As one of Mitsubishi Electric’s FR-A800 Plus Series the FR-A800-R2R inverter drive provides stable winding/unwinding control independently. Due to embedded functions like “automatic winding diameter calculation”, “automatic dancer speed control”, and “sensorless torque control for perfect tension”, the FR-A800-R2R is perfect to reduce PLC costs in winding applications.

Printing, slitting, coating, and twisting

In roll to roll applications, control is necessary for machining of elongated products. Processing types include printing, slitting, coating, and twisting. High productivity can be achieved by stable tension control. The FR-A800-R2R inverter can be used in a wide variety of systems with various dedicated functions.

Paper, steel, foil and thread

The FR-A800-R2R inverter has various dedicated functions such as winding diameter calculation, providing stable winding/unwinding control independently. For steel, paper and foil and thread, a variety of roll to roll dedicated functions are supporting various systems. These include

Automatic winding diameter calculation

The winding diameter calculation method can be selected to improve the tension control performance. The present winding diameter for the winding/unwinding shaft is calculated from the actual line speed or the actual motor speed.

Dancer feedback speed control

The wire drawing section pulls the wire at a constant speed to make the wire thinner. For the winding shaft, the inverter provides dancer feedback speed control to keep the dancer roll position, achieving constant tension winding. In addition, using the winding diameter calculation function, the circumferential speed of the winding bobbin is kept constant.

PID control is performed based on the feedback of the detected dancer roll position. Stable control can be achieved in combination with the winding diameter calculation. By adjusting the speed control proportional gain, response improvement is achievable according to the winding diameter. Gain compensation is achieved by automatically adjusting the tension PI gain, time required for adjustment is significantly cut down.

Tension sensorless torque control

The output torque of a motor is controlled so that the tension applied to a material is constant by calculating the winding diameter of a roll. The tension applied to the material is maintained constant by raising a commanded torque to compensate mechanical loss caused by factors such as friction on the dancer roll or winding/unwinding shaft.

During acceleration/deceleration, the tension applied to the material is maintained constant by adjusting the variable tension on the winding and unwinding sides. By adjusting the tension on the workpiece, it is possible to avoid imperfections such as wrinkles or deformation caused by the increase in diameter.

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