Attitude Tracking Control Of Spacecraft Research Articles

Capturing spacecraft attitude tracking control with angular velocity constraint

Capturing spacecraft attitude tracking control with angular velocity constraint

Robust Attitude Tracking Control for Spacecraft with Quantized Torques

The problem of spacecraft attitude tracking with limited communication to actuators is addressed in this paper. A hysteresis quantizer is employed to quantize the signal of control torque. The hysteresis quantizer requires low communication rate and avoids control chattering. An indirect (nonregressor-based) robust adaptive control scheme is proposed to deal with the effects of quantization error and external disturbances. The proposed control scheme together with the quantizer ensures global boundedness of all the signals in the closed-loop system and enables the attitude tracking error to converge toward a residual.

Attitude tracking with an adaptive sliding mode response to reaction wheel failure

This paper proposes an attitude tracking control for a rigid spacecraft that adapts to two types of faults that commonly occur in reaction wheels: a gain fault and a deviation fault. In its normal operating mode the tracking controller replicates that of a continuous quaternion feedback controller. When a fault occurs in the system the attitude of the spacecraft will deviate from the reference trajectory and will consequently trigger a sliding mode response of the control which introduces robustness. For the proposed control law, we construct a suitable Lyapunov function to prove the closed-loop system is asymptotically stable in the presence of such faults. However, the proposed control is not practically suitable over long periods as the gain on the sliding mode component will always increase unless the sliding surface is exactly zero (in practise this is never the case because of sensor noise). To address this problem a simple adaptive parameter is defined such that it converges to an appropriate upper-limit. Simulations of the attitude dynamics of a spacecraft are undertaken which compares the tracking performance in the presence of a fault with and without the adaptive sliding mode component.

Adaptive Fault-Tolerant Attitude Tracking Control of Spacecraft With Prescribed Performance

The science objectives of a spacecraft mission place stringent performance requirements on the spacecraft attitude control system. However, it remains an open problem how to guarantee consistent control performance necessary to meet these requirements, especially in the event of actuator faults and input saturation. Motivated by this fact, in this paper, we address the problem of attitude tracking control with prescribed performance guarantees for a rigid spacecraft subject to unknown but constant inertia parameters, unexpected disturbances, actuator faults, and input saturation. First, certain performance functions specified a priori by the designer are adopted to impose desired performance metrics on the attitude tracking errors. Then, the original attitude tracking error dynamics with performance constraints is transformed into an equivalent “state-constrained” one whose robust stabilization is shown to be sufficient to solve the stated problem via a novel error transformation. Subsequently, based on the transformed system, an adaptive fault-tolerant controller is derived by incorporating backstepping control, the barrier Lyapunov function, and Nussbaum gains. It is proved that the designed controller is able to guarantee the satisfaction of the prespecified constraints on the transformed errors, as well as the boundedness of all other closed-loop signals, without resorting to a judicious selection of the control parameters. Finally, the effectiveness of the proposed control scheme is evaluated by means of simulation experiments carried out on a microsatellite.

A Nonlinear Second-order Spacecraft Attitude Tracking Control Model for Control System Stabilization

A control model for the direct parameter approach for spacecraft attitude tracking is presented in this paper. First of all, the spacecraft attitude tracking control model is built up by the error equation of the second-order nonlinear quaternion-based attitude system. A problem of control system stabilization is raised based on the control model. Compared with other control models, the second-order can offer the advantages of noapproximation and clear control states. The basic spacecraft control model has to focus on to the two variables which are angular rate and attitude quaternion, however, the new attitude control problem is only with respect to one variable which is the spacecraft attitude quaternion. Therefore, the second-order model is simpler and clear than basic first-order model.

Dynamic Scaling–Based Noncertainty-Equivalent Adaptive Spacecraft Attitude Tracking Control

AbstractThis paper presents a novel dynamic scaling–based non-certainty-equivalent adaptive control method for the attitude tracking control problem of spacecraft in the presence of inertia uncerta...

Attitude tracking control of a flexible spacecraft under angular velocity constraints

ABSTRACTIn this paper, a new technique is proposed for trajectory tracking of a flexible spacecraft subject to angular velocity constraints. The problem is addressed using an output to input saturation transformation (OIST) which converts the prescribed bounds into state-dependent saturations on the control input signals. It is shown that an interval observer can be used in combination with the OIST technique to ensure that the constraints remain satisfied despite unmeasured flexible modes and torque disturbances. Some realistic simulations conclude the paper and validate our approach.

Disturbance observer-based fault-tolerant attitude tracking control for rigid spacecraft with finite-time convergence

In this paper, finite-time fault-tolerant attitude tracking control is investigated for rigid spacecraft system with external disturbances, inertia uncertainties and actuator faults. A novel finite-time disturbance observer combined with a nonsingular terminal sliding mode controller is developed. Using an equivalent output error injection approach, a finite-time disturbance observer with simple structure is firstly designed to estimate lumped uncertainty. Then, to remove the requirement of prior knowledge about lumped uncertainty and reduce chattering, an adaptive finite-time disturbance observer is further proposed, and the estimations converge to the neighborhood of the true values. Based on the designed observer, a unified finite-time attitude controller is obtained automatically. Finally, both additive and multiplicative faults are considered for simulations and the results illustrate the great fault-tolerant capability of the proposed scheme.

Disturbance observer-based second order sliding mode attitude tracking control for flexible spacecraft

Disturbance observer-based second order sliding mode attitude tracking control for flexible spacecraft

Attitude tracking control of flexible spacecraft with large amplitude slosh

This paper is focused on attitude tracking control of a spacecraft that is equipped with flexible appendage and partially filled liquid propellant tank. The large amplitude liquid slosh is included by using a moving pulsating ball model that is further improved to estimate the settling location of liquid in microgravity or a zero-g environment. The flexible appendage is modelled as a three-dimensional Bernoulli–Euler beam, and the assumed modal method is employed. A hybrid controller that combines sliding mode control with an adaptive algorithm is designed for spacecraft to perform attitude tracking. The proposed controller has proved to be asymptotically stable. A nonlinear model for the overall coupled system including spacecraft attitude dynamics, liquid slosh, structural vibration and control action is established. Numerical simulation results are presented to show the dynamic behaviors of the coupled system and to verify the effectiveness of the control approach when the spacecraft undergoes the disturbance produced by large amplitude slosh and appendage vibration. Lastly, the designed adaptive algorithm is found to be effective to improve the precision of attitude tracking.

A direct parametric approach to spacecraft attitude tracking control

Through the direct parameter approach, a solution for spacecraft attitude tracking is presented. First of all, the spacecraft attitude tracking control model is built up by the error equation of the second-order nonlinear quaternion-based attitude system. Based on the control model, a suitable controller is designed by the direct parameter approach. Compared with other control strategies, the direct parameter approach can offer all degrees of freedom for the controller to satisfy the requirements for system properties and turn the original nonlinear system into closed-loop linear system. Furthermore, this paper optimizes the controller according to the robustness, limitation of controller output and closed-loop eigenvalue sensitivity. Putting the controller into the original system, the state response of the closed-loop system and the output of controller are plotted in Matlab to verify the availability and robustness of the controller. Therefore, the controlled spacecraft can achieve the goal of tracking on the mobile target with the external disturbance torque.

Adaptive output feedback integral sliding mode attitude tracking control of spacecraft without unwinding

This article studies an output feedback attitude tracking control problem for rigid spacecraft in the presence of parameter uncertainties and external disturbances. First, an anti-unwinding attitude control law is designed using the integral sliding mode control technique to achieve accurate tracking responses and robustness against inertia uncertainties and external disturbances. Next, the derived control law is combined with a suitable tuning law to relax the knowledge about the bounds of uncertainties and disturbances. The stability results are rigorously proved using the Lyapunov stability theory. In addition, a new finite-time sliding mode observer is developed to estimate the first time derivative of attitude. A new adaptive output feedback attitude controller is designed based on the estimated results, and angular velocity measurements are not required in the design process. A Lyapunov-based analysis is provided to demonstrate the uniformly ultimately bounded stability of the observer errors. Numerical simulations are given to illustrate the effectiveness of the proposed control method.

Robust Spacecraft Attitude Tracking Control with Actuator Misalignments

Robust Spacecraft Attitude Tracking Control with Actuator Misalignments

Finite-time sliding mode attitude control for rigid spacecraft without angular velocity measurement

The continuous finite-time nonsingular terminal sliding mode (NTSM) attitude tracking control for rigid spacecraft is investigated. Firstly, a finite-time attitude controller combined with a new adaptive update law is designed. Different from existing controllers, the proposed controller is inherently continuous and the chattering is effectively reduced. Then, an adaptive model-free finite-time state observer (AMFFTSO) and an angular velocity calculation algorithm (AVCA) are developed to estimate the unknown angular velocity. The unique feature of the proposed method is that the finite-time estimation of angular velocity is achieved and no prior knowledge of quaternion derivative upper bound is needed. Next, based on the estimated angular velocity, a finite-time attitude controller with only attitude measurement is developed. Finally, some simulations are presented and the effectiveness of the proposed control scheme is illustrated.

Finite-Time Disturbance Observer Design and Attitude Tracking Control of a Rigid Spacecraft

This paper considers the problem of finite-time disturbance observer (FTDO) design and the problem of FTDO based finite-time control for systems subject to nonvanishing disturbances. First of all, based on the homogeneous systems theory and saturation technique, a continuous FTDO design approach is proposed. Then, by using the proposed FTDO design approach, a FTDO is constructed to estimate the disturbances that exist in a rigid spacecraft system. Furthermore, based on a baseline finite-time control law and a feedforward compensation term produced by the FTDO, a composite controller is constructed for the rigid spacecraft system. It is shown that the proposed composite controller will render the rigid spacecraft track the desired attitude trajectory in a finite-time. Simulation results are included to demonstrate the effectiveness of the proposed control approach.

Fault-tolerant sliding mode attitude tracking control for flexible spacecraft with disturbance and modeling uncertainty

This article investigates the attitude tracking control problem for a class of flexible spacecraft with a redundant four reaction wheels’ setting. In this study, inertia uncertainties, external disturbance, wheel torque saturation, and configuration misalignment are taken into account simultaneously. Two types of sliding mode controllers are presented to solve this design problem. First, supposing the norm upper bound of external disturbances, bounds of inertia, and input uncertainties are available, a terminal sliding mode attitude tracking control strategy is developed, where the controller and steering laws are synthesized together. Second, supposing these norm upper bounds are unavailable, an adaptive control law is designed to cope with attitude tracking problem. Under both control schemes, the system trajectory can be ensured to arrive on the specified sliding surface in finite time. Finally, an illustrative example is given to verify the effectiveness of the proposed attitude tracking control methodologies.

Finite‐time attitude tracking control for rigid spacecraft with control input constraints

This study considers the problem of attitude tracking control for rigid spacecraft subject to control input saturation. To address this problem, a smooth model is first proposed to describe the input magnitude saturation. The output of the model is always in agreement with the constraints imposed by the actuators. Then, two finite-time attitude tracking control schemes are designed based on the model derived here and the homogeneous method. The measurement of angular velocity is required in the first scheme while it is relaxed in the second one. Finally, the effectiveness of the proposed control laws is illustrated by numerical simulations.

Bounded finite-time attitude tracking control for rigid spacecraft via output feedback

This paper investigates a velocity-free finite-time attitude control scheme for a rigid spacecraft with actuator saturation and external disturbances. Initially, a finite-time observer is designed to compensate the unknown angular velocity information. With the estimated values, a finite-time controller is further developed under which the time-varying reference attitude trajectory can be tracked precisely. Moreover, input saturation problem is solved by adaptive method. Rigorous Lyapunov-based analysis shows that the states of the closed-loop system converge to a small neighborhood of the origin in finite time. Finally, the dynamic performance of attitude control system is presented by numerical simulation examples and the superiority of the finite-time control scheme is verified.

Finite-time attitude tracking control for spacecraft without angular velocity measurements

Finite-time attitude tracking control for spacecraft without angular velocity measurements

Robust adaptive spacecraft attitude tracking control based on similar skew-symmetric structure

This paper addresses robust adaptive attitude tracking control for spacecrafts with unknown inertia parameters and bounded external disturbances. The similar skew-symmetric structure is chosen as the desired structure for the closed loop system when there exist no uncertainties. Based on this idea, a backstepping scheme is proposed to design the controller, and adaptive compensation and robust compensation are introduced to deal with the uncertainty of the inertia parameters and the external disturbances respectively. Theoretical analysis shows that fast response and high tracking precision can both be obtained by regulating the related parameters in the proposed controller. Simulation results are provided to demonstrate the effectiveness of the proposed attitude tracking control algorithm.