Space subsystems design: (navigation, control, structure and…)
Arash Abarghooei; Hassan Salarieh; Pedram Hosseiniakram
Volume 16, English Special Issue , November 2023, , Pages 51-64
Abstract
Linear algorithms are the most widely used method for satellite attitude control using reaction wheels because of their simplicity and low computational cost. The first part of the paper introduces different attitude determination and control algorithms, and reviews resources that utilized optimal linear ...
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Linear algorithms are the most widely used method for satellite attitude control using reaction wheels because of their simplicity and low computational cost. The first part of the paper introduces different attitude determination and control algorithms, and reviews resources that utilized optimal linear and nonlinear control methods (such as LQR and SDRE). Next, dynamic equations for the control of the satellite using reaction wheels have been extracted, then the satellite controller has been designed by using optimal linear and nonlinear methods, which are robust against noise and disturbance, as an alternative for the PD controller. Finally, the designed control algorithms have been implemented for different satellite pointing scenarios, and by simulating these methods in MATLAB software, their performance has been studied and compared.
ehsan maani; Hossein Nejat Pishkenari; Amir Reza Kosari
Volume 11, Issue 3 , December 2018, , Pages 63-71
Abstract
In this paper, the combination of reaction wheels and thrusters is applied to attitude control of a satellite. First, governing equations of satellite attitude dynamics are given using quaternion and PID controller is designed based on the satellite quaternion to determine the applied control torque. ...
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In this paper, the combination of reaction wheels and thrusters is applied to attitude control of a satellite. First, governing equations of satellite attitude dynamics are given using quaternion and PID controller is designed based on the satellite quaternion to determine the applied control torque. By applying the reaction wheels physical constraints such as its maximum torque, its maximum momentum and maximum power on the desired torque, reaction wheels angular momentums and torques are found. The obtained results show that the unsaturated reaction wheels capabilities in attitude control. Results also show that the wheels saturation leads to error in control and increases the Euler angles and quaternions. Satellite thrusters are utilized to reaction wheels de-saturation and attitude control simultaneously.Three different strategies are proposed in this paper for wheels de-saturation using thrusters. Two well known methods, pulse width modulator (PWM) and pulse width pulse frequency (PWPF) modulator are used to attitude control using thrusters. All methods are compared together and the optimal method is proposed for the satellite attitude control. This paper results can be useful in design and control of different class of satellites.
Farhad Fani Saberi; Mansor Kabganian; Alireza Fazlyab; Abbas Ajorkar
Volume 9, Issue 1 , May 2016, , Pages 25-35
Abstract
In this paper, a robust attitude control algorithm is developed based on backstepping-sliding mode control for a satellite using four reaction wheels in a tetrahedron configuration. In this method, asymptotic stability of the proposed algorithm has been proven in the presence of reaction wheels dynamic ...
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In this paper, a robust attitude control algorithm is developed based on backstepping-sliding mode control for a satellite using four reaction wheels in a tetrahedron configuration. In this method, asymptotic stability of the proposed algorithm has been proven in the presence of reaction wheels dynamic model based on Lyapunov theory. Then, in order to evaluate the performance of the proposed algorithm, a low-cost real-time prossecor in the loop test bed is provided. The presented test bed is capable of real-time assessing the attitude backstepping-sliding mode control algorithm. In this test bed, real-time modeling of satellite dynamic, environmental disturbances and reaction wheels are achieved in a simulator computer and the proposed control algorithm performance is investigated by implementing it in an electronic control board of the prossecor in the loop test bed.
Hojat Taei; M. Mirshams; M. Ghobadi; M. A. Vahid D.; H. Haghi
Volume 8, Issue 4 , January 2016, , Pages 35-44
Abstract
This article describes the details of a Tri-axial Spacecraft Simulator Testbed (TSST) that has been developed as part of a research program on spacecraft multi-body rotational dynamics and control in Space Research Laboratory (SRL) at K. N. Toosi University of Technology. This dumbbell style simulator ...
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This article describes the details of a Tri-axial Spacecraft Simulator Testbed (TSST) that has been developed as part of a research program on spacecraft multi-body rotational dynamics and control in Space Research Laboratory (SRL) at K. N. Toosi University of Technology. This dumbbell style simulator includes a variety of components: spherical air-bearing, inertial measurement unit (IMU), rechargeable battery, reaction wheels (RW), on-board computer (OBC) and balancing masses. In this paper, an attitude control problem for the spacecraft simulator actuated by three reaction wheels is studied. Under the assumption of uniform gravity and frictionless air-bearing environment, reaction wheels generate control moments about the roll, pitch and yaw axes of the base body. The control objective is to perform attitude commands sent from users with the least power consumption and a high precision. To handle the non-linear model, a Linear Quadratic Ricatti (LQR) controller has been programmed and it efficaciously controlled the computer-modeled simulator for any given slewing maneuver. This control approach has been developed to facilitate the system to accomplish large-angle, three-axis slewing maneuvers using RWs as effective actuators.
A. R. Aghalari; M. Iranzad
Volume 6, Issue 1 , April 2013, , Pages 79-91
Abstract
Precision spacecrafts require high levels of pointing stability. Small levels of vibration can cause a significant reduction in image quality. There are many possible disturbance sources on spacecraft (mechanical systems or sensors), but the reaction wheel assembly (RWA) is anticipated to be the largest. ...
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Precision spacecrafts require high levels of pointing stability. Small levels of vibration can cause a significant reduction in image quality. There are many possible disturbance sources on spacecraft (mechanical systems or sensors), but the reaction wheel assembly (RWA) is anticipated to be the largest. Therefore, accurate models of reaction wheel disturbances are necessary to predict their effect on the spacecraft performance and develop methods to control the undesired vibration. In this paper, two types of reaction wheel disturbance models is presented. The first is a steady-state empirical model that was originally created based on a prototype RWA hard-mounted test data. The model assumes that the disturbances consist of discrete harmonics of the wheel speed with amplitudes proportional to the wheel speed squared. Experimental data obtained from RWA designed and manufactured by Aghalari and et al. are used to illustrate the empirical modeling process and provide model validation. The model captures the harmonic disturbances of the wheel quite well, but does not include interactions between the harmonics and the structural modes of the wheel which result in large disturbance amplifications at some wheel speeds. Therefore the second model, a nonlinear analytical model, is created using energy methods to capture the internal flexibilities and fundamental harmonic of an unbalanced wheel. Then the analytical model has been extended to capture all the wheel harmonics as well as the disturbance amplifications that occur due to excitation of the structural wheel modes by the harmonics. Finally experimental data obtained from hard-mounted test of RWA is used to determine the model parameters for both types of models and a comparison between the models and data is presented.
Farhad Fani Saberi; Amir Eslami Mehrjardi
Volume 5, Issue 4 , January 2013, , Pages 39-45
Abstract
In this paper we are going to design an attitude control system for a Stereo-Imaging Remote Sensing Satellite using of four pyramidal reaction wheels. In this method, in order to provide the power requirements of the satellite by the energy stored in the reaction wheels, a power management law will be ...
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In this paper we are going to design an attitude control system for a Stereo-Imaging Remote Sensing Satellite using of four pyramidal reaction wheels. In this method, in order to provide the power requirements of the satellite by the energy stored in the reaction wheels, a power management law will be designed and added to the attitude control law to charge and discharge the wheels according to the preset profiles. Therefore, attitude control and power management of the satellite will be carried out simultaneously. In this method, while the satellite is in the light and the batteries are charged, the speed of the wheels increase up to the limited speeds and while the power requirements of the subsystems are inadequate, Power will be returned to the subsystems by reducing the speed of the wheels. The design of this system has been conducted to consider the effects of saturation of the wheels to prevent attitude deviations of satellite while power management is done. Simulation results show the good performance of the designed attitude control and power management system of the satellite.
A. H. Tavakkoli; A. Kalhor; S. M. M. Dehghan
Volume 5, Issue 2 , July 2012, , Pages 59-68
Abstract
In this paper the performance of a three Degrees Of Freedom simulator is evaluated. This platform is considered as an important instrument generally used in performance tests of spacecraft attitude determination and control subsystem on the ground. A hemispherical air bearing is used to provide micro ...
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In this paper the performance of a three Degrees Of Freedom simulator is evaluated. This platform is considered as an important instrument generally used in performance tests of spacecraft attitude determination and control subsystem on the ground. A hemispherical air bearing is used to provide micro gravity condition. Reaction wheels produce required control torques and an integrated sensor is used for attitude determination. Commanding and visualization of the platform in monitoring station are provided by a wireless LAN. PD, QEF and LQR controllers are designed and implemented for slew maneuver to show the ability of the simulator. The desired attitude accuracy is obtained using these controllers. The test results verify the designed controllers and show the ability and functionality of the system, as a simulator for evaluating attitude controllers.
S. H. Miri Roknabadi; S. M. Mirshams; A. A. Nikkhah
Volume 2, Issue 3 , December 2009, , Pages 35-42
Abstract
This paper presents an optimal attitude maneuver by means of Reaction Wheels to achieve desired attitude for a Satellite. At first, Dynamic Equations of motion for a satellite with three Reaction Wheels as its active actuators has been educed, and then State Equations of this system has been obtained. ...
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This paper presents an optimal attitude maneuver by means of Reaction Wheels to achieve desired attitude for a Satellite. At first, Dynamic Equations of motion for a satellite with three Reaction Wheels as its active actuators has been educed, and then State Equations of this system has been obtained. In derivation of equations, coupling of Reaction Wheel electrical equations with dynamic equations of satellite motion, and Reaction wheel saturation avoidance approaches are considered. Then an optimal attitude control with the LQR method has exerted for a distinct satellite by its Reaction Wheels. As a result of simulation has presented an optimal effort by calculated Gain matrix to achieve desired attitude for chosen Satellite. It shows that satellite becomes stable in desired attitude with a low energy and time consumption.
S.H. Miri Roknabadi; M. Mirshams; A. A. Nikkhah
Volume 2, Issue 2 , July 2009, , Pages 61-68
Abstract
This paper presents a technical note of mathematic model, design and manufacturing steps of a Reaction Wheel, one of the most important active actuators of satellite. After that Reaction Wheels are tested for the satellite simulator of K.N.Toosi University of Technology, Iran. There were some requirements ...
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This paper presents a technical note of mathematic model, design and manufacturing steps of a Reaction Wheel, one of the most important active actuators of satellite. After that Reaction Wheels are tested for the satellite simulator of K.N.Toosi University of Technology, Iran. There were some requirements and restrictions such as needed maximum torque and control accuracy for attitude maneuver, receivable power, voltage and current. Accordingly fundamental components of Reaction Wheel have been designed and selected. Wheel, motor, bearings and retentive are the significant components. At the rest of the paper, the substantial parameters of the Reaction Wheels are confirmed by a new test set. The results of test guarantee a satisfactory stabilization and accurate maneuver.
