041504_unmanned

041504_unmanned - Model-based Programming of Cooperating...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
Model-based Programming of Cooperating Explorers Brian C. Williams CSAIL Dept. Aeronautics and Astronautics Massachusetts Institute of Technology
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
With Complex Autonomic Processes Programming Long-lived Embedded Systems Large collections of devices must work in concert to achieve goals • Devices indirectly observed and controlled • Need quick, robust response to anomalies throughout life • Must manage large levels of redundancy
Background image of page 2
Coordination Recapitulated At The Level of Cooperating Explorers (Courtesy of Jonathan How. Used with permission.)
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Coordination Issues Increase For Dexterous Explorers (Courtesy of Frank Kirchner. Used with permission.)
Background image of page 4
Outline • Model-based Programming • Autonomous Engineering Operations – An Example – Model based Execution – Fast Reasoning using Conflicts • Cooperating Mobile Vehicles – Predictive Strategy Selection – Planning Out The Strategy
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Approach Elevate programming and operation to system-level coaching. Î Model-based Programming – State Aware: Coordinates behavior at the level of intended state. Î Model-based Execution – Fault Aware: Uses models to achieve intended behavior under normal and faulty conditions.
Background image of page 6
Why Model-based Programming? Polar Lander Leading Diagnosis: • Legs deployed during descent. • Noise spike on leg sensors latched by software monitors. • Laser altimeter registers 40m. • Begins polling leg monitors to determine touch down. • Read latched noise spike as touchdown. • Engine shutdown at ~40m. Programmers often make commonsense mistakes when reasoning about hidden state. Objective: Support programmers with embedded languages that avoid these mistakes, by reasoning about hidden state automatically. Reactive Model-based Programming Language (RMPL)
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Interact Directly with State Model-based Programs Embedded programs interact with Model-based programs plant sensors and actuators: interact with plant state: • Read sensors • Read state • Set actuators •Wr i tes ta te Embedded Program S Plant Obs Cntrl Model-based Embedded Program S Plant S’ Model-based Executive Obs Cntrl Programmer must map between Model-based executive maps state and sensors/actuators. between state and sensors/actuators.
Background image of page 8
RMPL Model-based Program Titan Model-based Executive System Model Commands Observations Control Program Plant State goals State estimates Generates target goal states conditioned on state estimates Tracks likely plant states Tracks least cost goal states z Executes concurrently z Preempts z Queries (hidden) states z Asserts (hidden) state Closed Closed Valve Valve Open Open Stuck Stuck open open Stuck Stuck closed closed Open Open Close Close 0. 01 0. 01 0. 01 0.01 0.01 0.01 inflow = outflow = 0
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Outline • Model-based Programming • Autonomous Engineering Operations – An Example – Model based Execution – Fast Reasoning using Conflicts • Cooperating Mobile Vehicles – Predictive Strategy Selection – Planning Out The Strategy
Background image of page 10
Mission-critical sequences: Motivation images courtesy of NASA • Launch & deployment • Planetary fly-by • Orbital insertion • Entry, descent & landing (Courtesy of Mitch Ingham. Used with permission.)
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 87

041504_unmanned - Model-based Programming of Cooperating...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online