scholarly journals Prescribed Finite-time ESO-based Prescribed Finite-time Control and Its Application to Partial IGC Design

Author(s):  
Lei Cui ◽  
Nan Jin

Abstract This paper proposes a new extended stateobserver-based sliding mode control strategy with prescribed finite-time convergence. Firstly, a novel prescribed finite-time extended state observer is designed, which estimates the disturbance accurately within a prescribed finite time and effectively solves peaking value problem. Secondly, a new type of second-order prescribed finite-time sliding mode controller is designed to ensure system states converge within a prescribed finite time. Then, the proposed control strategy is applied to the design of partial integrated guidance and control with two-loop controller structure. Finally, the validity of the proposed methodology is verified through numerical simulation.

Author(s):  
Aijun Li ◽  
Yu Wang ◽  
Yong Guo ◽  
Changqing Wang

A finite-time blended control strategy is proposed for the reentry phase attitude control of the aerospace vehicle (ASV) based on the neural network, sliding mode control theory and control allocation. Firstly, a finite-time neural networks sliding mode controller is designed based on the attitude model of the ASV in the reentry phase to obtain the virtual control moments which can make the attitude error converge to the equilibrium point in finite time. Secondly, the desired control moments are mapped into the control commands on the aerodynamic deflectors and the reaction control system (RCS) by using the control allocation. Finally, simulation results are provided to demonstrate the effectiveness of the attitude blended control strategy proposed.


Author(s):  
Vo Anh Tuan ◽  
Hee-Jun Kang

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.


2020 ◽  
Vol 26 (17-18) ◽  
pp. 1425-1434 ◽  
Author(s):  
Sunhua Huang ◽  
Jie Wang

In this study, a fractional-order sliding mode controller is effectively proposed to stabilize a nonlinear power system in a fixed time. State trajectories of a nonlinear power system show nonlinear behaviors on the angle and frequency of the generator, phase angle, and magnitude of the load voltage, which would seriously affect the safe and stable operation of the power grid. Therefore, fractional calculus is applied to design a fractional-order sliding mode controller which can effectively suppress the inherent chattering phenomenon in sliding mode control to make the nonlinear power system converge to the equilibrium point in a fixed time based on the fixed-time stability theory. Compared with the finite-time control method, the convergence time of the proposed fixed-time fractional-order sliding mode controller is not dependent on the initial conditions and can be exactly evaluated, thus overcoming the shortcomings of the finite-time control method. Finally, superior performances of the fractional-order sliding mode controller are effectively verified by comparing with the existing finite-time control methods and integral order sliding mode control through numerical simulations.


Author(s):  
Cong Zhang

The finite-time convergence problem of an [Formula: see text]th nonlinear system with unmatched disturbance is primarily studied in this paper. During the recursive procedure, a new finite-time controller is designed and proven by adding a sign function and a power integrator. Meanwhile, a [Formula: see text] positive definite and proper Lyapunov function, which satisfies the finite-time Lyapunov stability law, is designed. Finally, the designed finite-time controller is applied to some examples and an application of integrated guidance and control system to test and verify its advantage and practicability.


2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Shang Jiang ◽  
Fuqing Tian ◽  
Shiyan Sun

In the terminal guidance section of large caliber naval gun-guided projectile while striking nearshore maneuvering target, an integrated guidance and control (IGC) method based on an adaptive fuzzy and block dynamic surface sliding mode (AFCBDSM) was proposed with multiple constraints, including the impact angle, control limitations, and limited measurement of the line of sight (LOS) angle rate. The strict feedback cascade model of rolling-guided projectile IGC in space was constructed, and the extended state observer (ESO) was used to estimate the LOS angle rate and uncertain disturbances inside and outside the system, such as target maneuvering, model errors, and wind. A nonsingular terminal sliding mode (NTSM) was designed to zero the LOS angle tracking errors and LOS angle rate in finite time, with the adaptive exponential reaching law. The cascade system was effectively stabilized by the block dynamic surface sliding mode, which prevented differential explosions. To compensate for the saturated nonlinearity of canard control constraints, an adaptive Nussbaum gain function was adopted. The switching chatter of the block dynamic surface sliding mode was reduced through adaptive fuzzy control. Proven by Lyapunov theory, the LOS angle tracking error and LOS angle rate were convergent in finite time, the closed-loop system was uniformly ultimately bounded (UUB), and the system states could be made arbitrarily small at the steady state. Hardware-in-the-loop simulation (HILS) experiments showed that the AFCBDSM provided the guided projectile with good guidance performance while striking targets with different maneuvering forms.


Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 634
Author(s):  
Tianyu Yang ◽  
Bin Wang ◽  
Peng Chen

We focus on the finite-time control of a hydro-turbine governing system (HGS) in this paper. First, the nonlinear mathematical model of the hydro-turbine governing system is presented and is consistent with the actual project. Then, based on the finite-time stability theory and terminal sliding mode scheme, a new finite-time terminal sliding mode controller is designed for the hydro-turbine governing system and a detailed mathematical derivation is given. Only three vector controllers are required, which is less than the HGS equation dimensions and is easy to implement accordingly. Furthermore, numerical simulations for the proposed scheme and an existing sliding mode control are presented to verify the validity and advantage of improving transient performance. The approach proposed in this paper is simple and provides a reference for relevant hydropower systems.


2021 ◽  
Vol 2021 ◽  
pp. 1-10 ◽  
Author(s):  
Meiling Tao ◽  
Xiongxiong He ◽  
Shuzong Xie ◽  
Qiang Chen

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.


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