Space subsystems design: (navigation, control, structure and…)
M. Navabi; M. Salehi
Volume 16, Issue 2 , June 2023, , Pages 63-77
Abstract
In a flying system, attitude control is one of the essential subsystems. In this subsystem, estimating the current state is very important to control the state, which is achieved by considering the attitude sensors. Comprehensive research is being done today to reduce the cost of Attitude sensors in ...
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In a flying system, attitude control is one of the essential subsystems. In this subsystem, estimating the current state is very important to control the state, which is achieved by considering the attitude sensors. Comprehensive research is being done today to reduce the cost of Attitude sensors in applications such as drones, satellite simulation platforms, etc. For this purpose, sensors based on Micro-electromechanical Systems have received much attention due to their small size and low energy consumption. This model of sensors, despite its many advantages, has various noises and disturbances that require the application of fusion and estimation algorithms to obtain an acceptable output. In this research, to determine the attitude of the test platform, data fusion algorithms including complementary filter, Kalman filter, and Extended Kalman filter are implemented on a low-cost sensor. The mentioned estimation methods were implemented on the test platform and by determining the effective parameters in the estimation algorithms, the desired accuracy was obtained. The module obtained in these experiments is comparable to more expensive sensors.
Space subsystems design: (navigation, control, structure and…)
Mohsen Ebrahimi; Amir Farhad Ehyaei
Volume 15, Issue 3 , September 2022, , Pages 11-22
Abstract
In this paper, in addition to investigation and analyzing the dynamic model of a maneuver target, a new method based on the Interaction Multiple Model (IMM) method is presented to solve the tracking problem in presence of measurement noise. In this procedure, two models are used along with an extended ...
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In this paper, in addition to investigation and analyzing the dynamic model of a maneuver target, a new method based on the Interaction Multiple Model (IMM) method is presented to solve the tracking problem in presence of measurement noise. In this procedure, two models are used along with an extended Kalman filter for each model, for estimation of the states related to stochastic target model. To this end, a specific weight is calculated adaptively for each model and the final estimation of the target is obtained from the weighted sum of the modes related to each model. In this paper, second order Markov models are used to better describe the system behavior which leads to a decrease in the number of required motion models. This means that the previous two models are used to decide on the next model, and a much better algorithm is provided than the first-order IMM algorithm.
H. Bolandi; M. H. Ashtari; M. Esmaeilzadeh; M. Haghparast
Volume 6, Issue 3 , October 2013, , Pages 27-37
Abstract
In this paper predicting of position of satellite based on extended kalman filter with considering hardware implementation consideration and simultaneously maintaining desired accuracy is investigated. For this purpose, first, effective forces on orbital dynamic and nonlinear equation of orbital motion ...
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In this paper predicting of position of satellite based on extended kalman filter with considering hardware implementation consideration and simultaneously maintaining desired accuracy is investigated. For this purpose, first, effective forces on orbital dynamic and nonlinear equation of orbital motion are presented. In order to increasing accuracy of prediction in position of satellite, J2, J3 and J4 harmonics of potentialfunction of the earth are considered and future position of satellite is predicted using linearized dynamic model and applying EKF on this model. Here Measurement data are position and velocity vector of satellite which are extracted by GPS receivers. Since in this paper systematic satellite design is considered, scenario of “ON TIME” of GPS receivers based on power consumption considerations is discussed. Finally simulation results for a LEO satellite and comparing these results with STK results, shows accuracy of presented modeling and equations.
M. Fakoor; A. R. Kosari; H. Salehghaffari
Volume 6, Issue 2 , July 2013, , Pages 67-74
Abstract
This paper deals with the estimation of gyro model parameters and GEO satellite moment of inertia at the same time in transfer orbit phase. In order to fuse information of attitude determination subsystem sensors, an extended Kalman Filter has been employed. The estimation variables are including: quaternion, ...
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This paper deals with the estimation of gyro model parameters and GEO satellite moment of inertia at the same time in transfer orbit phase. In order to fuse information of attitude determination subsystem sensors, an extended Kalman Filter has been employed. The estimation variables are including: quaternion, angular velocity, moments of inertia, and gyro sensor model parameters which are bias and scale factor vectors. The satellite motion equations along with gyro sensor and quaternion measurements have been used to design an Extended Kalman Filter in order to estimate the desired states. The disturbance torque effect on moment of inertia identification has been also considered. Estimation results via some case studies demonstrate the numerical simulation section exhibit robustness and efficiency of Kalman Fillter.
