Wireless Network Architectures for Collaborative Tele-operation

Dezhen Song

Ken Goldberg

University of California, Berkeley

Workshop on Wireless and Networked Robots, ICRA, 2004

Supported in part by

participants remoteenvironment

robot

Robot System Taxonomy (Tanie, Matsuhira, Chong 00)

Single Operator, Single Robot (SOSR):

Single Operator, Multiple Robot (SOMR):

Multiple Operator, Single Robot (MOSR):

Applications

Related Work• Recent Networked Robots

– Schenker et al. (01)– Goldberg and Siegwart (02)– Coppin, P. and Wagner, M.D. (02)– Konukseven, I., Erkmen, A. et al (02)– Meng et al. (03)– Bicchi et al. (04)

• SOSR– Tanie, K., Arai, H. et al. (00)– Lynch, K. and Liu, C. (00)– Fong, T., Thorpe, C., et al(01)

Related Work

• SOMR – Hu, Yu, Tsui, Zhou (01) – Jia, Takase (01)

• MOMR– Fukuda, Xi, Liu, Elhajj et al. (00,02)– Tanie, Chong, et al. (00)

• MOSR– Cinematrix (91)– Cannon, McDonald, et al. (97) – Goldberg et al. (00, 01, 02, 03)

RemoteEnvironment

Multi-Operator Single Robot (MOSR) System

Operators

The “Tele-Actor”:

Remote Environment

Operators

Requirements• Low cost• Omni-directional

• Light in weight

• Low power consumption

• Small in size

• Moderate range (>80M)

Analog vs Digital

RFTransmitter

RFReceiver

Digitizer

Transmitter ReceiverDigitizer

Analog Wireless

Digital Wireless

Analog Wireless CamerasProducts Price Weight Range Resolution Frequency

X10 XCam2 $80 >150 Grams

30M 380 horizontal lines

2.4Ghz

Microcam $250 20 Grams 100M 380 horizontal lines

2.4Ghz

System Architecture (2001)

Tele-Actor

Analog 2.4Ghz

Users

InternetInternet

Tele-Actor Server

Local Director

Remote SiteBerkeley

Anywhere

Field Test for Analog Wireless

July 18th, 2001, SF Opera House, 5th Annual Webby Awards

Microcam

Analog Wireless Summary

• Pros– Full motion picture in video transmission– Easy to configure– No noticeable time delay in transmission

• Cons– Interfere with 802.11b– Sensitive to noisy – Hard to expand due to peer to peer topology– Only transmit analogy signal– Not flexible in selecting hardware

Digital Wireless Options

Types Bluetooth 2G 802.11b

Range 10M 10KM 100M

Bandwidth 721 kbps 10~20Kbps 11Mbps

System Architecture (2002-)

Tele-Actor

Camera Person

Wireless Network

(802.11b)

Wireless Basestation

Users

InternetInternet

Tele-Actor Server

Local Director

Remote SiteBerkeley

Anywhere

Hardware

Helmet designed by E. Paulos

802.11b Field Tests

Nov. 8 & Dec. 19, 2001, UC Berkeley Micro-fabrication Laboratory

Jul. 26, 2002, Michael Eisen's Biotechnology lab at Lawrence Berkeley National Laboratory

802.11b Field Tests

Feb 13, 2002, SF Exploratorium

• HTTP• VoIP• Videoconferencing

Genetics Laboratory (LBL)November 2002

14 seniors from Galileo High, SF

Summary

• 802.11b– Pros

• Flexible in network topology

• Transmit all types of signals

• Widely accepted as standard

– Cons• Limited bandwidth

• Noticeable time delay in signal

• Sensitive to interference (2.4Ghz band is busy.)

• Problematic in roaming between networks

Future

Types 802.11a 3G 4G

Range 100m? >10km ?

Bandwidth 54Mbps 384kbps~1Mbps ?

Dez Song: dzsong@ford.ieor.berkeley.edu

Ken Goldberg: goldberg@ieor.berkeley.edu