Research On Axis-Axis Tracking Measurement Method Based On Electronic Gear

Measurement and control system is at the core of gear measurement centers and camshaft measuring instruments. Conventional measurement methods put harsh requirements on the control systems, and the control efficiency is low. To solve these problems, the axis-axis tracking measurement method based on electronic gears was proposed in this paper. Electronic gear realized the functions of changing the transmission ratio or movement forms of mechanical transmission and made driving axis linear with dead axis through making the frequency of digital pulse signal fractional or multiple by electrical control technology.Firstly, the whole scheme of axis-axis tracing measurement method based on electronic gear was designed through analysis of the components and performance requirements of domestic and abroad gear measurement centers and measure and control systems of camshaft measuring instruments, combining the measuring principle and features of involute gear and camshaft and the functions of electronic gear in this paper.Secondly, based on the research on the algorithm of control error on gear measurement center, the control error of conventional standard track method and axis-axis tracing measurement method presented in this paper were compared. The related measuring software was programmed on Visual C++software platform. The experimental results showed that the control errors of CNC system was reduced and the compound traces of CNC system was closer to standard theoretical curve of the measured contour.Thirdly, the measuring and correcting method of engine camshaft eccentricity and the cam’s "peach tip" location method were researched on the camshaft measuring instrument based on axis-axis tracking measurement method, the practical harmonic analysis technology was applied to the camshaft eccentricity measurement and correction, and the mathematical method of least square method and3-spline interpolation and the translation of the data were integrated with the thought of "sensitive-point" and "highest-point" to locate the cam’s "peach tip" accurately. The software for the measuring experiment was programmed in Visual C++. Experimental results show that system error caused by disunity of benchmark and location inaccuracy of cam’s "peach tip" were reduced effectively.Fourthly, the AC servo control system based on axis-axis tracking measurement method was designed and realized, the mathematical model of control system was established and the control algorithm was simulated in Matlab/Simulink, the influence of control parameters on the performance of the servo system was analyzed, and the efficiency and accuracy of servo system adjustment was improved.Finally, the experiment results demonstrated that the control error in the gear measurement center and the camshaft measuring instruments can reach-0.2μm-0.3μm when the threshold was set within reasonable scope; the repeated measurement accuracy of camshaft measuring instruments can reach1.8μm.