Intelligent Transport Systems
The Technologies can be Grouped by their
Functionality:
• Route Guidance
• Driver Assistance
• Vehicle Control
• Fleet Management
• Communications

POTENTIAL APPLICATION SYSTEMS
Traveller Services
Access for the Elderly and Disabled
Making Travel Safer
Helping Business
Intermodal Journeys
Environmental Safeguards
Law Enforcement
Coping with Congestion
Electronic Payment
MOST OF THESE APPLICATIONS CONTAIN MORE THAN ONE
FUNCTIONAL STREAM

WHY APPLICATION FOCUS?

• Applications will provide the User Value, not raw
Technologies
• Many Technologies will be shared between
Applications
• Much of the Application Value will be generated
OFF the Vehicle (eg by Service Providers)

WHAT IS OFFERED WILL DEPEND MORE ON USERS’ NEEDS
AND VALUE SYSTEMS THAN ON TECHNOLOY

CONTROL IMPLICATIONS

CONTROL SYSTEM BASICS

ACTUATOR
POWER
SOURCE

ACTUATOR
CONTROLLER
ACTUATOR

OUTPUT
SENSOR

CONTROL MESSAGE
FEEDBACK
LINK

DESIRED VALUE INPUT
Desired values:
•human input
•fixed values
•memorised personal factors
•pre-planned sequence
•mathematical model

POWER LINE
CONTROL LINE

CONTROL CALCULATION
Response calculation:
•proportional to difference
•integral of difference
•trend in difference
•look-up tbale
•mathematical model

LEARN TO IDENTIFY THE ELEMENTS OF EACH SYSTEM

CONTROL SYSTEM ISSUES
• These systems are “Soft” Systems, where there is usually a human link
• Actuators [Vehicles, Traffic Control
Equipment] have been in place for many
Years
• Four Enablers are now enabling Closed
Loop [Feedback] Operation:
–
–
–
–

Low-cost Electronic Sensing
High-density Communications
Automated Data Analysis
Automated Control Actions

TRAVELLER SERVICES

TRAVELLER SERVICES
[Basic Navigation System]
•MAPS
•SERVICE
LOCATIONS
•LEISURE
IDEAS
•BUSINESS
LOCATIONS
etc

GPS
SATELLITES
[5 needed for
3-D position]
CD-ROM
DRIVE
DISPLAY

GYRO-COMPASS
(FOR DIRECTION)
ANTENNA
ODOMETRY
(FOR DEADRECKONING)
ACCURACY (RAW GPS): ±5M
WITH DEAD RECKONING ±1M

CONTROL IMPLICATIONS OF
NAVIGATION SYSTEMS
Available
Traffic
System

Visual/Audio
Messages

Driver
+
Vehicle

GPS +
Dead Reckoning
+ DGPS

FEEDBACK
LINK

DIRECTION MESSAGE

Digital Map
Driver Destination Input

Response calculation:
•multi-sensor model
•Mathematical models
•AI models

GPS POSITIONING ACCURACY
Error Type

Typical GPS (m)

Worst-Case GPS (m)

Satellite Clock

2 to 3

25

Satellite Orbit

1 to 2

5

SA

30 to 50

100

Ephemeris Prediction

3 to 5

15

Ionosphere Delay

10 to 15

100

Troposphere Delay

3 to 5

30

Multipath

10

300

Receiver Noise

5

15

TOTAL EFFECT

100 (95%)

300 (99.9%)

GPS CHARACTERISTICS
ITEM

CHARACTERISTICS

Satellites

24 Satellites broadcasting signals autonomously.

Orbits

Six planes at 550 inclination, each orbital plane includes four satellites ak 20,231 Km