Attitude determination sensor for low Earth orbit satellite based on Lorentz force

2018 ◽  
Vol 233 (6) ◽  
pp. 2219-2230 ◽  
Author(s):  
Mohsen Rezaei ◽  
Kamran Raissi ◽  
Hamed Hashemi Mehne ◽  
Yaser Norouzi
Keyword(s):  
Magnetic Field ◽  
Lorentz Force ◽  
Attitude Control ◽  
High Speed ◽  
Attitude Determination ◽  
Low Earth Orbit ◽  
The Body ◽  
Body Frame ◽  
Specific Frequency ◽  
Better Than

Spacecraft attitude determination is a crucial task in attitude control subsystems. It provides the necessary feedback to close the control loop. Several sensors such as star trackers, Sun sensors, and horizon sensors are used for this purpose. The development of other methods can help control engineer with newer options to design their systems. Here, an innovative sensor for determining the attitude of a spacecraft is presented. The proposed sensor measures the Lorentz force vector due to the interaction between the magnetic field of the Earth, and the high linear velocity of the spacecraft. This sensor is composed of three series of orthogonal variable capacitors. The capacitors are connected in parallel to increase the total capacitance. The capacitors have movable plates which actuated by alternating current with specific frequency. Due to very high speed of spacecraft relative to magnetic field of earth in low orbit, the Lorentz force is exerted on the charges of the capacitor plates. The plates have same velocity as the spacecraft does. The applied Lorentz force to the plates affects their motion so that the harmonic can be seen in the output. Measuring the amplitude of the mentioned harmonic results in measurement of a component of the Lorentz force in the direction of capacitors. Installing the three capacitors orthogonally can measure the three rectangular components of the Lorentz force. This vector will be in the body frame of the spacecraft. The two-plate and three-plate capacitor are the two different proposed mechanisms and their performance is compared. Once the Lorentz force is known as a vector in the body frame, it can be applied along with data from another sensor to determine the attitude of the spacecraft. Based on simulation results, achievable resolution is better than 3°, which can be improved by further research.

Flight Test of Attitude Determination System using Multiple GPS Antennae

2005 ◽  
Vol 59 (1) ◽  
pp. 119-133 ◽  
Author(s):  
Jaegyu Jang ◽  
Changdon Kee
Keyword(s):  
Navigation System ◽  
Attitude Determination ◽  
Phase Measurement ◽  
Angular Rate ◽  
Flight Test ◽  
The Body ◽  
Body Frame ◽  
Carrier Phase Measurement ◽  
External Interference ◽  
Determination System

Small Unmanned Aerial Vehicles (UAVs) or inexpensive airplanes, such as a Cessna single engine aircraft, require a navigation system with a cheap, compact and precise sensor. Over the past ten years, GPS receivers have begun to be used as primary or alternative navigation sensors, because their use can significantly reduce the overall system cost. This paper describes a navigation system incorporating a velocity-based attitude estimation system with an attitude determination system using multiple antennae, which was implemented and tested using a UAV. The main objective was to obtain precise attitude information using low cost GPS OEM boards and antennae. Attitude boundaries are derived from the relationship between the body frame and the wind coordinates, which are used to validate the resolved cycle ambiguity in an Euler angle domain. Angular rate based on Doppler measurements was used to exclude the degenerate pseudo-roll angle information during severe uncoordinated flight. Searching for cycle ambiguity at every epoch of the flight showed that the developed system gave reliable cycle integer solutions, although the carrier phase measurement was subject to additional errors, such as multipath, external interference, and phase centre variation. A flight test was performed using a 1/4-scale Piper J3 Cub model, CMC Allstar OEM boards, OEM AT575-70 antennae, and 700 MHz PC104 board.

Least Squares Method for Attitude Determination Using the Real Data of CBERS-2 Satellite

2014 ◽  
Vol 706 ◽  
pp. 181-190 ◽  
Author(s):  
W.R. Silva ◽  
H.K. Kuga ◽  
M.C. Zanardi ◽  
R.V. Garcia
Keyword(s):  
Reference System ◽  
Attitude Determination ◽  
Least Squares Method ◽  
Real Data ◽  
The Body ◽  
Space Environment ◽  
Artificial Satellites ◽  
Body Frame ◽  
Control Center ◽  
Yaw Attitude

his work is applied to the dynamics of rotational motion of artificial satellites, that is, itsorientation (attitude) with respect to an inertial reference system. The attitude determination involvesapproaches of nonlinear estimation techniques, which knowledge is essential to the safety and controlof the satellite and payload. Here one focuses on determining the attitude of a real satellite: CBERS-2(China Brazil Earth Resources Satellite). This satellite was launched in 2003 and were controlled andoperated in turns by China (Xi’an Control Center) and Brazil (Satellite Control Center). Its orbit isnear polar sun-synchronous with an altitude of 778km, crossing Equator at 10:30am in descendingdirection, frozen perigee at 90 degrees, and providing global coverage of the world every 26 days.The attitude dynamical model is described by nonlinear equations involving the Euler angles. Theattitude sensors available are two DSS (Digital Sun Sensor), two IRES (Infra-Red Earth Sensor), andone triad of mechanical gyros. The two IRES give direct measurements of roll and pitch angles with acertain level of error. The two DSS are nonlinear functions of roll, pitch, and yaw attitude angles. Thegyros furnish the angular measurements in the body frame reference system. Gyros are very importantsensors, as they provide direct incremental angles or angular velocities. They can sense instantaneousvariations of nominal velocities. An important feature is that it allows the replacement of complexmodels (different torques acting on the space environment) by using their measurements to turn thedynamical equations into simple kinematic equations. However gyros present several sources of errorof which the drift is the most troublesome. Such drifts yield along time an accumulation of errorswhich must be accounted for in the attitude determination process. Herein one proposes to estimatethe attitude and the drift of the gyros using the Least SquaresMethod. Results show that one can reachaccuracies in attitude determination within the prescribed requirements, besides providing estimatesof the gyro drifts which can be further used to enhance the gyro error model.

scholarly journals Microsatellite Attitude Determination and Control Subsystem Design and Implementation: Software-in-the-Loop Approach

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Ho-Nien Shou
Keyword(s):  
Angular Velocity ◽  
Normal Mode ◽  
Attitude Control ◽  
Attitude Determination ◽  
Control Method ◽  
Measurement Data ◽  
Low Earth Orbit ◽  
Control Subsystem ◽  
Institute Of Technology ◽  
And Control

The paper describes the development of a microsatellite attitude determination and control subsystem (ADCS) and verification of its functionality by software-in-the-loop (SIL) method. The role of ADCS is to provide attitude control functions, including the de-tumbling and stabilizing the satellite angular velocity, and as well as estimating the orbit and attitude information during the satellite operation. In Taiwan, Air Force Institute of Technology (AFIT), dedicating for students to design experimental low earth orbit micro-satellite, called AFITsat. For AFITsat, the operation of the ADCS consists of three modes which are initialization mode, detumbling mode, and normal mode, respectively. During the initialization mode, ADCS collects the early orbit measurement data from various sensors so that the data can be downlinked to the ground station for further analysis. As particularly emphasized in this paper, during the detumbling mode, ADCS implements the thrusters in plus-wide modulation control method to decrease the satellite angular velocity. ADCS provides the attitude determination function for the estimation of the satellite state, during normal mode. The three modes of microsatellite adopted Kalman filter algorithm estimate microsatellite attitude. This paper will discuss using the SIL validation ADCS function and verify its feasibility.

scholarly journals A Fast in-Motion Alignment Algorithm for DVL Aided SINS

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Li Kang ◽  
Lingyun Ye ◽  
Kaichen Song
Keyword(s):  
Attitude Determination ◽  
Unscented Kalman Filter ◽  
Integral Form ◽  
The Body ◽  
Doppler Velocity ◽  
Alignment Algorithm ◽  
Body Frame ◽  
Attitude Error ◽  
Motion Condition ◽  
Alignment Problem

Doppler velocity log (DVL) aided strapdown inertial navigation system (SINS) is a common navigation method for underwater applications. Owing to the in-motion condition and the lack of the GPS, it is a challenge to align a SINS under water. This paper proposed a complete in-motion alignment solution for both attitude and position. The velocity update equation and its integral form in the body frame are studied, and the attitude coarse alignment becomes an optimization-based attitude determination problem between the body frame velocity and the integral form of gravity. The body frame velocity and the Earth frame position are separately treated, and the position alignment problem turns into an equation solving problem. Simulation and on-lake tests are carried out to examine the algorithm. The heading could reach around 10 deg accuracy and the pitch and roll could be aligned up to 0.05 deg in 60 s. With attitude error of this level, the heading could reach 1 deg accuracy in 240 s using unscented Kalman filter (UKF) based fine alignment. The final position error could achieve 1.5% of the voyage distance. This scheme can also be applied to other body frame velocity aided SINS alignments.

Robust integrated translational and rotational control for spacecraft rendezvous in unstructured environments

2017 ◽  
Vol 40 (11) ◽  
pp. 3293-3313 ◽  
Author(s):  
Zhang Feng
Keyword(s):  
Nonlinear System ◽  
Attitude Control ◽  
Closed Loop ◽  
The Body ◽  
Singular Perturbation Theory ◽  
Body Frame ◽  
State Transformation ◽  
Unstructured Environments ◽  
Highly Nonlinear ◽  
Loop Stability

The problem considered in this paper is the robust integrated translation and rotation control for spacecraft rendezvous in unstructured environments. The pursuer spacecraft considered is equipped with a single main thruster, capable of only providing thrust along one axis of the body frame, and attitude control actuators, capable of providing manoeuvrability in three axes of the body frame. The formulated coupled translational and rotational dynamics of the spacecraft with various uncertainties performs an under-actuated highly nonlinear system. A technical state transformation is then proposed to transform the coupled dynamics into a cascaded nonlinear system with the first subsystem being a linear perturbed system. This special cascaded nonlinear structure inspires the synthesization of the eigenstructure assignment parametric technique and the backstepping philosophy to guarantee not only robust closed-loop stability but also a robust trajectory tracking performance in the presence of various system uncertainties coming from unstructured environments. Moreover, rigorous closed-loop stability analysis is undertaken by using singular perturbation theory. Finally, a space interception is used to demonstrate the effectiveness of the proposed control scheme.

Modeling and Simulation of a Displacement Controllable Active Suspension System

2018 ◽  
Author(s):  
Beibei Liu ◽  
Lin Xu ◽  
Zhen Zhao ◽  
Mohamed A. A. Abdelkareem ◽  
Junyi Zou ◽  
...  
Keyword(s):  
Attitude Control ◽  
High Speed ◽  
Ride Comfort ◽  
Simulation Analysis ◽  
Body Position ◽  
Active Suspension ◽  
Suspension System ◽  
The Body ◽  
Vehicle Body ◽  
Dynamic State

Active suspension can adapt itself to the rigidity and the damping characteristics based on the vehicle dynamic state and the road condition, making the suspension in the best state of shock absorbing, which can increase the handling stability, the ride comfort and the passing ability of vehicles. As for strikingly rugged roads like off-road conditions, the traditional active suspension can hardly balance the contradiction between the wheel adhesion and the vertical accelerated speed of the body. In this paper, an active suspension in which the position of the vehicle body can be adjusted is proposed. In the proposed suspension, a series of electric cylinders are installed, which can actively adjust the position between the vehicle body and the suspension in order to achieve the purpose of controlling the relative body-wheels position. In this manner, AMESim is used to set up three suspension designs which include suspension supporter adaptation equipment with different locations in the system. Through simulation analysis, the paper has explored the feasibility of the vehicle attitude control of the three suspension designs under off-road conditions. The results proved that the active suspension system with adjustable body position can restrain the body roll or pitch efficiently in which this technology can be applied to the body attitude control when ORVs are at high speed.

scholarly journals APPLICATION OF THE APPARATUS OF BALL VECTORS IN PROBLEMS OF MECHANICS

2020 ◽  
Vol 82 (3) ◽  
pp. 317-327
Author(s):  
V.V. Novikov ◽  
L.N. Fevralskikh
Keyword(s):  
Magnetic Field ◽  
High Speed ◽  
Deformable Body ◽  
Decisive Role ◽  
The Body ◽  
Necessary Condition ◽  
Cubic Symmetry ◽  
Global Movement ◽  
Steady Rotation ◽  
Reynolds Magnetic Number

An approach to solving problems of dynamics of distributed mechanical systems with spherical symmetry based on the use of the ball vector apparatus is demonstrated. A number of problems of the dynamics of a solid deformable body, liquid fluid, and magnetic hydrodynamics are presented, for which an analytical solution is obtained that allows us to identify qualitative features of the dynamics of the studied objects. The problem of free angular movements of a deformable body close in shape to a ball is considered. The example of almost of ball possessing cubic symmetry, body shape and almost spherical the inertia tensor in the undeformed condition, demonstrates the ability of the global movement in the body axis of steady rotation (pole). The effect is due to the fact that when a body rotates at high speed, the elastic properties play a decisive role in its dynamics. Over time, the angular velocity of the drag decreases and the movement of the body is increasingly affected by its ellipsoidplicity. The motion of an incompressible viscous fluid in the space between a rotating non-concentric sphere and an ellipsoid is studied. It is shown that the asymmetry of the flow leads to the appearance of a radial flow of the liquid. The presence of such a flow in the case of a conducting liquid is a necessary condition for generating a magnetic field. Assuming that the liquid is conductive, a study of the possibility of generating a magnetic field is carried out on the basis of the obtained flow in the framework of the kinematic approach. The smallest value of the Reynolds magnetic number is found, which creates an exponentially growing magnetic field when passing through it. The results obtained can be useful for studying the dynamics of the Earth and the planets of the Solar system and the mechanism of generating a geomagnetic field.

scholarly journals A Miniature Resonant and Torsional Magnetometer Based on Lorentz Force

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 666 ◽  
Author(s):  
Lingqi Wu ◽  
Zheng Tian ◽  
Dahai Ren ◽  
Zheng You
Keyword(s):  
Magnetic Field ◽  
Lorentz Force ◽  
Structural Parameters ◽  
Chemical Mechanical Planarization ◽  
Low Earth Orbit ◽  
Anodic Bonding ◽  
Horizontal Magnetic Field ◽  
Excitation Coil ◽  
Torsional Beam ◽  
Lift Off

A microelectromechanical system (MEMS) torsional resonant magnetometer based on Lorentz force was investigated, consisting of torsional structures, torsional beams, metal plates, a coil, and a glass substrate. The Lorentz force, introduced by the interaction between the current in the MEMS coil and an external horizontal magnetic field, leads to displacement of the torsional structure. The strength of the magnetic field is proportional to this displacement, and can be detected with two sensing capacitors fabricated on the torsion structure and the substrate. To improve sensor sensitivity, a folded torsional beam and a double-layer excitation coil were introduced. The fabrication processes included lift-off, anodic bonding, chemical mechanical planarization, silicon nitride (SiNx) deposition, plasma-enhanced chemical vapor deposition, and inductively coupled plasma release. The prototype of the magnetometer was finished and packaged. The sensor performance, including its sensitivity and repeatability, was tested in a low-pressure environment. Additionally, the influences of structural parameters were analyzed, including the resistance of the excitation coil, the initial value of the capacitors, the elastic coefficient of the torsional beam, and the number of layers in the excitation coil. The test results demonstrated that this sensor could meet the requirements for attitude determination systems in low earth orbit satellites.

Some Special Aspects of Hypersonic Flow Fields

1959 ◽  
Vol 63 (585) ◽  
pp. 508-512 ◽  
Author(s):  
K. W. Mangler
Keyword(s):  
Hypersonic Flow ◽  
High Speed ◽  
Flow Fields ◽  
The Body ◽  
Lower Velocity ◽  
Bow Wave ◽  
Total Head ◽  
Bow Shocks ◽  
Lower Entropy ◽  
Subsonic Region

When a body moves through air at very high speed at such a height that the air can be considered as a continuum, the distinction between sharp and blunt noses with their attached or detached bow shocks loses its significance, since, in practical cases, the bow wave is always detached and fairly strong. In practice, all bodies behave as blunt shapes with a smaller or larger subsonic region near the nose where the entropy and the corresponding loss of total head change from streamline to streamline due to the curvature of the bow shock. These entropy gradients determine the behaviour of the hypersonic flow fields to a large extent. Even in regions where viscosity effects are small they give rise to gradients of the velocity and shear layers with a lower velocity and a higher entropy near the surface than would occur in their absence. Thus one can expect to gain some relief in the heating problems arising on the surface of the body. On the other hand, one would lose farther downstream on long slender shapes as more and more air of lower entropy is entrained into the boundary layer so that the heat transfer to the surface goes up again. Both these flow regions will be discussed here for the simple case of a body of axial symmetry at zero incidence. Finally, some remarks on the flow field past a lifting body will be made. Recently, a great deal of information on these subjects has appeared in a number of reviewing papers so that little can be added. The numerical results on the subsonic flow regions in Section 2 have not been published before.

Two-timescale magnetic attitude control of Low-Earth-Orbit spacecraft

2021 ◽  
pp. 106884
Author(s):  
Giulio Avanzini ◽  
Emanuele L. de Angelis ◽  
Fabrizio Giulietti
Keyword(s):  
Attitude Control ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Magnetic Attitude Control
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