Transponder Beacons Control Box

Head Mounted Display

Inertial Sensor

The IS600 Tracking System

Ultrasonic Coordinate Base

How the IS600 Works

Hybrid Tracking

*Inertial Sensor*motion detection*prediction capabilities

*Transponder Beacons*position detection

Projected CapabilitiesPosition Correction through Triangulation

Head Mounted Display

Transponder Beacons

Inertial Sensor

Project Goals

1.) Characterization of the IS600

2.) Integration of the IS600

into a Virtual Environment

Characterization of the IS600

Testing Facility

*National Institute of Health Laboratory

at the University of Rochester

Equipment

*Silicon Graphics Onyx

*Wire wound potentiometer

*Macintosh Power PC

Characterization of the IS600

Random Sampling Rate

8ms to 30ms

infrequent delays up to 80ms

Drift

NOT observed when stationary

Characterization of the IS600

Velocity Threshold

InterSense Detector Behaviorat High Angular Velocities

Rate of Rotation 449 degrees per second

0

50

100

150

200

2700 2800 2900 3000 3100 3200

time (ms)

rota

tio

n (

de

g) Potentiometer

InterSense

Characterization of the IS600Velocity Threshold

Intersense Detector Behavior at Low Angular Velocities

Average Rate of Rotation 2.8 Degrees Per Second

0

2040

60

80100

120

0 5000 10000 15000 20000 25000 30000 35000 40000 45000

time (ms)

rota

tion

(deg

)

Potentiometer

InterSense

Characterization of the IS600Prediction Options

InterSense Yaw Rotation without Prediction

InterSensey = 0.1292x - 45.705

R2 = 0.9964

Potentiometery = 0.1284x - 43.671

R2 = 0.998850

100

150

200

250

1000 1200 1400 1600 1800 2000time (ms)

rota

tio

n (

deg

)

Characterization of the IS600Prediction Options

InterSense Yaw Rotation with 50ms Prediction

Potentiometery = 0.2007x - 81.854

R2 = 0.9992

InterSensey = 0.1993x - 69.952

R2 = 0.9963

100

150

200

250

300

350

1000 1200 1400 1600 1800 2000time (ms)

rota

tio

n (

de

g)

Integration into a Virtual WorldUniversity of Rochester

*Department of Brain and Cognitive Science

*National Institute for Health Lab

Driving Simulator *Silicon Graphics Onyx

*Four R10,000 CPU’s*Infinite Reality Graphics Generator

Please Start Video

IS600 vs. Current System

Polhemus Fastrak InterSense IS600

Frequency 100Hz 500Hz

Average Sampling Lag 5ms 1ms

Tracker Processing Time 4ms 2ms

Serial Communication 5ms 5ms

Graphics Generation 16ms 16ms

Total 30ms 24ms

Conclusions

Software and Hardware Problems

No Magnetic Interference

Has Prediction Capabilities

GREAT POTENTIAL