scholarly journals SATELLITE GUIDANCE AND CONTROL DURING OPERATIVE OPTOELECTRONIC IMAGERY FOR DISASTER MANAGEMENT

2018 ◽  
Vol XLII-3/W4 ◽  
pp. 475-482
Author(s):  
Y. Somov ◽  
C. Hajiyev
Keyword(s):  
Disaster Management ◽  
Attitude Control ◽  
Attitude Determination ◽  
Earth Surface ◽  
Attitude Control System ◽  
Control Laws ◽  
Guidance And Control ◽  
The Earth ◽  
Synchronous Orbit ◽  
And Control

<p><strong>Abstract.</strong> We consider problems on surveying the Earth surface during operative optoelectronic imagery for disaster management with respect to attitude guidance and control of the agile spacecraft. The land surveying is carried out by a set of extended orthodromic routes of scanning optoelectronic observation for a given part of the Earth surface. We present developed methods for synthesis of nonlinear guidance and attitude control laws, dynamic research of the spacecraft attitude control system with the satellite astroinertial attitude determination and digital control by the excessive gyro moment cluster. We present results on the efficiency of the developed vector spline guidance laws, algorithms for discrete filtering and the digital gyromoment control of a satellite orientation during the areal landsurveying of Istanbul neighborhoods for the spacecraft on sun-synchronous orbit with altitude of 720&amp;thinsp;km when the allowed deviation of the target line from Nadir is within the cone with semi-angle of 40&amp;thinsp;deg.</p>

Guidance and control algorithms for mini UAV autopilots

2017 ◽  
Vol 89 (1) ◽  
pp. 133-144 ◽  
Author(s):  
Elisa Capello ◽  
Giorgio Guglieri ◽  
Gianluca Ristorto
Keyword(s):  
Attitude Control ◽  
Path Following ◽  
Adaptive Controller ◽  
Computationally Efficient ◽  
Control Laws ◽  
Content Type ◽  
Guidance And Control ◽  
Aerial Vehicle ◽  
Set Up ◽  
And Control

Purpose The aim of this paper is the implementation and validation of control and guidance algorithms for unmanned aerial vehicle (UAV) autopilots. Design/methodology/approach The path-following control of the UAV can be separated into different layers: inner loop for pitch and roll attitude control, outer loop on heading, altitude and airspeed control for the waypoints tracking and waypoint navigation. Two control laws are defined: one based on proportional integrative derivative (PID) controllers both for inner and outer loops and one based on the combination of PIDs and an adaptive controller. Findings Good results can be obtained in terms of trajectory tracking (based on waypoints) and of parameter variations. The adaptive control law guarantees smoothing responses and less oscillations and glitches on the control deflections. Practical implications The proposed controllers are easily implementable on-board and are computationally efficient. Originality/value The algorithm validation via hardware in the loop simulations can be used to reduce the platform set-up time and the risk of losing the prototype during the flight tests.

scholarly journals Neighboring Optimal Guidance and Constrained Attitude Control for Accurate Orbit Injection

2021 ◽  
Author(s):  
Mauro Pontani ◽  
Fabio Celani
Keyword(s):  
Attitude Control ◽  
Initial Position ◽  
Low Earth Orbit ◽  
Guidance And Control ◽  
Optimal Guidance ◽  
Combined Use ◽  
Upper Stage ◽  
Neighboring Optimal Guidance ◽  
And Control ◽  
Guidance Technique

AbstractAccurate orbit injection represents a crucial issue in several mission scenarios, e.g., for spacecraft orbiting the Earth or for payload release from the upper stage of an ascent vehicle. This work considers a new guidance and control architecture based on the combined use of (i) the variable-time-domain neighboring optimal guidance technique (VTD-NOG), and (ii) the constrained proportional-derivative (CPD) algorithm for attitude control. More specifically, VTD-NOG & CPD is applied to two distinct injection maneuvers: (a) Hohmann-like finite-thrust transfer from a low Earth orbit to a geostationary orbit, and (b) orbit injection of the upper stage of a launch vehicle. Nonnominal flight conditions are modeled by assuming errors on the initial position, velocity, attitude, and attitude rate, as well as actuation deviations. Extensive Monte Carlo campaigns prove effectiveness and accuracy of the guidance and control methodology at hand, in the presence of realistic deviations from nominal flight conditions.

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 ANALYSIS OF THE METHODS FOR REGISTRATION OF IMAGES RECEIVED FROM THE INFORMATION SYSTEMS OF NON-MOTORIZED AIRCRAFTS

2019 ◽  
Vol 5 (15) ◽  
pp. 1448-1455
Author(s):  
Venelin Terziev ◽  
Teodora Petrova
Keyword(s):  
Information Systems ◽  
Large Scale ◽  
Air Monitoring ◽  
Monitoring Systems ◽  
Earth Surface ◽  
Military Operations ◽  
Monitoring And Control ◽  
The Earth ◽  
The World ◽  
And Control

The non-motorized air systems for intelligence, monitoring and control of the earth surface have gained currency and are used for various tactic flight’s tasks and missions. The non-motorized aircrafts (NMA) and the air-monitoring systems that include board and land part are key elements of these systems. The world experience in using NMA for these uses shows that they are most suitable where the exploitation conditions are very extreme and there is an unacceptable risk for operations of piloted aviation. Such are intelligence and observation of strictly guarded sites, zones, where military operations are conducted as well as regions with large scale fires and floods. The use of people in these conditions is connected with actual threat for their lives and practically, NMA as a tool for collecting and processing of information is irreplaceable. Keywords: registration of images, methods, information systems, non-motorized aircrafts.

scholarly journals A Novel Concept for Guidance and Control of Spacecraft Orbital Maneuvers

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Matteo Dentis ◽  
Elisa Capello ◽  
Giorgio Guglieri
Keyword(s):  
Attitude Control ◽  
Linear Quadratic Regulator ◽  
Control Algorithms ◽  
Linear Quadratic ◽  
C Language ◽  
Orbital Maneuvers ◽  
Guidance And Control ◽  
Actuation System ◽  
Novel Concept ◽  
And Control

The purpose of this paper is the design of guidance and control algorithms for orbital space maneuvers. A 6-dof orbital simulator, based on Clohessy-Wiltshire-Hill equations, is developed in C language, considering cold gas reaction thrusters and reaction wheels as actuation system. The computational limitations of on-board computers are also included. A combination of guidance and control algorithms for an orbital maneuver is proposed: (i) a suitably designed Zero-Effort-Miss/Zero-Effort-Velocity (ZEM/ZEV) algorithm is adopted for the guidance and (ii) a linear quadratic regulator (LQR) is used for the attitude control. The proposed approach is verified for different cases, including external environment disturbances and errors on the actuation system.

scholarly journals Kane Method Based Dynamics Modeling and Control Study for Space Manipulator Capturing a Space Target

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Yanhua Han
Keyword(s):  
Attitude Control ◽  
Dynamics Modeling ◽  
Attitude Control System ◽  
Constraint Forces ◽  
Inertia Moment ◽  
Modeling And Control ◽  
And Control ◽  
Kane Method ◽  
Control Study ◽  
Space Target

Dynamics modeling and control problem of a two-link manipulator mounted on a spacecraft (so-called carrier) freely flying around a space target on earth’s circular orbit is studied in the paper. The influence of the carrier’s relative movement on its manipulator is considered in dynamics modeling; nevertheless, that of the manipulator on its carrier is neglected with the assumption that the mass and inertia moment of the manipulator is far less than that of the carrier. Meanwhile, we suppose that the attitude control system of the carrier guarantees its side on which the manipulator is mounted points accurately always the space target during approaching operation. The ideal constraint forces can be out of consideration in dynamics modeling as Kane method is used. The path functions of the manipulator’s end-effector approaching the space target as well as the manipulator’s joints control torque functions are programmed to meet the soft touch requirement that the end-effector’s relative velocity to the space target is zero at touch moment. Numerical simulation validation is conducted finally.

scholarly journals Roll Attitude Determination of Spin Projectile Based on GPS and Magnetoresistive Sensor

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Dandan Yuan ◽  
Wenjun Yi ◽  
Jun Guan
Keyword(s):  
Mathematical Model ◽  
Attitude Determination ◽  
Accurate Determination ◽  
Blind Spot ◽  
Gps Measurements ◽  
Guidance And Control ◽  
Magnetoresistive Sensor ◽  
Proposed Model ◽  
And Control

Improvement in attack accuracy of the spin projectiles is a very significant objective, which increases the overall combat efficiency of projectiles. The accurate determination of the projectile roll attitude is the recent objective of the efficient guidance and control. The roll measurement system for the spin projectile is commonly based on the magnetoresistive sensor. It is well known that the magnetoresistive sensor produces a sinusoidally oscillating signal whose frequency slowly decays with time, besides the possibility of blind spot. On the other hand, absolute sensors such as GPS have fixed errors even though the update rates are generally low. To earn the benefit while eliminating weaknesses from both types of sensors, a mathematical model using filtering technique can be designed to integrate the magnetoresistive sensor and GPS measurements. In this paper, a mathematical model is developed to integrate the magnetoresistive sensor and GPS measurements in order to get an accurate prediction of projectile roll attitude in a real flight time. The proposed model is verified using numerical simulations, which illustrated that the accuracy of the roll attitude measurement is improved.

scholarly journals Guidance Law and Neural Control for Hypersonic Missile to Track Targets

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Wenxing Fu ◽  
Binbin Yan ◽  
Xiaofei Chang ◽  
Jie Yan
Keyword(s):  
Neural Control ◽  
Controller Design ◽  
Sliding Mode ◽  
External Disturbance ◽  
Control Laws ◽  
Guidance And Control ◽  
Maneuvering Target ◽  
Guidance Law ◽  
Control Command ◽  
And Control

Hypersonic technology plays an important role in prompt global strike. Because the flight dynamics of a hypersonic vehicle is nonlinear, uncertain, and highly coupled, the controller design is challenging, especially to design its guidance and control law during the attack of a maneuvering target. In this paper, the sliding mode control (SMC) method is used to develop the guidance law from which the desired flight path angle is derived. With the desired information as control command, the adaptive neural control in discrete time is investigated ingeniously for the longitudinal dynamics of the hypersonic missile. The proposed guidance and control laws are validated by simulation of a hypersonic missile against a maneuvering target. It is demonstrated that the scheme has good robustness and high accuracy to attack a maneuvering target in the presence of external disturbance and missile model uncertainty.

scholarly journals ENSURING THE SURVIVABILITY OF SPACECRAFT CONTROL SYSTEM AT CRITICAL FAILURES OF REACTION WHEELS

2021 ◽  
Vol 23 (2) ◽  
pp. 66-74
Author(s):  
S.Ye. Somov ◽  
◽  
T.Ye. Somova ◽  
◽  
Keyword(s):  
Computer Simulation ◽  
Control System ◽  
Attitude Control ◽  
Spacecraft Attitude ◽  
Spacecraft Attitude Control ◽  
General Electric ◽  
Attitude Control System ◽  
Spacecraft Control ◽  
The Earth ◽  
Magnetic Drive

A method for ensuring the survivability of the spacecraft attitude control system with a minimally redundant cluster of flywheels by General Electric scheme and a magnetic drive in the event of the flywheels' failures is presented. The results of computer simulation were obtained and it was found that in case of failure of any two flywheels, the Earth survey satellite retains the ability to scanning observation given targets.

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