Filter design of a servomotor encoder

Abstract

The design and implementation of a set of three linear phase finite impulse response (FIR) filters to prevent the noise from corrupting the output signals of servomotor encoders is proposed. According to the estimated speed, one of the FIR filter is selected to eliminate the noise with a width less than three sample periods and/or with a frequency less than one fifth of the sampling frequency. Simulations and experiments at speeds of 30 rpm, 300 rpm, and 1000 rpm are given. These results illustrate the effectiveness of the designed FIR filters.