Data Acquisition & Field Test Data Analysis

Topics

• Overview - purpose of data collection
• Data archive overview
• Requirements on data
• Data acquisition
• Fleet monitoring

Data Acquisition System

• Phase I
  • Support Phase I development of IVBSS.
  • Provide data during Phase I testing.
• Phase II
  • Provide data from extended pilot FOT and from FOT itself.
• Allow remote monitoring of test fleet (IVBSS performance & health, driving behavior )

Data Uses

• UMTRI–
  • monitoring fleet
  • analysis of experimental data (performance, acceptance, safety)
  • debriefing test subjects
• Visteon/Eaton/Cognex –
  • technology performance
• Volpe Center/USDOT–
  • quality assurance
  • analysis of experimental data
• Side benefit – data archive for future research

Data Archive – “Raw” Objective Data

• Driver information
• Onboard data
  • Numerical (database)
  • Video
  • Audio
• Offboard data
  • Map & roadway feature databases
  • Weather data

Data Archive – Processed Objective Data

• Cleansed data – smoothing/fusing, managing dropouts & outliers, bias removal, validating trips, etc.
• Driving context characterization using roadway data, weather data, time, etc.
• Characterization of events & scenarios of interest
• Building measures of system performance, potential safety impacts, facts possibly affecting driver acceptance

Additional data may exceed size of original raw numerical data

Data Archive - Subjective Data

• Pre-drive questionnaire
  • Driving style and behavior questionnaires completed prior to FOT participation
• Post-drive questionnaires
  • Completed after FOT participation: on-site and take home
• Driver debriefs
  • Review of a subset of warnings to rate for usefulness
• Focus groups

Data Archive - Subjective Data: Questionnaires

• Pre-drive questionnaires
  • Driver style questionnaire (DSQ)
    • Evaluates 6 factors of drivers' style: focus, calmness, social resistance, speed, deviance, and planning
  • Driver behavior questionnaire (DBQ)
    • Examines drivers' errors, lapses, and violations
  • Drivers' scores from DSQ and DBQ will be used in statistical models as predictors of IVBSS acceptance
• Post-drive questionnaires
  • Extensive evaluation of drivers' opinions of IVBSS
  • Will evaluate safety, ease of use, comfort and convenience, and willingness to purchase
  • Two questionnaires
    • On-site: highest priority questions
    • Take home: questions of lesser priority

Requirements on Data Archive

• Complete and ‘auditable’ characterization of events & system performance
  • Highly robust & structured data set
  • Continuous 10 to100 Hz logging (depending on subsystem)
  • ~400 signals on light vehicle and ~300 signals on heavy truck
• Video collection to provide analysts with situational context for FOT data, especially IVBSS-related events.
  • What was happening inside and outside the vehicle?
  • What did the IVBSS system react to?
• Secure from data loss, privacy concerns
  

Data Archive Formats & Size

• Format when archived:
  • Numerical: enterprise-level relational database
  • Video: MPEG-4 compressed video with indexing for synching with numerical data
  • Compression & frame rates vary by video stream
  • Audio: Compressed 64 kbps with indexing
• Size estimates are preliminary
  • Numerical – depends on radar – 1-2 terabyte (TB) order of magnitude
  • Video – depends on compression levels – 10 TB?

Requirements on Data Archive

• Highly usable:
  • Analyst access to all data within seconds, including video
  • Analysis tools
• Sharing information between project team & independent evaluator

Data Acquisition System

• Two CPU system (CAN/radar + vision/audio)
• Automotive-grade hard disks
• CAN and J1939 buses - primary data sources
• Second GPS for analysis (differential)
• 5 cameras with video capture & compression
• Up to 7 radars
• Vehicle motion sensors
• GPRS/Edge cellular modem
• DAS power management system

Monitoring the fleet
Track:

• health of IVBSS & data system
• usage of vehicle
• driver experience with IVBSS (alert types & experience)
  Cellular modem:
• Trip characteristics, IVBSS actions, health information including histograms
  

Summary

• Data archive – several types of data
• Extensions from previous FOT analyses:
  • More advanced data collection
  • Power through joining diverse types of data: onboard, offboard, driver information.
  • Driving treated as more ‘holistic’ than previous studies – context considered in more detail