The positional accuracy and machining precision are mainly affected by backlash for semi-closed loop control CNC machine tool. And compensation for backlash is essential to improving the accuracy of machine tool. A method is developed to reduce contouring error in this paper. A simulated model of backlash and Open CNC system are used to verify compensation algorithm. Computational simulations and experimental results have shown that the contouring error due to backlash can be greatly reduced by using backlash compensation.

To improve the simulation accuracy of the thermal characteristic of ball screw feed drive systems, a dynamic thermal-structure coupling model, which considered the effect of the thermal contact conductance (TCC) of the solid joint on the accuracy of simulation results, was proposed to conduct thermal characteristic analysis of ball screw feed drive systems. The predictive model for TCC was proposed based on the micro morphology description of rough surfaces and the contact load distribution of solid joints. Then, the dynamic thermal-structure model of the ball screw feed drive system was established. To validate the effectiveness of the dynamic thermal-structure coupling model, thermal characteristic experiments of the ball screw feed drive system were conducted under different feed rates. The results showed that the simulation accuracy of temperature field and axial thermal elongation can be improved from 65% to 87% and from 70% to 85%, respectively.

The signal which is generated by the dynamic balance regulator for unbalanced spindle in the process of adjustment, having strong nonstationarity. The traditional signal processing methods could not deal with these signals, but also could not express the processing of signal changes. Aiming at the problem, a method combining mathematical morphology filter and the short-time Fourier transform is applied in the non-stationary signal processing in this paper. Using mathematical morphology filter could reduce the noise of spindle vibration signal, and improve the SNR. The amplitude of spindle vibration signal could be got by means of short-time Fourier transform method. Utilized the method proposed in this paper, non-stationary signal of the spindle dynamic balance regulator online adjustment process has been analysed, the results of the experiment show the feasibility of the method.

MLUPS functions without contact or friction. With the large current power, mcu control core, laser interferometer position feedback, the stage meets the precision requirements hardware. The positioning system includes two-level positioning system—one-phase coarse positioning and two-phase fine positioning. Based on mathematical model, the immune PI controller is proposed in terms of magnetic edge effect, current harmonic and nonlinear characteristics of magnetic field. By designing target function, antigen affinity, antibodies affinity, mutation, immune algorithm optimizes parameters and memory cells. The stage working range is 10mm, the simulation result shows that the positioning precision is ±10 nm; the positioning time is 50 ms. The stage has a good performance in robustness