Smooth adaptive fixed time convergent controller design for BTT missiles with uncertainties

2019 ◽  
Vol 124 (1273) ◽  
pp. 323-345
Author(s):  
Y. Yun ◽  
S. Tang ◽  
J. Guo ◽  
Y. Yun
Keyword(s):  
Control Algorithm ◽  
Performance Metrics ◽  
Controller Design ◽  
Sliding Mode ◽  
Fixed Time ◽  
Convergence Time ◽  
Control Input ◽  
Time Stability ◽  
Terminal Sliding Mode ◽  
Satisfactory Performance

ABSTRACTA smooth adaptive sliding-mode-based controller is developed for BTT missiles considering nonlinear couplings and aerodynamic uncertainties, wherein fixed-time stability theory is synthesised into sliding-mode control algorithm, such that control variables follow the desired command within fixed-bounded convergence time. Unlike other terminal sliding-mode-related works, the bound of settling time is independent of initial states, indicating that performance metrics, for instance the convergence rate, can be evaluated in advance. The control input is designed to be intrinsically smooth, based on adaptive estimations, and therefore the problem of singularity and chattering is effectively eliminated. Simulation results demonstrate the satisfactory performance and validate the effectiveness of the designed approach.

scholarly journals Robust Smooth Sliding-Mode-Based Controller with Fixed-Time Convergence for Missiles considering Aerodynamic Uncertainty

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yuhang Yun ◽  
Jie Guo ◽  
Shengjing Tang
Keyword(s):  
Performance Metrics ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Fixed Time ◽  
Convergence Theory ◽  
Control Technique ◽  
Control Input ◽  
Initial State ◽  
Terminal Sliding Mode ◽  
Signum Function

This paper designed a smooth fixed-time-convergent sliding mode controller for a missile flight system considering aerodynamic uncertainties. Fixed-time convergence theory is incorporated with the sliding mode control technique to ensure that the system tracks desired commands within uniform bounded time under different initial conditions. Unlike previous terminal sliding mode approaches, not only is the bound of settling time independent of initial state, indicating that performance metrics like convergence rate can be predicted beforehand, but the control input is designed to be smooth based on adaptive estimations and some mathematical results without introducing any discontinuous items like the signum function, which avoids the problem of chattering consequently. A cascade control structure is employed with the derived control algorithm, and therein, the control input signal is obtained. Finally, a number of simulations are carried out and demonstrate the effectiveness of the designed controller.

Smooth second-order nonsingular terminal sliding mode control for reusable launch vehicles

2014 ◽  
Vol 7 (1) ◽  
pp. 95-110 ◽  
Author(s):  
Shaobo Ni ◽  
Jiayuan Shan
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Tracking Error ◽  
Second Order ◽  
Convergence Time ◽  
Control Input ◽  
Terminal Sliding Mode ◽  
Content Type ◽  
Nonsingular Terminal Sliding Mode ◽  
Attitude Tracking

Purpose – The purpose of this paper is to present a sliding mode attitude controller for reusable launch vehicle (RLV) which is nonlinear, coupling, and includes uncertain parameters and external disturbances. Design/methodology/approach – A smooth second-order nonsingular terminal sliding mode (NTSM) controller is proposed for RLV in reentry phase. First, a NTSM manifold is proposed for finite-time convergence. Then a smooth second sliding mode controller is designed to establish the sliding mode. An observer is utilized to estimate the lumped disturbance and the estimation result is used for feedforward compensation in the controller. Findings – It is mathematically proved that the proposed sliding mode technique makes the attitude tracking errors converge to zero in finite time and the convergence time is estimated. Simulations are made for RLV through the assumption that aerodynamic parameters and atmospheric density are perturbed. Simulation results demonstrate that the proposed control strategy is effective, leading to promising performance and robustness. Originality/value – By the proposed controller, the second-order sliding mode is established. The attitude tracking error converges to zero in a finite time. Meanwhile, the chattering is alleviated and a smooth control input is obtained.

Fast fixed-time convergent smooth adaptive guidance law with terminal angle constraint for interception of maneuvering targets

2020 ◽  
pp. 095441002096509
Author(s):  
Peng Zhang ◽  
Xiaoyu Zhang
Keyword(s):  
Stability Theory ◽  
Sliding Mode ◽  
Fixed Time ◽  
Guidance System ◽  
Time Stability ◽  
Terminal Sliding Mode ◽  
Guidance Law ◽  
Maneuvering Targets ◽  
System States ◽  
Terminal Angle Constraint

This paper introduces a fast fixed-time guidance law with terminal angle constraint for interception of maneuvering targets, which is based on the structure of singularity-free fast terminal sliding mode and the fixed-time stability theory. Different from the finite-time stability, the fixed-time stability can predefine the maximum stabilization time of system states which is independent on the initial value of system states. Under the proposed guidance law, the guidance system can achieve stabilization within settling time which decides by the parameters of controller. In addition, an adaptive law is proposed which alleviate the chattering of sliding mode and smooths the guidance law. Meanwhile, the proof of the sliding mode manifold and system states fixed-time convergence is given by Lyapunov stability theory. Finally, numerical simulations demonstrate the performance of the proposed guidance law is satisfying.

Guidance and control with fixed-time convergence for an interception missile

2021 ◽  
pp. 095441002110440
Author(s):  
Lei Cui ◽  
Nan Jin ◽  
Yantao Zong
Keyword(s):  
Sliding Mode ◽  
Fixed Time ◽  
Convergence Time ◽  
Singular Problem ◽  
State Variables ◽  
Terminal Sliding Mode ◽  
Surface Design ◽  
Guidance And Control ◽  
Nonsingular Terminal Sliding Mode ◽  
And Control

This article deals with the problem of partial integrated guidance and control (IGC) design with fixed-time convergence. First of all, two new fixed-time stability systems are proposed, and a novel nonsingular terminal sliding mode with fixed-time convergence is constructed by switching the exponential term of system state variables, which can realize the transition from finite-time convergence to fixed-time convergence. Concurrently, in order to solve the singular problem of terminal sliding mode, a continuous piecewise function is used in the sliding mode surface design. Then, a novel nonsingular terminal sliding mode control with fixed-time convergence is proposed for partial IGC design; that is, the upper-bound of convergence time is independent of the initial states of both missile and target and can be set in advance. In addition, a radial basis function neural network (RBFNN) is used to adaptively estimate and compensate for the uncertainties caused by the target’s maneuvering, so that the design of fixed-time sliding mode controller does not need to know any information about the target maneuver in advance, which enables the proposed controller to be better with robustness. Finally, the effectiveness and merits of the proposed control strategy are shown by the numerical simulation results based on the nonlinear longitudinal model of missile.

scholarly journals Optimization of Urban Rail Automatic Train Operation System Based on RBF Neural Network Adaptive Terminal Sliding Mode Fault Tolerant Control

2021 ◽  
Vol 4 (3) ◽  
pp. 51
Author(s):  
Junxia Yang ◽  
Youpeng Zhang ◽  
Yuxiang Jin
Keyword(s):  
Neural Network ◽  
Control Algorithm ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Rbf Neural Network ◽  
Fault Tolerant Control ◽  
Control Input ◽  
Terminal Sliding Mode ◽  
Train Operation ◽  
Automatic Train Operation

Aiming at the problem of the large tracking error of the desired curve for the automatic train operation (ATO) control strategy, an ATO control algorithm based on RBF neural network adaptive terminal sliding mode fault-tolerant control (ATSM-FTC-RBFNN) is proposed to realize the accurate tracking control of train operation curve. On the one hand, considering the state delay of trains in operation, a nonlinear dynamic model is established based on the mechanism of motion mechanics. Then, the terminal sliding mode control principle is used to design the ATO control algorithm, and the adaptive mechanism is introduced to enhance the adaptability of the system. On the other hand, RBFNN is used to adaptively approximate and compensate the additional resistance disturbance to the model so that ATO control with larger disturbance can be realized with smaller switching gain, and the tracking performance and anti-interference ability of the system can be enhanced. Finally, considering the actuator failure and the control input limitation, the fault-tolerant mechanism is introduced to further enhance the fault-tolerant performance of the system. The simulation results show that the control can compensate and process the nonlinear effects of control input saturation, delay, and actuator faults synchronously under the condition of uncertain parameters, external disturbances of the system model and can achieve a small error tracking the desired curve.

scholarly journals Finite-Time Cooperative Tracking Control Algorithm for Multiple Surface Vessels

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Jianfang Jiao ◽  
Mingyu Fu
Keyword(s):  
Finite Time ◽  
Tracking Control ◽  
Control Algorithm ◽  
Sliding Mode ◽  
External Disturbance ◽  
Lyapunov Stability Theory ◽  
Control Input ◽  
Terminal Sliding Mode ◽  
Surface Vessels ◽  
Cooperative Tracking

We investigate the problem of finite-time cooperative tracking for multiple surface vessels in the presence of external disturbances. A robust finite-time cooperative tracking algorithm based on terminal sliding-mode control is proposed for multiple surface vessels. In light of the leader-follower strategy, a virtual leader vessel is defined to provide reference point for other surface vessels to form the desired formation. Specifically, the proposed algorithm only requires the communication topology among the surface vessels to be a directed graph with a directed spanning tree. The robustness is achieved by compensating the upper bound of external disturbance in the control input, and the global finite-time stability is proved by Lyapunov stability theory. Finally, the effectiveness of the proposed finite-time cooperative tracking control algorithm is demonstrated by simulation results.

Sign in / Sign up

Export Citation Format

Share Document