Nanosatellite Attitude Control System Research Articles

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.

Impact of non-latching booms on a nanosatellite attitude control system

The Scintillation Prediction Observations Research Task (SPORT) nanosatellite is being developed in partnership with the National Aeronautics and Space Administration agency and the Brazilian Space Agency, with its launch planned for 2022. Its goal is to collect data to improve our understanding of plasma bubbles and the condition that lead to their formation, helping to predict and mitigate their interference in navigation and communication systems. Therefore, to reach this goal, the satellite has several scientific instruments to perform in-situ measurements, with five of them positioned on four booms. These booms do not have a latching system to lock their position; instead, torsional springs are employed to keep them in the deployed state, holding them against their mechanism's structure. This configuration of torsional spring and collision may lead to vibration with the potential to degrade the Attitude Determination and Control System performance, impacting the whole mission. Motivated by the lack of literature covering the non-latching booms dynamics in satellites, this work proposes a framework based on multibody dynamics to simulate satellites with such booms. It also presents a practical method to acquire experimental data and identify the parameters of the booms' deployment mechanism. Later, this work applies the proposed framework and investigates the impact of non-latching booms on the satellite control system to verify if SPORT is able to complete the maneuver. Therefore, experiments were conducted to calibrate both spring and collision models. The multibody model of the satellite was developed and later validated using commercial software. The method for capturing booms' data and determining the mechanisms' parameters shows a satisfactory performance near the booms' deployment position. The proposed framework to simulate satellites with non-latching booms is applied to the SPORT satellite. Simulations in closed-loop indicate that the booms' influence on the SPORT's control system is negligible and the satellite meets its requirements.

Development of Fault Detection and Identification Algorithm Using Deep learning for Nanosatellite Attitude Control System

Satellites should have high reliability because they are required to operate autonomously, while performing a given mission. To realize this, it is necessary to use heritage parts or include redundancy. However, for nanosatellites, where it is difficult to include redundancy due to volume and weight limitations, fault management becomes crucial. In this study, a new method based on deep learning is proposed for detecting and identifying the faults in the reaction wheel, which is one of the satellite actuators. A deep learning model is applied to learn the fault and fault type using the residual between the measured attitude data and the estimated attitude date. In this study, it is assumed that three reaction wheels are installed, and fault detection is designed accordingly. The proposed model enables the satellite to detect faults autonomously, even when it is not communicating with the ground station, and is expected to be highly beneficial for the autonomous operation of the mega-constellation mission using nanosatellite that is to be activated in future.

Intelligent Fuzzy PD+I Controller with Stabilizer for Nano Satellite Attitude Control System

This paper discusses the variation of proportional and derivative gains in a system under the control of PD+I controller that uses fuzzy inference method an effort is made to design the fuzzy proportional-derivative (PD) + I controller for a nonlinear the proposed fuzzy PD + I structure shows superior performance in the Nano-satellite attitude control system. Given that 2-input PD type controllers are commonly used to control Nano satellite attitude systems (Innovative Satellite InnoSAT), This paper analysis the performance of Fuzzy PD+I on satellite system. Fuzzy PD+I controller design can control Nano satellite attitude control system nicely and utilized the Fuzzy PD+I controller which optimize the stability of the Nano Satellite control system. In addition, the scheme is robust to variations in nonlinearities, as well as the steady-state gain of the plant. We illustrate the effectiveness of our scheme In MATLAB / SMULINK simulation environment.

Mathematical model of angular motion of nanosatellites with inertial actuators

The problem of developing a nanosatellite attitude control system using three reaction wheels mounted along the main central axes of inertia is discussed in the paper. The law of controlling a nanosatellites attitude is based on a PD - controller. The stability of the process of controlling the nanosatellite attitude using the Lyapunov function method has been analyzed. It allows us to prove that the obtained control law provides the asymptotic stability of nanosatellite angular motion. Hereafter, the function of control voltage for electric motors of reaction wheels taking into account their specifications is obtained based on the developed mathematical model of reaction wheel dynamics. Numerical calculations of controlled angular motion have been carried out for the nanosatellite CubeSat3U with actuators on the basis of a commercial DC motor. Several cases of controlling the satellites rotation by different angles are considered in the course of the numerical experiments. The results of numerical experiments showed the adequacy of the developed mathematical model.

Design of Attitude Control Systems for CubeSat-Class Nanosatellite

We present a satellite attitude control system design using low-cost hardware and software for a 1U CubeSat. The attitude control system architecture is a crucial subsystem for any satellite mission since precise pointing is often required to meet mission objectives. The accuracy and precision requirements are even more challenging for small satellites where limited volume, mass, and power are available for the attitude control system hardware. In this proposed embedded attitude control system design for a 1U CubeSat, pointing is obtained through a two-stage approach involving coarse and fine control modes. Fine control is achieved through the use of three reaction wheels or three magnetorquers and one reaction wheel along the pitch axis. Significant design work has been conducted to realize the proposed architecture. In this paper, we present an overview of the embedded attitude control system design; the verification results from numerical simulation studies to demonstrate the performance of a CubeSat-class nanosatellite; and a series of air-bearing verification tests on nanosatellite attitude control system hardware that compares the performance of the proposed nonlinear controller with a proportional-integral-derivative controller.

Designing, Manufacturing, and Testing a Self-Contained and Autonomous Nanospacecraft Attitude Control System

AbstractThis paper describes the development of a three-axis attitude control system for nanosatellites and CubeSats, based on commercial electronics and capable to work autonomously for attitude stabilization or controlled from Earth to perform real-time orientation maneuvers. The system contains three microreaction wheels and related drivers, three magnetorquers with their control circuits, three magnetometers, and control electronics. The system is completely independent from the host spacecraft, with all systems included in its structure. For autonomous attitude control, an external sensor is required, providing the orientation of a reference source, such as the sun, eventually evaluated based on solar array outputs, Earth, or stars. The communication interface is based on a serial link and can be used to transfer commands, parameters, and housekeeping data. Miniaturization of the system components and of the whole assembly are among the main innovations introduced with respect to traditional attitude...

Laboratory tutorial practice with facility for attitude control simulation

The paper presents a combined approach to teaching of Spaceflight Dynamics, Theoretical Mechanics and Control Theory. In addition to a standard lecture course, this approach provides hands-on training at the laboratory, offering to the student a possibility to develop, design, assemble and test his/her own project of a nanosatellite attitude control system. We describe the software for mathematical modeling, the facilities for laboratory simulation of controlled system dynamics and student training based on these facilities.