Abstract—Incremental encoder combined with M/T method
is the most popular and more appropriate digital tachometer.
But if the speed is low or ultra-low, there will be several
questions, such as low precision, bad timeliness, the jitter
caused by Machine vibration. Aiming at resolving these
questions, this paper respectively proposes an eliminate-jitter
method based on FPGA, an enhanced method timeliness based
on extrapolation method and an enhanced M/T method to
expand speed range. These methods improve the performance
of the encoder at low speed, and make use of encoder in
research and practice better.
keywords-tachometer; M/T; low speed; encoder