En studie och design koncept för att förbättra reaktionshjul för precis attityd kontroll av CubeSats
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
This Master Thesis will briefly introduce the CubeSat and describe difficulties with precise pointing of the satellites. The major subsystem for attitude controlling, magnetic torquers and reaction wheels will be treated. Some basic design features of a reaction wheel and its motors power consumption is to be defined by mathematic equations. Further specifications of material, tolerances, ball bearings, lubricant and external disturbance torques are mentioned together with other requirements to space qualify a component or unit.The goal is to research, design, build, test and simulate a prototype model of a small, light and low power consuming four reaction-wheel-based attitude control system for cube-satellites using commercial off-the-shelf (COTS) motors.Based on the research and trade study a COTS brushless DC motor (BLDC) will be ordered and tested. The reason for choosing a BLDC is because it is the most common used motor for reaction wheel design according to a study made by NASA .Finally two motors were chosen for further testing, both are purchased from Micromo. The difference is that one of them (model 1525) have integrated drive electronics while the 1509 model have external drive components. The 1509 model provide more programming options for the motor and come in a smaller size, with the disadvantage that it need external drive electronics. The 1525 motor is a more compact device with standard drive features integrated in the motor.A structure to hold four motors is also designed with the purpose of holding the motors as a compact package. Eventually a final product might come out of this concept design.The conclusion of the motor testing is that the 1509 motor consumes less power, create a sufficient torque, more programmable options and it runs smoother with less induced vibration and noise then the 1525 motor. The 1509 motor is recommended for further investigation and testing together with the concept structure design.
Place, publisher, year, edition, pages
2012. , 88 p.
Technology, CubeSat, Reaction wheels, Attitude controll, Actuators, Structure design, Electric motors, Commercial off-the-shelf (COTS), Space qualification, Performance and survivability test
IdentifiersURN: urn:nbn:se:ltu:diva-51324Local ID: 8874cf92-33e8-4bde-9437-5c6c1265f14cOAI: oai:DiVA.org:ltu-51324DiVA: diva2:1024685
Subject / course
Student thesis, at least 30 credits
Space Engineering, master's level
Peymirat, ChristopheEjemalm, Johnny
Validerat; 20121002 (anonymous)2016-10-042016-10-04Bibliographically approved