Alireza Aghalari; Javad Tayebi
Volume 9, Issue 1 , May 2016, , Pages 13-23
Abstract
Recently, many researchers are examining the possibility of the small satellites or micro satellites, because small satellites are easier and faster to develop and thereby, provide increased launch opportunities. In this paper designing and experimental testing of three axis agility satellite simulator ...
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Recently, many researchers are examining the possibility of the small satellites or micro satellites, because small satellites are easier and faster to develop and thereby, provide increased launch opportunities. In this paper designing and experimental testing of three axis agility satellite simulator - equipped with pyramid configuration of SGCMG- with implementation of PID and feedback quaternion strategies are presented. These control strategies in the two different control gains and two different type of maneuvering about single and three axis are presented. First actuators and simulator of satellite have introduced and control strategies are simulated in Matlab/Simulink software. Then control strategies have implemented in the simulator’s computer and attitude control testing is executed. Finally the experimental data are compared with simulation results. In order to avoiding of singularity condition, SR method is used in steering law of single control moment gyros system. Results shown that agility maneuver of simulator realized and numerical results are almost according to experimental tests.
Ali Reza Aghalari; Ahmad Kalhor; Farhad Shamim
Volume 8, Issue 1 , April 2015, , Pages 73-77
Abstract
In this paper, a designing procedure of a Variable Speed Control Moment Gyro (VSCMG) for performing an agile maneuver in an attitude control simulator is described, then a prototype is fabricated and finally the test results are presented. The design of actuator mechanism is based on simulator limitations ...
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In this paper, a designing procedure of a Variable Speed Control Moment Gyro (VSCMG) for performing an agile maneuver in an attitude control simulator is described, then a prototype is fabricated and finally the test results are presented. The design of actuator mechanism is based on simulator limitations (power consumption, dimensions and weight, simplicity) and direction of produced torque.Two DC electrical motors are used for controlling the angular velocity of flywheel and the gimbal slew rate. The motors controller and driver units are designed and implemented, so that the maximum accuracy, minimum errors and best response time could be accessible. Structural Design is based on strength, stiffness, volume and weightalso Necessary analysis are performed using ANSYS. Finally the functional tests of actuator such as measuring the produced torque (using simulator and load transducer), accuracy of gimbal position and gimbal slew rate, accuracy of flywheel rotational speed and power consumption are performed and then the results are presented.
