DATABASE AND DATA ANALYSIS

Transcription

1 DATABASE AND DATA ANALYSIS FESTA for Beginners Pisa, May 2012 Andreas Pütz, ika, FOT-Net is a support action co-funded by the European Commission to network FOT activities at European, national and international level.

2 CONTENT Data analysis in FOT context Steps of Data analysis 2

3 CONTENT Data analysis in FOT context Steps of Data analysis 3

4 DATA ANALYSIS IN THE FESTA V Context 4

5 Result integration Data analysis Data management DATA ANALYSIS IN FOT PERSPEKTIVE... VMC fleet FOT data Data quality analysis Questionnaires Data processing Cost-Benefit Analysis Performance indicator calculation Research questions Impact assessment Testing of Hypotheses VMC specific SQL data base Common 5

6 CONTENT Data analysis in FOT context Steps of Data analysis 6

7 DATA ANALYSIS STEPS ACCORDING TO FESTA Data analysis FOT Database Data quality analysis Data processing Performance indicators calculation Hypothesis testing Global assessment Hypothesis to test/ Research question to answer Answer to hypothesis/rese arch question 7

8 DATA QUALITY STEP 1... Questionnaires Geo-map based data/ weather VMC-Fleet CO-, CV-, CV+E-data Assessing and quantifying missing data Controlling data values and units of measure Checking data dynamic over time Guaranteeing data fulfill specific hypotheses requirements Data Quality Analysis Database with quality certified data 8

9 DATA PROCESSING STEP 2 Data encryption & Data decompression Data conversion Conversion to standardizes file format (MATLAB format) Data anonymization Data enrichment Attributes from digital map (GPS information) Road type, Speed limit, Curve radius Event recognition and annotation Detection of relevant events Incidents, lane change maneuver, braking maneuver Derivation of additional signals Time-Headway (THW), Time-To-Collision (TTC) 9

10 DATA PROCESSING EXAMPLE Incoming data from DAS (encrypted and compressed) Data conversion MatLab-Files: Decompressed File-Server: Trip-based Pre-Processing MatLab Files: Processed (enriched with events, PIs etc.) Processing MatLab Files: Pre-processed (enriched with map-data) Translation into DB schema 10 SQL data base

11 PERFORMANCE INDICATOR STEP 3 Experimetal design Baseline (Driving without system) Treatment (Driving with system) Comparison measure Comparison measure = Performance indicator (PI) Performance indicator is calculated for baseline as well as treatment Testing of hypothesis by means of comparison of PI Examples: Number of incidents, Hard braking, Average speed 11

12 HYPOTHESIS TESTING STEP 4 Comparison situations Baseline vs. Treatment Filtering criteria Vehicle speed > 50km/h Minimum mileage for drivers Situational variables Road type, weather, lighting Performance Indicators Hard braking Used data set Mileage, number of subjects Distribution male/female Statistical method ANOVA, P-test 12

13 HYPOTHESIS TESTING EXAMPLE FOTware- Chalmers 13

14 GLOBAL ASSESSMENT STEP 5 Problem: How to generalize results from a certain FOT to a global level Two step solution: Step 1: Scaling up FOT results to higher level (higher penetration rates, larger regions) Step 2: Translate results from the PI level to the level of effect (e.g. what is the effect on safety from an increase in average speed) 14

15 GLOBAL ASSESSMENT EXAMPLE 1 15

16 GLOBAL ASSESSMENT EXAMPLE 2 16

17 LESSONS LEARNED Data analysis Check before data analysis, if selected data sets are feasible for data analysis Methods for automation of the analysis are necessary Video data analysis is generally quite time consuming Real-time data synchronization is mandatory 17

18 THANK YOU FOR YOUR ATTENTION! Dipl.-Ing. Andreas Pütz Institut für Kraftfahrzeuge RWTH Aachen University Steinbachstraße Aachen Germany Telefon Fax puetz@ika.rwth-aachen.de Internet 18