sensors presentation-06a
TRANSCRIPT
Sensors: Getting Engaged!
Sensors: Getting Engaged!
EventI/O: The Museum Inside-Out/Outside-In38th Annual MCN ConferenceAustin, TexasPresented byAbhijit RaoPlan A Computing AssociatesThere has been this surge in Wireless Sensors it is a reasonable mature market it is not anymore confined to the walls of an R& D Lab. We will look at some of the detail including the internals of a sensor, the structure etc,. the emerging uses, what has propelled their growth and how to use them. We take a look couple of potential applications and the framework. Other than sensors- affordable computing systems, mobile devices and wireless technologies are fueling the growth new possibilities in exploring and learning.Sensors will drive the next surge of innovation in Museums. With the advances in semiconductor technology, various sensors such as temperature, motion sensing, pressure, humidity, compass, touch and proximity are being made affordable and easy to use. Sensors will allow the museum to present the visitor with a whole new world of interactivity / engagement. Various forms of Wireless connectivity available today only make it more convenient to design and manage. This lecture will provide an introduction to the digital sensors- their characteristics and then the selection process. Also covered will be the common requirements to be considered in selecting wireless connectivity techniques, followed by a discussion of the approaches and likely challenges to integrating sensors into a comprehensive and useful system.
Sensors: Getting Engaged!
So are we looking at Sensors just because those are cool things? No I do not think so Sensors do have wide applicability and it is more than the cool factor - sensors are likely to cause paradigm shift. There is small use of Sensors but what I think will happened is much bigger acceptance in the usage sensors.
Traditionally sensors have been used in museums to measure the ambient conditions such as light and humidity for preservation purposes. The digital IC based sensors of today provide data that can be monitored remotely with an automated system configured to respond appropriately. The automated system can also log data to help in planning and maintenance.
Sensors: What are they?
Miniature devices that capture sensory data
React to external stimuli
Sensory data incl. heat, humidity, light....
Micro Electro-Mechanical Systems (MEMS)
Data transmission is wireless, whereas the Sensing mechanism and power supply are not
Sensor: Structure
Physical
Transducer + Control Logic
(Analog + Digital)
Abstract
Part of a bigger network
Sensors are much more accurate beyond; often beyond human levels of cognition huge mtbf unlike human...
Sensors: What are they all about?
Captures sensory data from real physical world
Detecting relevant quantities of the data
Monitoring and collecting the data
Assessing and evaluating collected data
Formulating meaningful information
To be conveyed to the user
To be stored for future
Performing decision making
Sensory data comes from multiple sensors of different modalities/requirements often in distributed locations
It is a pipeline one stage after the other
Sensors: Why Museums?
Traditional Uses
User interaction
Exhibit Design
Ubiquitous Computing
Where technology recedes into the background of our lives. - Mark Weiser
TetherlessExperiencePlanned Activity
Sensing CapabilityWow!Sensors provide
Physically unobtrusive, low power, form factor, low maintenance
New sensing paradigms
Combining Sensors with traditional computing systems hand held, PDA, Computer systems can enhance and extend the fun in learning.Smart environments instrumented with sensor-and-wireless-enhanced objects would be able to sense events and conditions about people/objects (basically the participants) and act upon the sensed information or use it as context when responding to queries and commands.
What you see here is sensing + wireless communication + embedded processingUbiquitous Computing term coined by mark Weiser he identified it as the thirdwave in Computing
Sensors: Outlining a Framework
Exhibit
Remote ExhibitBack Office ObserverLink / AgentSensor Net
Sensor FusionSensor Managementdb Management...
ServicesIn here the sensor talks to a Link / Agent it is also conceivable that Sensor Net elements can be designed/implemented in such a way that the data from one sensor will hop to the adjacent sensor until the data reaches the main LAN.
Sensor: Ecosystem Players
Multiple devices per square meter
Mixed data rate requirements
Varying streaming requirements
Real-time and tolerate latency
Databases
Static Database Content, Plan & Rules
Dynamic Database User activity context, Sensor data
Applications
Visitors
SensorsMiddlewareServicesApplicationsDatabase
Sensors: Sense Element
Transducer
Physical property to be sensed
Detectable signal
Source: Springer.com Author: J FortinMeasurand- A physical quantity, property, or condition which is measured. A transducer is a device that converts one type of energy to another. Can either be a Sensor or Actuator. Sensor detect energy in one form and report in another form. Such as Pressure, Temperature, Airbag,...Actuator receives energy and generates action such as loudspeaker, electric motor, .. (electromechanical output devices are generically called actuators)For high precision Capacitive sensors and longer range laser or optical based sensorsEddy-Current sensor tolerance of dirty environment also used for position measurement/sensing as in the disk drives
Sensors: Typical Sensor
Source: Springer.com Author: J FortinSense Element
Physical Property such as heat, light
Signal (Charge current)
Electric current depending on the context, a flow of electric charge (a phenomenon) or the rate of flow of electric charge (a quantity).
Pressure Sensor
Sensors: Transducer Details
Source: Silicondesigns.com
Sensors: SMART Sensor
Provides extra functions beyond just the correct representation of the sensed physical quantity
Moving the intelligence closer to the point of measurement
Control LogicVirtual SensorSense Element(MEMS)ApplicationAlgorithmCommunication InterfaceAnalog-to-Digital Conversion
Signal Conditioning
Digital Signal ProcessingUser Interfacebuttons/ledStorage(Threshold / Calibration)
Physical
InputBase StationHost
SMART SensorS.M.A.R.T.
Self-
Monitoring, Analysis, and Reporting Technology
SMART
Sensors: Virtual Sensor
Virtual Sensor
Source: sparkfun.comControl LogicVirtual SensorSensor ElementApplicationAlgorithmCommunication InterfaceAnalog-to-Digital Conversion
Signal Conditioning
Digital Signal ProcessingUser Interfacebuttons/ledStorage(Threshold / Calibration)
Base StationHost
Smart Sensor
Virtual sensor estimates the properties in conjunction with physical sensors. Virtual sensors manage drifts, calibration
Sensors: Wireless Connectivity
Source: laboratoryequipment.comMost wireless sensors, particularly those based on IEEE 802.15.4 or 900 MHz radios, are designed to use power very conservatively.900MHz can propagate further (less attenuation), whereas 2.4GHz based protocols handle obstruction better (900MHz ISM in NA, Aus. & Israel)802.15.4 standardizes the MAC and PHY the upper stacks (as in WirelessHART and ZigBee) are not compatible. (PHY 868MHz in Europe + 900Mhz elsewhere + 2.4GHz)Wireless Sensors the required data rate, low energy consumption and low cost are paramountWi-Fi/802.11 Security, QoS and Bandwidth are important
Sensors: Power & Networking
Source: laboratoryequipment.com
Source: techbriefs.comIn a cluster tree network, each node connects to a node higher in the tree until the data reaches the gateway. This simple algorithm may be used with any wireless radio technology. Finally, in a mesh network, nodes can connect to multiple other nodes in the system and pass data through the most reliable path available. If one link goes down, affected nodes can pass data through another path to reach the gateway. Most IEEE 802.15.4-based devices employ some type of mesh network topology, because of this self-healing effect.In Star all sensors transmit directly to the central data collection point. Mesh network best over large distances, harsh RF environments, to avoid 1 single point of failure
Sensors: Key Drivers
Improving Cost & Yield
Standardization efforts in Wireless Networking
Cheaper Efficient Tinier Processing Logic
Quick Integration Methods
Development of low power radio technologies
Advances in low-power embedded micro-controllers
Advances in the computing technology promotes the sensing and act on the physical environment suggesting the person to physical world connection is closer and achievable than ever.
Sensors: System Design
Wireless Networking
Middleware Services
Data Management
Sensory User Interaction (SUI)
Approach
Identify the use case scenarios
List sense element and energy domain details
Calculate anticipated workload
Identify the sensor network algorithms
Perform the Sensor System Design in conjunction with the Exhibit Design
Having sensors and wireless connectivity is only the first part of the puzzle the widdleware services is essential for a successful SUI
Sensor: Identifying a Sensor
Identify the measurand
Energy Domain
Usage Pattern
Bandwidth and other resource requirements
Characteristics
Power consumption
Network support
Form factor
Volume of sensors to deploy and use
Vendor selection
Minimum Quantity requirements
Lead time
Sensors: Technology restrictions
Size and packaging
Energy efficiency (Power constraints)
Data rates for the wireless data transfer
High data rates (Audio/Video) / Streaming
Low data rates (spatial sensors, environment sensing)
Fine grained estimation and tracking of location and orientation of large number of objects that are being sensed
Quality of Service needs
QoS - it maybe OK to miss temperature samples but not necessarily that of the orientation sensor
Sensors: System Example
Sensors - Lightweight
Location & Orientation
Identification
Network Agent Conduit for the sensors
Master Act upon sensor data
Location & OrientationIdentificationObject TrackingSpatial Configuration of multiple users and objects
Generate information such a Kid A is in the corner near Pyramid A
AgentHost Sensors: Outlining a Framework
Sensor 1Sensor 2Sensor 3ComputerWeb
Exploration & Learning PlanContent ManagementExploration & Learning Interaction HandheldSystem HardwareSoftware App stackSensors
ELP manages the purpose of the tool or the exhibit ...such as (i) Weather Station it will be weather science study that is adjusted to the age group (ii) Earth navigator it will be region & climate study lCM Manage local data, share if necessary data with similar systems (Database Mgmt)ELI It handles the UI and rules management To summarize the three key challenges are to be handled are- creating networked sensing approaches- networking protocols optimized for large scale and high density sensor presence- processing and analysis of data generated by all these sensors
Sensors are a mature market!
Using those sensors in a large scale, in Museums, will have a revolutionary effect in user experience.
Sensory User Interaction is here to stay!
If there is sufficient interest we can explore opening a SIG under MCN
To receive these slides, please send an email to [email protected]
Sensor: Getting Engaged!
Thank you!
Backup
Sensors: Experience Realms
Sensors can enhance the all experience realms
Sensor: Sample applications
Wireless network of toys
Learning individualized to the participant / each child
Unobtrusive evaluation of the learning process
Hidden in the infrastructure (walls, chairs, ...)
Music toys (MIT Media Lab's Toy Symphony)
Heavy on gestures and tactile in nature
Embed sensors for touch, pressure .. in toys and exhibit objects and detect their manipulation
Ubiquitous Computing "that which informs but doesn't demand our focus or attention."Problem solving in nature unstructured because of the kind of data that is collected to make sense out of it. And then react to it in realtime in a context sensitive fashionToys of Tomorrow and Music Toys programs at MIT's Media Lab
Sensors: Compare to a typical Computing System
Ad-hoc and Distributed structure
Likely to be large scale yet sparse in density
Unreliability due to nature of the link
Restricted system resources, Power management
Overcome by huge amount data that gets collected (redundancy)
Physical stimulus and reactionary in nature
Predominantly unstructured and asynchronous
Diversity of data types with large dynamic range of rate, latency, processing requirements
Sensors: Transducer Properties
Physical Properties
Used to measure Pressure, temperature, Humidity...
Motion Properties
Used to measure Acceleration, Position, Angular velocity, Direction
Contact Properties
Used to measure Vibration, Slip, Strain
Presence
Used to measure Tactile, Contact, Proximity, Motion, Light
Identification
Used to measure ID Data, Retinal, Voice, ...
Sensors: Sense Element Basics
Source: lionprecision.com
Source: analog.comSource: eetimes.com
For high precision Capacitive sensors and longer range laser or optical based sensorsEddy-Current sensor tolerance of dirty environment also used for position measurement/sensing as in the disk drivesSecurity aspects are key to while designing proximity sensors.Hall effect is another type of electromagnetic sensor - production of a voltage in a current-carrying semiconductor in the presence of a magnetic field.Thermocouples based on Seebeck effect.Resonant-Temperature sensor based on the property of SiO2 to exhibit a change in resonant frequency depending on temperature change.Optical transducers can be optimized for different frequencies of light visible and non-visible so that you can have infrared detectors, ultraviolet detectors and so on.
Sensors: Other Sensor Elements
Source: sandia.gov
Source: sensormag.comChemical Transducers used in environmental monitoringChemiresistors are expensive because of the specialized nature nevertheless it is very accurate. It uses electrodes that are coated with specialized chemical agents that change their resistance when exposed to certain challenge agents.Array of biosensors are put together for an Electronic nose.Em Spectrum sensors used in autonomous vehicle navigation. It requires expensive DSP techniques including edge detection, segmentation, motion analysis etc.,Acoustic sensors also uses Doppler techniques for the measurement of velocitiesAcoustic Wave Sensors uses the changes to the characteristic of the propagation path effect the velocity and/or amplitude of of the acoustic wave these sensors are often used in conjunction with materials that demonstrate Piezoelectric effect. It I perhaps the most versatile of sensors because it has been used to sense many physical properties
Sensors: Mapping a Smart Sensor
Control LogicVirtual SensorSensor ElementApplicationAlgorithmCommunication InterfaceAnalog-to-Digital Conversion
Signal Conditioning
Digital Signal ProcessingUser Interfacebuttons/ledStorage(Threshold / Calibration)
Base StationHost
Smart Sensor
Sensors: MEMS Sensor SoC
Control LogicVirtual SensorSensor ElementApplicationAlgorithmCommunication InterfaceAnalog-to-Digital Conversion
Signal Conditioning
Digital Signal ProcessingUser Interfacebuttons/ledStorage(Threshold / Calibration)
Base StationHost
Smart Sensor
Source: invensense.com
Sensors: Form factor
Standalone
Integrated onto a PCB
Source: monnit.com
Source: kcftech.com
Source: freescale.com
Sensors: Adoption Today
Building industry, Green evolution, Transportation, Home automation, ...
Importance indicated by IEEE driven standards in this space
Driven by affordability and ease of use
Efficient and low cost connectivity methods
Classified solutions based on data rates
Predominantly used as spatially distributed autonomous sensors to monitor physical environment conditions.
Backup
Sensor: Challenges
Power
Lack of ruggedness
Steep learning curve
Actuator: Display Technology
Source: flexlighing.com
Source: holografika.com
Source: microvision.com
Source: mirasoldisplays.comSensors when coupled with the growth in display technologies and tactile feedback technologies will open a wavefront of innovation in user interaction and exhibit design.
Actuator: Tactile Feedback
Source: densitron.com
Source: densitron.comSource: immersion.com
When the user touches the screen, a position signal is sent to the microprocessor. The host application interprets this position and commands the lightweight TouchSense player, embedded on the processor, to play a specified tactile effect, such as the perception of a button press.Haptics is a catchall term for sub-types including Tactile (the sense of pressure applied through skin), kinaestehtic (motion of the body),
Actuator and Sensor Combined: Touchable 3D Display
Source: docomo
References
Weiser, Mark The Computer for the 21st Century Scientific American Vol 265 p 66-75
http://www.ubiq.com/hypertext/weiser/SciAmDraft3.html
Smart Kindergarten: Sensor-based Wireless networks for Smart Developmental Problem-solving environments - ACM ISBN 1-58113-422-3/01/07
thepaca.net
Transducer typeInput (Property of Interest for Sensor)Output (Property of Interest for Actuator)Also known asSensorAcceleration measuredDigital representation (along the axes)AccelerometerSensorPressure measuredVoltage outputPressure sensorActuatorDigital SignalVoiceLoudspeakerActuatorDigital SignalRotary MotionElectrical Motor
???Page ??? (???)10/30/2010, 10:42:26Page / Energy DomainMeasurandSense PrinciplePhysical PropertiesPressurePiezoresistive, CapacitiveTemperatureThermistor, Thermo-mechanicalHumidityResistive, capacitiveMotion PropertiesPositionElectro-Magnetic, Contact SensorAccelerationVibration (Proof-Mass), CapacitiveGyroscopeCapacitive, Electro-MagenticContactStrainPiezoresistiveVibrationPiezoresistive, SoundPresenceTactile/ContactContact, capacitiveProximityHall effect, Magnetic, RFIdentificationID Fingerprint, data stored, retinal scan
???Page ??? (???)10/30/2010, 10:42:26Page / DriversToday's sensor future
ScaleMicroNano
Power consumptionlong life (> 2 years)energy harvesting
???Page ??? (???)10/30/2010, 10:42:26Page / Energy DomainCharacteristicTransduction PrincipleMechanicalRely on direct Physical contactCapacitive Sensors as in Touch Sensors Piezoelectric effect as in balls that lit when bounced Electromagnetic / Magnetic Useful for detecting proximity eventsEddy-current sensors allows bigger sensing range and bigger probe spot size RFID use power in the interrogating signals to send back small amounts of dataThermalMeasure temperature or heat fluxThermoresistive effect exploits resistance of a conductor/semiconductor changes with temperature Thermocouples sensor based on current flows between two materials are joined together and one is hotter than the other. It is less expensive and is very reliable Resonant Temperature sensors are expensive and very high accuracy.Opticalconvert light to various quantitiesPhotoelectric effect measures the flow of electrons based on incident light
???Page ??? (???)10/30/2010, 10:42:26Page / Energy DomainDescription / Uses
Chemical Interact with matter of all types Used in sensing pollutions causing gases
BiologicalMedical Diagnostic, detecting Pesticides
ChemiresistorsImplemented with an array of chemical sensors, interpreted using a pattern-recognition algorithm to sense a variety of chemicals. Used in Contamination assessment
Metal-Oxide Gas sensorsrelies on adsoprtion of gases onto certain semiconductors changes their resistivity. Used in smoke detectors
BiosensorsSensing depends upon selectivity of biomolecular reactions such as molecular binding sites detect property changes mass, resistance, spectral reading
EM spectrumRadar / Lidar, GPS
Acoustic Sound as the sensing medium detecting fluid leakages and earthquakes
Acoustic WaveEmploys two sets of fingers one to generate the surface Acoustic Wave and the other to detect the changes. Very versatile in its applications.
???Page ??? (???)10/30/2010, 10:42:26Page /