.125 The Mn Extruder Center-line Monitoring System Design And Monitoring Accuracy

With the development of transportation, aerospace and other industries, the market demand for large extrusion products increased rapidly and extruders tended to be larger and larger. Because of the special structure and working environment, the lead rail rubbed against the supporting cushion badly and the extrusion canister, the die, and the extrusion shaft would out of alignment if the large-scale extruders had worked for a long time. Together with the exquisite shake and impact during the working period, the extrusion center would offset. Under this circumstance, the quality of extrusion products would be affected, the abrasion would increase, the life of the extrusion would reduce, and even caused of hidden accidents.As the largest extrusion in china at present, 125MN extrusion' extrusion center was still measured by hand. In order to realize the automatic on-line monitoring, the main research and design work were as follows in this paper:1,The ordinary position detection methods by photoelectricity technology were analyzed, and a new extrusion center on-line monitoring system for 125MN extrusion was designed based on laser and image processing technique by technology of laser dispersion. The system had the characters of long distance,more points,large range,higher precision,no-touch,indirect monitoring. The perforation beam,movable perforation beam,fixed beam,moveable beam and extrusion room can be monitored on-line at the same time. The scheduled aims were achieved.2,The errors in the whole system were analyzed and studied both by theory and experiments. The souse and size about the system errors were studied. The analysis model of system errors was set up, which could provide the theory foundation for system calibration and static errors modification. Three experiments were carried out to analyses the effect factors of the precision caused by monitoring distance, disturbing light and the atmosphere turbulence.3,A whole data processing system was established. For gross errors and noise existed in the direct measuring results, so it's an important way to improve the measuring precision by data processing. Compared with all kinds of data processing methods, finally the data processing flow was established as follows: subsection method to test the stability of the data; improved 53H method to eliminate the gross errors; 7 points weighted moving average method to smooth filtering; adopt db1 wavelet to denoise by given threshold method under "sqtwolog theorem". The measuring precision was improved obviously.