This paper presents a new calibration method for larger size co-ordinate measuring machines (CMMs). This method provides 21 parametric errors by performing 1-dimensional length measurements in the workspace of a CMM. A special measurement set up is realised, which enables automated volumetric error compensation of CMMs at their production stage. Located in a corner of the measuring volume, this laser set up performs multiple spatial linear interferometer measurements by movement of a CMM automatically. In this paper emphasis is placed on; i) automation of spatial laser interferometer...
A new application of laser displacement sensors in measuring surface texture has been reported from industry recently. To achieve high measurement precision, laser sensors with high-resolution, which are expensive and usually means high-laser-class, are required, because if low-resolution sensors are used, the surface signal could be hidden in the internal noise of the sensor. In this paper, the mean of a number ( N ) of measurements of a specific distance between the sensor and the measured point is used to better represent the distance and reduce the internal noise. An artificial neural...
In the article, the algorithm and the method of the cylindrical gear measurement with a Co-ordinate Measuring Machine have been presented. The CMM with appropriate software enables to measure quickly and accurately both simple details like corpses and complicated ones like gears. All geometrical parameters of a gear may be measured, and program simulating single flank gear testing enables the complex analysis of the gear and the pair of gears.
In the paper some ways of straightness and roundness measurements with multipoint methods are presented. They are based on workpiece surface measurement in limited number of regularly dislocated points and on reconstruction of an actual profile. For this purpose different interpolation methods can be applied: linear function, polynomial, trigonometric series, third order spline interpolation. The main point when using these methods is to choose a number of measuring points correctly. It depends on character of examined surface, applied interpolation method and acceptable measuring error....
Refraction effects are generally caused by an inhomogeneous propagation medium for the optical beam and are recognized as today’s major source of systematic errors in the precise optical determination of angles and distances. Because meteorological point measurements do not deliver satisfactory correction values, the investigation of alternative methods motivated the development of a dispersometer, a metrological solution with a very sophisticated instrumental set-up. Furthermore, the compensation of deterministic refraction effects basing on atmospheric scintillation is envisaged: Optical...
Methods and devices for on-line measurements of produced thin metal tubes and rods are proposed. They are based on the use of a monitored article as a conductor of synthesised TEM-transmission line section. Resonance frequency of electromagnetic oscillations of such line section and period of pulses sequence excited in it serve as informative parameters of the designed length sensors.
In the paper, a dynamic measuring system is set up on basis of the precise angle-measuring instrument. The paper analyzes the dynamic characteristic of the test data and the measuring system and establishes the forecasting model of the dynamic error data of the system by use of the theory of time serial and fuzzy neural network. During training the model, the insertion correction method of a limited number of standard data is used to get model parameter. During using the model, based on the circular self-sealing feature of the angle measuring system, the paper puts forward that the...
The paper deals with the active error compensation effected by using links or components, made from piezoactive (piezoelectric or magnetostrictive) materials. It is shown that by implanting of active links into the technological chain of the measuring equipment both static and dynamic errors can be sufficiently reduced. Some considerations according to new approach to error compensation circuits and actuators are presented. Compensation covers not only generally accepted measurement systems, but also opens new ways of increasing the accuracy of such typical components of technological...
A non-contact measurement system, based on the principle of photogrammetry, developed at the Fraunhofer IPT, permits a highly exact 3D-shapemeasurement of objects. Because of the limited depth focus of the projection lens used, the axial measurement range is reduced to only a few centimetres. In order to digitize the 3D-shape of technical objects of various dimensions, the structured illumination on the object surface must be in focus for each axial depth. The principle of holographic projection offers a crucial benefit, in order to project a sharp pattern in any plane. By applying computer...
Temperature behaviour of machine tools is one of the main reasons for process dispersion of the modem accurate production. This paper presents a comparison of the effect of thermal expansion and positioning measuring System on the production accuracy of machine tools. In the project the positioning accuracy of pulse encoders and linear positioning measurement systems (two types) in different thermal conditions was compared and analysed. Both measuring systems were used interchangeably on each machine tool at the same time. The test environment includes a modern sheet metal turret punch press...