Distributed%20and%20Adaptive%20Communication%20Protocols%20for%20Autonomous%20Vehicles

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Distributed and Adaptive Communication Protocols
for Autonomous Vehicles

• Greg Pottie
• Charles Taylor

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Outline

• Reliable communication links
• Exploitation of redundancy
• Interaction with control hierarchy
• Development of robust, adaptive message sets

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Reliable Communication Links

• Robust, jam-resistant communications (ONR
  project)
• Spread spectrum
• Channel coding and retransmission
• Adaptive power control and bit rate
• Adaptive antenna arrays
• Fast adaptation through interpolation

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Trades

• Delayshorter delay implies less robust coding
  and adaptation
• Data ratehigher data rate demands more resources
• Securityhigher security implies reduced
  communications flexibility
• Error ratelower error rate demands increased
  complexity

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Exploitation of Numbers

• Variable link quality often acceptable if have
  routing choices
• Groups of autonomous vehicles may tolerate
  variable quality of service

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Interaction with Control Hierarchy

• Control hierarchy implies variable message
  priority, quality of service
• Delay
• Error rate targets
• Data rate
• Maximum time between control updates
• Demands new model for communications traffic and
  thus possibly new MAC

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Control Traffic Models
Within formation Low latency, high
rate, predictable locations, response to local
conditions
Between formations High latency, low
rate, location uncertainty, global objectives
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Evolving Control Language

• Different layers of control hierarchy will demand
  different message sets want these to be robust
  and to describe the phenomena of interest
• Limited set of events of interest at each level
  may permit automated evolution of languages

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Language Construction

• Bind utterances (description/meaning pairs) to
  events of interest this builds the basic
  vocabulary
• Determine the logic underlying the relationships
  between the events this underpins the grammar of
  the language
• Language builds in understanding and thus is a
  form of compression

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Logic of Language

• The events of interest and the certainty with
  which they are observed imply different logics
  for inference
• Logic takes into account unreliability of
  individual links, and considers actions of group
  as a whole

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Preliminary research

• Abstract model for constrained set of
  eventsneeded also for traditional communications
  protocol construction
• Extract vocabulary and logic
• Build grammar
• Aim is to gradually consider more complicated
  situations, to determine whether languages can be
  automatically evolved to deal with unexpected
  events.