Attitude Tracking Control Of Spacecraft Research Articles

Minimum-learning-parameter-based anti-unwinding attitude tracking control for spacecraft with unknown inertia parameters

This paper investigates the finite-time attitude tracking control problem for rigid spacecraft exposed to the external disturbance and unknown inertial parameters. Initially, the basic controller is developed under the assumption that the inertial parameters and the upper bound of external disturbances are available to the designer. However, this assumption is inapplicable in practical applications. Considering this limitation, adaptive laws and Minimum-learning- parameter (MLP) algorithm are employed in the second controller to estimate the unknown system dynamics. Finite-time stability for tracking errors is achievable under the proposed methods. Though theoretical analysis and numerical simulations, effectiveness of the proposed controllers has been validated.

Robust Adaptive Iterative Learning Control for High-Precision Attitude Tracking of Spacecraft

AbstractIn this paper, a robust adaptive iterative learning control (ILC) scheme is developed for the high-precision attitude tracking control of spacecraft in the presence of parametric uncertaint...

Observer-based fault-tolerant attitude tracking control for rigid spacecraft with actuator saturation and faults

This work mainly addresses the attitude tracking problem for rigid spacecraft subject to external disturbances, actuator saturation and faults. Firstly, a finite-time prescribed performance function (FTPPF) is defined to limit the tracking errors of original system into the boundary constraints and converge into a small residual set around zero within the preassigned time. An error transformation is employed to transform the constrained control system into an unconstraint one to simplify the relevant controller design. With the aid of the hyperbolic tangent function, the actuator saturation is approximated, and the approximation error is included into the external disturbances to be restrained. Then, a linear extended state observer (LESO) is developed to address the synthetic disturbances mentioned above with fewer tuning parameters. Wherein, the nominal matrix replaces the actual input gains is employed in the LESO design to avoid the singularity in disturbance rejection resulted from saturation approximation. Furthermore, an observer-based fault-tolerant tracking controller is derived to stabilize the attitude tracking error system and realize the disturbance compensation. Compared with the existing methods based on neutral networks (NNs) or fuzzy approximations, the developed scheme can achieve simultaneous estimations of multiple disturbances with simpler design. Meanwhile, the disadvantage that the NNs and fuzzy approximations are only effective on some compact sets is avoided. Finally, numerical simulations and analyses are employed to verify the superiority and robustness of the proposed method.

Adaptive fault-tolerant control for hybrid attitude tracking control system with quantized control torque and measurement

In this paper, the problem of fault tolerant control for spacecraft attitude tracking control system in the presence of actuator faults/failures, quantized control torque and measurement, uncertain inertial matrix and external disturbances is taken into account. The dynamical uniform quantizers are developed to quantize the signals of control torque and measurement, which can reduce the data transmission rate. In combination with the CA and FTC technique, a robust adaptive fault tolerant control scheme is proposed to cope with the effects of quantization errors in control torque and measurement, the unknown actuator faults/failures, uncertain inertial matrix and external disturbances. The developed control strategy combined with quantized control torque and measurement can guarantee the stability of overall closed-loop system and achieve satisfactory attitude tracking performance. Finally, simulation results are presented to verify the effectiveness of the proposed methods.

Adaptive Neural Network Model-based Event-triggered Attitude Tracking Control for Spacecraft

This article investigates the problem of attitude tracking control for spacecraft with limited communication, unknown system parameters, and external disturbances. An adaptive control scheme with an event-triggered mechanism (ETM) is proposed to alleviate the communication burden. Radial Basis Function Neural Network (RBFNN) estimation model is developed to provide the input signals for the control module in this control scheme. Estimated attitude information of the spacecraft generated from the estimation model will only be transmitted to the control module at the instants when the ETM is violated. The neural network (NN) and the estimation model will be updated complying with an adaptive algorithm at the discrete triggering instants. It’s substantiated that all the errors of attitude tracking converge towards corresponding residuals and there are no accumulated triggering instants. Numerical simulation also demonstrates the effectiveness of the proposed control method.

Finite-time fault tolerant attitude tracking control of spacecraft using robust nonlinear disturbance observer with anti-unwinding approach

This paper investigates the composite control scheme of robust nonlinear disturbance observer (RNDO) with adaptive non-singular fast terminal sliding mode control (NSFTSMC) technique for the attitude tracking of rigid spacecraft. The spacecraft is subjected to the parametric uncertainties, external disturbances, and actuator faults. The proposed RNDO estimates the overall lumped disturbance (combination of faults and disturbances) in finite-time. Moreover, it improves the disturbance rejection property of the composite control by feedforward compensation. An adaptive law is also employed in the composite control to enhance the robustness against the cases where RNDO takes some time for estimation, e.g., when there is a sudden change in the lumped disturbance. Further, the proposed controller is also enriched with anti-unwinding property to tackle the problem of unwinding in the quaternion based attitude representation. The stability analysis of the closed-loop system under the composite control scheme guarantees the finite-time convergence of relative state variables using the Lyapunov stability theory. The simulation analysis with the comparative study illustrates the effectiveness of the proposed strategy in terms of better disturbance rejection ability, higher accuracy, faster convergence, and better steady-state performance.

Reaction wheel fault‐tolerant finite‐time control for spacecraft attitude tracking without unwinding

SummaryThis article proposes fault‐tolerant finite‐time attitude tracking control of a rigid spacecraft actuated by four reaction wheels without unwinding problem in the presence of external disturbances, uncertain inertia parameter, and actuator faults. First, a novel antiunwinding finite‐time attitude tracking control law is derived with a designed control signal which works within a known actuator‐magnitude constraint using a continuous nonsingular fast terminal sliding mode (NFTSM) concept. Second, a finite‐time disturbance observer (FTDO) is introduced to estimate a lumped disturbance due to external disturbances, uncertain inertia parameter, actuator faults, and input saturation. Third, a composite controller is developed which consists of a feedback control based on the continuous NFTSM method and compensation term based on the FTDO. The global finite‐time stability is proved using Lyapunov stability theory. Moreover, the singularity and unwinding phenomenon are avoided. Simulation results are conducted under actuator constraints in the presence of external disturbances, inertia uncertainty, and actuator faults and results are illustrated to show the effectiveness of the proposed method. In addition, to show the superiority of the proposed control method over the recently reported control methods, comparative analysis is also presented.

Distributed Finite-Time Coordinated Attitude Tracking Control for Multiple Spacecraft with Actuator Saturation

For multi-spacecraft with actuator saturation, inertia uncertainties and external disturbances, a distributed finite-time coordinated attitude tracking control problem for the spacecraft with the communication topology containing fewer information paths is investigated. Aiming at reducing the communication path, a class of distributed finite-time state observers is designed. To speed up the convergence rate of the multiple spacecraft system, a fast nonsingular terminal sliding mode function is proposed. Moreover, an adaptive control term is proposed to suppress the impact of the external state-dependent disturbances and unknown time-varying inertia uncertainties. Further considering the actuator saturation owing to its physical limitations, a saturation function is designed. With the distributed finite-time observers, the fast nonsingular terminal sliding mode function, the adaptive update law and the saturation function, a distributed finite-time coordinated attitude tracking saturation controller is designed. Using the proposed controller, the follower can synchronize with the common leader with time-varying trajectory in finite time. Simulation results demonstrate the effectiveness of the designed controller.

Model-Free Prescribed Performance Control for Spacecraft Attitude Tracking

The problem of flexible spacecraft attitude tracking control with guaranteeing the prescribed performance is investigated. First, the Lagrangian model of the flexible spacecraft is derived. Then, a model-free control law is proposed, in which information of spacecraft and flexible appendage is not required. The proposed control law is able to guarantee the prescribed transient and steady-state behavior for both attitude and angular velocity errors in the presence of bounded external disturbances. The stability of the resulting closed-loop system is guaranteed by the Lyapunov approach. Two special forms of the proposed control law are subsequently obtained. The effectiveness of both complete form and special forms of the proposed control law is verified by numerical simulations. Since the modal information of spacecraft is not involved in the control design, the proposed control law can also be used for rigid spacecraft.

Fixed‐time attitude tracking control for rigid spacecraft

This study addresses the fixed-time attitude tracking for rigid spacecraft with inertia uncertainties and external disturbances. Firstly, a new fixed-time sliding surface based on the bi-limit homogeneous theory is proposed. Secondly, a non-singular sliding mode control is designed to solve the robust fixed-time attitude tracking problem. It is proved that the proposed control can ensure that the sliding surface and attitude tracking errors converge to zero within fixed time. The appealing features of the proposed control are exact fixed-time tracking stability with fast convergence, high precision, strong robustness and easy implementation. Simulations verify the effectiveness and improved performance of the proposed approach.

Fixed‐time attitude tracking control for spacecraft based on adding power integrator technique

SummaryIn this article, the fixed‐time attitude tracking problem for rigid spacecraft is investigated based on the adding‐a‐power‐integrator control technique. First, a fixed‐time attitude tracking controller is designed to guarantee fixed‐time convergence of tracking errors. Then, by considering the presence of random disturbance and actuator faults, an adaptive fault‐tolerant attitude tracking controller is designed to guarantee tracking errors converge to a residual set of zero in a fixed time. The complete bounds on settling time are derived independently of initial conditions. The simulation results illustrate the highly precise and robust attitude control performance obtained by using the proposed controllers.

Attitude Tracking Control for Spacecraft With Fixed-Time Convergence

This work mainly discusses the attitude tracking issue of spacecraft which ensures fixed-time convergence property. To achieve this, the attitude tracking dynamics model is first established. Then a novel sliding manifold is constructed based on the presented sufficient condition of fixed-time stability. Moreover, a sliding mode controller is developed to ensure fixed-time convergence. Also, the closed-loop fixed-time stability of the whole system is proven to be guaranteed based on Lyapunov stability theory. Finally, the simulation results are provided to verify the superior performance of the designed controller.

Fixed-time attitude tracking control for rigid spacecraft

The problem of fixed-time attitude tracking control for rigid spacecraft is addressed in this paper. Based on the backstepping technique and the idea of “adding a power integrator”, a novel fixed-time attitude control law is proposed. The control scheme derived here is continuous and nonsingular, and can guarantee the attitude tracking errors converging to the origin within fixed time if there are no uncertainties and measurement noises and to a small bounded region around zero if there are uncertainties and measurement noises. Finally, numerical simulations are presented to demonstrate the effectiveness of the proposed scheme.

Neural-Network-Based Adaptive Event-triggered Control for Spacecraft Attitude Tracking.

The problem of attitude tracking control for spacecraft with limited communication rate is addressed in this article. To reduce the communication burden, an adaptive event-triggered control scheme is proposed. In the control scheme, only the sampling states at the event-triggering instants are sent to the control module, which can considerably decrease the data transmission rate. To address the inertia uncertainties and external disturbances, a radial basis function neural network (NN) is introduced. The bound of the uncertainties and disturbances is estimated for the proposed control scheme, which can simplify the NN and reduce the computation. Since the event-triggered error signal is discontinuous due to the event-triggered mechanism, the closed-loop system is formulated as an impulsive dynamical system to obtain the stability properties of the system. Finally, simulation results are given to demonstrate the effectiveness of the proposed control scheme.

A fault-tolerant attitude tracking control of spacecraft using an anti-unwinding robust nonlinear disturbance observer

This paper investigates the application of an integral sliding mode control with a robust nonlinear disturbance observer to obtain an anti-unwinding spacecraft attitude tracking response with robustness against external disturbances, inertia matrix uncertainties, and actuator faults. In the controller design, external disturbances, uncertainties, and actuator faults are lumped together and estimated by the robust nonlinear disturbance observer. The proposed robust nonlinear disturbance observer guarantees the convergence of estimated lumped disturbance error to origin in finite time. The estimated disturbance is then used in the controller as a feed-forward compensator. Further, an adaptive law is also incorporated in the proposed controller to ensure additional robustness. The stability of the overall system and anti-unwinding characteristic are proved using the Lyapunov stability theory. Finally, numerical simulation analysis is performed in the presence of all the sources of lumped disturbances. It is observed that the proposed control strategy is ensuring higher accuracy, good steady-state precision, and eliminates the unwinding phenomenon.

Fixed-Time Attitude Tracking Control for Rigid Spacecraft Without Angular Velocity Measurements

This article considers the problem of velocity-free fixed-time attitude tracking control for rigid spacecraft. With the help of the homogeneity theorem, a semiglobal observer is introduced to estimate the unmeasured angular velocities within fixed time. Then, a velocity-free attitude tracking controller is designed to make the spacecraft attitude track a time-varying reference signal in finite time, which can be up bounded by a fixed number regardless of the initial conditions. Finally, numerical examples are provided to illustrate the efficiency of the present control scheme.

Fault-tolerant attitude tracking control of combined spacecraft with reaction wheels under prescribed performance

Capture and control of a failed spacecraft can be achieved by a space manipulator installed in a service spacecraft. After this target has been captured, the combined spacecraft must be controlled in a prescribed way. The attitude attacking control of the combined spacecraft system is one major challenge since the mass properties of the whole spacecraft system and configuration matrix of the reaction wheels change, especially when actuator fault occurs. In this paper, a nonlinear disturbance-observer-based fault-tolerant attitude control scheme is developed for the combined spacecraft with prescribed performance. Firstly, an approach is given to reconstruct the attitude tracking dynamics of the combined spacecraft with reaction wheels. Then, a fault-tolerant controller, based on dynamic surface method and nonlinear extended state observer, is developed whereby performance in the light of convergence time, stability and accuracy with inertia uncertainty, actuator saturation and external disturbance can be prescribed. Finally, comparative simulations in both actuator faults and actuator fault-free cases are conducted to show the superiority of the developed attitude tracking control method.

Adaptive Fixed-Time Attitude Tracking Control for Rigid Spacecraft With Actuator Faults

This paper investigates fixed-time attitude tracking maneuver of rigid spacecraft in the presence of actuator faults, external disturbances, and inertia uncertainties. First, a fast finite-time stable system is investigated in the sense of fixed-time concept. Then, a nonlinear observer is designed to estimate the information of the lumped uncertainties, and this observer, integral sliding mode and geometric homogeneity are used to formulate one attitude controller, which can guarantee attitude tracking errors can be stabilized to the origin. Second, another adaptive controller is presented to steer attitude tracking errors to the equilibrium point. Lyapunov techniques are implemented to ensure the fixed-time stability of the closed-loop system. Finally, numerical simulations are carried out to demonstrate the performance of the proposed controllers.

Appointed-time fault-tolerant attitude tracking control of spacecraft with double-level guaranteed performance bounds

This paper investigates the issue of appointed-time fault-tolerant control for spacecraft attitude tracking in the presence of external disturbances and actuator faults. By “appointed-time”, it is meant that the maneuver completion time can be preassigned offline according to mission-oriented demands. Firstly, appointed-time performance functions are tactfully developed, which seek to impose a priori desired performance metrics on both the attitude and angular velocity errors (double-level). After that, an adaptive fault-tolerant controller is derived using structurally simple error transformations in combination of asymmetric barrier Lyapunov functions. Based on Lyapunov synthesis, it is then shown that the derived controller is capable of guaranteeing the boundedness of all the signals in the closed-loop system, and of achieving double-level guaranteed performance bounds for output tracking errors, despite the presence of external disturbances and actuator faults. In particular, the attitude tracking can be accomplished in a user-appointed time without resorting to judicious control parameters selection. Finally, simulation results are presented to illustrate the efficacy of the proposed control scheme.

Dynamic infinity‐norm constrained control allocation for attitude tracking control of overactuated combined spacecraft

In this study, a dynamic L ∞ (infinity-norm) constrained control allocation scheme is designed for attitude tracking control of combined spacecraft with inertia uncertainties and external disturbances. A disturbance-observer-based constrained backstepping control law is developed to generate the control command signals considering non-symmetric constraints on control input, where the lumped disturbance containing inertia uncertainties and external disturbances is compensated by the output of stable non-linear disturbance observer. The control scheme can guarantee that the attitude and angular velocity tracking error converge to small neighbourhood of zero by appropriately tuning the control parameters. With the consideration of physical amplitude and rate constraints on actuators, the dynamic L ∞ constrained control allocation problem is solved by linear programming technique. Numerical examples demonstrate the effectiveness of the proposed disturbance-observer-based constrained backstepping control method and the dynamic L ∞ constrained control allocation algorithm.