Capability-Enhanced PARAMICS Simulation with Developed API Library

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Capability-Enhanced PARAMICS Simulation with
Developed API Library

• Lianyu Chu, Henry X. Liu, Will Recker
• California Partners for Advanced Transit and
  Highways (PATH) University of California, Irvine

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Presentation Outline

• Introduction
• Methodologies
• Capability enhancements
• Development of advanced API modules
• Applications
• Conclusions

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Introduction

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

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Motivations

• Replicate the real-world traffic operations
• e.g. actuated signal control, HOV, etc.
• 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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Two approaches

• Modifying the source code
• API Programming
• API Application Programming Interface
• gt our practices of enhancing capabilities of
  PARAMICS via API
• PARAMICS high-performance, ITS-capable,
  user-programming micro-simulation package

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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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Current components of API-enhanced PARAMICS
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Capability enhancements

1. Basic control modules
2. Traffic data collection and communication
3. Database connection
4. Overall performance measures

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Basic control modules

• Signal (Actuated signal control)
• Dual-ring, 8-phase logic
• Signal controller Interfaces with advanced
  signal modules
• Ramp metering
• Fixed-time, time-of-day basis
• n-cars-per-greenbasis
• HOV bypass
• Ramp metering controller Interfaces with
  advanced metering algorithms
• 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 intermediate 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, Bool
  status)

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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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Sample Applications

• Signal
• Hardware-in-loop, testing 170 controller
• On-line signal control based on real-time delay
  estimation
• Ramp metering
• Evaluating adaptive ramp metering algorithms
• TMS master plan
• Evaluating potential ITS strategies

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User groups

• Caltrans Transportation planning Traffic
  operation
• California PATH headquarter at Berkeley
• UC Davis
• National University of Singapore
• Consultant companies
• Dowling Associates
• Cambridge Systematics

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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

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More information

• PCTSS website
• http//www.its.uci.edu/paramics/
• PATH website
• http//www.path.berkeley.edu/
• Contact PATH ATMS Center _at_ UC Irvine
• Lianyu Chu lchu_at_translab.its.uci.edu
• Henry Liu hliu_at_translab.its.uci.edu
• Will Recker recker_at_translab.its.uci.edu