As title, I can't find out how main system of this linear actuators knows each carriage absolute position. This system is iTRACK from Rockwell, but there are some other brands that do this.
As it's possible to read from their system description, each carriage have just a magnet on internal side of the linear.
I never read about "reverse" linear encoders where stator is actually the sensor and mover is passive.
I've tough about Capacitive and Inductive PCBs on each module, but as I know this system are not very fast (and in some case precise). On system description there's +/-0.5mm and some +/-0.15mm at speed of 2meters/s to 5meters/s.
Maybe there's also possibility to place a lot of hall sensors and interpolate their results, but the complexity and price of components will be incredibly high.
Someone can explain me how this is possible and how this system works? (or references) Is this position technology something that is largely applied and commercial?