Development of PARAMICS Plugins with Application Programming Interfaces

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Development of PARAMICS Plug-ins with
Application Programming Interfaces

• Henry X. Liu, Lianyu Chu, Will Recker
• PATH / UC-Irvine

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Presentation Outline

• Introduction
• Development Approach
• Basic Modules
• Advanced Modules
• Applications
• Conclusions

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Introduction

• Microscopic simulation
• PARAMICS
• VISSIM
• AIMSUN2
• Applications
• Evaluations
• Testing models / algorithms

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Why Use API?

• Model / Evaluate ITS
• e.g. VMS, adaptive signal control, ramp metering,
  bus rapid transit, etc.
• Test new models algorithm
• e.g. a control strategy combining several ITS
  components

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Role of API
Core Model
API
(source FHWA)
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How PARAMICS API works
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PARAMICS API Development A Hierarchical Approach
Signal
Provided API Library
Ramp
Basic controller
Routing
Demand...
Basic API Modules
CORBA
Data Handling
Databases
XML
Adaptive Signal Control
Advanced API Modules
Adaptive Ramp Metering
Network Load Management...
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Capability enhancements

• Basic control modules
• Traffic data collection and communication
• Database connection
• Overall performance measures

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Basic control modules

• Signal (Actuated signal control)
• Dual-ring, 8-phase logic
• Signal Coordination
• Ramp metering
• Fixed-time, time-of-day basis
• n-cars-per-greenbasis
• HOV bypass
• Path-based routing
• Specified vehicles follow a given path

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Data collection and broadcasting

• Data collection
• Loop detector data collection and aggregation in
  each polling cycle, emulating the real-world loop
  data collection
• Probe vehicle data link / section travel time
  data collection at certain time interval
• Data broadcasting to shared memory, accessible
  through interface functions

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Database connection

• MYSQL highly efficient database
• Purposes of this module
• Storing data during simulation and simulation
  results
• Exchange data with other API modules / outside
  programs

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Overall performance measures

• PARAMICS powerful in MOE data collection
• MOE API can collect
• System performance
• Freeway performance
• Arterial performance
• Statistical Measures
• Mean
• Variance
• Etc.

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Development of advanced modules
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Development of advanced modules (contd.)

• Interface from loop data aggregator
• LOOPAGG loop_agg (char detectorName)
• Interfaces from ramp metering controller
• (1) Get current metering rate
• RAMP ramp_get_parameters (char rampnode)
• (2) Set a new metering rate
• void ramp_set_parameters (RAMP ramp)

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Developed advanced modules

• Actuated signal coordination
• Adaptive ramp metering algorithms
• ALINEA, ZONE, BOTTLENECK, SWARM
• PARAMICS-DYNASMART
• Demand-responsive Transit

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Conclusions

• Our practices on developing a capability-enhanced
  PARAMICS simulation environment
• Accessible to the core models of micro-simulation
  simulation shell
• Applicability of the same mechanism to other
  micro-simulators