VR Locomotion

Hi! Does anyone try to use standard TPS locomotion system in VR? Now I am trying to apply this locomotion to my VR pawn and have some problems unresolved such as at FPS/TPS mode to calculate the speed for locomotion is easy - just get the vector length of Pawn’s velocity. How can I get speed to VR pawn ? How can I calculate the speed of headset to apply it in my animation blueprint?

this works just fine (in tick)