In this paper, chatter recognition is carried out for milling based on dynamic characteristics and wavelet packets. The relationship between the dynamic characteristics of the machine tool spindle system and chatter recognition is established by constructing a recombined signal containing chatter signal information.

We propose a kind of permanent magnet linear motor (PMLM) with inequality constraints to transform the constraint tracking control method based on the equality constraint and U–K inequality status transformation. This method solves the problem of the control system of equality constraints and inequality constraints without the need for the localization of a nonlinear system, proving that the method has certain advantages and can be extended to the safety constraint control of other products.

This paper proposes a global interpolation algorithm that uses the trajectory pattern method for synthesizing low-harmonic trajectories. The synthesized trajectories and axis kinematic profiles are all smooth and only contain the fundamental frequency and its first three harmonics, which could avoid excitation of the system modes of vibration and reduce demand on the actuator dynamic response, thereby allowing the system to operate at higher speed and precision.

In the high-precision servo feed system, when the permanent magnet synchronous motor is operated at low speed in the classical drive feed system, the speed fluctuation caused by the motor torque harmonics seriously affects the speed smoothness of the servo system. In this paper, a novel double-drive differential feed system is proposed to effectively suppress the effect of torque harmonics of PMSM on speed fluctuation of a linear feed system at low-speed operation.