Comprehensive System Identification of Ducted Fan UAVs - Cal Poly

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transfer functions (Equations 3.1-3.3) will show that the longitudinal and lateral modesare heavily reliant on the values of L v and M u , respectively. If these derivatives were theonly ones in the hovering cubic forms (Equations 3.4 and 3.5), the equations wouldreduce to the degenerate forms seen in Equations 3.14 and 3.15. These forms contain onereal and one complex root for negative values of L v and M u . These roots describe thedynamics of the system and show that L v and M u are the dominant terms required todepict the three modes.3∆lateral −hover= s − gLv(Equation 3.14)3∆longitudinal−hover= s − gMu(Equation 3.15)CIFER allows for a measure of merit, or cost, of the final model fit to thefrequency responses. Lower costs are better fits. The final model had an excellentaverage cost of 23.6. For the best possible fit, pure time delays were identified as0.04205, 0.08730, and 0.07189 seconds for roll, pitch, and yaw responses, respectively.The longitudinal delay was bigger in both the state space model and the transfer functionfits. However, the Cramer-Rao bound for the longitudinal delay was rather big (29%)revealing that it was a correlated term in the minimization process. This may be due toCIFER adjusting the value to make up for inconsistencies in the model or it is due to thepitch sensor or flight control computer. All other Cramer-Rao bounds were acceptable,(CR< 15%) indicating good reliability of the identified derivatives.Table 3.4 contains the identified variables and their respective certainty during theidentification. A comparison with the control derivatives extracted from the transferfunctions (Table 3.3) reveals very close matches.- 22 -
Table 3.4 – OAV DERIVID Identified Parameters and CertaintiesTable 5 shows the cost functions for the transfer functions. They were all very acceptable.Table 3.5 – OAV DERIVID Frequency Response CostsThe asymmetric design of the vehicle accounts for the difference in the valuesbetween L v and M u . Figure 1.3 depicts the fact that the OAV design has nacelles or cargopods making it asymmetric. The ratio of the identified values (L v : M u = 0.7510) reflectsthe relationship of the lateral and longitudinal inertias specified (I yy : I xx = 0.6312).- 23 -
Page 1 and 2: Comprehensive System Identification
Page 3 and 4: APROVAL PAGETITLE:AUTHOR:Comprehens
Page 5 and 6: ACKNOWLEDGMENTSThe author would lik
Page 7 and 8: 3.4.4 Magnetometer Identification..
Page 9 and 10: LIST OF FIGURESFigure 1.1 - Land Wa
Page 11 and 12: Figure 3.48 - Magnetometer Depictio
Page 13 and 14: CHAPTER 1 - INTRODUCTION AND MOTIVA
Page 15 and 16: The vehicles examined within the sc
Page 17 and 18: tunnel testing to study the charact
Page 19 and 20: Figure 1.8 - Helicopter Body Axes S
Page 21 and 22: GPSRate GyrosAccelerometersIMUInner
Page 23 and 24: CHAPTER 2 - METHODS AND TECHNIQUES2
Page 25 and 26: 2.2.1 Flight Test TechniquesThere a
Page 27 and 28: manufacturer specifications are mod
Page 29 and 30: 3.2 Bare-Airframe IDThe bare-airfra
Page 31 and 32: Table 3.2 - OAV Frequency Range of
Page 33: ⎧ p⎫⎪ ⎪y = ⎨q⎬⎪ r ⎪
Page 37 and 38: The identified state-space model yi
Page 39 and 40: Better sensors, at higher sampling
Page 41 and 42: Figure 3.3 - Yaw response frequency
Page 43 and 44: Figure 3.4 shows that even though t
Page 45 and 46: It can be seen that the Aerovironme
Page 47 and 48: 3.2.2 Allied Aerospace MAVFlight te
Page 49 and 50: 30MAGNITUDE(DB)-10-50250PHASE(DEG)5
Page 51 and 52: A 0th/2nd order transfer function i
Page 53 and 54: Figure 3.12 shows the same for the
Page 55 and 56: Techsburg) the pitching moment resp
Page 57 and 58: Table 3.11 shows that all of the di
Page 59 and 60: Figure 3.14 shows how increasing th
Page 61 and 62: the duct, the effects of the man ne
Page 63 and 64: ft-lbMu PLATFORM= 5.11ftsecThis dim
Page 65 and 66: apparent that the size of the duct
Page 67 and 68: adequate way to characterize the di
Page 69 and 70: actuators varied in size, weight, c
Page 71 and 72: It is noticeable from the figure th
Page 73 and 74: Table 3.17 - Actuator Calibration F
Page 75 and 76: Figure 2.1 shows an example frequen
Page 77 and 78: The test matrix is provided as Tabl
Page 79 and 80: frequency response curves shown in
Page 81 and 82: Table 3.22 shows that for the first
Page 83 and 84: The time delays all seemed to be ar
Page 85 and 86:
400035003000250020001500y = -13429x
Page 87 and 88:
higher data rates, and tighter tole
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esponse and the response obtained f
Page 91 and 92:
The time histories show that the ou
Page 93 and 94:
Figure 3.31 - Magnitude Comparison
Page 95 and 96:
Performing the frequency response a
Page 97 and 98:
Results from STI utilizing the exac
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The fact that the rate saturated du
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Table 3.23 for the maximum rates an
Page 103 and 104:
Verification of the identified mode
Page 105 and 106:
from testing (3.22), it was found t
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3.4.1 Accelerometer IdentificationM
Page 109 and 110:
Figure 3.43 shows that gyros were m
Page 111 and 112:
5 meter circle centered about the t
Page 113 and 114:
Figure 3.46 shows the modeled fluct
Page 115 and 116:
Figure 3.49 - Pressure Altimeter Mo
Page 117 and 118:
Figure 4.1 - Simulink MAV ModelFigu
Page 119 and 120:
Figure 4.3 - Simulink Sweep Generat
Page 121 and 122:
cause a pitching moment to be exert
Page 123 and 124:
Figure 4.6 - Cross Control Decoupli
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⎡ Lp Lq Lr Lu Lv Lw0 0 0⎤⎢MpM
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It can be seen right away that the
Page 129 and 130:
Figure 4.8 shows that the coherence
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CHAPTER 5 - CONCLUSIONSThe need for
Page 133 and 134:
6. Mettler, B., Tischler, M. B., an
Page 135 and 136:
Appendix AOAV Proposal VehicleIdent
Page 137 and 138:
DS8417 - 5V- 125 -
Page 139 and 140:
HS512MG - 5V- 127 -
Page 141 and 142:
DS368 - 5V- 129 -
Page 143 and 144:
94091 - 5V- 131 -
Page 145 and 146:
CS-10BB - 5V- 133 -
Page 147 and 148:
Appendix CActuator Generated Transf
Page 149 and 150:
DS8417 - 100% - 5V- 137 -
Page 151 and 152:
DS8417 - 100% - 6V- 139 -
Page 153 and 154:
HS512MG - 100% - 5V- 141 -
Page 155 and 156:
HS512MG - 100% - 6V- 143 -
Page 157 and 158:
DS368 - 100% - 5V- 145 -
Page 159 and 160:
DS368 - 100% - 6V- 147 -
Page 161 and 162:
94091 - 80% - 5V- 149 -
Page 163 and 164:
94091 - 80% - 6V- 151 -
Page 165 and 166:
CS-10BB - 100% - 5V- 153 -
Page 167 and 168:
CS-10BB - 100% - 6V- 155 -
Page 169 and 170:
Appendix DActuator Time Domain Veri
Page 171 and 172:
94091 5V94091 6V- 159 -
Page 173 and 174:
DS368 5VDS368 6V- 161 -
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Comprehensive System Identification of Ducted Fan UAVs - Cal Poly

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