Method and device for damping a chatter oscillation in a processing machine

A method for attenuating a chatter oscillation in a processing machine with at least one feed system which includes a linear motor controlled by a field controller, comprising the steps of:

• generating an actual signal that is proportional to the chatter oscillation;
• comparing the actual signal with a predetermined desired value for a chatter oscillation for determining a control variable;
• and
• applying the control variable as a desired current value of a secondary current control of the field controller for controlling a current of the linear motor,
• wherein the controlled current has a phase so as to produce an attractive force between a movable section and a stationary section of the feed system.

A device for attenuating a chatter oscillation in a processing machine with at feast one feed system driven by a linear motor having a primary section and a secondary section, the secondary section comprising permanent magnets, the device comprising:

• an acquisition system for generating an actual signal which is proportional to the chatter oscillation,
• a control circuit having a first input connected to an output of the acquisition system, and a second input receiving a predetermined desired value for the chatter oscillation, said control circuit producing at an output of the control circuit a signal representing a d-component of a magnetic field in the primary section of the linear motor, said d-component being in phase with a magnetic field distribution of the permanent magnets of the secondary section;
• and
• a current control circuit connected to the output of the control circuit and producing, in response to the d-component, a field current in the primary section of the linear motor that attenuates the chatter oscillation.