Velocity estimation for slow motion devices equipped with encoder

This paper addresses the problem of velocity estimation for slow motion elements equipped with encoders. The slow movement causes rare pulses generated from the encoder, rarer than the sampling frequency. In such conditions, the velocity calculation by numeric derivative or Luenbergera observer fails. For that, it is proposed a new velocity estimation algorithm that uses information specific for encoder operating mode. Simulation and real-time experiments have shown a significant reduction in velocity error estimation of the proposed algorithm in comparison to conventional algorithms.