An Online Simultaneous Measurement of the Dual-Axis Straightness Error for Machine Tools

The position error of two parallel surfaces is generally constrained by parallelism. However, as a range of change, it cannot represent the positional relation between two parallel surfaces. Large-scale equipment such as machine tools are complex and difficult to move. It is also an engineering problem to perform field measurements on it. To this end, a method of describing the positional relation between two horizontal parallel surfaces and two vertical parallel surfaces on-site is proposed in this paper, which is a novel kind of position error, enriching the form of parallel surface position error, and solves the inconvenience problem of large equipment position error measurement. The measurement mechanisms are designed, and the measurement principle is given. Firstly, the combined projection waveform of the measured surface can be obtained by the geometric relationship between the measurement mechanism and the measured surface. Secondly, an algorithm is studied to process the obtained waveform, and the combined projection curve of the measured surface is acquired. Then, under the condition of considering the shape contours of the two surfaces, an algorithm is developed to acquire the calculated shape contour of the measured surface. According to the difference between the calculated surface shape contour and the known shape contour of the measured surface, the positional relation of the two surfaces can be determined. Meanwhile, the mathematical models of algorithms are established, and the measurement experiments are carried out, and the algorithms are verified by the mutual measurement method of the two surfaces. The results show that this method can accurately obtain the positional relation of two horizontal parallel surfaces and two vertical parallel surfaces.

Section: Results and Analysismentioning

confidence: 99%

“…Especially for two vertical surfaces, it is more difficult to perform field measurement. However, Jywe et al [18] performed an online measurement of the machine tool's two-axis straightness error. Hsien et al [19] designed an online measurement system for measuring the linearity and parallelism of linear guides.…”

Section: Introductionmentioning

confidence: 99%

A Method of On-Site Describing the Positional Relation between Two Horizontal Parallel Surfaces and Two Vertical Parallel Surfaces

Zhong-wu

Bao

et al. 2020

“…where d 1 and d 2 are the diameters of the measuring beam and imaging spot, respectively, and s is the sensitivity (s = f c / f r ) of the measurement system. Equation (11) shows that the diameter of the imaging spot is linearly related to the diameter of the measuring beam. Generally, the accuracy of the system can be improved by increasing the sensitivity of the system appropriately, which means that the system sensitivity can be improved by increasing the focal length of the convergent lens or by reducing the focal length of the rotating paraboloid.…”

Section: Optimization Of Measurement Configurationmentioning

confidence: 99%

“…Displacement measurement methods have a wide range of application requirements in different fields, such as structural health monitoring [4,5], civil engineering [6][7][8], and manufacturing industries [9,10]. In particular, with the development of science and technology, the demand for precision displacement measurement technology has increased in precision instrument manufacturing, precision machine tools, and precision movement platforms [11,12]. Displacement measurement technology is mainly divided into non-optical measurement technology and optical measurement technology.…”

Section: Introductionmentioning

confidence: 99%

Displacement Measurement Method Based on the Rotating Paraboloid Array

Zhang

et al. 2019

Using an optical freeform surface to realize the precision measurement of displacement has become a research focus in the present day. However, the measurement range of this method is limited by the size of the freeform surface processed. In order to overcome this difficulty, this paper presents a two-dimensional displacement measurement system with a large range, which is composed of a slope sensor and a rotating paraboloid array. The slope sensor utilizes the optical structure of an autocollimator with minor optimization, and the rotating paraboloid array expands the measurement range of the system in a discrete manner. The experimental results showed that the optimized optical system enhanced the measurement accuracy to ±0.4 μm within the range of 1500 μm and the overall measurement error was approximately ±2 μm when measured within the range of 450 mm. The developed measurement system has potential applicability for detection of errors, such as the position error and straightness error of multi-axis systems.

“…The measurement of micro angle and displacement plays an important role in science and technology [1,2]. Optical angle or displacement apparatuses have been applied in many fields, such as in the calibration of machine tools and the measurement of multi-degrees-of-freedom systems [3].…”

Section: Introductionmentioning

confidence: 99%

A Novel 2D Micro-Displacement Measurement Method Based on the Elliptical Paraboloid

et al. 2019

The micro-displacement measurement system with 2D/3D has become increasingly important in the field of scientific research and technology application. In order to explore the application of an optical surface in micro-displacement measurement, a novel and simple 2D micro-displacement measurement method based on the elliptical paraboloid was designed and subjected to experiment. The measurement system takes advantage of the elliptical paraboloid instead of a plane mirror in the optical structure of an autocollimator which has been ameliorated to adapt to curved surface measurement. Through the displacement of the light spot on the CCD (Charge Coupled Device) detector, the displacement of the target could be measured with a linear correlation coefficient of 0.9999. The accuracy of the system is about ± 0.3 µm in a wide range in two dimensions. The results were in good agreement with the theoretical analysis and indicated the potential applicability of the proposed system in the detection of geometric errors of CNC (Computerized Numerical Control) machine tools.