Safety cv software

CV-based Safety Logic

Component owners: Laci, Bálint
Date of assessment: 2016-05-09

Current status

• A live model is maintained

  • The train can move either clockwise or counterclockwise on the track

  • The live model contains the following:

    • Section model: describes sections and switches

    • Train model: current position, direction and speed of the trains

• VQL patterns describe unsafe situations

• The live model is built from the information obtained from CV

  • Markers have different colors

  • The markers define the component for the CV. A marker for a train consists of three collinear dots, the color of the middle dot is unique for all trains

  • Special markers: 4 markers in the corners of the desk to identify the system boundary

  • Red, Green and Blue colors are used

  • Helper marker: must be placed to a visible place in order to aid computer vision. It is a small black dot (~1.5 cm in diameter) in the middle of a white square

Issues and TODOs

• The live model is "buggy": it can only represent operation on cyclic tracks due to the clockwise-counter clockwise categorization

• The patterns are not maintained currently, hard to decode their semantics

• Lighting and a better camera is needed (actually, a better camera is already available, but not installed)

• The project and the codebase is not very portable, specific to Bálint’s Mac

  • Needs specific OpenCV build to support GPU (CUDA) acceleration

  • It would be nice to be able to compile the project with cmake

• The base color of the table affects the white-balance in an undesired way. A white desk or some A4 sized blank papers would mitigate this issue

  • A short term advice: fix the helper marker to the desk permanently

Development directions and plans

• The metamodel for the live model should be replaced

  • This is a big task

  • Bálint has started developing this

• According to the new metamodel, the pattern should also be rewritten

  • According to Laci, this wouldn’t take too long to do

• The new lamps should could be mounted to the camera scaffold

  • Alternate configuration: 4 lamps to the 4 different corners

• A long-term plan is to integrate the live model with the distributed logic. The low-level distributed logic implements a fail-stop operation mode, and only a manual interaction (toss the train further on the track) can bring the system back to operation. The purpose of the CV would be to prevent the intervention of the low level logic, and use the latter as a second (backup) safety mechanism

• A sensor fuson-like mechanism would be nice to have: combine both the CV result and the section occupancy detector

• Bálint plans to continue the work with the project (not all summer)

• Laci: almost the same as Bálint, wants to limit the amount of work on the project