Anatomy of a Robot

286 CHAPTER ELEVEN dissimilar metals must be used, consider metal plating to decrease this effect. See the following web sites for further information: I www.seaguard.co.nz/corrosion.html I www.engineersedge.com/galvanic_capatability.htm I http://corrosion.ksc.nasa.gov/html/galcorr.htm FATIGUE Most materials suffer damage when they are bent or otherwise deformed. Even if they return to the original shape, the damage still exists. With repeated bending, the material will eventually give way and fail. During the design of the robot, evaluate all the repeated operations. Make sure none of the materials will be stressed beyond their limits of fatigue. Consult companies that specialize in bendable materials of the type required. CORROSION We’ve already spoken briefly about corrosion in a few places, including Chapter 4. Materials can be clad in plastic or plated with other metals to decrease the rate of cor- rosion. If corrosion is a strong possibility, consider using materials that will not cor- rode. The Kennedy Space Center offers information on the causes and prevention of corrosion at the following sites: I http://corrosion.ksc.nasa.gov/html/corr_fundamentals.htm I http://corrosion.ksc.nasa.gov/html/publications.htm LUBRICATION AND DIRT Moving parts, especially bearings, sometimes require lubrication. Just remember, the basic function of oil and grease is to smear all over everything! A buildup of grease and dirt can engender a host of problems. I Electrical problems Lubricants can coat electrical contacts and insulate them from the mating contact. These sorts of failures are common. I Dirt Lubricants trap dirt, causing extra friction and sluggish action. Eventually, the dirt swamps out the positive effects of the lubricant. If the robot cannot be serviced, this becomes a critical problem. In the design of the robot, try to find sealed bearings and other moving parts that do not require lubricants. If a lubricant must be used, find an exotic one that is a bit tamer. Graphite and Teflon are possibilities, but each have their own faults.

MECHANICS 287 TOLERANCES In most mechanical designs, the parts must fit together cleanly. Moreover, the parts must continue to fit as the robot gets older. One of the most difficult tasks in building a robot is making it sound. Parts that bend and screws that come loose can make a design degrade rapidly. Such mechanical failures are probably the single worst problem plaguing robot designs. Here’s one small example of a trick that may help. Consider a three-part robot with parts A, B, and C. Also, assume all fasteners have some play that increases over time. Let’s call the typical play T millimeters; the unintended movement that can occur because of inexact mechanical tolerances. Another common term for this is slop, although I suspect the robot would be offended. Although this is a gross oversimplifi- cation (and in one dimension), it can be used to illustrate the design of tolerances. Here are two ways a design can be built under these conditions. I Bad design A bad design would attach A to B, and B to C. Part C will move with respect to part A with movements that could be the sum of the other two tolerances, or 2T. The other two pairings will move respectively within the tolerance T. I Good design A good design would attach A to B, B to C, and A to C. Slop within the system will be limited to roughly T, not 2T. In general, consider having a central, rigid chassis that sets the tolerances for all play within the robot. Try to avoid the accumulation of play within the design. This advice would apply to all robot designs except certain exceptional designs that actually rely on the flexibility of the design. Static Mechanics We’ve already spoken about topics like compression, tensile strength, hardness, flex- ing, and materials. The derivation of the mechanical static properties of shaped materi- als (like compression strength, tensile strength, flexibility, etc.) is beyond this text, but this does not mean that the design has to be done blindly. If preformed materials are used, the manufacturer should be able to specify these properties for the parts in ques- tion. If the manufacturer cannot, then consider finding another manufacturer. The parameters in question are not difficult to calculate or measure empirically, but the engi- neer must have the right tools and knowledge. If the tensile strength or compression strength of a structural member must be cal- culated, consider finding an ME consultant to perform the work. One other option

288 CHAPTER ELEVEN would be to find a similar part of roughly the same shape and extrapolate the parame- ters. Here’s one example. Suppose you want to know the compression strength of an L-shaped beam made of a specific type of plastic. If the manufacturer has already specified the compression strength of a single slab of material with the same thickness, you have enough infor- mation to make an estimate. Simply add together the compression strength of the two flat portions of the L-beam. This estimate of the compression strength for the L-beam will probably be low, but that’s just fine. Dynamic Mechanics The field of dynamics is vast and complicated. Even without the complications of rel- ativistic motion, the physics and math are difficult and beyond the scope of this text. However, a couple of useful tips must be passed on. ENERGY CALCULATIONS It’s useful to be able to estimate the energy required to make parts move within the robot. The calculations required for making these estimates vary with the types of motions involved. Consider a bicycle. How much energy does it take to accelerate a bike to a fixed speed? Let’s assume the following: The bike chassis, without the wheels, has a mass of W1. Each wheel has a mass of W2 and has a radius of R. The bike will accelerate to a speed of V. The energy of a mass moving in a straight line is 0.5 ϫ m ϫ v2 where m is the mass and v is the velocity. Notice the similarity here with Einstein’s famous E ϭ mc2 formula! Now, if the wheels were not spinning, the energy of the bike would be E ϭ 0.5 ϫ 1W1 ϩ W2 ϩ W22 ϫ V2 But the tires are indeed spinning and contain energy as well. The energy in a mass constrained to rotate about a central point is E ϭ 0.5 ϫ m ϫ r2 ϫ 1du>dt22

MECHANICS 289 where m is the mass, r is the radius of rotation, and u is the angular position of the rotat- ing mass. This is the best equation for measuring the energy, but there’s an easier way. If all the weight, W1, of the tire were at the edge (radius r), then each particle of the tire would be moving at a speed of V. Each tire’s rotational energy would be E ϭ 0.5 ϫ W2 ϫ V2 As a practical matter, not all of the tire’s mass is at the rim. Some of the mass is within the spokes. For the bicycle, the previous equation is a good conservative estimate, but for wheels shaped like a hockey puck, significant weight would exist on the inside of the wheel, closer to the axle. The rotational energy of the wheel would be lower than the pre- vious number. It would take a bit of calculus to compute the proper number. However, estimating the number can be done in an easier way. The energy of a rotating particle of mass grows as r2, but the number of such particles grows with the circumference of travel as r increases. The calculus shows the energy increasing as r3. If we want to estimate the rolational energy in the wheel, we want to find r1 such that r13 ϭ 0.5 r3. This radius, r1, turns out to be about 80 percent of r. Although the outside of the wheel might be mov- ing at a speed of V, the average part of the wheel at a radius of r1 is moving at .8 ϫ V. So a good first approximation for the rotational energy in a solid core wheel would be E ϭ 0.5 ϫ W2 ϫ 10.8 ϫ V22 ϭ 0.32 ϫ W2 ϫ V2 This would put the total energy within the bike between the following two energies: I High estimate This estimate assumes all the mass of the wheel is at the edge near the rim: E ϭ 0.5 ϫ 1W1 ϩ W2 ϩ W22 ϫ V2 ϩ 2 ϫ 10.5 ϫ W2 ϫ V22 E ϭ 0.5 ϫ 1W1 ϩ 4 ϫ W22 ϫ V2 I Low estimate This estimate assumes all the mass of the wheel is evenly dis- tributed throughout the wheel: E ϭ 0.5 ϫ 1W1 ϩ W2 ϩ W22 ϫ V2 ϩ 2 ϫ 10.32 ϫ W2 ϫ V22 E ϭ 0.5 ϫ 1W1 ϩ 2.64 ϫ W22 ϫ V2 Do not forget that imparting energy to parts within the robot cannot be done effi- ciently. These equations are only theoretical and are used to estimate only the energy

290 CHAPTER ELEVEN within the moving parts. The energy needed to accelerate the parts to the speeds in ques- tion will be greater than the estimate. NATURAL FREQUENCIES We’ve already covered natural vibration in a previous chapter. All mechanical structures will vibrate easily at specific “natural” frequencies. The materials and the structure con- tribute to this particular type of vulnerability. At worst, the robot may shake apart. At best, the robot may make noise as it moves. The best way to eliminate this problem is to vary the design in ways that make cooperative vibrations less likely. Notice that the solutions for damping out vibrations are much the same as adding friction to our sec- ond-order control system. Here are a couple web sites about natural frequency vibrations: I www.ideers.bris.ac.uk/resistant/vibrating_build_natfreq.html I www.newport.com/Vibration_Control/Technical_Literature/Fundamental_of_ Vibration/Fundementals_of_Vibration/ HEAT TRANSFER A couple of short notes must be made about heat transfer. Often heat must be taken out of a component. Heatsinks, for example, remove heat from integrated circuits like microprocessors. Although heat transfer is a general problem, we can use a processor and a heatsink in our example without a loss of generality. Heat flows from the proces- sor, through the heatsink, and into the ambient air. Each component has a well-specified thermal impedance that can be used to measure its effectiveness. Low thermal imped- ance means the component can transfer heat more effectively. Here’s how the calcula- tions are done. Suppose the processor dissipates 20 watts, that the ambient air is at 25 degrees Celsius, and that the thermal impedance of the heatsink is 2 degrees Celsius per watt. The processor will rise to a temperature of 25 ϩ 2 ϫ 20 ϭ 65 degrees Celsius This temperature may be too high for the processor. If that’s the case, then lower the temperature of the ambient air, get a heatsink with a lower thermal impedance, or find a lower-energy processor.

MECHANICS 291 Here are a few web sites describing thermal impedance calculations: I http://sound.westhost.com/heatsinks.htm#asample%20calc I www.hardwarecentral.com/hardwarecentral/tutorials/743/1/ I www.hardwarecentral.com/hardwarecentral/tutorials/950/1/

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INDEX Note: Boldface numbers indicate analog filters and, 204–206, batteries, 149, 165–166 illustrations. 204, 205 altitude and, 135 charge level in, 165 10BT/100BT/1000BT distortion and, 203 discharge cycle in, standards for baseband filters for, 207 165–166, 166 communication, 232, 272 ideal design of, 202, 202, 203 intelligent, 149 inductors in, 205 internal resistance in, 166 802.11b, 269 resistors in, 205 lifetime of, 166 rolloff in, 203 rechargeable, 155 A stopband in, 203 reliability and, 127 Anti-Robot Militia, 129 safety and, 129–130 abrasion, 127, 285 Apollo moon landing, 154 voltage level in, 165–166 cable wear and, 127 Application layer, OSI layered network model, 225 benchmarks for computer AC motors (See also motors), application specific integrated performance, 116–117, 119 275–276 circuits (ASIC), 82, 216 arithmetic capabilities, computer beta testing, 137 acceleration, 32–39, 57–59, hardware and, 117 bidirectional communication 69–71 array processors, 84 assembly language, 99–100 channels, 241 acid test, 136 authentication, 267 bill of material (BOM), 125 ACK/NACK, 245–246 automation, high level design binary instructions, 99–100 actuators, 275–279 and, 148–151 bit error rate (BER), 234–236, availability, 125–126 digital, 5, 53, 54, 55 235, 239 addressing memory, 91–92, B bits, 89–90 Blackman window for FIR 95, 97 backup plans, 136–137 advanced RISC machines, 82 balance, 58 filters, 214–215, 214 algorithms, in computer band stop filters in, 210, 210 block checksums, 241–244 bandpass filters in, 210, 210 Bluetooth, 270 performance, 115 bandwidth allocation for braking, 184–186 Aloha time division communication, 103, 118, energy and power supplies in, communication systems, 261 228, 252–254, 258–259 184–186 alpha testing, 137 changes in, 258–259 altering design parameters, guarantee of, 259 motor type, 186, 278 reverse channel, 259 pad type, 186 48–49, 65 bandwidth limited power failures and, 185 alternating current (AC), 169 communications, safety and, 185 altitude, 135 254–256, 256 speed and, 185–186 amplitude shift keying (ASK), Bartlett (triangular) windows for branching, in parallel FIR filters, 212–213, 213 processing, 84 233, 236 baseball pitching robot, 47 broadcasting, 273–274 analog computers and baseband transmission (See also brushes in DC motors, 277 communications), 228–232 brushless DC motors, 277–278 electronics, 78–79 bulbs, reliability and, 128 analog controllers, 82–83 burst errors, 251 analog noise, 200 analog to digital (A/D) converters, 191–192, 192, 198–201 anti-aliasing filters (See also digital signal processing), 192–197, 196, 201–207, 202 293 Copyright 2003 by The McGraw-Hill Companies, Inc. Click Here for Terms of Use.

294 INDEX buses, input/output (I/O), commercial off the shelf (COTS) Eb/No curves in, 234–236, 103–104 hardware/software, 121 235, 239, 247 bytes, 89–90 communications, 21–22, 102, encoding/decoding in, 229 221–274 encryption and, 266–269 C 10BT/100BT/1000BT energy and power supplies standards for, baseband, cable networks, 271–272 232, 272 in, 175 cabling, interference and, Aloha type systems, 261 error control in (See also error amplitude shift keying (ASK) 142–143 in, 233, 236 control), 238–257 cache memory, 95–98 bandwidth allocation for, 228, error distribution in, 240 carbon fiber, 283 252–254, 258–259 eye patterns and \"open eye\" in, carrier signals, 233 bandwidth limited, caution, in control systems 254–256, 256 238–239, 239 baseband transmission in, forward error correction (FEC) design, 57–58 228–232 central control systems, 24 bidirectional channels in, 241 in, 248 central processing unit bit error rate (BER) in, Fourier transforms for 234–236, 235, 239 (CPU), 88 broadcasting, 273–274 compression in, 265–266 centralization of energy code, cable networks in, 271–272 frequency allocation/separation carrier signals in, 233 161–162 channel tuning in, 246–247 in, 262 channel tuning in, 246–247 channels in, 251–252 frequency division shared channels, 250, 251–252 checksums, block checksums characteristic differential in, 241–244 access systems in, 262 closed system, 260 frequency shift keying (FSK) equation, for control systems, code division multiple access 37–39 (CDMA) in, 246, 263–264 in, 234 characterizing robot code division shared access global positioning system performance and altering systems in, 262–264 control system design, 41–48 compression in, 265–266 (GPS), 82 charge level, batteries and, 165 concatenated codes in, Huffman compression in, 266 checklist in project 248–252, 249 information signal in, 233 management, 16 convolutional codes in, infrared, 107 checksums, 241–244 250, 252 interleaver/deinterleaver in, IP type, 243 cooperative user, 260 polynomial, 243 data density in, 229 250, 252, 257 Reed-Solomon, 244–245 defining communications role Internet and, 82 clock time, and energy and and purpose, 221–223 Internet protocol (IP) in, 82 power supplies, 171–173, 172 delays in, 259 intersymbol interference (ISI) closed loop control systems (See demodulators for, 236–238 also control systems), 26–39, direct current (DC) balance in, 230–231, 230, 231, 262 26, 47–48, 48 in, 229 jamming in, 228 closed system distortion in, 262 load limits for, 260 communications, 260 distributed control system, 23 local area network (LAN), 82, code division multiple access distribution of errors in, 240 (CDMA), 246, 263–264 downloading times and, 91 102, 105–108, 272 code division shared access duplicate or redundant data modems in, 271 systems, 262–264 transmission in, 239, 240 modulation in, 232–238 coefficient of friction, in control modulator/demodulator in, systems, 41, 45 coefficient test, in FIR 250, 251–252 filters, 216 nonreturn to zero (NRZ) codes column address select (CAS), 95 in, 229 open loop control system, 25 Open Systems Interconnection (OSI) layered model for networks in, 224–228 parity bits in, 244 phase shift keying (PSK) in, 234

INDEX 295 Physical layer of OSI reference unidirectional communication control systems, 61 model in, 226–228 channels in, 247–248 cooling for, 118 coprocessors for, 102 privacy issues in, 260 user datagram protocol (UDP) cost of, 74, 120 pulse distortion in, 230–231, in, 273–274 development time/expense in, 230, 231 Viterbi codes for, 240, 247, 74, 120–121 quadrature amplitude 252–257 digital signal processing (DSP) modulation (QAM) in, 238, voice, text to speech engines in, 82, 85–88, 191–220 238, 255–256, 255, 256, 271 for, 274 display system in, 83, 104–106, quadrature phase shift keying (QPSK) in, 271 wired systems for, 271–274 112–113 radio frequency (RF), 82, wireless, 82, 106–107, embedded processors for, 106–107 raised cosine filters (RCF) in, 269–270 113–114 230–231, 231 comparable systems, 136 execution time in, 115–117 Reed-Solomon checksums in, compilers, 99–100 fabless semiconductors in, 82 244–245 complementary metal oxide FIR filters in, 216 retransmission in, ACK/NACK, freeware and, 76 245–246 semiconductors (CMOS), game units and, 83 robustness of coding schemes 167–168 general purpose processors in, in, 230 complex instruction set RS encoder/decoder, 250, 252 computer (CISC), 100, 88–89 RS232/432 standard for, 101–102 hard disk drives in, 109–111 baseband, 232 complexity in control system high level design (HDL) RS422 standard for, design, 46, 135 baseband, 232 composites, 283 specifications and, 113, run-length compression compression strength, 284, 288 148–151 in, 266 compression, 265–266 input/output (I/O) in (See also security in, 266–269 computation registers, 98–99 input/output), 103–108 self-clocking in, 229 computer assisted design instruction set in, 99–100 Shannon capacity limit in, (CAD), 150 leveraging existing technology 226–228, 226 computer hardware, 73–121 in, 75–76 shared access, 258–264 analog controllers in, 82–83 licensing of software and, 76 signal to noise (S/N) ratio in, analog type, 78–79 low-power units, personal 226–228, 226, 234–236, 235 application specific IC (ASIC) digital assistants (PDAs), 83 single/multiple error detection memory in (See also memory), and correction in, 241–244 in, 82 79–81, 90–98, 117–118 spread spectrum (SS) in, arithmetic capabilities of, 117 mixed signal circuitry in, 263–264, 270 array processors, 84 82–83 spy hopping networks and, 176 bandwidth and, 118 multimedia extension (MMX) standards for baseband benchmarks for performance instructions sets for, 102 communications, 231–232 neural networks and, 79–81, symbol space in modulation in, 116–117, 119 80, 81 for, 236–238, 236, 237, 238 central processing unit (CPU) overhead and, 179 TCP error-free communication parallel processors in, in, 273 in, 88 83–85, 84 telephone networks for, 271 commercial off the shelf performance of, 115–117 time division shared access peripherals for, 108–113 systems, 261 (COTS) hardware/software power supplies for, trellis coding in, 264–255 in, 121 90, 118, 119 Turbo coding in, 256–257 communication technology printers in, 112 in, 82 read only memory (ROM) complex instruction set in, 101 computer (CISC), 100, 101–102 connections and cables in, 111 constraints in design, selection of, 114–121

296 INDEX computer hardware (continued) characterizing robot maneuverability in, 57 reduced instruction set performance and altering mass at heights (potential computer (RISC), 100 design of, 41–48 redundant array of inexpensive energy) in, 31 disks (RAID) in, 110–111 closed loop, 26–39, 26, mass in design of, 40, 48 registers in, computation and 47–48, 48 mechanical stress in, 58 storage, 98–99 mechanical wracking and, 53, reliability of, 119 coefficient of friction in design removable storage media of, 41, 45 55, 58 in, 111 motor force in, 31, 276, 277, reprogramming in, 119 complementary metal oxide resource utilization in, 118 semiconductors (CMOS) in, 278, 279 risks of, 74–75, 121 167–168 moving mass (kinetic energy) selection process for, 113–121 shareware and, 76 complexity in, 46 in, 31 software tools and, 120 computers for, 61 multivariable, 58–67 space requirements for, 119 continuous vs. discontinuous nonlinear control elements in, special purpose processors in, 81–83, 118 functions in, 51–52, 52 46, 51–52, 52 speed of execution in, 81–82 convergence and, 66 open loop, 24–26, 25 tape drives in, 111–112 cost function in, 63, 64–67 oscillation frequency (ringing) temperature limits and, damping and, 32–35, 34, 35, 132–133, 133 and, 44–47 third-party hardware/software 36, 42–44, 42, 48, 50, 51 overshoot in, 44, 46, 50 and, 76 design of, 39–58 performance and, 50, 65 time to completion, digital actuators in, 53, 54, 55 position in, 32–39 engineering and, 77 displacement (spring constant) power in, 57 voltage for, 119 quadratic equations in, 37–39 word size in, 89–90, 117 in design of, 40–41 ratchet mechanisms in, 56 distributed, 22–24 reaction of robot vs. design of, concatenated codes, dynamic response in, 29–39 248–252, 249 energy and power supplies in, 40–41 resonant frequencies in, 45 connectors/connections, 111 30, 159–189 response time in, 43–44 interference and, 142–143 errors in, 24–25, 25, 27–29, safety and, 57 reliability and, 126–127 second-order, 32–39, 42, 42, 27, 28, 64 contaminants, 126, 135 evaluation of, 64 43, 47–48, 48 content addressable memory feedback in, 26, 48 sensors in, 55 force conversion in, 41 settling time in, 44 (CAM), 97 force evaluation in, 31 solutions and problem solving continuous vs. discontinuous frameworks for, 61–63 frequency response and, 54–55 for, 66–67 functions, in control systems, frequency selection in, 45 space effects in, 69–71 51–52, 52 friction blocks in, 55 speed and, 57, 60–61, 67 control systems, 19–71 friction force in, 31–32, 40, spring constant in design of, acceleration in, 32–39, 57–58, 41, 45 40–41 69–71 gain changes in, 56, 56 springs (potential energy) and, altering parameters of, headroom in, 50–51 hunting in, 53–56, 55 30, 31, 48, 49, 50–51, 55 48–49, 65 hysteresis elements in, stability in, 45, 64, 66 balance in, 58 steady-state error in, 64 cautions in, 57–58 55–56, 56 step input function in, central, 24 iteration of computations in, characteristic differential 29–30, 29 61–62 thermostats in, 52–53, 54 equation in, 37–39 Laplace transforms and, 37–39 time effects in, 67–68 least mean square (LMS) traction and, 58 undershoot in, 50 algorithm in, 62–65 variables controlled simultaneously in, 64

INDEX 297 velocity in, 32–39, 57 deliverables, 8 Hanning window for FIR filter weight on spring as example of denial of service (DoS) in, 213, 213 second-order system in, attacks, 267 hardware for, 88, 216 32–39, 33–36, 36 design (See also high level high pass filters in, 210, 210 controller area network infinite impulse response (IIR) (CNA), 105 design), 147–151 controllers, analog controllers designing control systems (See filters in, 217–219, 218 in, 82–83 low pass filters in, 209, 210 convergence of control also control systems), 39–58 multirate, 220 systems, 66 destructive readout of noise and, 200, 201 convolutional codes, 250, Nyquist-Shannon sampling 252–257 memory, 94 cooling development time for computer theorem in, 192–197, computer hardware and, 118 195, 196 motors, 276, 277, 278, 279 hardware, 74, 120–121 overflow in, 87–88 cooperative user dial-up Internet services, 271 phase shift in IIR filters for, communications, 260 differential equation, control 219, 219 coprocessors, computer physical implementation of hardware and, 102 systems, 37–39 filters in, 215–219 corrosion, 285–286 digital actuators, 53, 54, 55 raised cosine filters in, 213 cost function, in control systems, digital noise, 201 random shifting and, 200–201 63, 64–67 digital signal processing (DSP) rectangular window for FIR costs filter in, 212, 212 computer hardware and, (See also filters), 82, 85–88, sample and hold (S/H) in, 201 74, 120 191–220, 248 signal to noise (S/N) ratio in, distributed control system, 23 analog filters and, 204–206, 198–201, 199 material, 284 sinc function and filter design creep, 285 204, 205 in, 207, 211, 211 current, reliability and, 126 analog-to-digital (A/D) software for FIR filters in, 215–216 D converters and, 191–192, Taylor series and, 85–86 192, 198–201 testing FIR filters for, damping in control systems, anti-aliasing filters and, 216–217, 217, 218 32–35, 34, 35, 36, 42–44, 192–197, 196, 201–207, 202 windows for FIR filters and, 42, 48, 50, 51 band stop filters in, 210, 210 211–215, 212, 213, 214 bandpass filters in, 210, 210 digital subscriber line data density in Bartlett (triangular) windows (DSL), 271 communications, 229 for, 212–213, 213 digital to analog (D/A) Blackman window for FIR converters, 191–192, 192, 207 data encryption standard filters in, 214–215, 214 digital video broadcast satellite (DES), 268 central processing unit (CPU) (DVBS) standard, 245 in, 88 direct current (DC), 169 Data Link layer, OSI layered delay in IIR filters for, direct current (DC) balance, network model, 224 219, 219 baseband communication, 229 digital to analog (D/A) direct memory access (DMA), Data over Cable Structured converters and, 191–192, 104, 118 Interface Standard (DOCSIS), 192, 207 dirt and wear, 286 271, 272 distortion and, 203 discharge cycle, in batteries, dithering (A/D) in, 200–201 165–166, 166 DC motors (See also motors), filter design for, 208–219 discrete cosine transform 276–279 finite impulse response (FIR) (DCT), 87 filters and, 86, 208–219, DC stepper motors, 278–279 209, 215–217 dead man power controllers, 174 fixed vs. floating point delay in communications, 259 numbers in, 87–88, 117 delay in IIR filters, 219, 219 Fourier transforms and, 86–87 Hamming window for FIR filter in, 214, 214

298 INDEX displacement (spring constant) encryption, 266–269 path checking and, 175 in design of control systems, energy and power supplies, peripheral power control 40–41 147–148, 153–189, 288–290 and, 175 display systems, 83 algorithms for, 178–179 pipelining for, 179–181 energy and power supplies alternating current (AC) planning for, 160 in, 175 position prediction and, video bus in, 104–106 in, 169 batteries in, 165–166, 166 183–184 distortion, 262 braking and, 184–186 power failure detect (PFD) anti-aliasing filters and, 203 calculating requirements for, pulse distortion in, 230–231, signals in, 182 230, 231 154–155, 288–290 power failures and, 182–183 centralization of energy code premission and, 181 distributed control systems, prioritizing needs for, 160 22–24 for, 161–162 processors and, 170–174 comparisons of requirements range of supply in, 168 dithering (A/D), digital signal rechargeable batteries in, 155 processing (DSP) and, for, 156 reclaiming/reusing energy and, 200–201 computer hardware and, 187–189 documentation of design, 144 118, 119 regulation of, 165, 168–170 downloading times and conservation of, 160, 162–164 requirements for, 166–168 control systems for, 159–189, routing for minimum energy memory, 91 dynamic mechanics, 288–290 167–168 consumption, 184 dynamic random access memory dead man power controllers safeguards and, 181–182 scheduling and, 179–181 (DRAM), 93–95, 96–97, 98 and, 174 security and, 181–182 dynamic response (See direct current (DC) in, 169 selection of, constraints display systems and, 113 also control systems), efficiency of use of, on, 157 29, 50–51, 52 sensors, 174, 175 162–164, 169 shared motors and, 183 E electric motor curves in, software considerations in, eavesdropping, 267 156, 156 178–183 Eb/No curves, 234–236, 235, field effect transistors (FETs) sources for, 157 spy hopping and, 176–178, 176 239, 247 in, 166–167 subsystem power control effective address, 91 filtering, 140 efficiency, of energy and power hardware considerations and, and, 174 switching regulators for, 170 supplies, 169 164–175 technology selection in, Einstein, Albert, 67, 68, 69 heatsinks in, 165 electric motor curves, 156, 156 high level design and, 147–148 160–161 electrocution hazards, 132 interference and emissions thrashing in, 182 electromagnetic interference torque control and, 186–187 from, 169 energy evaluation, for control (EMI), display systems interference and, 140–141 systems, 30 and, 113 interrogation at sensors, drain environmental considerations, electrostatic and electromagnetic 132–135 emissions/interference, on, 174 error control (See also 138–139 linear regulators for, 169–170 communications), 238–257 embedded processors, 113–114 linear, 141 bandwidth limited, emissions (See also looping and, 189 interference), 138–143 mechanical considerations in, 254–256, 256 emotions in robots, 20–22 bidirectional channels in, 241 empowerment of team members, 183–189 channel tuning in, 246–247 143–144 memory and, 174, 182–183 channels in, 251–252 encoding/decoding in motors and, requirements for, communications, 229 166–167 noise and, 168 operating system and, 178 overhead and, 179

INDEX 299 checksums, block checksums F rectangular window for FIR in, 241–244 filter in, 212, 212 fabless semiconductors, 82 concatenated codes in, failing, 136–137 sinc function in, 207, 211, 211 248–252, 249 fast Fourier transform (FFT), 87 software for FIR filters in, fatigue in materials, 286 control systems, 24–25, 25, Federal Communications 215–216 27–29, 27, 28, 64 testing FIR filters, 216–217, Commission (FCC), 139, 228 convolutional codes in, feedback, for control systems, 217, 218 250, 252 windows for FIR filters and, 26, 48 display systems and, 112 fiberglass, 283 211–215, 212, 213, 214 duplicate or redundant data field effect transistors (FETs), finite impulse response (FIR) transmission in, 239, 240 166–167 filters (See also filters), 86, eye patterns and \"open eye\" in, filters 208–219, 208 fire hazards, 130, 132, 277, 278 238–239, 239 analog, 204–206, 204, 205 Firewire, IEEE1394, 105 forward error correction (FEC) anti-aliasing filters and, fixed vs. floating point numbers, in digital signal processing in, 248 192–197, 196, 201–207, 202 (DSP), 87–88, 117 hard disk drives and, 110 band stop filters in, 210, 210 flash memory, 93 interleaver/deinterleaver in, bandpass filters in, 210, 210 flexing strength, 284 Bartlett (triangular) windows flexing, cable ware and, 127 250, 252, 257 floating point numbers, in digital modulators/demodulator in, for, 212–213, 213 signal processing (DSP), Blackman window for FIR 87–88, 117 250, 251–252 flowchart of project parity bits in, 244 filters in, 214–215, 214 management, 3, 4 quadrature amplitude delay in IIR filters for, force conversion control systems, 41 modulation (QAM) in, 219, 219 force evaluation in control 255–256, 255, 256 digital signal processing (DSP) systems, 31 Reed-Solomon checksums in, forward error correction 244–245 and (See also anti-aliasing (FEC), 248 reliability and, 126 filters), 207, 215–219, Fourier transforms retransmission in, ACK/NACK, 208–219 compression, 265–266 245–246 finite impulse response (FIR) digital signal processing RS encoder/decoder, 250, 252 filters and, 86, 208–219, single/multiple error detection 209, 215–217 (DSP) and, 86–87 and correction in, 241–244 Fourier transforms in design filter design and, 210 steady-state, in control system, of, 210 Fourier, Joseph, 86, 86 27–29, 27, 28 Hamming window for FIR FPGAs, 216 TCP error-free communication filter in, 214, 214 frame dragging, 70 in, 273 Hanning window for FIR filter frameworks for control systems, trellis coding in, 264–255 in, 213, 213, 230 61–63 Turbo coding in, 256–257 hardware for FIR filters in, 216 freeware, 76 unidirectional communication high pass filters in, 210, 210 frequency division shared access channels in, 247–248 infinite impulse response (IIR) communication systems, 262 Viterbi codes for, 240, 247, filters in, 217–219, 218 frequency response, in control 252–257 low pass filters in, 209, 210 systems, 54–55 Ethernet, 269, 272 phase shift in IIR filters for, frequency selection, 45, 139 execution time, computer 219, 219 frequency shift keying hardware and, 115–117 power cord, 143 (FSK), 234 expenses, 8–9 power supplies, vs. frequency sweep test, in FIR explosion, in batteries, 130 interference, 140 filters, 216–217, 217, 218 eye patterns and \"open eye\" in, raised cosine filters (RCF) in, 238–239, 239 213, 230–231, 231

300 INDEX frequency, natural, 290 documentation of, 12–13 energy and power supplies friction, 31–32, 40, 41, 45, 290 locomotion system and, 148 in, 169 friction blocks, 55 power supply and, 147–148 full test, 145 high pass filters in, 210, 210 FCC guidelines on, 139 Huffman compression, 266 generation of, 138–141 G human brain vs. computer grounding vs., 140 power, 21 intersymbol interference (ISI) gain changes, 56, 56 humidity, 135 galvanic corrosion, 285–286 hunting, 53–56, 55 in, 230–231, 230, 231, 262 game units, 83 hysteresis, in control systems, isolating noisy circuitry Gantt bar chart, 9, 10 55–56, 56 Gauss, 62, 63 and, 141 general packet radio service I linear power supplies and, 141 low frequency and, 139 (GPRS), 270 improving the design, 143 motors and, 141 general purpose processors, inductors, anti-aliasing filters package openings and, 142 power cord filters vs., 143 88–89 and, 205 power supply filtering vs., 140 general purpose (GP) registers, industry standard architecture pretested components vs., 141 rise time of signals and, 140 98–99 (ISA) bus, 104 shielding vs., 141–143 General Theory of Relativity, infinite impulse response (IIR) Inter-IC (I2C) bus, 105 interleaver/deinterleaver, 69–71 filters in, 217–219, 218 250, 252 global positioning system information signal, 233 internal resistance, in infrared data association (IRDA) batteries, 166 (GPS), 82 Internet, 82 global system for mobile wireless, 270 Internet protocol (IP), 82 infrared wireless networks, intersymbol interference (ISI), communication (GSM), 270 230–231, 230, 231, 262 governor, 60, 60 25–26, 107, 270 inverse Laplace transforms, gravitational lens, 70–71, 71 input/output (I/O), 103–108 control systems, 37–39 gravity, 69–71, 69, 70 IP checksums, 243 grounding, interference vs., 140 bandwidth and, 103 iteration of computations in gyroscopic torque buses for, 103–104 control systems design, 61–62 direct memory access (DMA) display systems and, 112 J–L hard disk drives and, 109–110 and, 104, 118 local area networks (LAN) and, jamming communications, 228 H jewelry, safety concerns of, 130 105–108 hackers, 267–269 memory bus in, 104 kinetic energy (moving Hamming window for FIR filter video bus in, 104–106 mass), 31 Institute of Electrical and in, 214, 214 Electronics Engineers (IEEE), Laing, Ronald David, 22 Hanning window for FIR filter reliability parameters Lamarr, Hedy, 263, 263 definition, 124 Laing, R.D., 22, 222 in, 213, 213, 230 instruction set, 99–100 Laplace transforms, in control hard disk drives, 109–111, 175 intelligence in robots, 20–22, headroom, in control systems, 79–81, 80, 81 systems, 37–39 intelligent batteries, 149 laser safety, 132 50–51 interference and emissions, layered model for network hearing and safety, 131 138–143 heat transfer, 290–291 connectors and cabling and, communications, 224–228 heatsinks, 165, 290–291 leadership, 13–14, 160 high level design (HDL), 142–143 electrostatic and 147–151 automation and, 148–151 electromagnetic fields in, computer hardware and, 113, 138–139 148–151

INDEX 301 leakage, in batteries, 130 M chips for, 93–95 learning, 79–81 content addressable (CAM), 97 least mean square (LMS) machining and forming of destructive readout in, 94 materials, 282–283 direct memory access (DMA) algorithm, 62–65 Legendre, 62, 63 maneuverability, 57 and, 104, 118 level one (L1)/level two (L2) mass, 40, 48 downloading times and, 91 mass at heights (potential dynamic random access cache memory, 97 leverage and safety, 131 energy), 31 (DRAM), 93–98 leveraging existing technology, materials, 282–287 energy and power supplies 75–76 availability of, 284 in, 174 licensing of software and, 76 composites, 283 flash type, 93 licensing software, 120 cost of, 284 level one (L1)/level two (L2) life testing, 144–145 dynamic mechanics and, limit of operations, testing cache, 97 288–290 looping and, 96 for, 144 fatigue in, 286 memory management unit linear regulators, 169–170 fiberglass, 283 liquid crystal display (LCD), 83 galvanic corrosion in, 285–286 (MMU) and, 92 load limits, communication, 260 heat transfer in, 290–291 pages in, 92 local area networks (LAN), 82, lubrication and dirt, 286 PCMCIA cards for, 93 machining and forming of, power failures, 182–183 102, 105–108, 272 random access (RAM), 10BT/100BT/1000BT 282–283 metals, 283 117–118 standards for, baseband, 106, natural frequencies and RAS/CAS cycle in, 95 232, 272 read only (ROM), 101, Aloha time division vibration, 290 communication systems plastics, 283 117–118 in, 261 resins, 283 refresh time in, 94 Ethernet and, 272 static mechanics and, 287–288 static random access (SRAM), infrared wireless, 107 strength of, 284–285 Physical layer in, 272 strength to weight ratios in, 282 94–95 TCP error-free communication tolerances for, 287 static type, 93–94 in, 273 wood, 283 stored programs in, 90–91 user datagram protocol (UDP) mathematics of reliability, 124 thrashing in, 97–98 in, 273–274 Maxwell, James Clerk, 138, 139 memory bus, 104 wireless (802.11b), Maxwell’s Equations, 138 memory management unit 106–107, 269 mean time between failure (MMU), 92 locomotion system, 148 (MTBF), 110, 125 metals, 283 Loebner Prize, 21 mean time to failure (MTTF), galvanic corrosion in, 285–286 longevity 124, 125, 126 millions of instructions per display systems and, 112, 113 mean time to repair a failure second (MIPS), 115–116 hard disk drives and, 110 (MTTR), 125 Minkowski, 67 loops mechanical stress, 58 mission statement, 14 energy and power supplies mechanical threats and mixed signal circuitry, 82–83 in, 189 safety, 131 modems, 271 memory and, 96 mechanical wracking, 53, 55, 58 modulation, 232–238 low frequency and mechanics (See also materials), modulator/demodulator, 250, interference, 139 281–291 251–252 low pass filters in, 209, 210 memory, 79–81, 90–98, 117–118 motor brakes, 186 lubrication, 286 addressing, 91–92, 95, 97 motor force, in control Lunar Excursion Module buses for, 104 systems, 31 (LEM), 154 cache, 95–98 motors, 275–279 AC motors, 275–276 braking in, 186

302 INDEX motors (continued) N overhead, in energy and power brushes in, DC type, 277 supplies, 179 brushless DC, 277–278 naming the robot, 14 control systems for, natural frequencies, 290 overshoot, in control systems, 276, 277, 278 Network Equipment 44, 46, 50 cooling for, 276, 277, 278, 279 DC motors, 276–279 Building System (NEBS) P DC stepper, 278–279 standards, 135 electric motor curves in, network interface cards pad brakes, 186 156, 156 (NIC), 232 pages of memory, 92 energy and power supplies in, Network layer, OSI layered panic buttons, 129 requirements for, network model, 224 parallel processors, 83–85, 84 166–167, 183 networks, Open Systems parity bits, 244 field effect transistors (FETs) Interconnection (OSI) layered path checking, energy and power in, 166–167 model for, 224–228 fire hazards of, 277, 278 neural networks, 79–81, 80, 81 supplies for, 175 interference and, 141 Newton, Isaac, 75, 75 PCMCIA cards, 93, 104 noise from, 277, 278 noise (See also interference), 290 Pentium™ processors, 102 organic, 279 analog, 200 performance, 50 piezo-electric, 279 digital, 201 reliability of, 277, 278 energy and power supplies benchmarks, for computers, revolutions per minute (RPM) 116–117, 119 in, 276 in, 168 shared, for energy motors, 277, 278 computer hardware and, efficiency, 183 nonlinear control elements, 46, 115–117 speed of, 276, 277, 278 51–52, 52 stopping and braking, 278 nonreturn to zero (NRZ) control systems, 50, 65 codes, 229 testing for, 145 moving mass force (kinetic Nyquist, 197, 197 performance testing, 145 force), 31 Nyquist-Shannon sampling peripheral component interface theorem in, 192–197, (PCI) video bus, 104 moving parts 195, 196 peripheral power control, 175 reliability and, 128 peripherals for computer (See safety and, 131 O also computer hardware), 108–113 MPEG compression, 220, 245, \"open eye\" pattern, personal digital assistants 247, 248, 251, 252, 265 238–239, 239 (PDAs), 83 personalities in robots, 21 multimedia extension (MMX) open loop control systems, personnel, 8 instructions sets, 102 24–26, 25 phase shift in IIR filters, 219, 219 multiple access/media access Open Systems Interconnection phase shift keying (PSK), 234 control (MAC) layer, OSI (OSI) layered model for Physical layer, OSI layered network model, 224 networks, 224–228 layered network model, 224, 226–228, 272 multiply and accumulate (MAC) operating system, energy and piezoelectric motors, 279 chips, 85, 216 power supplies for, 178 pipelining, energy and power supplies for, 179–181 multirate DSP, 220 operations per second, in plastics, 283 multivariable control systems computer performance, Politics of Experience, The, 115–116 22, 222 (See also control systems), polynomial checksums, 243 58–67 organic motors, 279 position, in control systems, oscillation frequency (ringing), 32–39 in control systems, 44–47 overflow, in digital signal processing (DSP), 87–88

INDEX 303 position prediction, energy and flowchart for, 3, 4 RAS/CAS cycle, in memory power supplies for, 183–184 Gantt bar chart in, 9, 10 and, 95 high level design (HLD) potential energy (mass at ratchet mechanisms, 56 heights), 30, 31 documents in, 12–13 reaction of robot vs. control leadership in, 13–14 power, 57 progress, problems, plans system design, 40–41 computer hardware and, 90 read only memory (ROM), 101, distributed control system, 23 (PPP) weekly report, 15 project manager (PM) role in, 5 117–118 power cord filters, 143 project plan in, 9–11 rechargeable batteries, 155 power failure detect (PFD) proposals in, 7–9 reclaiming/reusing energy, reasons for, 2–3 signals, 182 record keeping in, 7 187–189 power failures, 182–183 resource management in, 6, 11 record keeping in project PowerPC™ processors, 102, 117 reviews in, 6, 15 power states, 173 risk analysis in, 12 management, 7 power supplies (See energy and specifications in, 6, 11–13 rectangular window for FIR starting date for, 7 power supplies) strategies and tactics in, 14–15 filter in, 212, 212 premission (See also timelines for, 5 reduced instruction set computer vision and mission statements pipelining), 181 (RISC), 100 Presentation layer, OSI layered in, 14 redundant array of inexpensive project manager (PM) role, 5, 6 network model, 225 proposal, in project disks (RAID), 110–111 pretty good privacy (PGP)™ Reed-Solomon checksums, management, 7–9 encryption, 268–269 pulse distortion, 230–231, 244–245 printed circuit boards refresh of memory, 94 230, 231 registers, computation and (PCBs), 150 printers, 112 Q–R storage, 98–99 prioritizing needs, 160 regression test, 145 privacy issues, 260, 268–269 quadratic equations, in control regulation of power supply, 165, processors systems, 37–39 168–170 energy and power supplies in, quadrature amplitude modulation relativity, 67–71 170–174 (QAM), 238, 238, 255–256, reliability, 123–128, 145 255, 256, 271 memory and, 174 availability and, 125–126 power draw in, 174 quadrature phase shift keying batteries and power power states in, 173 (QPSK), 271 special purpose, 81–83 supplies, 127 varying clock in, 171–173, 172 quality issues, 143–144 bulbs, 128 varying voltage in, 171–173 computer hardware and, 119 voltage requirements for, radio frequency (RF) (See connector, 126–127 also wireless communication), distributed control system, 23 171–173 82, 106–107 mathematics of, 124–125 programming and software, mean time between failure raised cosine filters (RCF) in, centralization of energy code 213, 230–231, 231 (MTBF) in, 125 for, 161–162 mean time to failure (MTTF) programming languages, 99–100 random access (RAM) memory, progress, problems, plans (PPP) 117–118 in, 124, 125, 126 weekly report, 15 mean time to repair a failure project management, 1–17 random errors, 251 appointing the project manager random shifting, digital signal (MTTR) in, 125 motors, 277, 278 (PM), 6 processing (DSP) and, moving parts, 128 checklist for, 16 200–201 transistors, 127 corrective actions needed in, 6 removable media, 111 executing plan for, 13–15 reports, progress, problems, plans (PPP) weekly report, 15 reprogramming computers, 119

304 INDEX reserved Aloha, 261 sampling, Nyquist-Shannon sound pressure safety, 131 resins, 283 sampling theorem in, space, required by control resistors, anti-aliasing filters 192–197, 195, 196 systems, 69–71 and, 205 scheduling, 9 special-purpose computer resonant frequencies, control energy and power supplies in, 179–181 hardware, 81–83, 118 systems, 45 Gantt bar chart in, 9, 10 specifications, 6, 11–12, 13, 144 resource management, speed science fiction and robots, 1–2 6, 8, 11, 118 second-order control systems, braking and, 185–186 response time, in control control systems for, 32–39, 42, 42, 43, 47–48, 48 systems, 43–44 security 57, 60–61, 67 retransmission of motors, 276, 277, 278 communications and, 266–269 time and, 67–68 communications, energy and power supplies in, speed governor, 60, 60 ACK/NACK, 245–246 speed of execution reverse channel bandwidth, 259 181–182 computer hardware and, 81–82 reviews, 6, 15, 143 self-clocking pipelining and, 180–181 revolutions per minute spin up time (RPM), 276 communications, 229 display systems and, 112 ringing (See oscillation sensors, 55, 174, 175 hard disk drives and, 110 frequency) Session layer, OSI layered spoofing, 267 rise time of signals and spread spectrum (SS), interference, 140 network model, 225 263–264, 270 risk analysis, 12, 74–75, 121 settling time, in control spring constant in design of robot toy, 167 control systems, 40–41 rolloff, in anti-aliasing systems, 44 spring force in control filters, 203 Shannon capacity limit, systems, 31 rotational energy, 288–290 springs in control systems, 30, routing for minimum energy 226–228, 226 48, 49, 50–51, 55 consumption, 184 Shannon, Claude, 197, 197 spy hopping, 176–178, 176 row address select (RAS), 95 shared access communications stability in control systems, RS encoder/decoder, 250, 252 45, 64 RS232/432 standard for (See also communications), standards for baseband baseband communication, 232 258–264 communications, 231–232 RS422 standard for baseband shared motors, energy efficiency starting date in project communication, 232 and, 183 management, 7 RSA encryption/security, 268 shareware and, 76 statement of work, 8 run-length compression, 266 sharp parts, 131 static mechanics, 287–288 shielding, 138, 141–143 static memory, 93–94 S shock strength, 284 static random access memory shock (See also electrocution) (SRAM), 94–95 safety, 57, 128–132, 145 display systems and, 112, 113 steady-state error, in control batteries, 129–130 hard disk drives and, 109 systems, 27–29, 27, 28, 64 fire and electrocution, 132 reliability and, 127 step input function, in control human, 128–129 signal to noise (S/N) ratio, systems, 29–30, 29 lasers and light, 132 198–201, 226–228, 226, stepper motors, 278–279 mechanical threats and, 131 234–236, 235 stopband anti-aliasing moving parts and, 131 sinc function, filter design, filters, 203 panic buttons for, 129 207, 211, 211 storage registers, 98–99 sound pressure, 131 single board computers stored programs, 90–91 (SBCs), 168 strategies, 14–15 Sagan, Carl, 20 slotted Aloha, 261 sample and hold (S/H), 201 software, 76, 120, 121, 149–151 energy and power supplies in, 178–183 FIR filters in, 215–216

INDEX 305 strength of materials, 284–285 time division multiplexing vision statement, 14 strength to weight ratios in (TDM), 270 Viterbi codes, 240, 247, 252–257 voice, text to speech materials, 282 time division shared access stress tests, 144–145 communication systems, 261 engines, 274 stress, mechanical, 58 voltage, computer hardware subsystem power control, 174 timelines for project switching regulators, 170 management, 5 and, 119 symbol space in modulation, voltage level, of batteries, tolerances, material, 287 236–238, 236, 237, 238 torque (See gyroscopic torque) 165–166 synchronization, spy hopping torque control, in energy and voltage regulators, 165, 168–170 coordination in, 176–177 power supplies, 186–187 W system engineers (SE), 11 total quality management watchdog circuits, 136 T (TQM), 143 weight on spring as example of traction, 58 tactics, 14–15 transistors, reliability of, 127 second-order control system, tape drives, 111–112 translator, 173 32–39, 33–36, 36 Taylor series, in digital signal transmission control wheels and tires, 58 windows for FIR filters and, processing (DSP), 85–86 protocol/Internet protocol 211–215, 212, 213, 214 Taylor, Brook, 85–86, 85 (TCP/IP), 224 WinZip™, 265 TCP error-free Transport layer, OSI layered wired communication systems, network model, 224 271–274 communication, 273 trellis coding, 264–255 wireless communication, 82, TCP/IP, checksums in, 243 tuning, channel, 246–247 106–107, 269–270 teams for development, 150 Turbo coding, 256–257 Wireless fidelity (WiFi), 269 technologic advance, 75–76 Turing Test, 21 wood, 283 telephone networks, 271 Turing, Alan M., 21 word length, 89–90, 117 temperature, 132 TUV, 129 wracking, mechanical, 53, 55, 58 display systems and, 112, 113 U hard disk drives and, 109 semiconductor failure and, undershoot, in control systems, 50 132–133, 133 thermostats in, 52–53, 54 Underwriters Labs, 129 tensile strength, 284, 287–288 unidirectional communication testing, 9, 137, 144–145 FIR filters, 216–217, 217, 218 channels, 247–248 theft, 134–135 unit test, 145 thermostats, 52–53, 54 universal serial bus (USB), 105 third-party hardware/software, use tests, 145 76, 121 user datagram protocol (UDP), thrashing cache memory, 97–98 273–274 energy and power supplies V in, 182 time vandalism, 134–135 velocity, in control systems, control systems, 67–68 spy hopping coordination of, 32–39, 57 vibration, 133–134, 290 176–177 time division multiple access display systems and, 112 hard disk drives and, 109 (TDMA), 270 reliability and, 126 video bus, 104–106

ABOUT THE AUTHOR Charles Bergren has an MSEE from Cornell University and has been a top-notch EE for over 30 years. He has a consulting engineering firm, http://www.bdesigncorp.com, and has served as VP of Engineering in numerous companies. His design work includes: I Robotic Tape Libraries Building high-speed network control processors for storage systems. I Voice Processing Systems For voice recognition and text-to-speech applications I Vision Systems For the visual tracking of bacteria and DSP I Video Systems For MPEG video compression and satellite broadcasting I Power Control Systems For solar powered systems and nuclear reactor monitors I Communication Systems For wireless RF and free space laser networks He has taught academic and technical courses from kindergarten through college. His work teaching and playing lacrosse has led to two observations: I Nothing prepares you for the world like teaching proxy warfare to JHS boys I After people chase you with sticks for 2 hours, nothing else can hurt you the rest of the week. Copyright 2003 by The McGraw-Hill Companies, Inc. Click Here for Terms of Use.