On Tue, 22 Jun 2021 at 07:09, Chris Albertson <albertson.ch...@gmail.com> wrote:
> Quantization happens even in an electrically quiet > environment and results from design decisions made such as the sample > interval, number of lines of the sensor, and the rotation speed. It gets > worse as you go slower. I believe that the LinuxCNC encoder counters attempt to mitigate this by timestamping the edges. If you know that the first edge seen in the current period was seen at time t1 and the last at time t2, and that there were 2 edges in the period, then the speed estimate is (2 x scale) / (t2 - t1) This should shift the quantisation noise down the internal sample interval, rather than the encoder counting interval. One source of noise that is not covered by this is any actual periodic noise in the edge timing (ie, the mechanical quality of the encoder disc) -- atp "A motorcycle is a bicycle with a pandemonium attachment and is designed for the especial use of mechanical geniuses, daredevils and lunatics." — George Fitch, Atlanta Constitution Newspaper, 1912 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
