| As the main drive components of spindle feed motion, the ram has a direct impact on the precision of the large-scale high-end CNC equipment. For ram overhang deformation error, the existing detection and compensation means cannot reach the requirements of fast, high precision and in machine detection in modern industry. The real-time measurement system which is based on non-interference light collimation techniques can solve the first key technical problems of ram real-time compensation closed loop control system, and has a great significance for developments in the field of CNC manufacturing. Against ram overhang deformation error in complex conditions, combining theoretical knowledge of optics and other fields, the main research work was done as follows:(1) Analyze the ram materials, structures, and the force, and under different contact conditions apply ANSYS to simulate Ram deformation characteristics. Draw the main factors of ram sagging deformation error are from Flexural deformation, the discontinuity in the site, as well as cutting load and other factors common interference, especially the discontinuity. In the long-term using, the increasing gap will further exacerbate the ram’s sagging.(2) Based on non-interference, Presents a light detection technology which can be applied to real time detection method of a duplex milling machine. In the ram’s end and machine’s top, laser detectors are installed. This dual-detector integrated detection system can detect the full deflection, tilt of ram and the tilt produced by the light source itself, and the amount of data collected through the PCI-1716L card is sent to the computer. In the LabVIEW development environment, prepare and coordinate data collection solver which combines CNC ram feed movement, the PSD will double the value of real-time detection solution is calculated according to the geometric relationship between the amount of ram total bow.(3) during the design process of measuring circuit’s hardware and software systems, in order to improve the spatial interference measuring circuit, this paper took the sample and hold circuit, an optical filter, low-pass digital filtering and other noise reduction methods. Through repeated testing, determine the optimum sampling intervals and filter parameters. With detection experiments of positioning accuracy, the stability of the spot, positioning accuracy, linearity, distortion of the possible positioning errors were analyzed. The results show that the measurement circuit can achieve accuracy of0.01mm, linearity up to0.128%, which show that this method can be applied to the ram fast, high-precision measurement of the CNC machine. On this basis, simulate the phenomenon of machine ram bow and implement this method in machine detection experiments, the obtained test results match with the theoretical value of factory. |
