions. If the designed parameters of control algorithms and adaptive laws are appropriately chosen, then it can be proved that the position errors between arbitrary two mechanical systems will converge to a small region of zero in finite time as well as the velocity errors. Finally, the effectiveness of the proposed control scheme is verified by numerical simulation.

scholarly journals Finite-Time Control for Attitude Tracking Maneuver of Rigid Satellite

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Mingyi Huo ◽  
Xing Huo ◽  
Hamid Reza Karimi ◽  
Jianfei Ni
Keyword(s):  
Upper Bound ◽  
Finite Time ◽  
Sliding Mode ◽  
Tracking System ◽  
External Disturbance ◽  
Adaptive Sliding Mode Control ◽  
Tracking Errors ◽  
Time Control ◽  
Attitude Tracking ◽  
Inertia Parameters

The problem of finite-time control for attitude tracking maneuver of a rigid spacecraft is investigated. External disturbance, unknown inertia parameters are addressed. As stepping stone, a sliding mode controller is designed. It requires the upper bound of the lumped uncertainty including disturbance and inertia matrix. However, this upper bound may not be easily obtained. Therefore, an adaptive sliding mode control law is then proposed to release that drawback. Adaptive technique is applied to estimate that bound. It is proved that the closed-loop attitude tracking system is finite-time stable. The tracking errors of the attitude and the angular velocity are asymptotically stabilized. Moreover, the upper bound on the lumped uncertainty can be exactly estimated in finite time. The attitude tracking performance with application of the control scheme is evaluated through a numerical example.

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