scholarly journals Adaptive Backstepping Attitude Control Law with L2-Gain Performance for Flexible Spacecraft

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Rui-Qi Dong ◽  
Yu-Yao Wu ◽  
Ying Zhang ◽  
Ai-Guo Wu

In this paper, an observer-based adaptive backstepping attitude maneuver controller (briefly, OBABC) for flexible spacecraft is presented. First, an observer is constructed to estimate the flexible modal variables. Based on the proposed observer, a backstepping control law is presented for the case where the inertia matrix is known. Further, an adaptive law is developed to estimate the unknown parameters of the inertia matrix of the flexible spacecraft. By utilizing Lyapunov theory, the proposed OBABC law can guarantee the asymptotical convergence of the closed-loop system in the presence of the external disturbance, incorporating with the L2-gain performance criterion constraint. Simulation results show that the attitude maneuver can be achieved by the proposed observer-based adaptive backstepping attitude control law.

Author(s):  
Yabo Hu ◽  
Baolin Wu ◽  
Yunhai Geng ◽  
Yunhua Wu

In this paper, a trajectory optimization method for generating smooth and approximate time-optimal attitude maneuver trajectories of flexible spacecraft is proposed. Smooth attitude maneuver is highly desirable for flexible spacecraft, since vibration of flexible appendices can be suppressed. In order to obtain smooth and approximate time-optimal attitude trajectory, a novel objective function composed of two terms is developed in the problem of trajectory optimization: the first term is proportional to the total maneuver time and the other one is proportional to the integral of the squared control torque derivatives. This latter term ensures that the generated trajectory is smooth. The degree of the smoothness of the trajectory can be adjusted by the weights of these two terms. The constraints on angular velocity and angular acceleration are considered in the proposed method. A closed-loop tracking control law is then employed to track the optimized reference attitude trajectory. Numerical simulations and frequency domain analysis show that the proposed method can generate smoother trajectory than traditional time-optimal methods, which leads to less vibration during attitude maneuver of a flexible spacecraft.


Author(s):  
Haihui Long ◽  
Jiankang Zhao

In this paper, robust constrained fault-tolerant attitude controllers are proposed for flexible spacecraft subjected to external disturbance, model uncertainty, input saturation, and actuator faults. Three types of actuator faults of spacecraft, i.e. partial loss of effectiveness, stuck fault, and outage fault, are modeled explicitly. To handle these actuator faults, a significant lemma is proposed and rigorous proof is conducted at length. By introducing two e-modification parameter update laws to online estimate the unknown parameters caused by actuator faults, constrained fault-tolerant attitude controllers of flexible spacecraft are designed to accommodate these faults without the need of any prior information about these faults. The proposed controllers can achieve the disturbance attenuation in the sense of [Formula: see text] gain. The effectiveness of the proposed algorithms is assessed through numerical simulations.


2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Jiawei Tao ◽  
Tao Zhang ◽  
Yongfang Nie

A robust adaptive constrained control scheme is proposed for flexible spacecraft attitude maneuver and vibration suppression, in which multiple constraints are simultaneously considered, such as uncertain inertia parameters, external disturbance, unmeasured elastic vibration, actuator saturation, and even actuator misalignment. More specifically, a novel path planning scheme based on quintic polynomial transition is firstly developed to realize smooth acceleration variate and therefore decrease the vibration of flexible appendages. Secondly, an elastic modal estimator is employed to estimate the unmeasured variables, such as the modal position and velocity. Thirdly, an adaptive updating technique is used to spare the extra knowledge of system parameters and the bound of the external disturbance. In addition, an auxiliary design system is constructed to address the actuator saturation problem, and a compensation term is synthesized and integrated into the controller to handle the actuator misalignment. Finally, overall system stabilization is proved within the framework of Lyapunov theory, and numerical simulation results are presented to illustrate the effectiveness of the proposed scheme.


Author(s):  
Chuan Lian Zhang ◽  
Kil To Chong

<span>In this paper, one nonlinear hybrid controller, based on backstepping and sliding mode, was developed and applied to a quadrotor for waypoint navigation application. After dynamics modeling, the whole quadrotor dynamics system could be divided into two subsystems: rotational system and translational system. Backstepping control law was derived for attitude control whereas sliding mode control law was developed for position control. By using Lyapunov theory and satisfying sliding stable rules, the convergence of system could be guaranteed. A nonlinear equation was proposed to solve the under-actuated problem. To validate the effectiveness of proposed nonlinear hybrid controller, waypoint navigation simulation was performed on the nonlinear hybrid controller. Results showed that the nonlinear hybrid controller finished waypoint navigation successfully.</span>


2016 ◽  
Vol 33 (1) ◽  
pp. 125-136 ◽  
Author(s):  
M.-L. Deng ◽  
B.-Z. Yue

AbstractThis paper focuses on the attitude dynamics and control of liquid filled spacecraft, and the large amplitude fuel slosh dynamics is included by using an improved moving pulsating ball model. The moving pulsating ball model is an equivalent mechanical model that is capable of imitating the whole liquid reorientation process, specifically for the occurrence of large amplitude slosh. This model is improved by incorporating a static capillary force and an effective mass factor. The improvements on this model are validated with previously published experiment results. The spacecraft attitude maneuver is implemented by the momentum transfer technique, and the feedback control strategy is designed based on Lyapunov theory. The effects of liquid viscosity, tank location and desired steady time on sloshing torque and control torque are investigated. The attitude control strategy applied in this paper is proved to be applicable for the coupled liquid filled spacecraft system. The obtained conclusions are useful to aid in liquid filled spacecraft overall design.


2016 ◽  
Vol 9 (1) ◽  
pp. 61-73 ◽  
Author(s):  
Romulus Lungu ◽  
Mihai Lungu

The paper focuses on two automatic systems for the attitude and position’s control of the microaerial vehicles—insect type by using a nonlinear dynamic model, which describes the motion of microaerial vehicles with respect to the Earth tied frame. The attitude control is adaptive type, with the estimation of the inertia moments’ matrix and of the dynamic damping coefficients’ matrix in two variants: by means of the attitude vector or by using the quaternion vector. The new resulting control architectures use a vector for the control of the microaerial vehicles’ attitude, a proportional-derivative linear dynamic compensator, an error vector (whose elements are the estimated deviations of the inertia moments and dynamic damping coefficients with respect to the real ones), and the Lyapunov theory. In the two variants of the adaptive control, the control law is represented by the command aerodynamic moments and the wing rotation’s command vector, respectively; the control law for the microaerial vehicle position’s control is deduced in the same way. The two obtained control systems are validated by complex numerical simulations.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bing Hua ◽  
Nan Zhang ◽  
Mohong Zheng

Purpose Taking into account the factors of torque saturation and angular velocity limitation during the actual attitude maneuver of the satellite, as well as the difficulty of parameter selection in the design of attitude control algorithm, the purpose of this paper is to propose a satellite magnetic/momentum wheel attitude control technology based on pigeon-inspired optimization (PIO) cascade-saturation control law optimization. Design/methodology/approach The optimal parameters are calculated through the PIO algorithm and then the parameters are used in the cascade-saturation control law to control the actuator findings-mathematical simulation results show that the cascade-saturation control law optimization algorithm based on PIO can shorten the adjustment time and reduce the steady-state error. Findings Compared with traditional attitude maneuver control with given parameters, the PIO algorithm can accurately calculate the optimal parameters needed to achieve the control objective and this method has better stability and higher accuracy. Originality/value The innovative PIO algorithm is used to calculate the optimal parameters, and the cascade saturation control law is used to control the actuator. Compared with the traditional algorithm, the regulation time is shortened and the steady-state error is reduced.


2011 ◽  
Vol 467-469 ◽  
pp. 1116-1121
Author(s):  
Hai Yan Li ◽  
Yun An Hu

For the model of induction motors(IMs) in field-oriented coordinates, a novel design method of controller is proposed, which combining block adaptive backstepping method with neural networks, introducing PD-type feedback, and making use of the diagonal feature of the unknown control matrix and the boundedness of its derivative. The control law and parameter updating law are derived using Lyapunov theory, which guarantees the stability of the whole system. The proposed approach can track the rotor speed and flux reference signals under parameter uncertainties. Simulation results show the effectiveness of the proposed approach.


2011 ◽  
Vol 268-270 ◽  
pp. 528-533
Author(s):  
Hai Yan Li ◽  
Yun An Hu

Based on the model of induction motors in field-oriented coordinates, a block adaptive backstepping method is used to design a controller for induction motor. The control law and parameter updating law are derived using Lyapunov theory, which guarantees the stability of the whole system. The proposed approach can track the rotor speed and flux reference signals under parameter and load uncertainties. Simulation results show the effectiveness of the proposed approach.


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