S.N.A.K.E.: A Dynamically Reconfigurable Artificial Sensate Skin ...

More documents

Recommendations

Info

sampling, along with some images of the stimuli events that generated them. Additionally, there will be a brief evaluation of the performance of the sensors. Strain and Bending Results Much was mentioned about strain gages in the hardware section, as they were one of the two sensing modalities that had to be custom-designed. How well did they perform though? To answer this question, we must first calibrate them; this was done by the method of Shunt Calibration[15]. Shunt calibration is an indirect way of calibrating strain gages that consists of simulating a strain by changing the resistances of the Wheatstone bridge. This is a popular method because it can be used whenever the required instruments to conduct a direct calibration are not available. This is a tricky exercise though, as the gage factor and total resistances of the gages must be known. Gage factor being an intrinsic property of the used material it is easily obtained from the manufacturer or material property tables; in the other hand, resistances had to be manually measured. Calibration Referring back to Chapter 3 when strain gages were mentioned, it was said that it is critical to match the resistances of the strain gages so that the amplifier is not saturated by a resistance mismatch. Table 5.1 shows the actual measured resistances of each one of the two strain gages contained in every one of the 32 fabricated nodes along with the proposed matching and bridge resistors that were used. The first column is just an index while the second one refers to the serial code imprinted on the node and it was used as a reference. The third and fourth columns indicate the actual measured resistances in Ohms for each one of the two strain gages included in every node. The fifth and sixth columns list the commercially available resistors with the closest resistance values to those listed in the previous two columns. Columns seven and eight show the difference between these two. The next two show the necessary resistor to use in series 110
Node SG1 SG2 R(X) R(Y) Δ(X) Δ(Y) Rb(X) Rb(Y) Δ(Xc) Δ(Yc) 1 001-1 168.9 173.3 169 174 0.1 0.7 0 0.5 0.1 0.2 2 001-2 161.4 165 162 165 0.6 0 0.5 0 0.1 0 3 001-3 169 173 169 174 0 1 0 1 0 0 4 001-4 178.2 182.2 178 182 -0.2 -0.2 0 0 -0.2 -0.2 5 001-5 175.9 176.5 178 178 2.1 1.5 2 1.5 0.1 0 6 001-6 166.9 167.5 169 169 2.1 1.5 2 1.5 0.1 0 7 001-7 167.2 167 169 169 1.8 2 2 2 -0.2 0 8 001-8 173.5 176.7 174 178 0.5 1.3 0.5 1 0 0.3 9 001-9 171.1 173.9 174 174 2.9 0.1 3 0 -0.1 0.1 10 001-10 165.5 166.1 169 169 3.5 2.9 3.6 3 -0.1 -0.1 11 002-3 184.5 184.7 187 187 2.5 2.3 2.4 2.4 0.1 -0.1 12 002-5 180.8 183.4 182 187 1.2 3.6 1 3.6 0.2 0 13 002-6 183.1 184.7 187 187 3.9 2.3 3.9 2.4 0 -0.1 14 002-10 181.5 182.3 182 182 0.5 -0.3 0.5 0 0 -0.3 15 003-7 173.4 174.3 174 174 0.6 -0.3 0.5 0 0.1 -0.3 16 004-1 172.9 174.7 174 178 1.1 3.3 1 3 0.1 0.3 17 004-2 175.7 179.8 178 180 2.3 0.2 2.4 0 -0.1 0.2 18 004-3 167.8 174.2 169 174 1.2 -0.2 1 0 0.2 -0.2 19 004-6 171 174.9 174 178 3 3.1 3 3 0 0.1 20 004-8 170.3 171.4 174 174 3.7 2.6 3.6 2.4 0.1 0.2 21 004-9 166 171 169 174 3 3 3 3 0 0 22 004-10 173.5 178 174 178 0.5 0 0.5 0 0 0 23 005-1 171.2 177.2 174 178 2.8 0.8 3 1 -0.2 -0.2 24 005-2 170.4 177 174 178 3.6 1 3.6 1 0 0 25 005-3 172.5 177.8 174 178 1.5 0.2 1.5 0 0 0.2 26 005-4 174.6 178.8 178 180 3.4 1.2 3.6 1 -0.2 0.2 27 005-5 178.5 179.8 180 180 1.5 0.2 1.5 0 0 0.2 28 005-6 177 180.3 178 180 1 -0.3 1 0 0 -0.3 29 005-7 175.9 180.9 178 182 2.1 1.1 2 1 0.1 0.1 30 005-8 176.4 180.7 178 182 1.6 1.3 1.5 1 0.1 0.3 31 005-9 176.1 181.4 178 182 1.9 0.6 2 0.5 -0.1 0.1 32 005-10 177.3 183.1 178 187 0.7 3.9 0.5 3.9 0.2 0 Table 5.1: Strain gage measured resistances 111
Page 1:
Author S.N.A.K.E.: A Dynamically Re
Page 5:
S.N.A.K.E.: A Dynamically Reconfigu
Page 9 and 10:
Table of Contents Abstract 3 Acknow
Page 11 and 12:
List of Figures 2-1 Created by MIT
Page 13:
E-1 OpenGL Control Header File . .
Page 17 and 18:
Chapter 1 Introduction “Imaginati
Page 19 and 20:
The current project, named S.N.A.K.
Page 21:
Hardware Each Skin Patch is compose
Page 24 and 25:
living tissue. Particularly in the
Page 26 and 27:
Figure 2-2: Leonardo’s Hand great
Page 28 and 29:
Artificial Sensate Skins elsewhere
Page 30 and 31:
2.1.2 Ultra-dense Sensor Arrays Thi
Page 32 and 33:
2.2 Flexible Circuits Although, not
Page 34 and 35:
2.2.2 Other Technologies Figure 2-6
Page 36 and 37:
human skin. The following design pr
Page 38 and 39:
(a) Skin Patches as data extraction
Page 40 and 41:
Figure 3-3: I 2 C Routing pattern T
Page 42 and 43:
3.2.2 Peer to Peer As we already me
Page 44 and 45:
5. Audio: by adding a MEMS micropho
Page 46 and 47:
Table 3.1: Material thicknesses and
Page 48 and 49:
(a) Node Front (b) Node Back Figure
Page 50 and 51:
Figure 3-9: Skin Patch mechanical t
Page 52 and 53:
used, which only further complicate
Page 54 and 55:
8. Teardrops and filleting were add
Page 56 and 57:
(a) 7.4V, 2.2mAh Li-ion Battery (b)
Page 58 and 59:
in more detail in the Results Chapt
Page 60 and 61: has a 30mA forward current with a f
Page 62 and 63: Figure 3-14: Strain gage layer prot
Page 64 and 65: an unbalanced Wheatstone bridge, fr
Page 66 and 67: Figure 3-16: QTC response curve for
Page 68 and 69: (a) Prototype boards used to calibr
Page 70 and 71: whisker is epoxied to the package o
Page 72 and 73: Sound The only sensing modality add
Page 74 and 75: Figure 3-20: Brain regular PCB fabr
Page 76 and 77: 3.4.3 Communications unit The Commu
Page 79 and 80: Chapter 4 Software “A Scientist d
Page 81 and 82: Networks. Why is this relevant? Mai
Page 83 and 84: Figure 4-1: Bootloader memory map C
Page 85 and 86: Bit Flag Name Description 0x01 FILE
Page 87 and 88: Figure 4-3: Sampling timing example
Page 89 and 90: We also mentioned before that there
Page 91 and 92: Code Instruction Description 0xA0 R
Page 93 and 94: Component Description 1 Indicates t
Page 95 and 96: last chapter. Figure 4-5: Automatic
Page 97 and 98: An important point to stress is tha
Page 99 and 100: (a) Rotation control (b) Zooming co
Page 101 and 102: 4.3 Communications Software The las
Page 103 and 104: 4.3.2 Peer to Peer Peer to peer com
Page 105 and 106: Chapter 5 Analysis of Results and E
Page 107 and 108: Figure 5-1: Stress concentration po
Page 109: of the assembled skin patch don’t
Page 113 and 114: Or, ∆R = R3 R3 R3 + RC (5.2) Howe
Page 115 and 116: R3 Microstrain 162Ω −99.7337969
Page 117 and 118: Figure 5-3: Strain Gage electronic
Page 119 and 120: (a) Data from both strain gages (b)
Page 121 and 122: (a) Pressure data being extracted f
Page 123 and 124: many of these did not work as expec
Page 125 and 126: Data plots were also extracted for
Page 127 and 128: (a) Temperature sensor data plots (
Page 129 and 130: Figure 5-12: Raw microphone data wi
Page 131 and 132: (a) Activity sensor data (b) Whiske
Page 133 and 134: 5.3 Performance Metrics We have pre
Page 135 and 136: (a) I 2 C data when a 1500Ωs resi
Page 137 and 138: Component # per node Current consum
Page 139 and 140: Finally, since power is readily ava
Page 141 and 142: Chapter 6 Conclusions and Future Wo
Page 143 and 144: surface can be used to sense pressu
Page 145 and 146: Implement P2P Communications: curre
Page 147 and 148: Appendix A Abbreviations and Symbol
Page 149 and 150: Appendix B Bill of Materials 149
Page 151 and 152: Appendix C Schematics and PCB Layou
Page 153 and 154: 1 1 2 2 3 3 4 4 D D C C B B A A Tit
Page 155 and 156: Amp1 P0Amp101 P0Amp102 P0Amp103 P0A
Page 157 and 158: P0Cin02 P0East06 P0North06 P0South0
Page 159 and 160: Cain P0C ain01 P0Cain02 L1 P0L101 P
Page 161 and 162:
Figure C-10: Node Bottom Overlay 16
Page 163 and 164:
4 3 2 1 A A Brain Communications Ac
Page 165 and 166:
C3v P0C3v01 P0C3v02 Cavcc P0Cavcc01
Page 167 and 168:
Appendix D Firmware 167
Page 169 and 170:
C:\Documents and Settings\Gerardo\M
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Appendix E PC Code 183
Page 185 and 186:
1 c:\Documents and Settings\Gerardo
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
12 c:\Documents and Settings\Gerard
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Bibliography [1] John C. Ansel. Ski
Page 209 and 210:
[33] Joseph Jacobson, B Comiskey, C
Page 211:
[68] Vilis Tutis. The physiology of
show all

S.N.A.K.E.: A Dynamically Reconfigurable Artificial Sensate Skin ...

Create successful ePaper yourself

Delete template?

Save as template?