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Resolve "Implement Lambda: check_limits"

Fabian Herbert Margreiter requested to merge 15-implement-lambda-check_limits into main

Implemented all queries to get and put data is required:

  • Retrieve street data:
    • List of camera IDs covering that street
    • ID of station covering that street
    • Maximum traffic capacity of that street
    • Air quality limit of that street
  • Get car count predictions and emergency vehicle counts for cameras on that street
  • Get air quality prediction for the station covering that street
  • Store finally calculated information

Algorithms to calculate information:

  • Traffic load is calculated by:
    1. Select the 3 cameras with the highest traffic counts
    2. Calculate relative load (considering the limit defined for the street)
    3. Total street load is mean of 3 calculated relative loads
  • Emergency vehicles are considered to be active, when there is at least one emergency vehicle visible on any camera
  • Air quality load is calculated as:
    • Load = 0.0 -> best possible air quality
    • Load = 1.0 -> air quality at defined limit for street
    • Load > 1.0 -> air quality below limit for street
    • Air quality ... the higher, the better, but always in range [0.0, 1.0]
    • Air quality limit on same scale as air quality

Tested by manually creating entries in DynamoDB table:

Street:

  • PK: baseEntity
  • SK: street#street_1
  • airQualityLimit: 0.7
  • cameras: [ { "S" : "camera_1" }, { "S" : "camera_2" } ]
  • station: station_1
  • trafficCapacity: 42

Traffic count for camera 1:

  • PK: camera#camera_1
  • SK: trafficCount#1703157200
  • carCountPrediction: 20
  • emergencyVehicleCount: 2

Traffic count for camera 2:

  • PK: camera#camera_2
  • SK: trafficCount#1703157200
  • carCountPrediction: 32
  • emergencyVehicleCount: 1

Prediction for station 1:

  • PK: station#station_1
  • SK: prediction#1703157200
  • airQuality: 0.65

Created item in DynamoDB:

  • PK: street#street_1
  • SK: info#1703157200
  • airQualityLoad: 1.1666666666666665
    • CORRECT -> limit for street is at 0.7, prediction is at 0.65, meaning that the air quality is BELOW the defined limit (and thereby too bad) -> air quality is "overloaded" and in further step mitigation measurements should take place
  • emergencyVehiclesActive: true
    • CORRECT -> on camera_1 there are 2 emergency vehicles, on camera_2 there is 1 emergency vehicle
  • trafficLoad: 0.6190476190476191
    • CORRECT -> limit for street is 42 vehicles, camera_1 predicts 20 vehicles (20/42 = 0.476), camera_2 predicts 32 vehicles (32/42 = 0.762), average for both values is 0.619

Closes #15 (closed)

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