Feedback control numerical machine tool and method thereof

A feedback control numerical machine tool, comprising:

• at least two spindles that machine a workpiece;
• an acoustic frequency detector comprising at least one first microphone configured to detect an acoustic frequency of the at least two spindles when machining the workpiece;
• at least two spindle position detectors configured to correspond to the at least two spindles, respectively, and detect position information of the at least two spindles when machining the workpiece;
• and
• a processor connected to the acoustic frequency detector and the at least two spindle position detectors, and configured to acquire the acoustic frequency and the position information of the at least two spindles, monitor whether at least one of the at least two spindles chatters according to the acoustic frequency of the at least two spindles, wherein the processor has a numeric control unit, the numeric control unit includes a plurality of working program segments having mechanical coordinates of the at least two spindles, and the working program segments having the mechanical coordinates are uploaded by batches to perform chattering avoidance,
• wherein the numeric control unit configured to perform the chattering avoidance by adjusting a rotation speed, a feeding rate or a cutting depth of the spindle that chatters according to the position information of the at least two spindles.