ACS LiteACS Lite
EconoliteEconolite
PerspectivePerspective
ACS LiteACS Lite
Outline
•Development Experience
•Implementation
•Outlook
ACS Lite - Development ExperienceACS Lite - Development Experience
•Involved from outset of project – bleeding edge
•Initial effort focused on architecture and ACS LiteObject development
–Preliminary concept of working through Master was notpractical due to high development costs and risk.
•USE of NTCIP and ACS Lite Objects allowed developteams (Siemens ITS, ITT and Econolite) to work fairlyindependent of each other
–Teams worked well together and open and frequentcommunications kept developers in the loop.
–Initial lab integration with CORSIM went fairly well after allinterfaces were understood.
•No major surprises during field integration
ACS Lite - ImplementationACS Lite - Implementation
•Field Test – Gahanna, Ohio
–CORSIM lab simulations and Gahanna field testsimplemented with ASC/2S controllers.
–Modified version of ASC/2S NTCIP 1B software.Modifications implemented support and functionality ofrequired ACS Lite MIB objects.
–NTCIP 1202 ASC Objects used by ACS Lite applicationthat were not supported by ASC/2S were handled usingASC/2S MIB objects via ACS Lite API.
–Additional detection required for phase utilization dataas test intersections were semi-actuated.
ACS Lite - ImplementationACS Lite - Implementation
•Communication Architecture
–Standard interface maintained for Master (ASC/2M)to Local communications. Allows full functionalityof existing closed loop system (Aries).
–Separate NTCIP communication path to Localcontroller for ACS Lite application. Uses ASC/2SPort 2 in test site application.
–Separate data rates and interfaces supported on thetwo communications paths (Gahanna used twistedpair at 1200 & 9600 bps).
–User could disable ACS Lite remotely via closed loopsystem if problems found.
ASC/2S
Local
Controllers
ASC/2M
Master
Aries
Central System
ACS Lite
Application
Full
Duplex
ECPIP
9600bps/FSK
Full
Duplex
NTCIP
1200bps/FSK
RS 232
RS 232
PSTN
Internet
ACS Lite - OutlookACS Lite - Outlook
•Promising cost effective adaptive control systemsolution for small systems
•Good alternate to traditional Traffic Response controlin closed loop systems
–Typically easier to implement.
–May require additional detection for phase utilization and flowprofile.
–Comparison with well timed Traffic Responsive system needs tobe evaluated.
•Next generation Field Masters will support NTCIP sointegration will be simplified
–ACS Lite algorithms should be able to run on the same fieldprocessor as the Master giving user option of TOD, TR orAdaptive control
–Single communications channel to locals
ACS Lite - OutlookACS Lite - Outlook
•Next Steps
–Become familiar with software and algorithms afterformal handoff by research team.
–Port ACS Lite MIB to ASC/3.
–Find early adopter opportunities for further fieldtesting/experience and evaluation.