Robust Finite-Time H∞ Control of Stochastic Jump Systems

Shu-Ping He,Fei Liu 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.6

This paper provides the stochastic finite-time stabilization and H∞ control problem of Markov jump systems with norm-bounded uncertainties and state delays that possess randomly jumping parameters. The transition of the jumping parameters is governed by a finite-state Markov process. The finite-time H∞ controller via state feedback is provided to guarantee the stochastic finite-time boundedness and stochastic finite-time stabilization of the resulting closed-loop system for all admissible uncertainties and unknown time-delays. The control criterion is formulated in the form of linear matrix inequalities and the designed finite-time stabilization controller is described as an optimization one. Simulation re-sults illustrate the effectiveness of the developed approaches.

Adaptive Neural Finite-time Trajectory Tracking Control of MSVs Subject to Uncertainties

Qiang Zhang,Meijuan Zhang,Renming Yang,Namkyun Im 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.6

This paper provides two finite-time trajectory tracking control schemes for marine surface vessels (MSVs) which are influenced by dynamic uncertainties and unknown time-varying disturbances. Neural networks (NNs) are applied to reconstruct the vehicle’s dynamic uncertainties, and the sum of upper bound of approximation error and external unknown disturbances is estimated by designing an adaptive law. According to the backstepping technique and finite-time stability theory, a finite-time trajectory tracking control scheme is presented. Further, to decrease the conservatism of the presented control scheme caused by estimating the upper bound, a multivariate sliding mode finite-time disturbance observer (MSMFTDO) is designed to estimate the unknown external disturbances and the part that is not completely reconstructed by NNs, and then a MSMFTDO-based adaptive neural finite-time trajectory tracking control law is designed. Rigorous theoretical analyses are provided to prove that,owing to the developed finite-time trajectory tracking control strategies, all the signals of the closed-loop trajectory tracking control system are bounded, and that the actual trajectory of MSVs is able to track the reference trajectory in finite time. Simulation results illustrate the effectiveness of the developed schemes.

FTESO-based Nonsingular Fast Integral Terminal Sliding Mode Finite Time Control for the Speed and Tension System of the Cold Strip Rolling Mill

Le Liu,Ranyang Deng,Zhuang Ma,Yiming Fang 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.1

To weaken the influences of uncertainties on the finite time tracking control performance of the speed and tension system of the reversible cold strip rolling mill driven by alternating current (AC) asynchronous motors, a dynamic surface backstepping nonsingular fast integrated terminal sliding mode control (DSBNFITSMC) strategy is proposed based on finite time extended state observers (FTESOs). Firstly, the FTESOs are constructed to dynamically observe the system’s mismatched uncertainties, and the observation errors can converge to zero in finite time. Next, the dynamic surface backstepping control is combined with the nonsingular fast integrated terminal sliding mode finite time control to complete the controller designs for the speed and tension system of the reversible cold strip rolling mill, which solve the “differential explosion” problem in conventional backstepping control, and simplify the design processes of the system controllers. Again, theoretical analysis shows that the proposed control strategy can guarantee the closed-loop system is practical finite time stability in the Lyapunov sense. Finally, the simulation research is carried out on the speed and tension system of a reversible cold strip rolling mill by using the actual data, and results show the validity of the proposed control strategy.

Finite-time sliding surface constrained control for a robot manipulator with an unknown deadzone and disturbance

Ik Han, Seong,Lee, Jangmyung Elsevier 2016 ISA transactions Vol.65 No.-

<P><B>Abstract</B></P> <P>This paper presents finite-time sliding mode control (FSMC) with predefined constraints for the tracking error and sliding surface in order to obtain robust positioning of a robot manipulator with input nonlinearity due to an unknown deadzone and external disturbance. An assumed model feedforward FSMC was designed to avoid tedious identification procedures for the manipulator parameters and to obtain a fast response time. Two constraint switching control functions based on the tracking error and finite-time sliding surface were added to the FSMC to guarantee the predefined tracking performance despite the presence of an unknown deadzone and disturbance. The tracking error due to the deadzone and disturbance can be suppressed within the predefined error boundary simply by tuning the gain value of the constraint switching function and without the addition of an extra compensator. Therefore, the designed constraint controller has a simpler structure than conventional transformed error constraint methods and the sliding surface constraint scheme can also indirectly guarantee the tracking error constraint while being more stable than the tracking error constraint control. A simulation and experiment were performed on an articulated robot manipulator to validate the proposed control schemes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Design an assumed model feedforward finite-time sliding mode controller for a robot manipulator system. </LI> <LI> Design a finite-time sliding mode controller with a tracking error constraint. </LI> <LI> Design a finite-time sliding mode controller with a sliding surface constraint. </LI> <LI> Design a finite-time sliding mode controller with tracking error and sliding surface constraint controls without requiring an extra deadzone compensator. </LI> </UL> </P>

Finite-time extended state observer-based area keeping and heading control for turret-moored vessels with uncertainties and unavailable velocities

Tuo Yulong,Wang Shasha,Guo Chen 대한조선학회 2022 International Journal of Naval Architecture and Oc Vol.14 No.1

This paper investigates the finite-time extended state observer-based Dynamic Positioning (DP) control of turret-moored vessels with unavailable velocities and uncertainties. The control objective is to assist the mooring system of vessel in achieving area keeping and heading control. Firstly, unavailable velocities and uncertainties are estimated simultaneously by the designed finite-time Extended State Observer (ESO), where finite-time convergence and high accuracy of estimated values are guaranteed. Then, a reliability index is introduced to quantify the breakage probability of mooring lines. Based on estimated values and reliability index, a finite-time DP controller is proposed for area keeping and heading control of turret-moored vessels. The proposed controller can improve utilization efficiency of mooring system and guarantee finite-time convergence of all signals in closed-loop control system. Meanwhile, a saturation function is integrated into the controller to decrease the thrusters’ energy consumption. Finally, simulations and comparisons demonstrate the performance of finite-time ESO and DP controller.

Finite-Time Control for Linear Systems with Impulse Control

Hiroyuki Ichihara,Hitoshi Katayama 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

This paper deals with finite-time stabilization and finite-time boundedness control problems for continuoustime linear time-varying systems with impulse control, which control is governed by discrete-time linear time-varying systems. Sufficient conditions are given for the existence of observer-based output feedback controllers that make a system finite-time stable and finite-time bounded, in terms of differential-difference linear matrix inequalities (DDLMIs). Assuming periodic solutions of the DDLMIs, numerically tractable design conditions for impulse control are given by LMIs. Numerical examples illustrate the design methods of observer-based output control as well as state feedback control.

Finite-time Function Projective Synchronization in Complex Multi-links Networks and Application to Chua’s Circuit

Xi Wang,Peng Miao 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.8

The article focuses on the problem of finite-time function projective synchronization which is happened in complex multi-links networks with constant time delay or time-varying delay problems and it is applied to Chua’s circuit. The main contribution is that a special class of nonlinear feedback controllers are proposed to make finitetime function projective synchronization. The proposed two nonlinear feedback controllers contain the constant time delay or time-varying delay and they all can make finite-time function projective synchronization in complex multi-links networks with constant time delay or time-varying delay problems. In addition, their finite-time criteria are derived based on finite-time stability theory and the convergence time are estimated. At last, the presented controllers are applied to Lorenz system and Chua’s circuit the numerical simulations demonstrate the power of our method.

Finite-time Controller Design for Four-wheel-steering of Electric Vehicle Driven by Four In-wheel Motors

Qing-Hua Meng,Zong-Yao Sun,Yushan Li 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4

A smooth control method may do not obtain a desired convergence. On the other hand, a no-continuous method may cause a close-loop system to chatter. In order to avoid the aforementioned disadvantages, a non-smooth finite-time control method is proposed and applied on an active four-wheel-steering electric vehicle driven by four in-wheel motors to improve the safety and manoeuvrability in this paper. Based on an ideal electric vehicle steering tracking model, a non-smooth finite-time convergence controller is constructed for controlling the four wheels’ steering angles of an electric vehicle. The front wheel cornering stiffness, rear wheel cornering stiffness and external disturbance of a practical car are regarded as bounded uncertain parameters according to practical conditions. An A-class car model in the Carsim software is utilized to simulate the designed controller. The simulation results show that the controller based on finite-time convergence can track the ideal vehicle steering model better to obtain zero sideslip angle and expected yaw rate even when there exist perturbation of cornering stiffness and disturbance of lateral wind. It means the control system of the electric vehicle is robust with uncertainty. The simulation results also show that the non-smooth finite-time control method is better than the slide mode control method for the active four-wheel-steering system of the electric vehicle.

Robust Finite-Time Backstepping Control with a Nonlinear Disturbance Observer for Uncertain Strict-Feedback Nonlinear Systems

Seong-Ik Han(한성익) 제어로봇시스템학회 2019 제어·로봇·시스템학회 논문지 Vol.25 No.9

This paper proposes a robust finite-time backstepping control scheme using a nonlinear disturbance observer for uncertain single-input single-output (SISO) full-order strict-feedback nonlinear systems, in which the dynamics are partially known. To improve the convergence time and robustness of the conventional backstepping control, a new finite-time control method is proposed to estimate uncertainties that appear in each step of the controller design based on the finite-time virtual tracking errors and a nonlinear disturbance observer. The finite-time virtual controls and control input are derived by using the finite-time Lyapunov stability criterion. Simulation results for example of a strict-feedback SISO nonlinear system confirm that the proposed control scheme exhibits better performance than a conventional backstepping control scheme.

Quaternion-based Finite-time Control for Attitude Tracking of the Spacecraft without Unwinding

Yong Guo,Shen-Min Song,Xue-Hui Li 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.6

This paper investigates two finite-time controllers for the attitude tracking control of the spacecraft based on the quaternion by terminal sliding mode control. Because quaternion is unable to represent the set of attitudes both globally and uniquely, it can result in unwinding. Unwinding makes a spacecraft perform an unnecessary large-angle maneuver when a small-angle maneuver in the opposite rotational direction is sufficient to achieve the objective. The first controller converges to the equilibrium without singularity in finite time, while the second one converges to the region near the equilibrium without singularity, chattering and unwinding in finite time. Saturation function is introduced to the first controller to eliminate singularity, while a novel fast terminal sliding mode control is introduced to the second controller to eliminate singularity and unwinding. Theoretical analysis shows that the controllers can make the spacecraft follow a time-varying reference attitude signal in finite time and guarantee the stability of the overall closed-loop system. Numerical simulations also demonstrate the effectiveness of the proposed control schemes.