Abstract: It analyzes two methods of needle position tracking of flat knitting machine. The algorithm of needle position tracking of flat knitting machine has been presented in this paper, which is based on quadrature encoding signals feeding back from AC servo motor. The algorithm, based on Q15, has been successfully applied to convert floating-point into fixed-point. A hardware experimental platform of flat knitting machines has been built. As an experimental result, the average time consumption of computing needle position tracking with Q15 is 141.05ns. It greatly increased computing efficient with 65.43% comparing with the traditional algorithm. The algorithm can be applied to other knitting machine’s needle position tracking, such as socks knitting machine, circular knitting machine, underwear machine etc.

Key words: TMS320LF2812 , Q format , flat knitting machine control system , quadrature encoding