滚珠丝杠伺服进给系统机电耦合特性的分析-机械制造及其自动化专业论文.docxVIP

哈尔滨工业大学工学硕士学位论文 哈尔滨工业大学工学硕士学位论文 II II Abstract Servo feed system is an important part of machine tools, its performance directly affect machining precision and efficiency and it’s of great importance improving their properties. As a kind of typical mechatronic system, the conventional design method has been used in designing servo feed systems which design mechanical structure and control subsystem separately and assemble them when finished. Nevertheless the function of servo feed system is a consequence of mutual effect of control subsystem and mechanical subsystem which means there must be some coupling effects in these two subsystems which affect the performance of the whole system. If the coupling effects can be considered in the design phase, apparent advantages can be found in improving system performance and working efficiency. First, this paper built a theoretical model of ball screw drive system under the assumption of rigid body of table, screw, nut and so on. Of cause, the ‘rigid body’ here isn’t meaning that there isn’t any elastic deformation in these components, it means that these components deform only in z direction in the coordinate system. By building this model, effects of structure parameters, control parameters and their combinations on servo feed system’s contour err ratio, magnitude margin and bandwidth were considered. Considering the limitations of the theoretical model, such as unable to take lateral deformation of screw, vibration and mass distribution into consideration, this paper built a finite element model of ball screw drive system. In the FEM model, bearing assembly and nut were not built in solid elements, they were defined by MATRIX27 elements based on theoretical calculations in this paper. This will avoid contact scenario which is highly nonlinear and computing-cost. After that, a classic PID controller was integrated into this FEM model. Based on this model, effects of mass and their distribution on table were taken into consi