Feed Servo System Parameters On The "s" Shape Test Research On The Effects Of Specimen Contour Error

The “S”-shaped test specimen is put forward for evaluating the dynamicperformances of five-axis machine tools by Chengdu Aircraft Industry Group. There arethe contour shift between convex and concave and the thin web on the specimen. It isused to investigate cutting of the five-axis CNC machine tools. The “S”-shaped testspecimen is mainly used in the performance test of machining aerospace parts for highspeed machining centers, and is becoming important in the aviation manufacturingindustry. Based on modeling space contour error, the inaccuracies of “S”-shaped testspecimen caused by various feed servo system parameters are listed in this thesis. Themain contents are:1. The feed servo system is analyzed and modeled. Referring to the variousmechanical transmission mechanisms of the rotational axis and the translational axis,the mathematical models of the feed servo system are proposed. Based on thekinematical analysis of the five-axis CNC machine tool, the mathematical model ofspace contour error is suggested.2. The servo system simulation models of five-axis CNC machine tools areestablished with Simulink. Then the dynamic performances related to the simulationmodel with various parameters are shown. The impacts of various feed servo parametersto the dynamic circular trajectory errors related to synchronous motion of rotational axisare analyzed in five-axis machining center.3. Based on the post-instruction of cutting “S”-shaped test specimens, motionconstraints of each axis are analyzed. With the time inverse method, the feed rates ofcutting “S”-shaped test specimens are predicted and the real interpolation instructions ofaxis are listed.4. Based on the analysis process of the dynamic trajectory error, the main factors ofcontours errors on “S”-shaped test specimen are extracted. Then, the contours errors of“S”-shaped test specimens caused by the main factors are investigated. It is verifiedwith cutting. The results show that the simulations are valuable. The influence laws ofthe contour error related to the feed servo system parameters are effectively revealed. It provides guidance to the detection of the processing performance of CNC machine toolsand the error tracing to the source.