scholarly journals Neural Extended State Observer Based Intelligent Integrated Guidance and Control for Hypersonic Flight

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2605
Author(s):  
Liang Wang ◽  
Ke Peng ◽  
Weihua Zhang ◽  
Donghui Wang
Keyword(s):  
State Observer ◽  
Lyapunov Theory ◽  
Extended State Observer ◽  
Control Surface ◽  
Extended State ◽  
Actuator Dynamics ◽  
Guidance And Control ◽  
Hypersonic Flight ◽  
Integrated Guidance And Control ◽  
And Control

Near-pace hypersonic flight has great potential in civil and military use due to its high speed and low cost. To optimize the design and improve the robustness, this paper focuses on the integrated guidance and control (IGC) design with nonlinear actuator dynamics in the terminal phase of hypersonic flight. Firstly, a nonlinear integrated guidance and control model is developed with saturated control surface deflection, and third-order actuator dynamics is considered. Secondly, a neural network is introduced using an extended state observer (ESO) design to estimate the complex model uncertainty, nonlinearity and disturbance. Thirdly, a command-filtered back-stepping controller is designed with flexible designed sliding surfaces to improve the terminal performance. In this process, hybrid command filters are implemented to avoid the influences of disturbances and repetitive derivation, meanwhile solving the problem of unknown control direction caused by nonlinear saturation. The stability of the closed-loop system is proved by the Lyapunov theory, and the controller parameters can be set according to the relevant remarks. Finally, a series of numerical simulations are presented to show the feasibility and validity of the proposed IGC scheme.

Three-dimensional integrated guidance and control for terminal angle constrained attack against ground maneuvering target

2018 ◽  
Vol 233 (7) ◽  
pp. 2393-2412
Author(s):  
Chao Lai ◽  
Weihong Wang ◽  
Zhenghua Liu ◽  
Zheng Ma
Keyword(s):  
Three Dimensional ◽  
Dynamic Surface Control ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Dynamic Surface ◽  
Guidance And Control ◽  
Integrated Guidance And Control ◽  
Nonlinear Extended State Observer ◽  
And Control

A neuro-adaptive fast terminal sliding-mode dynamic surface control method based on a finite-time stable nonlinear extended state observer is applied to integrated guidance and control design for skid-to-turn missile attacking a ground maneuvering target with terminal angle constraints. A three-dimensional integrated guidance and control design model against a maneuvering target for skid-to-turn missile is established without the assumption that the missile velocity vector and the line of sight coincide with each other. The non-singular fast terminal sliding surface is applied to construct the first error surface of dynamic surface control and the first virtual control law is designed to guarantee hitting accuracy with desired terminal angles. The finite-time stable nonlinear extended state observer is designed separately to estimate uncertainties in the system. And the neuro-adaptive technique is applied to compensate estimation errors of nonlinear extended state observer by training a three-layer feedforward neural network online. Synthesizing all of above, a neuro-adaptive fast terminal sliding-mode dynamic surface control based on nonlinear extended state observer is derived on Lyapunov stability theory, which guarantees stability of the system. Finally, the numerical simulations are conducted to demonstrate the effectiveness of the proposed three-dimensional integrated guidance and control scheme.

Integrated guidance and control design considering system uncertainty

2018 ◽  
Vol 233 (6) ◽  
pp. 2278-2290 ◽  
Author(s):  
Tao Chao ◽  
Denghui Zhang ◽  
Songyan Wang ◽  
Ping Ma
Keyword(s):  
Parameter Uncertainty ◽  
Finite Time ◽  
External Disturbance ◽  
Control Design ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Guidance And Control ◽  
Integrated Guidance And Control ◽  
And Control

The hypersonic vehicle has the characteristics of strong coupling, high uncertainty and complex nonlinearity, leading to an unsatisfactory control performance with the traditional design method. In this paper, an integrated guidance and control design approach is proposed to cope with this problem. A time-varying longitudinal integrated guidance and control model is first formulated, and then the overall uncertainty consisting of the un-modeled dynamic, parameter uncertainty and external disturbance is taken into account. A novel finite-time extended state observer is developed to estimate and compensate it in real time. Furthermore, an integrated guidance and control algorithm utilizing back-stepping method and the dynamic inverse is put forward. It has been theoretically proved that the finite-time extended state observer system and the cascade system are globally finite-time stable. Numerical simulation results under different kinds of uncertainty with different amplitude and frequency are presented to illustrate the effectiveness and feasibility of the proposed approach. The proposed integrated guidance and control possesses a better convergence performance and stronger disturbance rejection property in existence of the mismatched uncertainty and parameter uncertainty.

scholarly journals Neural Extended State Observer Based Command Filtered Back-stepping Hypersonic Vehicle Integrated Guidance and Autopilot

2018 ◽  
Author(s):  
Liang Wang ◽  
Ke Peng ◽  
Weihua Zhang ◽  
Donghui Wang
Keyword(s):  
Input Saturation ◽  
State Observer ◽  
Complex Model ◽  
Lyapunov Theory ◽  
Extended State Observer ◽  
Control Surface ◽  
Control Input ◽  
Extended State ◽  
Actuator Dynamics ◽  
Unknown Control Direction

This paper focuses on the integrated guidance and autopilot design with control input saturation in the end-game phase of hypersonic flight. Firstly, uncertain nonlinear integrated guidance and autopilot model is developed with third actuator dynamics, where the control surface deflection has magnitude constraint. Secondly, neural network is implemented in extended state observer (ESO) design, which is used to estimate the complex model uncertainty, nonlinearity and state coupling. Thirdly, a command filtered back-stepping controller is designed with hybrid sliding surfaces to improve the terminal performance. In the process, different command filters are implemented to avoid the influences of disturbances and repetitive derivation, meanwhile solve the problem of unknown control direction caused by saturation. The stability of closed-loop system is proved by Lyapunov theory, and the principles abided by the controller parameters are concluded through the proof. Finally, series of 6-DOF numerical simulations are presented to show the feasibility and validity of the proposed controller.

Sampled-data extended state observer-based backstepping control of two-link flexible manipulator

2019 ◽  
Vol 41 (13) ◽  
pp. 3581-3599 ◽  
Author(s):  
Umesh Kumar Sahu ◽  
Bidyadhar Subudhi ◽  
Dipti Patra
Keyword(s):  
Control Strategies ◽  
Estimation Error ◽  
Experimental Studies ◽  
State Observer ◽  
Lyapunov Theory ◽  
Extended State Observer ◽  
Flexible Manipulator ◽  
Sampled Data ◽  
Extended State ◽  
Model Uncertainties

Currently, space robots such as planetary robots and flexible-link manipulators (FLMs) are finding specific applications to reduce the cost of launching. However, the structural flexible nature of their arms and joints leads to errors in tip positioning owing to tip deflection. The internal model uncertainties and disturbance are the key challenges in the development of control strategies for tip-tracking of FLMs. To deal with these challenges, we design a tip-tracking controller for a two-link flexible manipulator (TLFM) by developing a sampled-data extended state observer (SD-ESO). It is designed to reconstruct uncertain parameters for accurate tip-tracking control of a TLFM. Finally, a backstepping (BS) controller is designed to attenuate the estimation error and other bounded disturbances. Convergence and stability of the proposed control system are investigated by using Lyapunov theory. The benefits (control performance and robustness) of the proposed SD-ESO-based BS controller are compared with other similar approaches by pursuing both simulation and experimental studies. It is observed from the results obtained that SD-ESO-based BS Controller effectively compensates the deviation in tip-tracking performance of TLFM due to non-minimum phase behavior and model uncertainties with an improved transient response.

Attitude stabilization of a rigid spacecraft with actuator delay and fault

2017 ◽  
Vol 40 (7) ◽  
pp. 2340-2351 ◽  
Author(s):  
Alireza Safa ◽  
Mahdi Baradarannia ◽  
Hamed Kharrati ◽  
Sohrab Khanmohammadi
Keyword(s):  
Feedforward Control ◽  
State Observer ◽  
Extended State Observer ◽  
Actuator Faults ◽  
State Variables ◽  
Extended State ◽  
External Disturbances ◽  
Modelling Uncertainties ◽  
Rigid Spacecraft ◽  
And Control

Time delays and actuator faults are phenomena which are frequently encountered in practical control systems and are found to have significant effects on the performance of operation and control. It is shown that even a very small delay may destabilize the spacecraft system. Therefore, besides considering the effects of modelling uncertainties and external disturbances, time delay and actuator fault effects should be properly handled in the spacecraft to achieve reliable and accurate control. This paper describes a simple and effective method to attitude stabilize a spacecraft. The proposed method works by augmenting a backstepping controller with a modified extended state observer-based feedforward control law. The backstepping control is used to compensate for an unknown delay in the inputs, while the feedforward term attenuates the effects of modelling uncertainties, external disturbances and actuator faults. In particular, actuator faults, modelling uncertainties and external disturbances are viewed as unknown nonlinear functions of the measurable state variables, estimated using a modified extended state observer, and then compensated for. The effectiveness of the proposed control algorithm is analytically authenticated and verified via simulation studies.

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