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Senses, sensing, and sensors with applications to ICT for sustainable development mel siegel robotics institute school of computer science.

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Presentation on theme: "Senses, sensing, and sensors with applications to ICT for sustainable development mel siegel robotics institute school of computer science."— Presentation transcript:

1 senses, sensing, and sensors with applications to ICT for sustainable development mel siegel robotics institute school of computer science

2 starting points sensing is often the problematic element in the sense-think-act-communicate paradigm –it is all well-and-good to say, e.g., “what we need to halt the spread of AIDS is a 50-cent battery operated pen-sized sensor for HIV infection...”, but where is that sensor? the unavoidable tradeoff between sensitivity and specificity threatens system robustness sensor fabrication technology lags – so can ride the coat tails of – VLSI technology

3 what senses do we want? at least the human ones... vision: eyes (optics, light) hearing: ears (acoustics, sound) touch: skin (mechanics, temperature) odor: nose (vapor-phase chemistry) taste: tongue (liquid-phase chemistry) sixth sense (proprioception): joint angles

4 human senses are dual-use balance –ears (in addition to hearing) acceleration –stomach (in addition to digestive senses) sound –chest cavity (in addition to breathing senses) touch –touch: tongue (in addition to taste) –temperature: skin (in addition to force)

5 a blessing and a curse artificial sensors also respond to multiple stimuli –almost all respond to temperature –many respond to acceleration and pressure –many respond to light and other radiation –sensors are “physics experiments that failed” these can often be “compensated” using differential techniques however noise is always present –environmental stimuli of same sort as signal –thermal and other noise internally generated

6 we can’t escape it... it’s the Joe BFSTPLK effect …

7 but with clever techniques...... we can extract very small signals from overwhelming quantities of noise military communications hide small signals in overwhelming environmental noise, so your adversary doesn’t even know you are talking – encryption is a backup in case he somehow manages to actually hear you

8 we would also like to have extended ranges and modalities vision outside the RGB spectrum active vision –radar and laser range measurements hearing outside 20 Hz – 20 kHz range –ultrasonic range measurement chemical senses beyond taste and smell radiation: , ,  -rays, neutrons, etc

9 and sensors for modalities that humans might have... electric fields? magnetic fields? radio (electromagnetic) waves? pheromones? (probably yes) “weather”? what else??

10 we need artificial sensing for … everything the human senses can do … without handicaps (specs, hearing aids, …) able to use human sensory aids –telescopes, microscopes, etc –stethoscopes, sound amplifiers, etc –micromanipulators w/ haptic feedback, etc plus all the senses that we don’t have (or we don’t have with good cognition) but which our applications demand

11 here’s the textbook I recommend Handbook of Modern Sensors Physics, Designs, and Applications Jacob Fraden 3rd ed., 2004, XVII, 589 p. 403 illus., Hardcover ISBN: 0-387-00750-4 $89.95

12 Ch1 Data Acquisition(3) digital interface Ch2 Sensor Characteristics(1) raw signals Ch3 Physical Principles of Sensing(0) materials science Ch4 Optical Components of Sensors(0) optical science Ch5 Interface Electronic Circuits(2) analog interface Ch6 Occupancy and Motion Detectorsis someone there? Ch7 Position, Displacement, and Levelwhere is something? Ch8 Velocity and Accelerationhow fast? Ch9 Force, Strain and Tactile Sensorshow heavy? Ch10 Pressure Sensorshow heavy (fluid)? Ch11 Flow Sensorshow fast (fluid)? Ch12 Acoustic Sensorshow loud? Ch13 Humidity and Moisture Sensorshow wet? Ch14 Light Detectorshow bright? Ch15 Radiation Detectorshow radioactive? Ch16 Temperature Sensorshow hot or cold? Ch17 Chemical Sensorswhat is it made of? Ch18 Sensor Technologies(0) sensor fabrication

13 old: transduce to human vision thermometers: temperature-to-length barometers: air pressure-to-length scales: weight-to-angle humidity: hair curl-to-angle indicator dyes: chemistry-to-color photo film: light/radiation-to-silver density speedometers: velocity-to-angle

14 new: transduce to electronics thermistor: temperature-to-resistance electrochemical: chemistry-to-voltage photocurrent: light intensity-to-current pyroelectric: thermal radiation-to-voltage humidity: absorbed water-to-capacitance length (LVDT): displacement-to-inductance microphone: sound pressure-to-

15 sense-think-act loop measurandmeasurand transduce perception to electrical signal measure in volts, amps, ohms, henrys, farads, etc. convert from signal to symbol compute control action transduce signal to heat, displacement, illumination, etc convert from symbol to signal SENSOR ACTUATOR ADC DAC

16 sense-think-act loop transduce perception to electrical signal measure in volts, amps, ohms, henrys, farads, etc. convert from signal to symbol compute control action transduce signal to heat, displacement, illumination, etc convert from symbol to signal SENSOR ACTUATOR ADC DAC measurandmeasurand e n v i r o n m e n t

17 measurand & measurement system immersed in environment nature confounds measurement with: –temperature –quantization –chaos environment confounds measurement with: –complex universe: 3 K radiation, weather,... –interfering signals: power lines, radio/TV,... –engineering and materials limitations,...

18 distribution of replicated measurements 0 1 2 3 4 5 6 7 8 9 998.0998.5999.0999.51000.01000.51001.01001.51002.0 Measured Height [mm] Number of Measurements

19 sensor fusion: people & robotics Barfogenesis : Does Virtual Reality Make You Sick? –... I was getting nauseous from the film. My eyes wanted me to "stop flying," while my body said, "you're not moving at all"... –http://serendip.brynmawr.edu/bb/neuro/neuro00/web3/Pili.htmlhttp://serendip.brynmawr.edu/bb/neuro/neuro00/web3/Pili.html... the only things consistently real about Virtual Reality were headaches and motion sickness... (Steve Ellis) –http://www.firstscience.com/site/articles/virtual_reality.asphttp://www.firstscience.com/site/articles/virtual_reality.asp some corresponding problems in “artificial” sensing: –multi-modality image registration (e.g., light + ultrasonic) –multi-media synchronization (e.g., sound + video) –one modality, several measurements, how to combine them? –several measurements contribute to a calculated result; given component confidences, how to calculate overall confidence?

20 combining multiple measurements three thermometers give measurements T 1 = 19.1 ± 2.0 C T 2 = 18.6 ± 2.5 C T 3 = 19.3 ± 1.0 C what is your best estimate of the actual temperature, and what is your estimate of the error in your estimate of the actual temperature? weight by reciprocals of respective uncertainties (actually weight by reciprocals squared) this is what we mean by “sensor fusion”

21 combining multiple errors you compute the volume of a box by multiplying together measurements of its height, width, and depth: V = (h ± Δh) (w ± Δw) (d ± Δd) what is your estimate of the error ΔV? it is the (quadrature) sum of { ∂ V /∂ h,∂ V /∂ w,∂ V /∂ d} weighted by {Δh, Δw, Δd} this is what we mean by “error propagation”

22 electronic sensors many sensors are just resistors, capacitors, or inductors (sometimes containing “unusual” materials) whose parameters depend on some feature of the environment: –thermistors: R (temperature T) –humidity sensors: C (absorbed water vapor) –proximity sensors: L (distance to a surface) –magneto-resistive sensors: R (magnetic field B) –photo-conductors: R (incoming light intensity)

23 other sensors are fundamentally voltage sources: –electrochemical sensors: V (chemistry) –photovoltaic sensors: V (light intensity) –magnetic pickup loops: V (B(t))

24 still other sensors are fundamentally current or charge sources: –Faraday cup (e.g., solar wind collector) –photocell (e.g., “electric eye”) –CCD camera sensor –many kinds of radiation detectors for example, smoke detectors in which vapors accompanying the smoke affect the charge collected in a radioactive environment

25 and other sensors fundamentally extract power from radiated fields: –antennas: directed radio frequency energy –microphones: directed acoustic energy

26 many kinds of sensors are essentially perturbed communication devices: –a signal transmitter –a signal receiver –the nature of the path between them disturbs (or sometimes enhances) the communication between them –from which disturbance an interesting property of the medium is deduced for example, smoke detectors in which the smoke just attenuates a light beam

27 instruments vs. sensors many devices thought of as “sensors” at an applications level are very complex instrument systems at an engineering level analog-to-digital conversion scan generation background subtraction curve fitting library searching pattern recognition

28 sensing needs in context of the WEHAB agenda Water and Sanitation Energy Health and Environment Agriculture Biodiversity and Ecosystem Management

29 water & sanitation good clean water essential to all WEHAB: energy, health, agriculture, biodiversity humans not good sensors of water quality: awful seeming can be safe, & vice versa complex instruments, e.g., GC-MS, too big, expensive, hard to use and maintain semiconductor, MEMS, organic polymer sensors all promising –but require IT support for linearization, library searching, pattern recognition, alarms, etc

30 see : http://www.geocities.com/RainForest/5161/lab2.htm http://www.geocities.com/RainForest/5161/lab2.htm –separation techniques –measurement techniques gravimetric electrochemical colorimetry / spectrophotometry titration chromatrography mass spectrometry

31 alternative 3 rd world appropriate water quality sensing arrays of discrete sensors  integrated sensor arrays / chemical imagers  hand-held smart instruments (Cyrano Inc.)

32 energy (& off-grid capability) reliable IT requires reliable hardware even in the absence of a reliable power grid –sensors needed for controls that provide local backup and stability to compensate for global unreliability and instability IT can ensure reliability of the power grid and power generation infrastructures –sensors needed to detect faults (and theft!), compensate for environmental perturbations, monitor and correct power quality, etc

33 see : http://www.electrotek.com/seminars/hirel.htm http://www.electrotek.com/seminars/hirel.htm –living with an unreliable power grid better batteries: modern batteries include complex circuitry to sense and regulate changing and discharging local generation means: a lot of low-grade energy is available, but it takes smart adaptable systems to utilize it uninterruptible power supplies: batteries + inverters + means to intelligently shut down when batteries run down and intelligently re-start when power becomes available again –making the power grid reliable rapidly sensing fault, diagnosing problem, taking corrective action remote sensing to detect illegitimate usage (e.g., theft) measuring, assessing, and improving power quality integrating local and national generating capacity by allowing users to become suppliers when they have excess local capacity

34 power availability and quality http://portland.indymedia.org/en/2004/08/294881.shtml

35 health & environment instruments for rapid, reliable, sensitive detection of illness – or impending illness –diabetes: disease of modern diet and lifestyle –identification of infectious agents (viruses etc) protecting employees, residents, and their environments from industrial pollution detecting bad side effects of good projects, e.g., arsenic in ground water detecting side effects of war, e.g., mines

36 see: http://www.sciencedaily.com/releases/200 3/09/030924054754.htm Livestock Health Sensors And Wireless Data Storage In The Works http://www.sciencedaily.com/releases/200 3/09/030924054754.htm see: http://www.cis.rit.edu/~rlkpci/urssra_Krem ens.pdf Low Cost Autonomous Field-Deployable Environment Sensors http://www.cis.rit.edu/~rlkpci/urssra_Krem ens.pdf

37 health & environmental sensors http://www.yenra.com/ glucose-monitor/ glucose monitor + insulin pump http://www.weathertools.com/oregon4.html http://www.weathertools.com/oregon4.html weather station w/ wireless sensor module transmitters

38 agriculture many sensing requirements intimately tied to health (e.g., animal health), weather sensing and prediction, water availability many chemical sensing requirements: soil and water pH and nutrient content, oxygen availability and demand many physical sensing requirements: water availability, retention, evaporation for advanced technology, need the full robotic arsenal for navigation and work

39 see http://www.agrotechnology.kvl.dk/teaching/p hddanetpft/pdf/04_sensingsystems.pdf Sensor Technology in Agriculture http://www.agrotechnology.kvl.dk/teaching/p hddanetpft/pdf/04_sensingsystems.pdf see http://www.kuleuven.ac.be/onderwijs/aanbo d/syllabi/I0F33AE.htm syllabus of a course (in Dutch) on physical sensors, chemical sensors and bio-sensors for agricultural and food applications http://www.kuleuven.ac.be/onderwijs/aanbo d/syllabi/I0F33AE.htm

40 sensors for agriculture http://www.sentek.com.au/ products/products.asp?lang=en portable soil monitoring system http://www.ntechindustries.com/ mapping.html greenseeker optical plant health monitor http://www.trimble.com/ AgGps_autopilot.html automatically steers tractor perfectly straight, center pivot, curves or headlands

41 biodiversity & ecosystems large- and small-scale characterization and monitoring of animal and plant species evaluation and exploitation of medicinals, both unknown and used traditionally control of poaching, encroachment, etc, while preserving indigenous cultures tracking animal movements tagging legitimately collected specimens enabling transport of more fragile species

42 see http://www.digitalgovernment.org/search/ projects/project.jsp?ID=108 Biodiversity and Ecosystem Informatics - Wireless Sensor Networks for Dense Spatio-Temporal Environmental Monitoring http://www.digitalgovernment.org/search/ projects/project.jsp?ID=108 see http://investigate.conservation.org/xp/IB/ex peditions/pantanal/day8/day8_tools.xml neat night pictures of animals in jungle http://investigate.conservation.org/xp/IB/ex peditions/pantanal/day8/day8_tools.xml

43 sensors for biodiversity & ecosystems http://www.esa.int/export/esaEO/ SEMPMB0XDYD_environment_1.html pressure map above hurricane Frances http://www.landcareresearch.co.nz/ services/ecosat/presentations/ wetland.pps#7 wetland mapping project in New Zealand

44 parting points sensing is often the problematic element in the sense-think-act-communicate paradigm –it is all well-and-good to say, e.g., “what we need to halt the spread of AIDS is a 50-cent battery operated pen-sized sensor for HIV infection...”, but where is that sensor? the unavoidable tradeoff between sensitivity and specificity threatens system robustness sensor fabrication technology lags – so can ride the coat tails of – VLSI technology


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