Method and a system for reducing vibrations in a mechanical processing for removal of chippings

A method for reducing vibrations originating from a mechanical processing for removing swarf, the mechanical processing being carried out by a machine tool having a mandrel rotating at a relative operating speed on which it is mounted a predetermined tool equipped with one or more cutting edges defining a plurality of characteristic frequencies of the machine, the method comprising the following steps:

• monitoring the vibration which arises from the contact between the tool and a workpiece;
• measuring the occurrence of a regenerative vibratory phenomenon when the vibration exceeds a pre-set limit value or has a frequency content which is not related to the characteristic frequencies;
• calculating the frequency of the vibratory phenomenon;
• estimating a value representing a resonance frequency of the machine as a function of the frequency of the vibratory phenomenon;
• determining at least one threshold value on the basis of the value representing a resonance frequency;
• comparing between a real-time value of the operating speed of the mandrel and the threshold value;
• reducing the intensity of the vibratory phenomenon by the execution of:
• a first reduction strategy based on a correction of the operating speed when the real-time value of the operating speed of the mandrel is greater than the threshold value;
• a second reduction strategy based on a continuous modulation which imparts an oscillation to the value of the operating speed about the real-time value, when the real-time value of the operating speed ω of the mandrel is less than the threshold value.