Master Thesis - OUFTI-1

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tip, but this one is subject to the "bounce" eect, which can cause perturbations on the vibration response of the structure. No additional mass was used to increase the hammer impact. Note that an exponential window was applied to the excitation signal. This is a current practice when a hammer is used to perform the test. It should also be noted that no impact averaging was performed. Indeed, to apply this method, impacts include in a series must be the same and, any dierence in the impact location or intensity has a signicant eect on the results. Now, the OBC 2 card is so small that the reproduction of the same impact several time can not be assured. In our case, the excitation point was chosen on a corner of the card (see Figure 4.15). Acquisition system Finally, the acquisition system, which takes measurements on the structure, has to be chosen. An important requirement, that will be discussed in section 4.3.8, is that this acquisition system does not interfere with the dynamic response of the structure. In our case, it was decided to use an accelerometer. This type of sensor is currently used when the signal to measure is a high-frequency one (e.g., a shock), which is the case here. Once again, owing to the restricted dimensions and mass of the electronic card, this accelerometer has to be as lightweight and small as possible, to avoid any interference with the OBC 2 dynamic response. In our case, the accelerometer used weights only 0.2 g and is enough small for being placed everywhere on the electronic card. It was chosen to realize 22 measurements on the card. According to this particular choice, the best solution to attach the accelerometer is the beeswax, which allows a good grip without interfering with the dynamic response, and an easy handling. The measurement points are presented in Figure 4.15. 89
Figure 4.15: Location of measurement and excitation points The acquisition parameters applied to the measured signal, are: • A frequency sampling of 512 Hz • A resolution of 2.5 Hz The complete set-up is presented in Figure 4.16. Figure 4.16: Experimental set-up for the test of the OBC 2 card 90
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University of Liège Faculty of App
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Abstract OUFTI-1, standing for "Orb
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3.4 Initial idea . . . . . . . . .
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List of Figures 1.1 The Pumpkin's C
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4.18 MAC matrix using the simple me
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List of Acronyms ADCS Al AlNiCo ASI
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Thesis outline This thesis focuses
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of larger satellites. So, the CubeS
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1.2 OUFTI-1 project 1.2.1 Genesis O
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• XatCobeo (Vigo - Spain): Develo
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Chapter 2 OUFTI-1: Flight system co
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Figure 2.2: Product tree of OUFTI-1
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2.3.2 Solar panels The armor panels
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• We do not want to drill or manu
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In our case, because of the limited
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Figure 2.13: Magnetic eld obtained
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Figure 2.17: Pictures of the ADCS c
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consider the possibility of oshorin
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Figure 2.20: Exploded view of OUFTI
Page 39 and 40: I xx , I yy and I zz are called the
Page 41 and 42: Subsystem: Structure & Conguration
Page 43 and 44: Subsystem: Thermal Control Parts Co
Page 45 and 46: Chapter 3 Design of a new support f
Page 47 and 48: Figure 3.3: Batteries during and af
Page 49 and 50: The concept is the following one: F
Page 51 and 52: A test under vacuum conditions was
Page 53 and 54: Thermal Expansion (CTE) of the mate
Page 55 and 56: Figure 3.9: Classication by density
Page 57 and 58: The last property to determine is t
Page 59 and 60: • So, it was decided to use two t
Page 61 and 62: is to prevent the batteries' bulge.
Page 63 and 64: • Then, the thermostats, that wil
Page 65 and 66: Figure 3.23: Schematics of the cove
Page 67 and 68: • Other components, including the
Page 69 and 70: 3.9.3 Dynamic behavior Finally, it
Page 71 and 72: 3.10 Summary Through this chapter,
Page 73 and 74: Chapter 4 Electronic cards dynamic
Page 75 and 76: Figure 4.1: Example of manufacturin
Page 77 and 78: Figure 4.4: Illustration of the exp
Page 79 and 80: Figure 4.5: MAC between the two mod
Page 81 and 82: • Global mass/stiness smearing me
Page 83 and 84: 4.2.6 Modeling of the chassis A gen
Page 85 and 86: Q = ω k = 1 ω b − ω a 2 ζ ⇒
Page 87 and 88: Their study was based on the fact t
Page 89: Figure 4.14: Example of spacecraft
Page 93 and 94: Figure 4.18: MAC matrix using the s
Page 95 and 96: 4.3.6 Application of the local mass
Page 97 and 98: ρ P C 104 connector = 10.12 × 10
Page 99 and 100: According to this particular shape,
Page 101 and 102: This is due to the fact that this c
Page 103 and 104: environment. Then, this model is ex
Page 105 and 106: 5.2.4 Antenna support For the anten
Page 107 and 108: Components Young's moduli (GP a) Po
Page 109 and 110: Components Young's moduli (GP a) Po
Page 111 and 112: 5.3 Static analysis As described in
Page 113 and 114: Figure 5.9: Illustration of the com
Page 115 and 116: Figure 5.11: Maximal Von Mises stre
Page 117 and 118: Figure 5.12: First mode of OUFTI-1
Page 119 and 120: Figure 5.15: Precise PSD of Vega [5
Page 121 and 122: Chapter 6 Conclusions This master t
Page 123 and 124: provided for each method used. We h
Page 125 and 126: last versions of the Verication Con
Page 127 and 128: [13] Ph. LEDENT. "Design and Implem
Page 129 and 130: [40] "Dejond - Aluminum Catalog ".
Page 131 and 132: Appendix A Schemas of solar panels
Page 133 and 134: Appendix B Schemas of electronic ca
Page 135 and 136: Appendix C Fixations of the endless
Page 137 and 138: Appendix D Datasheet of the battery
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Master Thesis - OUFTI-1

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