Papers by Mohammad Chessab Mahdi
https://www.irjet.net/archives/V4/i1/IRJET-V4I1140.pdf
This paper describes speed control of separately excited DC motor using Chopper as power converte... more This paper describes speed control of separately excited DC motor using Chopper as power converter and PI as speed and current controller. The separately excited DC motor can be controlled from below and up to rated speed. Optimization filter of speed is obtained using Modulus Hugging Approach. After obtaining the complete model of DC drive system, the model is simulated by MATLAB. The simulation is done and analyzed under varying speed and varying load torque conditions like rated speed and load torque, half the rated load torque and half speed .
In this paper, a fuzzy PID controller has been suggested to use in attitude determination and con... more In this paper, a fuzzy PID controller has been suggested to use in attitude determination and control subsystem of kufasat equipped with three magnetic coils. Using the linearized equations of motion for a rigid body in space, the linearized stability, effectiveness and robustness of a fuzzy PID controller design were compared with that of a fuzzy PD controller design. The detailed design procedure of the fuzzy controllers is presented. When fuzzy PID controller is applied simulation results show that more precise attitude control is accomplished and less time of satellite maneuver is required comparing with applying fuzzy PD controller.
The probability of KufaSat collisions with different sizes of orbital debris and with other satel... more The probability of KufaSat collisions with different sizes of orbital debris and with other satellites which operating in the same orbit during orbital lifetime was determined. Apogee/Perigee Altitude History was used to graph apogee and perigee altitudes over KufaSat lifetime. The required change in velocity for maneuvers necessary to reentry atmospheric within 25 years was calculated. The prediction of orbital lifetime of KufaSat using orbital parameters and engineering specifications as inputs to the Debris Assessment Software (DAS) was done, it has been verified that the orbital lifetime will not be more than 25 years after end of mission which is compatible with recommendation of Inter-Agency Space Debris Coordination Committee (IADC).
The equation of two body motion was derived with the assumption of mass with spherically symmetri... more The equation of two body motion was derived with the assumption of mass with spherically symmetric distribution. This equation includes perturbions which represent the deviation from the ideal Kepler's orbit as a result of external forces effect. These forces can be classified into two types: gravitational forces and non-gravitational forces. In this work gravitational forces includes Earth's oblateness effect and non-gravitational include Atmospheric drag and Solar radiation pressure. The prediction of orbital lifetime of KufaSat using orbital parameters and engineering specifications as inputs to the Debris Assessment Software (DAS) was done, it has been verified that the orbital lifetime will not be longer than 25 years after completion of mission which is compatible with recommendation of Inter-Agency Space Debris Coordination Committee (IADC).The probability of KufaSat collisions with orbital debris and satellites which operating in the same orbit during orbital lifetime was determined. Apogee/Perigee Altitude History was used to graph apogee and perigee altitudes over KufaSat lifetime .The change in velocity required for maneuvers needed to achieve atmospheric reentry within 25 years was calculated.
كوفة سات هو برنامج قمر صناعي نانوي ينفذ من قبل طلبة جامعة الكوفة, الهدف من هذا البرنامج هو تصميم ... more كوفة سات هو برنامج قمر صناعي نانوي ينفذ من قبل طلبة جامعة الكوفة, الهدف من هذا البرنامج هو تصميم وتجميع واطلاق قمر صناعي نانوي نوع كيوبسات وفق المعايير العالمية لاغراض التحسس النائي والاستكشافات العلمية لسطح الارض من الفضاء الخارجي من خلال تصوير سطح الارض باستخدام كاميره (CMOS) تعمل بالطيف المرئي والاشعه تحت الحمراء. القمر ذو استقرارية المحاور الثلاثة وتأثير عزم انحدار جاذبية الارض يتضمن بوم انحدار الجاذبيه بطول 1.5 م وكتله طرفيه قيمتها 40 غم . النموذج الحالي هو نموذج هندسي اولي تم تصنيع اجزاءه من مواد محلية الصنع لا تحمل المواصفات الفضائيه. من المؤمل استبدال هذه الاجزاء بأخرى ذات مواصفات فضائيه.
Orbit design for KufaSat Nano-satellites is presented. Polar orbit is selected for
the KufaSat mi... more Orbit design for KufaSat Nano-satellites is presented. Polar orbit is selected for
the KufaSat mission. The orbit was designed with an Inclination which enables the satellite to
see every part of the earth. KufaSat has a payload for imaging purposes which require a large
amount of power, so the orbit is determined to be sun synchronous in order to provide the
power through solar panels. The KufaSat mission is designed for the low earth orbit. The six
initial Keplerian Elements of KufaSat are calculated. The orbit design of KufaSat according to
the calculated Keplerian elements has been simulated and analyzed by using MATLAB first
and then by using General Mission Analysis Tool.
The aim of research is to find compression methods which are more appropriate to compress files w... more The aim of research is to find compression methods which are more appropriate to compress files with different extensions, and what the effect of changing the size of the file on the compression ratio .
In this research have been selected eight most common of file extensions and for each one of these extensions have been selected ten different size files as a samples to compress by using three lossless compression methods(RLE, Huffman ,LZW ) have also been discussed the response of each extension to the three methods. All programs have been written using visual basic language
Kufasat is a student satellite program and the goal of this program is to design
and launch a cub... more Kufasat is a student satellite program and the goal of this program is to design
and launch a cube satellite .The purpose of this study is to design and to
develop an efficient Attitude Determination and Control System- ADCS for
the satellite. The satellite is intended to fly in a low earth orbit at 600km
altitude and its mission is to perform scientific measurements.
The satellite is to be cubic with 10 cm on all sides and have a total mass of
approximately 1kg and be three -axis gravity gradient stabilized. The satellite
consists of (1.5) m long gravity gradient boom. The gravity gradient boom
has a tip mass of (40) g to improve the gravity gradient stabilization .A
gravity gradient stabilized satellite has a limited stability and a pointing
capabilities, and a magnetic coils are added to improve both the three axis
stabilization and the pointing properties. Magnetic coils around the satellite's
XYZ axes can be fed with a constant current-switched in two directions-to
generate a magnetic dipole moment which will interact with the geomagnetic
field to generate a satellite torque, which is used to control the rotation of the
satellite. A problem is that both the direction and the strength of the
geomagnetic field change and magnetic control become non-linear and time
dependent .The magnetic coils are controlled by using a fuzzy logic
controller, based on a combination of membership functions and rules. The
controller consists actually of 3 MISO fuzzy control laws, one for each
magneto torquer (MX, MY and MZ coils). Each control law embodies a
fuzzy rule base to decide on the control desirability and output level when
using the corresponding torquer. Magnetic coils allow cheaper satellite, and
are an attractive solution to small, inexpensive satellite in low earth orbit. The
satellite will be during separation from the launch vehicle is exposed to forces
from the release mechanism and tumbling may occur. A detumbling mode is
activated in order to calm down the movement .The gravitation boom will be
deployed first when the movement of the satellite is sufficient small. This
study deals with attitude control after the detumbling mode has successfully
been completed and the boom is fully deployed.
The aim of research is to building high performance lossless data compression
engine which achiev... more The aim of research is to building high performance lossless data compression
engine which achieve high compression ratio by using combination of two lossless compression methods (Huffman and LZSS) . The engine is being built in two methods ,the first is to compress the file by Huffman then compress the file resulting from the compression process by LZSS and the second is to compress the file by LZSS then compress the file resulting from the compression process by Huffman
In this research two common file extensions were selected and for each one of these extensions ten different size files were selected as a samples to compress by using four compression methods(Huffman ,LZSS ,Huffman +LZSS ,LZSS +Huffman ) the response of each extension to the four methods have been discussed . Results are discussed to determine the method which achieve the highest compression ratio .The effect of changing the size of the file on the compression ratio has been studied .
paper describes speed control of separately excited DC motor using Chopper as power
converter and... more paper describes speed control of separately excited DC motor using Chopper as power
converter and PI as speed and current controller. The separately excited DC motor can be
controlled from below and up to rated speed . Optimization filter of speed is obtained using
Modulus Hugging Approach . After obtaining the complete model of DC drive system, the
model is simulated by MATLAB. The simulation is done and analyzed under varying speed
and varying load torque conditions like rated speed and load torque, half the rated load torque
and half speed .
In this paper, Linear Quadratic Regulator (LQR)controller is applied to the attitude stabilizatio... more In this paper, Linear Quadratic Regulator (LQR)controller is applied to the attitude stabilization control of Kufasat. Using the linearized equations of motion for a rigid body in space, the linearized stability, effectiveness and robustness of a linear quadratic regulator (LQR) control design were compared with that of a Proportional-Integral-Derivative (PID) control design. The detailed design procedure of the LQR controller is presented. Simulation results show that precise attitude control is accomplished and the time of satellite maneuver is shortened in spite of the uncertainty in the system.
This paper presents the design and simulation of communication subsystem of KufaSat Nano-Satellit... more This paper presents the design and simulation of communication subsystem of KufaSat Nano-Satellite in general and focuses on the terminal node controller as a key part of the communications subsystem. A transceiver, terminal node controller (TNC), and antenna has been selected as communications subsystem hardware. A terminal node controller consists of a micro con-trol unit, a modem, EPROM and software that implement the AX.25 protocol.
Satellite orbit simulation and analysis based on data collected from NASA/ North American Defense... more Satellite orbit simulation and analysis based on data collected from NASA/ North American Defense Command (NORAD)
as a Two Line Elements (TLE) files is presented. General Mission Analysis Tool (GMAT) is used to simulate the orbital motion of
TIGRISAT. The analysis includes orbit determination and prediction of satellite’s position and velocity, satellite tracking, and
command summary. Orbital path of the TIGRISAT projected onto a two-dimensional world map over some time for one and two
revolution of the satellite is plotted.
A new design for increased power extraction for NanoSatellites is proposed, which is used for Kuf... more A new design for increased power extraction for NanoSatellites is proposed, which is used for KufaSat. This
proposed design contains four expandable panels with additional sixteen solar cells, two solar cells on each side of panel.
The proposed design with additional panels and how these additional panels are assembled to the body of KufaSat and how
they are deployed after the launching are presented. Comparison between original design and proposed design in addition
to discussion the increasing in power production and charge current are included.
In this paper the design of attitude determination and control subsystem of KufaSat Nanosatellite... more In this paper the design of attitude determination and control subsystem of KufaSat Nanosatellite is presented. A three
axis magnetometer, six single axis sun sensors, three axis gyroscope and GPS receiver are used as the sensors for
attitude determination. TRIAD, algorithm are used for determining attitude estimate from two vector measurements This
estimate is then passed to extended Kalman Filter, along with the gyroscope measurements, to obtain a finer attitude.
The attitude controller is designed to achieve desired attitude with an accuracy of 5 degrees in nadir pointing using three
orthogonal magnetic coils. Two attitude control modes has been considered , detumbling mode and stabilization mode ,
B-Dot control algorithm is used in detumbling mode while quaternion feedback regulator algorithm is used in
stabilization mode. Performance of the control system is verified through closed loop simulations involving models of
satellite kinematics and dynamics, space environment, sensors, control law and actuators. Simulations and results of
both detumbling mode, and stabilization mode are presented. The simulations show that the satellite will detumble in 60
minutes after separation from the launcher and the stabilization mode controller able to point the satellite with a
maximum error of 5 degrees.
In this paper, a direct fuzzy controller is applied to
the attitude stabilization control of a Cu... more In this paper, a direct fuzzy controller is applied to
the attitude stabilization control of a CubeSat. The Takagi-
Sugeno (T-S) model fuzzy controller is evaluated for attitude
control of magnetic actuated satellites based on the attitude
error including error in the angles and their rates. The
detailed design procedure of the fuzzy control system is
presented. Simulation results show that precise attitude
control is accomplished and the time of satellite maneuver is
shortened in spite of the uncertainty in the system.
Design of electrical power system for Nano-satellites is presented. The role of this electrical p... more Design of electrical power system for Nano-satellites is presented. The role of this electrical power system is to provide
electrical power for all the subsystems of KufaSat .This was achieved by the use of solar cells when the satellite is in direct sunlight and
by two Lithium Polymer batteries when the Sun is eclipsed .The batteries are charged by the solar panels through three battery charge
regulators which optimize the solar arrays’ voltages independently for maximum power transfer. Power is then transferred to subsystems
through a number of power buses, 3.3V, 5V and unregulated.
Uploads
Papers by Mohammad Chessab Mahdi
the KufaSat mission. The orbit was designed with an Inclination which enables the satellite to
see every part of the earth. KufaSat has a payload for imaging purposes which require a large
amount of power, so the orbit is determined to be sun synchronous in order to provide the
power through solar panels. The KufaSat mission is designed for the low earth orbit. The six
initial Keplerian Elements of KufaSat are calculated. The orbit design of KufaSat according to
the calculated Keplerian elements has been simulated and analyzed by using MATLAB first
and then by using General Mission Analysis Tool.
In this research have been selected eight most common of file extensions and for each one of these extensions have been selected ten different size files as a samples to compress by using three lossless compression methods(RLE, Huffman ,LZW ) have also been discussed the response of each extension to the three methods. All programs have been written using visual basic language
and launch a cube satellite .The purpose of this study is to design and to
develop an efficient Attitude Determination and Control System- ADCS for
the satellite. The satellite is intended to fly in a low earth orbit at 600km
altitude and its mission is to perform scientific measurements.
The satellite is to be cubic with 10 cm on all sides and have a total mass of
approximately 1kg and be three -axis gravity gradient stabilized. The satellite
consists of (1.5) m long gravity gradient boom. The gravity gradient boom
has a tip mass of (40) g to improve the gravity gradient stabilization .A
gravity gradient stabilized satellite has a limited stability and a pointing
capabilities, and a magnetic coils are added to improve both the three axis
stabilization and the pointing properties. Magnetic coils around the satellite's
XYZ axes can be fed with a constant current-switched in two directions-to
generate a magnetic dipole moment which will interact with the geomagnetic
field to generate a satellite torque, which is used to control the rotation of the
satellite. A problem is that both the direction and the strength of the
geomagnetic field change and magnetic control become non-linear and time
dependent .The magnetic coils are controlled by using a fuzzy logic
controller, based on a combination of membership functions and rules. The
controller consists actually of 3 MISO fuzzy control laws, one for each
magneto torquer (MX, MY and MZ coils). Each control law embodies a
fuzzy rule base to decide on the control desirability and output level when
using the corresponding torquer. Magnetic coils allow cheaper satellite, and
are an attractive solution to small, inexpensive satellite in low earth orbit. The
satellite will be during separation from the launch vehicle is exposed to forces
from the release mechanism and tumbling may occur. A detumbling mode is
activated in order to calm down the movement .The gravitation boom will be
deployed first when the movement of the satellite is sufficient small. This
study deals with attitude control after the detumbling mode has successfully
been completed and the boom is fully deployed.
engine which achieve high compression ratio by using combination of two lossless compression methods (Huffman and LZSS) . The engine is being built in two methods ,the first is to compress the file by Huffman then compress the file resulting from the compression process by LZSS and the second is to compress the file by LZSS then compress the file resulting from the compression process by Huffman
In this research two common file extensions were selected and for each one of these extensions ten different size files were selected as a samples to compress by using four compression methods(Huffman ,LZSS ,Huffman +LZSS ,LZSS +Huffman ) the response of each extension to the four methods have been discussed . Results are discussed to determine the method which achieve the highest compression ratio .The effect of changing the size of the file on the compression ratio has been studied .
converter and PI as speed and current controller. The separately excited DC motor can be
controlled from below and up to rated speed . Optimization filter of speed is obtained using
Modulus Hugging Approach . After obtaining the complete model of DC drive system, the
model is simulated by MATLAB. The simulation is done and analyzed under varying speed
and varying load torque conditions like rated speed and load torque, half the rated load torque
and half speed .
as a Two Line Elements (TLE) files is presented. General Mission Analysis Tool (GMAT) is used to simulate the orbital motion of
TIGRISAT. The analysis includes orbit determination and prediction of satellite’s position and velocity, satellite tracking, and
command summary. Orbital path of the TIGRISAT projected onto a two-dimensional world map over some time for one and two
revolution of the satellite is plotted.
proposed design contains four expandable panels with additional sixteen solar cells, two solar cells on each side of panel.
The proposed design with additional panels and how these additional panels are assembled to the body of KufaSat and how
they are deployed after the launching are presented. Comparison between original design and proposed design in addition
to discussion the increasing in power production and charge current are included.
axis magnetometer, six single axis sun sensors, three axis gyroscope and GPS receiver are used as the sensors for
attitude determination. TRIAD, algorithm are used for determining attitude estimate from two vector measurements This
estimate is then passed to extended Kalman Filter, along with the gyroscope measurements, to obtain a finer attitude.
The attitude controller is designed to achieve desired attitude with an accuracy of 5 degrees in nadir pointing using three
orthogonal magnetic coils. Two attitude control modes has been considered , detumbling mode and stabilization mode ,
B-Dot control algorithm is used in detumbling mode while quaternion feedback regulator algorithm is used in
stabilization mode. Performance of the control system is verified through closed loop simulations involving models of
satellite kinematics and dynamics, space environment, sensors, control law and actuators. Simulations and results of
both detumbling mode, and stabilization mode are presented. The simulations show that the satellite will detumble in 60
minutes after separation from the launcher and the stabilization mode controller able to point the satellite with a
maximum error of 5 degrees.
the attitude stabilization control of a CubeSat. The Takagi-
Sugeno (T-S) model fuzzy controller is evaluated for attitude
control of magnetic actuated satellites based on the attitude
error including error in the angles and their rates. The
detailed design procedure of the fuzzy control system is
presented. Simulation results show that precise attitude
control is accomplished and the time of satellite maneuver is
shortened in spite of the uncertainty in the system.
electrical power for all the subsystems of KufaSat .This was achieved by the use of solar cells when the satellite is in direct sunlight and
by two Lithium Polymer batteries when the Sun is eclipsed .The batteries are charged by the solar panels through three battery charge
regulators which optimize the solar arrays’ voltages independently for maximum power transfer. Power is then transferred to subsystems
through a number of power buses, 3.3V, 5V and unregulated.
the KufaSat mission. The orbit was designed with an Inclination which enables the satellite to
see every part of the earth. KufaSat has a payload for imaging purposes which require a large
amount of power, so the orbit is determined to be sun synchronous in order to provide the
power through solar panels. The KufaSat mission is designed for the low earth orbit. The six
initial Keplerian Elements of KufaSat are calculated. The orbit design of KufaSat according to
the calculated Keplerian elements has been simulated and analyzed by using MATLAB first
and then by using General Mission Analysis Tool.
In this research have been selected eight most common of file extensions and for each one of these extensions have been selected ten different size files as a samples to compress by using three lossless compression methods(RLE, Huffman ,LZW ) have also been discussed the response of each extension to the three methods. All programs have been written using visual basic language
and launch a cube satellite .The purpose of this study is to design and to
develop an efficient Attitude Determination and Control System- ADCS for
the satellite. The satellite is intended to fly in a low earth orbit at 600km
altitude and its mission is to perform scientific measurements.
The satellite is to be cubic with 10 cm on all sides and have a total mass of
approximately 1kg and be three -axis gravity gradient stabilized. The satellite
consists of (1.5) m long gravity gradient boom. The gravity gradient boom
has a tip mass of (40) g to improve the gravity gradient stabilization .A
gravity gradient stabilized satellite has a limited stability and a pointing
capabilities, and a magnetic coils are added to improve both the three axis
stabilization and the pointing properties. Magnetic coils around the satellite's
XYZ axes can be fed with a constant current-switched in two directions-to
generate a magnetic dipole moment which will interact with the geomagnetic
field to generate a satellite torque, which is used to control the rotation of the
satellite. A problem is that both the direction and the strength of the
geomagnetic field change and magnetic control become non-linear and time
dependent .The magnetic coils are controlled by using a fuzzy logic
controller, based on a combination of membership functions and rules. The
controller consists actually of 3 MISO fuzzy control laws, one for each
magneto torquer (MX, MY and MZ coils). Each control law embodies a
fuzzy rule base to decide on the control desirability and output level when
using the corresponding torquer. Magnetic coils allow cheaper satellite, and
are an attractive solution to small, inexpensive satellite in low earth orbit. The
satellite will be during separation from the launch vehicle is exposed to forces
from the release mechanism and tumbling may occur. A detumbling mode is
activated in order to calm down the movement .The gravitation boom will be
deployed first when the movement of the satellite is sufficient small. This
study deals with attitude control after the detumbling mode has successfully
been completed and the boom is fully deployed.
engine which achieve high compression ratio by using combination of two lossless compression methods (Huffman and LZSS) . The engine is being built in two methods ,the first is to compress the file by Huffman then compress the file resulting from the compression process by LZSS and the second is to compress the file by LZSS then compress the file resulting from the compression process by Huffman
In this research two common file extensions were selected and for each one of these extensions ten different size files were selected as a samples to compress by using four compression methods(Huffman ,LZSS ,Huffman +LZSS ,LZSS +Huffman ) the response of each extension to the four methods have been discussed . Results are discussed to determine the method which achieve the highest compression ratio .The effect of changing the size of the file on the compression ratio has been studied .
converter and PI as speed and current controller. The separately excited DC motor can be
controlled from below and up to rated speed . Optimization filter of speed is obtained using
Modulus Hugging Approach . After obtaining the complete model of DC drive system, the
model is simulated by MATLAB. The simulation is done and analyzed under varying speed
and varying load torque conditions like rated speed and load torque, half the rated load torque
and half speed .
as a Two Line Elements (TLE) files is presented. General Mission Analysis Tool (GMAT) is used to simulate the orbital motion of
TIGRISAT. The analysis includes orbit determination and prediction of satellite’s position and velocity, satellite tracking, and
command summary. Orbital path of the TIGRISAT projected onto a two-dimensional world map over some time for one and two
revolution of the satellite is plotted.
proposed design contains four expandable panels with additional sixteen solar cells, two solar cells on each side of panel.
The proposed design with additional panels and how these additional panels are assembled to the body of KufaSat and how
they are deployed after the launching are presented. Comparison between original design and proposed design in addition
to discussion the increasing in power production and charge current are included.
axis magnetometer, six single axis sun sensors, three axis gyroscope and GPS receiver are used as the sensors for
attitude determination. TRIAD, algorithm are used for determining attitude estimate from two vector measurements This
estimate is then passed to extended Kalman Filter, along with the gyroscope measurements, to obtain a finer attitude.
The attitude controller is designed to achieve desired attitude with an accuracy of 5 degrees in nadir pointing using three
orthogonal magnetic coils. Two attitude control modes has been considered , detumbling mode and stabilization mode ,
B-Dot control algorithm is used in detumbling mode while quaternion feedback regulator algorithm is used in
stabilization mode. Performance of the control system is verified through closed loop simulations involving models of
satellite kinematics and dynamics, space environment, sensors, control law and actuators. Simulations and results of
both detumbling mode, and stabilization mode are presented. The simulations show that the satellite will detumble in 60
minutes after separation from the launcher and the stabilization mode controller able to point the satellite with a
maximum error of 5 degrees.
the attitude stabilization control of a CubeSat. The Takagi-
Sugeno (T-S) model fuzzy controller is evaluated for attitude
control of magnetic actuated satellites based on the attitude
error including error in the angles and their rates. The
detailed design procedure of the fuzzy control system is
presented. Simulation results show that precise attitude
control is accomplished and the time of satellite maneuver is
shortened in spite of the uncertainty in the system.
electrical power for all the subsystems of KufaSat .This was achieved by the use of solar cells when the satellite is in direct sunlight and
by two Lithium Polymer batteries when the Sun is eclipsed .The batteries are charged by the solar panels through three battery charge
regulators which optimize the solar arrays’ voltages independently for maximum power transfer. Power is then transferred to subsystems
through a number of power buses, 3.3V, 5V and unregulated.