Today, profiles of involute gears are measured with conventional or specialized coordinate measuring devices. The measuring speed of such instruments decrease with an increasing density of measuring points. Therefore, coordinate measuring devices often scan only a few lines of the gear surface. But these profiles represent only partially the functional behavior of the gear. This contribution describes a method, which measures the complete surface of a tooth in only a few seconds. A structured light pattern is directed towards the tooth. A CCD-camera records the stripes, deformed by the...
In this paper, we propose a new design artifact to calibrate a ballplate. Ballplates are usually used to calibrate CMMs (Coordinate Measuring Machines). At present, for the calibration of ballplates, gauge blocks are being used. Gauge blocks are not appropriate as length transfer gauges because of their shape. Therefore, we developed a new artifact, which we call a one-dimensional ballplate. It consists of a steel bar that is designed as an H section and balls. It has two advantages, namely, it can be calibrated by a laser interferometer and the positions of balls do not change in the event...
A surface roughness measurement technique, based on an optical method using a computer vision system, was investigated for applicability to inprocess monitoring of surface quality. The developed vision system uses a CCD camera for scanning gray-scale images from an area of the machined workpiece. This images were analysed with digital image processing system. Some new optical roughness parameters were derived from the images based on their histograms and optical objects of machined surface. New parameters were plotted against the corresponding average roughness values (Ra ) determined using...
This study proposes a new coordinate measuring machine (CMM) based on a spatial 3DOF parallel mechanism. The use of this mechanism will potentially improve the stiffness, accuracy and efficiency. This paper describes the fundamentals and an experimental CMM. The influence of link layout on the measurement uncertainty, moreover, has been investigated analytically and experimentally. Obtained results show that the uncertainty has been decreased when the measuring point is in the extensional direction of the scale unit. Consequently, the Abbe’s principle can be applied to proposed parallel...
The paper describes a conception of a scanning system applied to the complex inspection of turbine blades. The implementation of the scanning technique on CMM produced in IOS required to use a new scanning probe, as well as the implementation of an extended control and processing data procedures. In accordance to the technical documentation the analysis program is capable to perform the evaluations of the parameters of blade features. A very accurate comparison with nominal features with graphical presentation can be achieved. The usage of above method has been checked in industrial...
This research is aimed at improving accuracy of stereolithography (Rapid prototyping) system. The objective of this paper is to detect the flatness of freeform liquid surface. The principle of measurement is performed by obtaining grating image of total reflection from freeform liquid surface. The detection is performed by two steps, coarse detection and fine one. Coarse detection is used for searching widely deformed area and fine detection is used for verifying flatness of freeform liquid surface. The phase detection of grating image is based on Linear Digital Phase-Locked Loop (L-DPLL).
In this paper the principle and device NME 90° for large square standards calibration is described. The self-calibration methods of measurement are used. They allow very low uncertainty of the square calibration with mathematical elimination of measuring column straightness deviations. The process of measurement is full automated and controlled by PC, which collects and evaluates measured data. The uncertainties of the square measurement are also discussed in the paper.
Last years the scale of microsystems production is higher and higher. Because of this fact the requirements for traditional measurement equipment applied for measurement and control of microdetails geometry are changing. These changes are connected with new needs in the range of measurement and programme possibilities. In the paper the examples of microdetails measurements carried out using PG-2/200 Form Meter, which was worked out and produced at the Institute of Metal Cutting are presented. The analysis of measured microdetail profiles contains linear dimensions, angles and radii. The...
Guaranteed surface roughness is required because of functional demand for active surfaces of machine parts. Such as for example: clamping surfaces of tools, thread flanks of guide screws and others. Therefore we are finding out the roughness magnitude during production process. If these surfaces are inaccessible for profilprojector roughness measuring the off print method can be used. The using of appropriate material of the offprint will determine the best correlation of measured results of the offprint roughness and real surface roughness magnitude. Our contribution contains methods for...
Measurements of surface roughness by scattering methods are the subjects of this paper. Theoretical and experimental studies of the light scattering from machined surfaces are presented. Two-dimensional fast Fourier transform (2-D FFT) algorithm for computer simulation of diffraction field is applied. A discussion of modelling scattered light from periodical and random surfaces is given as well. Survey of scattering methods for measuring of rough machined surfaces is concise presented. A description of method for evaluation of moving rough surface is also given. This method involves...