Attitude Control System Design Research Articles

A novel smooth quaternion-based attitude tracking control

The fact that two antipodal points in the quaternion characterize the same physical attitude depicts that the design of the global attitude control system is uneasy. This study deals with a smooth quaternion-based attitude tracking control system that is composed of a differential equation known as the augmented dynamical system. The augmented dynamical system plays such an important role that it is possible to conduct a novel perspective on viewing the set containing all possible motions as not a manifold. Therefore, the topological obstruction does not exist. The designed attitude tracking control system has a guarantee of stability in the large within a set containing all possible motions. It is able to avoid the unwinding phenomenon, and it is noise-induced chattering-free since there is no discontinuity. Furthermore, we show that the smooth attitude tracking control system has an integral input-to-state stability (iISS) guarantee in the presence of uncertainties in the moment of inertia and environmental disturbance. Simulations carried out show the effectiveness of the designed attitude tracking control system.

Nonlinear modeling and validation of spacecraft dynamics for space-based gravitational wave detector

The development of the Drag-Free and Attitude Control System is crucial for space-based gravitational wave detectors. The Drag-Free and Attitude Control System includes for spacecraft attitude control, drag-free control, moving optical subassemblies pointing control, and test masses electrostatic control during multiple phases of the mission lifetime. An accurate model of the spacecraft dynamics model is not only a precondition for the control design of Drag-Free and Attitude Control System, but also can serve as a valuable reference to assess the noise budget of gravitational wave detectors. This paper presents a generic, nonlinear mathematical model that describes the multi-body dynamics for the gravitational wave detectors. The model fully considers the couplings between the bodies involved, with a particular focus on the impact of the moving optical subassemblies on the spacecraft attitude. Additionally, a corresponding reduced model for the control design of the science mode is divided. Both models are validated numerically by Monte Carlo simulations and motion analysis, respectively.

Coaxial Helicopter Attitude Control System Design by Advanced Model Predictive Control under Disturbance

This paper proposes an advanced model predictive control (MPC) scheme for the attitude tracking of coaxial drones under wind disturbances. Unlike most existing MPC setups, this scheme embeds steady-input, steady-output, and steady-state conditions into the optimization problem as decision variables. Consequently, the coaxial drone’s attitude can slide along the state manifold composed of a series of steady states. This allows it to move toward the optimal reachable equilibrium. To address disturbances that are difficult to accurately measure, an extended state observer is employed to estimate the disturbances in the prediction model. This design ensures that the algorithm maintains recursive stability even in the presence of disturbances. Finally, numerical simulations and flight tests are provided to confirm the effectiveness of the proposed method through comparison with other control algorithms.

Innovative design and development of attitude determination and control systems for CubeSats with reaction wheels

Attitude determination and control systems (ADCS) represent a critical facet of CubeSat missions, orchestrating the precise orientation and stabilization of these small satellites in the space environment. This paper presents a comprehensive design and development of an ADCS tailored for CubeSats, harnessing a reaction wheel system to deliver a cost-effective and dependable solution for small satellite applications. The research begins by elucidating the requisites and specifications for the ADCS and then delves into the design phase, complemented by intricate modelling and simulation employing MATLAB Simulink and the Webots Simulator. The results of this study underscore the exceptional performance of the proposed ADCS configuration, leveraging the reaction wheel model. This system demonstrates an unparalleled capacity to achieve precise and controlled attitude adjustments, well within the defined parameters. Furthermore, this research underscores the pivotal role played by efficient system design, meticulous simulation, and rigorous testing in the triumphant implementation of ADCS, greatly enhancing CubeSat missions and their contributions to the realm of space exploration and technology innovation. This comprehensive approach to the design and testing of an ADCS for CubeSats ensures that these diminutive satellites continue to make significant strides in space missions, paving the way for an exciting future of space research and technology development.

Design of anti-unwinding attitude coupling controller for flexible spacecraft using positive position feedback control

Flexible vibration has a great impact on flexible spacecraft attitude control, which will reduce the pointing accuracy of the spacecraft platform and bring severe challenges to the design of a high-precision attitude control system for flexible spacecraft. Aiming at the problem of attitude and vibration coupling control of flexible spacecraft, an anti-unwinding attitude coupling controller using the positive position feedback (PPF) control is proposed in this paper. The model compensation control term is constructed based on the prior information to improve the tracking performance. The proposed attitude coupling control method can effectively suppress the flexible vibration while achieving more accurate attitude control. The obtained closed-loop system under the proposed control scheme is asymptotically stable, which is proved by the Lyapunov stability theory. The numerical simulation illustrates that the proposed method can effectively improve the attitude control accuracy of the flexible spacecraft and is capable of large-angle attitude maneuver control because of its prominent performance in attitude tracking and its unwinding-free performance.

Precision space telescope attitude determination and control system design principles

In order to preclude the impact of atmospheric factors on the quality of received data, state of the art astronomy research projects require spacecraft mounted telescopes. However, such designs entail the issue of sustaining the accuracy of telescope boresight attitude relative to the object of observation for the required period of time. This paper is a summary of design principles for an attitude determination and control system of a space telescope mounted rigidly onboard a spacecraft. The paper formulates requirements for attitude accuracy, and proposes a viable equipment configuration as well as a three- stage attitude control algorithm. The first stage of the algorithm ensures primary boresight pointing towards the target object prior to the object being captured in the telescope’s FoV based on star tracker and angular rate sensor data. The second stage of the algorithm ensures boresight positioning relative to the target object direction up to an error value allowing for the required image quality, based on telescope readings. The third stage of the algorithm ensures telescope boresight holding relative to the target object direction with a required accuracy for the duration of exposure. Interferences from operating satellite equipment are reviewed, and the principles of reducing their impact on sighting accuracy are formulated. Low inclination, low eccentricity geostationary orbit is recommended as the best operating environment for the space telescope’s scientific instrumentation, as well as for providing a continuous data interface between spacecraft and ground segment.

Machine learning-based design of a linear self-resistant attitude control system for UAV string level

Abstract This paper mainly investigates the attitude control method of the quadrotor against unknown external interference and improves the control accuracy for the subsequent design of the control algorithm by establishing a more accurate mathematical model of the quadrotor. The extended Kalman filtering algorithm is used to obtain the real-time attitude state of the vehicle for attitude solving. The inertial guidance fusion uses the Kalman filter algorithm with delay correction to estimate the vehicle’s position and velocity information. Finally, the attitude control method of serial linear self-immunity control is proposed, which estimates and compensates for the external perturbation and internal uncertainty in real-time by linear expansion observer, while the position controller is designed by using PIV control. The simulation study analyzes that this paper’s method reduces the UAV attitude angle maximum error magnitude between about 1.04° and 4.07°compared with the traditional ADRC and serial PID. The maximum tracking error of pitch angle under white noise interference is only 0.37°using the control method of this paper, and the fluctuation amplitude is reduced by 0.81 on average, which shows a stronger anti-interference ability.

Design and analysis of a nanosatellite attitude control system using processor-in-the-loop approach

This paper presents an approach for the design and analysis of an attitude control system dedicated to a 3U nanosatellite using a low-cost, safe, and reliable processor-in-the-loop system for the rapid prototyping of the final product. It mainly concerns the selection between the two standard configurations of the four reaction wheels, namely the pyramid and tetrahedron configurations. The analysis was carried out by considering the presence of the mechanical uncertainties of the reaction wheels, estimated at 20% of the torque generated, and the environmental disturbances such as magnetic and gravity disturbances, solar pressure, and aerodynamic forces. It also investigates how the regulation is affected by placing the reaction wheels at or outside the spacecraft’s center of gravity. From the results obtained, it turns out that the satellite can be regulated very well regardless of the location of the reaction wheels in the satellite. When placing the actuators outside the center of gravity, a greater effort is required from the reaction wheels to change the satellite attitude, which will consume more electrical energy and wear out the wheels quickly. The torque allocation is used to distribute the forces on the four reaction wheels by means of an optimization adapted to each configuration. The analysis of degraded operation when one or two wheels fail is also studied in detail for the two mechanical configurations discussed.

Quaternion feedback attitude control system design based on weighted–[formula omitted]–gain performance

The operation and accomplishment of a satellite's mission depend on its capacity to control its attitude. A rotation matrix parameterization, such as a (unit) quaternion, is frequently used to represent the attitude information needed for attitude control. The quaternion can represent the attitude globally. However, the non-uniqueness property of the quaternion causes difficulty in ensuring stability. A quaternion-based attitude control system with an augmented dynamical system is a class of nonlinear continuous quaternion feedback system to tackle that problem. However, tuning the control law's parameters causes further difficulty. This paper addresses the parameters tuning based on weighted–L2–gain performance in the form of linear matrix inequalities such that the equilibrium set of the attitude control system has the guarantee of the asymptotically stable in the large. The proposed parameter tuning method reduces the setting complexity of the controller parameters that comprise scalars and matrices, i.e., from five to two parameters. It is equivalent to reducing from 37 to 4 parameters' elements. In addition, a disturbance observer is proposed as an additional control torque to overcome angular velocity bias and external disturbance bad effects. We proved that the disturbance estimation error is bounded. Simulations verified the effectiveness of the proposed control systems.

Remote Laboratory for the Design of Attitude Control Systems for Small Satellites

Remote Laboratory for the Design of Attitude Control Systems for Small Satellites

Design of Magnetorquer-Based Attitude Control Subsystem for FORESAIL-1 Satellite

The magnetorquer-based attitude control system capable of attaining high spin rates and precise pointing control is required for a 3U CubeSat satellite FORESAIL-1. The satellite, developed by the Finnish Centre of Excellence, needs to maintain a spin rate of 24°/s and precise pointing of the spin axis toward the Sun for the particle telescope instrument, as well as to reach 130°/s spin rate for the deployment of the plasma brake. Mission requirements analysis and attitude system requirements derivation are presented, followed by actuator tradeoff and selection, with a detailed design of the complete attitude control system, including the air-cored type of magnetorquer actuators and their drivers, made of H-bridge and filtering components. The design is based on several theoretical and practical considerations with emphasis on the high-power efficiency, such as effects of parallel and serial magnetorquer connections, modeling the magnetorquers with equivalent circuit models for finding a suitable driving frequency and extrapolation methods for efficient dipole moment usage. The in-house manufacturing process of magnetorquers, using a custom 3-D-printer setup, is described. Finally, the testing and verification are performed, by measuring the performance of the manufactured hardware, circuit simulations, and attitude control simulations. It is shown that the manufactured attitude control system fulfills all system requirements. Simulations also confirm the capability to satisfy mission requirements.

Simulink-based simulation platform design and faults impact analysis of attitude control systems

AbstractThe satellite attitude control system (SACS) is a complicated system. In order to reflect the relationship among different components in SACS and analyse the impact of component faults on system performance, a complete simulation platform of the SACS based on Simulink is built in this paper. With the embedding of the specific reaction flywheel, gyroscope and earth sensor model, and the design of the controller based on the quaternion feedback, the simulation platform can not only simulate the real SACS at the component level, but it can also realise the injection of component faults for analysing the system performance. Simulations are conducted to verify the performance of the simulation platform. Simulation results show that this simulation platform has the ability to accurately reflect the control performance of the SACS, and the output accuracy of the component model is high. The research results reveal that this simulation platform can provide model support for verifying the algorithm of fault diagnosis, prediction and tolerant control of the SACS. This simulation platform is easy to use and can be expanded and improved.

Antidisturbance Controllability Analysis and Enhanced Antidisturbance Controller Design With Application to Flexible Spacecraft

For a practical engineering system, disturbances usually have a negative impact on system performance. Especially, when the system physical constraints (e.g., actuator amplitude saturation and input channel constraint) are present, the study for antidisturbance controllability (ADC) is of paramount importance. This article presents the concepts of disturbance estimability, disturbance compensability, and an enhanced antidisturbance control (EADC). From the viewpoint of control system design, an example of spacecraft attitude control is given. The control constraints and multiple disturbances are explicitly analyzed for the sake of attitude control system design of flexible spacecraft. Subsequently, an EADC approach with integration of the disturbance observer-based control (DOBC) and active disturbance rejection control (ADRC) is proposed, based on the characteristics of disturbances exposed. Moreover, prescribed performance approach is incorporated into the spacecraft attitude tracking control. In consequence, the presented control can not only achieve superior antidisturbance capability than DOBC or ADRC, but also quantify the control performances. Numerical simulations and hardware-in-the-loop tests exemplify the applicability of the proposed scheme.

Lyapunov differential equations and inequalities for stability and stabilization of linear time-varying systems

This paper studies exponential stability and stabilization of linear time-varying systems without assuming that the coefficient matrix is bounded, which is generally necessary in the existing literature. First, by introducing the notions of uniformly exponentially stable and uniformly exponentially expanding functions, some Lyapunov differential inequalities based characterizations for exponential stability of linear time-varying systems are established. Second, it is shown that the linear time-varying system is both uniformly exponentially stable and uniformly exponentially expanding if and only if the corresponding Lyapunov differential equation has a unique positive definite solution. Third, some degenerated Lyapunov differential equations, where the Q matrix is only positive semi-definite, are also re-examined. Finally, a weighted controllability Gramian, which contains a weighting time-varying function that can be properly designed to reveal a trade-off between the convergence rate/regulation time of the closed-loop system and the control effort, based stabilization approach is established to ensure that the closed-loop system is both uniformly exponentially stable and uniformly exponentially expanding. The effectiveness of the proposed approach is illustrated by the design of the spacecraft attitude control system with magnetic actuation.

Comparison of the Satellite Attitude Control System Design using the H∞ Method and H∞/MLI with Pole Allocation Considering the Parametric Uncertainty

This paper presents the comparison of the Attitude Control System (ACS) design for a rigid-flexible satellite with two vibrations mode, using the traditional H∞method and the H∞/LMI with pole allocation considering the parametric uncertainty. In the ACS design is important take into account the influence of thestructure’s flexibility, since they can interact with the satellite rigid motion, mainly, during translational and/or rotational manoeuvrer, damaging the ACS. Usually the mathematics model obtained from the linearization and/or reduction of the rigid flexible model loses information about the flexible dynamical behaviour and introduces some uncertainty. The satellite model is represented by a flexible beam connected to a central rigid hub considering a setof parametric uncertainties. Simulations results have shown that the control law designed by the H∞/LMI method has better performance and it is more robust than H∞method since the first was able to support the action of the uncertainty perturbation and to control the rigid flexible satellite attitude and suppressing vibrations.

End-to-end design of a robust attitude control and vibration suppression system for large space smart structures

The standard approach of controlling in-orbit large flexible structures only by adopting actuators and sensors located at platform level is currently being challenged by new missions’ stringent requirements in terms of demanding guidance profiles and instrument performance. In this perspective, smart materials offer a different solution to improve the performance of space systems by controlling the vibrations of such lightweight structures. In this paper, the problem of designing an end-to-end architecture for active control of large in-orbit structures is addressed. First, a FE model of a large space antenna is derived by using commercial software. The instrument is designed to be supported by an active deployable frame hosting an optimal minimum set of collocated smart actuators and sensors. To this purpose, a comparison among different placement techniques, as Gramian and Modal Strain Energy (MSE) based methods, is proposed to find the final configuration for both actuators and sensors. Attention is paid to create a GNC strategy combining collocated control on flexible appendages with platform control, while minimizing the relative displacements among the most critical points of the antenna. To achieve high performance, Linear Fractional Transformation (LFT) modelling and advanced multivariable techniques are implemented. Finally, to validate the proposed controller, the control system is tested by simulating typical spacecraft manoeuvre profiles.

Correction: Attitude Determination and Control System Design of Sub-Arcsecond Pointing Spacecraft

Correction: Attitude Determination and Control System Design of Sub-Arcsecond Pointing Spacecraft

Attitude Control System Design and Simulation for the SVOM Mission

SVOM is an astronomical satellite used to observe a collection of Gamma Ray Burst and other targets. The general pointing attitude is inertial pointing in J2000 coordinate. As the telescope’s exposure time will be 100s or even longer, the satellite platform should provide severe stability during the exposure period. This article describes the design of Attitude Control System (ACS) for SVOM satellite. First, ACS’ key performance requirements are presented which include the extremely high stability target, 0.8 arcsec/100s along Ys and Zs axes. Second, ACS hardware selected and bus design are discribed. Then, the ACS modes and transfer logic are introduced. Next, the controller design and simulation results are given. At last, the conclusion is obtained and all the required index are fulfilled by current ACS design.

Design and Verification of Attitude Control System for a Boost-Glide Rocket

The boost-glide rocket needs to maneuver in the atmosphere with complex flight conditions, which is a big challenge for the attitude control system. In this paper, the design process of the control system is analyzed. With specific points of the flight trajectory, the design of an improved proportional-integrative-derivative (PID) controller based on the small perturbation theory is carried out. Design approach of the attitude control system is verified by the six-degree-freedom model simulation. The rocket flight control program is written to the onboard computer so that hardware-in-the-loop simulation experiment is completed. Experimental results show that the mean and standard deviation of the error between simulation value and experiment value are below 0.5°, so the control parameters and design method are reasonable with a great attitude tracking effect. This paper proposes the design and verification method of a boost-glide rocket attitude control system, which can provide a reference for design of the boost-glide rocket around the world.

Attitude Determination and Control System Design of Sub-Arcsecond Pointing Spacecraft

Spacecraft pointing accuracies with sub-arcsec to milli-arcsec levels are becoming a norm for the future space missions, which is mainly achieved by employing mission-specific fine guidance sensor (FGS). European Space Agency’s Herschel is the only spacecraft to date that has achieved an accuracy between 0.8 and 0.9 arcsec without employing FGS and by using only precise commercial-off-the-shelf (COTS) sensors. This paper improves upon Herschel’s pointing accuracy by at least [314, 925, 925]% for German Aerospace Center’s future mission named “Infrared Astronomy Satellite Swarm Interferometer (IRASSI).” IRASSI’s closed-loop attitude determination and control system (ADCS) is carefully developed by selecting high-precision COTS sensors and actuators, implementing two optimal attitude estimation algorithms for the sensor data fusion, three robust control algorithms for the attitude control, and a pseudoinverse distribution algorithm for spacecraft momenta allocation among the redundant reaction wheels in three different configurations. Monte Carlo simulations of IRASSI’s ADCS demonstrate that an unprecedented three-axis absolute pointing error of [0.193, 0.078, 0.078] arcsec is achieved. Furthermore, performance comparison between the rate-integrating and rate-gyroscope-based multiplicative extended Kalman filter for this mission is demonstrated. Finally, performance comparison of three attitude controllers establishes their feasibility for this mission.