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Hybrid Deliberative Reactive Paradigm

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					Hybrid Deliberative/ Reactive
         Paradigm




   Name: Jianhua (Sam) Xie
        Id:05172055
                      Introduction

 Reactive
      Cheap low memory processing
      no world model
 Deliberative
      making maps
      selecting behaviours
      monitor performance
      reactive planning
 Hybrid deliberative/reactive paradigm
      Hybrid Deliberative/ Reactive
               Paradigm
Hybrid are the best general architectual
solution for several reasons:

 First, the use of asynchronous processing
  techniques allow deliberative functions to execute
  independent or reactive behaviors
 Second,good software modularity allows
  subsystems or objects in Hybrid architectures to
  be mixed and matched for specific application
              Hybrid Paradigm

   Deliberation
     reasoning using symbols
     global world model


                      PLAN




            SENSE               ACT
            Hybrid Sensor Model

                            World Map/
                            Knowledge Rep

                                             virtual sensor

                                 Behaviour

                                 Behaviour


                                 Behaviour

Sensor 3   Sensor 2   Sensor 1
      Architectural Components

 Sequencer
 Resource Manager
 Cartographer
 Mission Planner
 Performance Monitor
 Problem Solving
      Architectural Components -
              Sequencer
Generates the set of behaviors to use in order to
 accomplish a subtask, and determines any
 sequences and activation condition

Represented as:
  • Dependency network
  • Finite state machine
      Architectural Components-
         Resource Manager
Allocates resources to behaviors, including
 selecting from libraries of schemas
                 • Stereo vision processing
                   speed fast enough
                 • Sonar have enough power
                   to produce reliable reading
                 • ……
      Architectural Components -
             Cartographer
Responsible for creating, storing, and
 maintaining map or spatial information, plus
 methods for accessing the data

Contains:
  • Global world model
  • Knowledge representation
     Architectural Components –
          Mission Planner
Interacts with the human, operationalizes the
  commands into robot terms, and constructs a
  mission plan
      Architectural Components –
   Performance Monitoring & Problem Solving

Allows the robot to notice if it is making
 progress or not


This requires the robot to
 exhibit some type of
 self-awareness
                   Hybrid Styles

 Managerial
     Layed system based on scope of control
 State Hierarchies
     Select reactive and deliberative based in internal
      state
 Model-Oriented
     Uses some kind of (partial) world model
      Hybrid Styles - Managerial

Focus on subdividing the deliberative portion
  to layers based on scope of control of each
  deliberative function
• Pass off the plan from
  high level to low level agent
• High level can see and direct
  subordinate low level agent
• “Fail upwards”
       Managerial Style - AuRA

 AuRA : Autonomous Robot Architecture
 The oldest of the Hybrids
 Designed and implemented by Arkin
 Based on schema theory and consists of five
  subsystem
       Managerial Styles - AuRA

 Planner
  Responsible for mission and task planning. It’s
     three components:
  1. Mission planner: interface with human
  2. Navigator: work with cartographer
  3. Pilot: interacts with Motor subsystem
 Cartographer
  Cartographer can also be given an a priori map
       Managerial Styles - AuRA

 Sensor & Motor
  Make up the reactive portion of the architecture,
   includes perception and motor schemas
 Homeostatic Control
  Modify the relationship between behaviors by
   changing the gains as a function of the “health”
   of the robot or other constraints
             Managerial Style - AuRA
                                               Mission Planner,
                      Planner                  Sequencer,
                                               Performance Monitoring
Cartographer       mission planner
                      navigator
                        pilot
                                                           Homeostatic      Deliberative Layer
                                                             Control        Reactive Layer
                                Behaviour Manager
                                     Motor
                          Motor schema manager
    Sensor
      ps1                    ms1

                                                                       actuators
      ps2                          ms2

      ps3                                ms3



   sensors
         Managerial Style - SFX

 SFX: Sensor Fusion Effects
 Started out as an extension to AuRA , and
  has reorganized the reactive and delibrative
 SFX is an example of how robustness can be
  build into an architecture
 SFX has been used on eight robots for indoor
  and outdoor
                   Managerial Style –
                  SFX: Cognitive Model
                  Cerebral Cortex

                                  cognitive
                                  influences


                       Superior                            Neurophysiologic
                       Collicus                            al model of
                                                           sensing in cats
receptive
   receptive
  field              Focus-of attention
      receptive
     field               feedback for          muscle
        field                                   muscle
                  recallibration, adaptation      muscle
 sense
   sense
     sense
      Managerial Style –
     SFX: Implementation




                                                                                           layer
                                                                                           Deliberative
Cartographer        Sensor                 Task               Efffector
                    manager               Planner             manager


                  sensor allocation     Behaviour instantiation




                                                                  BEHAVIOURAL WHITEBOARD




                                                                                           layer
                                                                                              Reactive
     WHITEBOARD



                    behaviour
                              behaviour
     SENSOR




                                      behaviour




receptive
   receptive
  field                   Focus-of attention
      receptive
     field                    feedback for                    effector
        field                                                   effector
                       recallibration, adaptation                 effector
 sense
   sense
     sensor
         Managerial Style – SFX

 Mission Planner
 Find a set of behavious which can accomplish the
 mission
 Resource Manager
 Task manager, sensing manager and effector manager
 Sensing Management
  Particularly noteworthy because of its explicit
    commitment to performance monitoring and
    problem solving
         Managerial Style – SFX

 Reactive Component two layers:
   Strategic
   Tactical behaviors
  Next slice is a behaviors for following an outdoor
    path
Managerial Style – SFX
   Hybrid Styles - State Hierarchies

Select reactive and deliberative based in
  internal state, organize activities by the scope
  of time knowledge
Time is generally thought of as being:
  • Past
  • Present
  • Future
          State Hierarchies – 3T

 The roots of 3T stem from continue work at
  NASA
 As the name, 3T includes 3 layers:
   Reactive
   Deliberative
   Layer in the middle
                                      3 Tiered (3T)
                                             Performance Monitor,
Planner
                       Goal                    Mission Planner
                                                                       Planning
                                                                      Monitoring
  Subgoal           Subgoal             Subgoal
                                                                            Cartographer
                                                                        World
Task   Task     Task       Task       Task       Task
                                                                        Model


 Resource                                               Sequencer
              Agenda
 Manager      Task                                                                         Deliberative Layer
                                             Interpreter                 RAP
               Subtask                                                  Memory
               Primitive                                                                   Reactive Layer
               wait-for
               Subtask
Sequencer

               Skill                     Skill                      Event

Skill
Manager                       Skill                                 Event
   Hybrid Styles – Model-Oriented

It’s more top-down and concentrate symbolic
   manipulation around a global world model
• Less ambitious in scope and more cleverly
  organized
• Perceptual processing is done with distributed
  processing , slow perceptual routines run
  asynchronous of faster routines
   Hybrid Styles – Model-Oriented

• Sensor errors and uncertainty can be
  filtered using sensor fusion over time.
  This can improve the performance of
  the robot
• Increases in processor speeds and
  optimizing compilers have mitigated
  the processing bottleneck
       Model-Oriented – Saphira

 Has been used at SRI on a variety of robots
 Three keys to a mobile robot operating
  successful:
   Coordination its actuators and sensors
   Coherence maintain global world worlds
   Communication with human being
        Model-Oriented – Saphira

 PRS-lite(a type of reactive planner):
   Procedural Reasoning System-lite
   Capable of taking natural language voice
    commands from humans and
   Operationalizing into navigation tasks and
    perceptual recognition routines
 Virtual sensor:input from the central world
                                 Saphira
                                                 Resource Manager,
  Software                 Planning Agent          Mission Planner,
   Agents                                      Performance Monitoring

                  Cartographer
  People
 Tracking
                                                            Topological
                            Local Perceptual                  Planner
  Object                      Space (LPS)
Recognition
                                                            Navigation
                                                              Tasks
  Surface
Construction
                                     Virtual
                Localisation,        Sensors
               Map Maintenance
                                                                           Deliberative Layer

                                                                           Reactive Layer
                        Reactive
                          Reactive              Fuzzy
  sensors              Behaviours
                           Reactive                                     actuators
                        Behaviours              Logic
                          Behaviours
         Model-Oriented – TCA

 TCA: Task Control Architecture
 Used extensively by robots designed for
  NASA
 Curvature velocity method(CVM): respond
  with a smooth trajectory for the robot’s
  current velocity
 Task Control Architecture
         (TCA)
          Task Scheduling              Mission Planner




                    Path Planning        Cartographer
 GLOBAL
 WORLD
 MODELS
                                          Sequencer,
                      Navigation
                                       Resource Manager


                                         Deliberative Layer

                  Obstacle Avoidance     Reactive Layer
                       (CVM)

Sensors                 Effectors
                         Summery

 Hybrid concept
      Reactive and deliberative

 Architecture components
 Hybrid style
 Five hybrid architectures introduction