An improved servo control system for high speed flat industrial sewing machine

This paper presents a permanent magnet synchronous motor (PMSM) servo drive system for high speed flat industrial sewing machine. In order to satisfy the special function of sewing machine, several approaches are applied in this servo system: Using voltage feed-forward decoupling control in current loop to improve speed and position control performance; Variable gain control is adopted in system to compensate incomplete decoupling caused by disturbance and inaccuracy of parameter; PMSM used in system is specially designed with concentrated winding and lean charge magnetism barrel-drain rotor, which can effectually improve motor operating and reduce torque harmonics. The experimental curves of sewing procedure show that: the speed feedback can accurately track speed reference under different sewing conditions, which proof the servo control system meet purpose of industrial sewing machines well.