Dynamics stiffness enhancement of fast tool servo by acceleration feedback

Fast Tool Servo (FTS) devices are widely used in manufacturing of micro features on large areas. Dynamic stiffness of such devices is usually poor due to their low inertia which cause profile errors. In this paper, a triple feedback scheme is proposed to enhance the dynamic stiffness by introducing acceleration feedback. Position and acceleration signals together with motor current were combined to estimate the cutting force. Then the force is compensated by the controller output. Frequency response tests showed supressed disturbance response around the cross over frequency. Further face turning experiments demonstrated that the new feedback scheme helped reducing the dynamic errors caused by sudden change of cutting forces.