Two Wheel vehicle: Mindstorms stops to respond at some point

[RubenHaag]

Dear @ChristophGaukel, We are using your ev3 python class for a university project, were we control the Mindstorms through a raspberry pi, that orientates itself in space via a webcam with opencv.

When we start our program everything works fine for some time. The robot can orient itself and drive along a pregiven track. At some point however, the robot simply stops driving. In verbose mode we see, that the mindstorms stops responding to USB commands from the raspberry pi. We suspect, that because of this the thread lock in _physicalEV3 can not be released, blocking a further continuation of the program. could the problem be the webcam, which is attached over usb?

All other threads (camera and positioning) in our program work fine, without problems.

Do you have any idea how we could solve this issue? Or even just how we could find the source of the problem? We have tried everything that we could think of for several weeks and could not find the issue.

Thank you for the help!