sewing machine in chennai - VS SewingMachine
sewing machine in chennai - VS SewingMachine
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.
The robotic sewing system is shown in Fig.1 . A piece of fabric is gripped by a robot manipulator holding the right edge while the opposite left edge of the fabric is moving with unknown velocity by the feed dog mechanism of the sewing machine. During the sewing process the fabric should be kept taut so as to prevent the buckling and ensure qualitative stitches. The desired tensional forces for each fabric are depended on the fabric type and properties
The aim of the presented approach is to develop a flexible controller that could be able to guide a wide range of fabric types without knowing the properties or the model of each fabric.
The target of the proposed controller is to apply a desired constant tensional force to the fabric in the begging and during the sewing process, independently of the sewing machine velocity. The force sensor mounted on the wrist of the robot manipulator is used to measure the force applied to the fabric which is the only feedback signal in the outer control loop relative to the internal controller of the robot. The tensile stiffness coefficient of the fabric is non-linear and changes by decreasing the nominal length as the sewing proceeds
The sewing machine model was defined as a structural model consisting of four component models (Sensor / Work / Forward / Control). Sensor model detects raw material or semi-finished products arrived at the sewing machine. Work model performs sewing process for the arrived raw material or semi-finished products. Forward model chooses the next forwarding facility and passes the processed semi-finished product on the selected next facility. Finally, Control model governs the whole operations of the sewing machine.
