Presentation Transcript
CS 546: Intelligent Embedded Systems: CS 546: Intelligent Embedded Systems Gaurav S. Sukhatme
Robotic Embedded Systems Lab
Center for Robotics and Embedded Systems
Computer Science Department
University of Southern California
gaurav@usc.edu
http://robotics.usc.edu/~gaurav/CS546
Administrative: Administrative The CS dept is working on a bigger room for the class
The class cap has been raised to 45
Is there anyone here
who has not yet filled the questionnaire ?
who has filled the questionnaire and not got a response from me ?
who wants to be in the class, and is not on the class mailing list ?
Today: Today Overview of the ENS box (Richard Pon and Jeff Tseng, Aevena)
TinyOS tutorial
Homework #2
Karthik will give a brief explanation
Homework is online on the class website
Sensing, sensor calibration, and actuation basics
Homework #2: Homework #2 Karthik just gave you details
Due a week from today – no extensions
Last week: Last week Platform
OS and SW architecture
Tools
User interface
Application Figure adapted from [Pottie and Kaiser 2005]
Today: Today Platform
OS and SW architecture
Tools
User interface
Application Figure adapted from [Pottie and Kaiser 2005]
Sensors: Sensors Basic principles
Noise and figures of merit
Types of sensors
Calibration
Sensing Architecture: Sensing Architecture
Sources of Noise: Sources of Noise
Figures of Merit: Figures of Merit Responsivity:
output signal/input signal
Sensitivity:
(output signal without input)/(responsivity)
Drift: slow change in output due to low-frequency noise
Cross talk
Types of Sensors: Types of Sensors Environmental
Pressure, gas phase composition, automotive exhaust gas oxygen,
Motion and force
Accelerometers, rotation and rotation rate, piezoresistive strain, microphone, capacitative position
Electromagnetic transducers
Antennas, magnetometers, digital cameras. laser rangefinders
Chemical and biochemical
Oxygen, nitrate (amperometric)
Transduction Principles: Transduction Principles Pressure – capacitance change
Gas – absorption changes conductivity
Accelerometer and rate gyros – proof mass displacement changes
Microphone – diaphragm displacement changes resistance
Piezoelectric – force changes polarization charge
Magetometer – motion wrt coil induces a current
Camera – photodetectors and CCD arrays
Nitrate – use microfluidics to reduce an electrode and measure current
Calibration: Calibration Compare measurements to a reference
Performed while manufacturing
Tuning parameters (say a resistor)
Need calibration methods in situ
Usually non-linear interpolation
Next time: Next time Network and programming models