Shaft system profile reconstruction method based on L-shaped axial four-probe method

Abstract

The inability to extract spatial axis and radial multi-error coupling phenomenon exists in the process of axial profile reconstruction, which is essentially a first harmonic suppression problem as well as a multi-error decoupling problem. In this paper, a four-probe system is constructed based on an L-shaped arrangement in two adjacent planes. First, the mathematical model of the first harmonic suppression problem of the shaft system is established in the first plane, and the first harmonic component of roundness error is used as the axial reference for reconstructing the profile, and the value of the first-order harmonic component is solved by theoretical derivation, and the spatial axis of the reconstructed shaft system profile is fitted with it, which proves the correctness of the established mathematical model by the data simulation. Then, the radial mixed error detection is carried out in two adjacent planes in the axial direction, and the results measured at the two measurement positions are analyzed theoretically to obtain the tilt error decoupling formula. It breaks through the limitation that the error separation online detection cannot be performed in the standard ball measurement method. The experiment verifies that the accuracy of the spatial axis is improved by up to 0.5 μm after decoupling the tilt error, and the accuracy of the reconstructed circularity profile of a single section is improved by up to 2.657 mm. In the comparison experiment with the standard ball measurement method, the difference of the measured roundness error between the two methods does not exceed 1.2 μm, which proves that the online inspection method proposed in this paper can guarantee the accuracy of the reconstructing circularity profile.

Five-degrees-of-freedom error motion measurement method of precision rotary table based on BMPES

“…Substituting A and B into equations ( 10) and (11), the radial error motion can be obtained as follows:…”

“…At present, the detection of 5-DOF error motion of the rotary axis is mainly divided into two methods: one is the method of detection by photoelectric detector (laser) [6][7][8][9]; the system built by this measurement method is more complex, and it is difficult to achieve online measurement, and then it is impossible to achieve real-time compensation of the rotary table error. The other method is to use a probe as the core detection element, where the probe acquires the displacement variation of the measured part mounted above the rotary table at a specific angle, and analyzes the difference between the signals acquired by the probe at different phases to obtain the error motion of the rotary table [10,11]. Xu et al proposed a dedicated system capable of simultaneously measuring tilt, radial and axial displacements online, which combines five capacitive probes and a standard cylinder, which demonstrated high accuracy [12].…”