Generic instantaneous force modeling and comprehensive real engagement identification in micro-milling

The group diagram shows the actual engagement identification results of tools in micro milling. The specific implementation steps of the iterative algorithm for determining tool runout parameters are as follows:1) A section of milling force signal is extracted, and the average sampling frequency is one revolution, which is used to determine the tool runout. The sampling angle set is arbitrarily set according to the sampling frequency fs (Hz) and the spindle speed n, and the adjacent sampling angles have the same spacing angle. The synchronization of the measured milling force signal can be obtained through the simulation of Fy.2) Set the initial value (0, 0) of the tool runout parameter, and substitute it into the instantaneous cutting thickness formula, and gradually change the tool runout parameter to realize the cycle program. The angle set is the set of sampling angles set in step 1, which makes the value of instantaneous cutting thickness h at all cutting heights on the cutting edge exceed the critical instantaneous cutting thickness at the shearing stage.3) The cutting force coefficient sets Kn and Kf are obtained by Cramer criterion (Kyrchei 2010). The cutting force coefficients Kn and Kf are the average values of the cutting force coefficient set Kn and Kf.4) Use the cutting force coefficient obtained in step 3 to simulate the milling force, and then take δ It is the square sum of the simulated and measured milling force errors at all angle sets.5) Select the tool run out parameter as "in cycle" δ Tool runout parameter when the minimum value is obtained.