Prototype Optical Sensor for CubeSat Attitude Determination with Air Bearing Validation

2013 ◽  
Author(s):  
Matthew W. Knutson ◽  
Sungyung Lim ◽  
Christopher M. Pong
Keyword(s):  
Optical Sensor ◽  
Attitude Determination ◽  
Air Bearing

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.

scholarly journals A Dynamic Testbed for Nanosatellites Attitude Verification

Aerospace ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 31 ◽  
Author(s):  
Dario Modenini ◽  
Anton Bahu ◽  
Giacomo Curzi ◽  
Andrea Togni
Keyword(s):  
Attitude Determination ◽  
Vision System ◽  
Ground Truth ◽  
Cost Effective ◽  
Air Bearing ◽  
Dynamic Testbed ◽  
Commercial Off The Shelf ◽  
Low Earth Orbits ◽  
Three Degree Of Freedom ◽  
Earth Orbits

To enable a reliable verification of attitude determination and control systems for nanosatellites, the environment of low Earth orbits with almost disturbance-free rotational dynamics must be simulated. This work describes the design solutions adopted for developing a dynamic nanosatellite attitude simulator testbed at the University of Bologna. The facility integrates several subsystems, including: (i) an air-bearing three degree of freedom platform, with automatic balancing system, (ii) a Helmholtz cage for geomagnetic field simulation, (iii) a Sun simulator, and (iv) a metrology vision system for ground-truth attitude generation. Apart from the commercial off-the-shelf Helmholtz cage, the other subsystems required substantial development efforts. The main purpose of this manuscript is to offer some cost-effective solutions for their in-house development, and to show through experimental verification that adequate performances can be achieved. The proposed approach may thus be preferred to the procurement of turn-key solutions, when required by budget constraints. The main outcome of the commissioning phase of the facility are: a residual disturbance torque affecting the air bearing platform of less than 5 × 10−5 Nm, an attitude determination rms accuracy of the vision system of 10 arcmin, and divergence of the Sun simulator light beam of less than 0.5° in a 35 cm diameter area.

Rocket attitude determination by a Fourier method

1979 ◽  
Vol 57 (5) ◽  
pp. 728-732 ◽  
Author(s):  
D. W. Green ◽  
B. G. Wilson
Keyword(s):  
Optical Sensor ◽  
Additional Data ◽  
Attitude Determination ◽  
Fourier Method ◽  
Angular Motion ◽  
Sounding Rocket ◽  
Free Flight ◽  
Transverse Axis ◽  
Magnetometer Data

It is shown that the parameters completely specifying the angular motion of a symmetrical sounding rocket in torque-free flight may in general be determined from a Fourier-transformed segment of transverse-axis magnetometer data, with limited additional data from an auxiliary optical sensor. The method is simple and rapid, and an example is worked out.

Low-Cost, High-Performance Monocular Vision System for Air Bearing Table Attitude Determination

2014 ◽  
Vol 51 (1) ◽  
pp. 66-75 ◽  
Author(s):  
Yun-Hua Wu ◽  
Yang Gao ◽  
Jia-Wei Lin ◽  
Robin Raus ◽  
Shi-Jie Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Attitude Determination ◽  
Vision System ◽  
Low Cost ◽  
Monocular Vision ◽  
Air Bearing

Influence on Inertia the Moment of Inertia Matrix of Three Degrees of Freedom Air-Bearing Testbed

2013 ◽  
Vol 706-708 ◽  
pp. 1393-1396
Author(s):  
Yan Bin Li ◽  
Ren Song Zou ◽  
Tong Jiang
Keyword(s):  
Attitude Control ◽  
Degrees Of Freedom ◽  
Attitude Determination ◽  
Euler Angle ◽  
Element Model ◽  
Moment Of Inertia ◽  
Attitude Motion ◽  
Air Bearing ◽  
The Moment ◽  
And Control

To improve the accuracy of attitude determination and control stabilization when simulating attitude motion of satellites in the space, the finite element model of the platform of 3-DOF spacecraft attitude control simulator was founded. Gravity field of air bearing testbed and formula for platform’s moment of inertia on the action of gravity was induced The result shows platform’s attitude accuracy error exist because of main principal axis of inertia change of direction.on the action of gravity, The more large value it is, the more error is .Error of inertia main axis changes as sine curve with the change of two horizontal Euler angle.

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