papanikolopoulos

Distributed Robotic TeamsDistributed Robotic Teams

Nikos Papanikolopoulos Professor, Department of Computer Science

and EngineeringDigital Technology CenterUniversity of Minnesota

npapas@cs.umn.edu

AI, Robotics, and Computer AI, Robotics, and Computer Vision Laboratory, CSE, UMN Vision Laboratory, CSE, UMN

Faculty Maria Gini (Artificial Intelligence, Robotics, Intelligent Agents) Nikos Papanikolopoulos (Robotics, Computer Vision, Transportation Systems) Stergios Roumeliotis (Robotics, Robot Localization and Mapping) Rich Voyles (Robotics, Computer Vision, Multi- Agents) Paul Schrater (Computer Vision, Pattern Recognition, Haptic Interfaces)

AI, Robotics, and Computer AI, Robotics, and Computer Vision Laboratory, CSE, UMN Vision Laboratory, CSE, UMN

Mission Statement

The goal of the laboratory is to combine algorithm development with strong system building efforts that validate our algorithms. With respect to teaching, the goal is to educate top researchers/teachers and use AI, robotics, and computer vision as the vehicle to promote science/engineering principles to our students.

Rangers and ScoutsRangers and Scouts

Heterogeneous robotic team

RangersGeneral purpose

off-road robots

ScoutsCustom portable

sensor platforms

Technical Overview of Technical Overview of the Project: Goals the Project: Goals

Develop distributed robots (main unit is roughly the size of a soda can) with various mobility and sensory modes for exploration of structures in an urban warfare scenario.

Emphasize the development of innovative mobility modes for these robots.

Data fusion and analysis are to be at a remote operator station.

Effective combination of software and hardware design.

Some ApplicationsSome Applications Special Unit Operations Law Enforcement Agencies:

– Hostage situations– Counter terrorist units in large cities– Fire and rescue– Disaster relief

Coast Guard: vessel boarding and search FBI Fugitive Task Forces, FBI Crisis Response Team NASA space exploration programs Toy and Entertainment industries

Scout DesignsScout Designs

Grasshopper

Rolling Ball

Scout 2001

Scout 2001 vs. Scout 1999Scout 2001 vs. Scout 1999

Scout 2001

Scout 1999

Complete electronic and electrical redesign

Significantly improved power management

Encoders have been added to the drive motors.

The internal components have all been modularized to decrease assembly and repair time from hours to minutes.

The jumping spring and winching motor have been improved to increase overall mechanical efficiency and the height of jumps.

Scout Jumping TrialScout Jumping Trial

(a) (c)(b)

(f)(e)(d)

Scout VideoclipScout Videoclip

Hardware EffortsHardware Efforts

Mobility improvements

Communication improvements

Rooftop scout with grappling hook

COTSScout and MegaScout

Scout repeaters

Variable-size actuated scout wheels

Variable-Size Actuated Variable-Size Actuated Scout WheelsScout Wheels

wheel extended wheel retracted

Rooftop ScoutRooftop Scout

User feedback indicated the need for a scout that can operate on a roof or a ceiling.

The goal again is to achieve the desirable functionality without significant changes to the scout design.

The idea was to have an external scout attachment with a spring-loaded mechanism and a grappling hook.

Two prototypes have been built.

Rooftop ScoutRooftop Scout

Grappling HookMechanism

Scout with the Scout with the Pan-Tilt Camera SystemPan-Tilt Camera System

Motion Detection and TrackingMotion Detection and TrackingA computer vision algorithm was written to detect motion in the field of view and automatically track the center of motion.

Low Cost AlternativesLow Cost Alternatives Commercial Off-The-

Shelf (COTS) Scout– Designed to be a low cost, nearly

disposable alternative with reduced functionality and slightly improved resilience

– Physical Characteristics: 44 mm x 97 mm cylinder with 3 wheel sizes (57 mm, 64 mm, 76 mm)

– Sensing Capability: Camera– Locomotion:

• Rolling: Top speed – 57 mm wheel: 0.39 m/s– 64 mm wheel: 0.42 m/s– 76 mm wheel: 0.50 m/s

– Operational Life: 190 minutes in quiescent mode, 60 minutes at top speed broadcasting video

– Cost: < $300

Low Cost AlternativesLow Cost Alternatives

Commercial Off-The-Shelf (COTS) Scout

Modified Scout PlatformsModified Scout Platforms

MegaScout

Control and SimulationControl and Simulation

Control architecture is layered and based on behaviors.

Rangers are the control and communication central units (utility units).

Lego-based platforms were used initially for rapid prototyping and experimentation.

Software ImplementationSoftware Implementation

CORBAXMLC++

Backbone

Mission Control

Resource Pool

User Interface

Supervisory WorkstationPalm Pilot/Wristwatch TV’s

Scouts, Rangers, Radios, Video Frequencies,

Framegrabbers,Launchers, etc.

Prioritized Behaviors,Mission Decomposition,

Parallel Execution

Scheduling, System Configuration,Starting/Stopping Components, Load Balancing,

etc.

Behavior: Servo to a TargetBehavior: Servo to a Target

Human selects target Robot handles servoing process Assumption: known target geometry

– Deployment and retrieval of robot– Navigation between waypoints

Examples of Vision-Based Examples of Vision-Based Behaviors (Image Mosaics)Behaviors (Image Mosaics)

The scout rotates 360 deg and blends the individual images in order to

create mosaics of urban spaces.

General InnovationsGeneral Innovations

Design and functionality of the scouts. Design of the ranger-scout system (launching, communication,

navigation). Simple control and communication primitives that can be

reconfigured for a variety of robot behaviors. Development of a large heterogeneous distributed robotic

system based on these scalable, reconfigurable behaviors and physical components.

Miniaturization of the scout hardware peripherals (e.g. sensing, communication, etc.) required significant innovation.

Creation of a large variety of mobility modes in order to increase the scout functionality.

Technical ChallengesTechnical Challenges

Communication!!!!! Power requirements and management* Design of the jumping mechanism Hardening* Assembly and disassembly of the scout Miniaturization* Human-scout interaction given a large number of

scouts Software issues

*High risk issues

ConclusionsConclusions

The scout has proven to be a simple and effective design. It has been featured on CNN, BBC, NBC, Comedy Central, and was a finalist for the Discover award.

Feedback from military users (Lincolnia exercises) indicates that the scout is the right design and the right size.

There is a patent for the overall design. Various innovative mobility enhancements have been

developed. The COTSScout has a long life and a satisfactory set of

capabilities at a very low-cost. A variety of user interfaces has been developed. Communication remains a challenge.

AcknowledgementsAcknowledgements

This material is based upon work supported by National Science Foundation through grant #EIA-

0224363, Microsoft Inc., INEEL, and the Defense Advanced Research Projects Agency, MTO (“Distributed Robotics”

Program), ARPA Order No. G155, Program Code No. 8H20, issued by

DARPA/CMD under Contract #MDA972-98-C-0008

URL InformationURL Information

Videoclips and papers can be found at:http://distrob.cs.umn.edu

Scout Coverage by BBCScout Coverage by BBC