Electrospray Thrusters as Precise Attitude Control Actuators for Small Satellites

2017 ◽  
Vol 40 (3) ◽  
pp. 642-649 ◽  
Author(s):  
Fernando Mier-Hicks ◽  
Paulo C. Lozano
Keyword(s):  
Attitude Control ◽  
Small Satellites

scholarly journals Three-axis air-bearing based platform for small satellite attitude determination and control simulation

2005 ◽  
Vol 3 (03) ◽  
Author(s):  
J. Prado ◽  
G. Bisiacchi ◽  
L. Reyes ◽  
E. Vicente ◽  
F. Contreras ◽  
...  
Keyword(s):  
Attitude Control ◽  
Attitude Determination ◽  
Center Of Mass ◽  
Measurement Unit ◽  
Simulation Platform ◽  
Air Bearing ◽  
Small Satellites ◽  
Main Components ◽  
Free Environment ◽  
And Control

A frictionless environment simulation platform, utilized for accomplishing three-axis attitude control tests in small satellites, is introduced. It is employed to develop, improve, and carry out objective tests of sensors, actuators, and algorithms in the experimental framework. Different sensors (i.e. sun, earth, magnetometer, and an inertial measurement unit) are utilized to assess three-axis deviations. A set of three inertial wheels is used as primary actuators for attitude control, together with three mutually perpendicular magnetic coils intended for desaturation purposes, and as a backup control system. Accurate balancing, through the platform’s center of mass relocation into the geometrical center of the spherical air-bearing, significatively reduces gravitational torques, generating a virtually torque-free environment. A very practical balancing procedure was developed for equilibrating the table in the local horizontal plane, with a reduced final residual torque. A wireless monitoring system was developed for on-line and post-processing analysis; attitude data are displayed and stored, allowing properly evaluate the sensors, actuators, and algorithms. A specifically designed onboard computer and a set of microcontrollers are used to carry out attitude determination and control tasks in a distributed control scheme. The main components and subsystems of the simulation platform are described in detail.

Monolithic Silicon-Based Microthruster for Orbital and Attitude Control Fabricated by Using MEMS Technologies

2006 ◽  
Author(s):  
Marco Chiarini ◽  
Paolo Cerabolini ◽  
Giuseppe Pennestri` ◽  
Gian G. Bentini ◽  
Roberto Cocomazzi ◽  
...  
Keyword(s):  
Attitude Control ◽  
Vapour Phase ◽  
Catalyst Design ◽  
Design Parameters ◽  
High Concentration ◽  
General Increase ◽  
Small Satellites ◽  
Mems Fabrication ◽  
Silicon Based ◽  
Remarkable Reduction

In the last decades there has been an increasing development of small satellites allowing remarkable reduction of both cost and fabrication time. In parallel, there has been a general increase of LEO missions for Earth observation based on small satellites. The miniaturization technologies developed in the 80’s have allowed the development of microsensors and microactuators compatible with applications on microsatelites. This trend has stimulated the need of microthrusters to maintain orbital and attitude control requiring thrust ranging from some micro-Newton to some milli-Newton. In this work is described the design and development of a Micro Thruster, monolithically fabricated in Silicon with photolithographic technologies usually applied for MEMS fabrication. The thrust is obtained by using, as propellant, high concentration H2O2 that is induced to the liquid-to-vapour phase exothermal transition by means of a suitable catalyst. Design parameters, fabrication details as well as preliminary tests will be presented and discussed.

scholarly journals Adaptive Neural Network-Based Satellite Attitude Control by Using the Dynamic Inversion Technique and a VSCMG Pyramidal Cluster

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Mihai Lungu ◽  
Romulus Lungu
Keyword(s):  
Neural Network ◽  
Attitude Control ◽  
Approximation Error ◽  
Inversion Method ◽  
Dynamic Inversion ◽  
Control Law ◽  
Feed Forward Neural Network ◽  
Small Satellites ◽  
Control Moment ◽  
Satellite Attitude Control

The paper presents an adaptive system for the control of small satellites’ attitude by using a pyramidal cluster of four variable-speed control moment gyros as actuators. Starting from the dynamic model of the pyramidal cluster, an adaptive control law is designed by means of the dynamic inversion method and a feed-forward neural network-based nonlinear subsystem; the control law has a proportional-integrator component (for the control of the reduced-order linear subsystem) and an adaptive component (for the compensation of the approximation error associated with the function describing the dynamics of the nonlinear system). The software implementation and validation of the new control architecture are achieved by using the Matlab/Simulink environment.

scholarly journals Integrated Power and Attitude Control Design of Satellites Based on a Fuzzy Adaptive Disturbance Observer Using Variable-Speed Control Moment Gyros

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Zhongyi Chu ◽  
Jing Cui
Keyword(s):  
Attitude Control ◽  
Disturbance Observer ◽  
Peak Power ◽  
Speed Control ◽  
Variable Speed ◽  
Control Approach ◽  
Small Satellites ◽  
Control Moment ◽  
Fuzzy Adaptive ◽  
Variable Speed Control

To satisfy the requirements for small satellites that seek agile slewing with peak power, this paper investigates integrated power and attitude control using variable-speed control moment gyros (VSCMGs) that consider the mass and inertia of gimbals and wheels. The paper also details the process for developing the controller by considering various environments in which the controller may be implemented. A fuzzy adaptive disturbance observer (FADO) is proposed to estimate and compensate for the effects of equivalent disturbances. The algorithms can simultaneously track attitude and power. The simulation results illustrate the effectiveness of the control approach, which exhibits an improvement of 80 percent compared with alternate approaches that do not employ a FADO.

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