How good are analogue hall sensors as a form of position control? Has anyone had experience with these?

Such analog halls are used as sin/cose encoder inside Servo Tube motors allowing reach resolution down to tens um by internal interpolation inside Copley digital drives.

Hi Leonid,

Thanks for your comment. As the signals are interpolated, what kind of repeatability is possible? With all interpolated encoder methods there is this issue as the counts are not "real!" like an optical encoder.

ServoTube motors' manufacturer declines 12um resolution, +/-12um repeatability with absolute accuracy +/-350um as max error over 1m. Yes such analog Halls have lower accuracy due to higher pitch (51.2mm vs. 20um with optical linear encoders) and poor shapes. But you can use Position Error mapping by motion controller for increase servo accuracy as well.

That is a very good point Leonid. Thanks for your comments.