Transcript Real Time Systems

REAL
TIME
Live, Full-scale
Giga-Places
Peta-Bytes, Tera-OPS
Femto-time
Learn
Observe
Interoperable,
pervasive networking
Ubiquitous sensors
7/10/11
Now Digitized:
Sense/Observe
Collect/Distribute
Analyze
Simulate
Decide
Act
Real-time, massive
analysis
Automated learning
Vast, evolving
knowledge stores
What is “real time”?
What If?
Now
Then
Real Time Systems: Live, always-on, reactive,
interactive, stable, controllable, adaptive
What If?
What If?
Now
Then
Rate-1
7/10/11
Rate-1
Later
Rate-1
Time Frames and Operation Rates
Observation time – measure, discriminate
Analysis time – communicate, contextualize,
understand
Decision time – choose, formulate, distribute
Action time – energize,drive
7/10/11
Sample rates vary with applications
Pico to milliseconds
Speed of a
process
Days to weeks
Decades
Stock trading incl’d
programmed
trading
Automobile
controls
engines to
driverless
control
Water resources
measurement,
modeling & controls
SCIENCE
Surveillance
Memory recall
Climate change
Content
distribution
Power grid
demand
It all begins with
simulation…
Sensors*
Simulator with
Human
*Sensors may be people
Model of
System e.g.
airplane
MIT Whirlwind (c1951) first real time computer.
Begot SAGE (Semi-Automatic Ground Environment)
Sample rate versus utility
Pico to milliseconds
Speed of a process
Days to weeks
Decades
Stock trading incl’d
programmed
trading
Automobile controls
engines to driverless
control; Power grid
demand
Water resources
measurement,
modeling &
controls
SCIENCE
Surveillance
Memory recall
Climate change
Content distribution
Wes Clark, Lincoln Laboratory, and LINC, first PC.
LINC: Laboratory Instrument Computer c. 1962
Real time processing for bio-medical research.
Real time Sensing
e.g. laboratory control, simulators
Sensors*
REAL WORLD
System
*Sensors may be people
Observers,
Model
Builders e.g.
Scientists
LINC 2007 Vintage Computer Fair
(At age 45 … turns 50 next year)
Some other real time computers
Whirlwind: Bright Boys
1962 LINC that influenced PDP-5
8/1963 PDP-5 for interfacing a Canadian research
reactor to a PDP-4 (controller)
RT-11 from OS/8 begot CPM >> DOS
RSX-11
Sensing…
Observations
by human
operators
Sensors*
REAL WORLD
System
*Sensor/effector may be people
Sharing of data
To effect change
Real time Control
Plain old closed loop control
Model of
REAL WORLD
System
Advice (t+1)
Controller
Sensors*
REAL WORLD
System
Effectors*
*Sensor/effector may be people
(Processing,
policies and
people)
Real time and Control
with/wo Real World Modeling
Model of
REAL WORLD
System
Advice (t+1)
Delays and
Noise
Sensor
s* WORLD
REAL
System
Effector
s*
*Sensor/effector may be people
Delays and
Noise
Controller
(Processing,
policies and
people)