9762 papers found
The article deals with possibilities of surface roughness evaluation of machined parts. Non-standard methods are mentioned here, as well as a standard methods (ISO, DIN). It made survey of different approach to surface roughness evaluation.
The aim of reverse engineering is to create a computer-aided design (CAD) model of an existing physical object. This paper deals with technology for acquiring measured point data by use of an optical 3-D measuring system. This system is suited for measuring objects, at a high speed and in a high density, which have smooth shapes and character areas with steep slopes. Smooth curves are approximated by fitting non-uniform cubic B-spline curves with curvature taken into consideration. Free-form surfaces in higher-order continuity are derived from the fitted B-spline curves as the boundary...
The paper deals with a short review of length and angle measurements from the stage of linear and circular scales production and calibration to the process of mounting them into the rotary encoders and linear translational transducers with subsequent calibration and, finally, a calibration of the informational measuring systems assembled into the automatic technological and measurement equipment, as co-ordinate measuring machines. Systematic pitch errors and uncertainty of the scales calibration are determined before using them for measurement systems of the machines. A systematic error...
This paper presents a new multi-probe method for accurately measuring straightness profiles of cylinders. This scanning probe method is developed from the traditional three-probe method, which can measure the profile accurately without the influence of motion errors of the scanning stage. Two sets of three-probe method sensor units are used in the developed method so that the zero-adjustment errors between the probes can be evaluated. The two sensor units are placed in the two sides of the cylindrical workpiece and are used to scan the two opposed generatrices of the cylindrical workpiece...
We proposed the probe system for CMM, which consisted of elastic hinges, QPD and ball lens to detect the small displacement of stylus. The contact force increases rather than other probes; touch trigger probe etc., we try to totally reduce the contact force by the more sensitive detector.In our concept, as the stylus of this probe is supported by the elastic hinge rigidly, the probe system should detect the displacement of the stylus before the stylus make the plastic deformation on workpiece. Therefore, the detector should demand high sensitivity in order to prevent the deformation on...
This paper presents an Internet Based Roundness and Cylindricity Analysis System, which applies Java and Internet technology to engineering metrology. The package includes most of the standardized and advanced analysis tools for roundness and cylindricity. The most distinct feature of this package is that it can run on the Internet, which enables platform independent and remote analysis of roundness and cylindricity data.
Nano-Probe System is described in this paper. Recently industrial parts have been smaller in size of sub-micrometer order. Therefore it is needed to measure such small mechanical parts in high accuracy. For this purpose we have developed nano-CMM(Coordinate Measuring Machine), whose resolution is nano-meter order. We are now developing a probe attached to nano-CMM, which is named nanop- Probe. It must be small enough and be able to detect touch of an object with high sensitivity. As a principle of nano-Probe system, we have proposed Optical Sensing System, new system that can detect displace...
Due to the cylindrical shape of drill-holes and inner threads the acquisition of high-resolution images has not yet been solved satisfactorily. Different possibilities for taking pictures from the inside of a drilled hole are reviewed and evaluated with respect to the quality of the images. Results show, that a ring-shaped CMOS-Sensor works best for the purpose of automatic inspection. Additionally, the analysis of these images requires a special algorithmic approach, which is able to take care of the cylindrial shape of the object. To achieve this, the use of the Z-transformation is...
The idea of high resolution (0,01 µm) displacement encoder with laser diode light beam focused on the scale surface is presented. Due to application of the focused laser beam the acceptable tilts of the encoder head relative to the grating in the prototype device reach about of 0,5 arc degree in all directions and the tolerance of the distance between head and the grating is equal to about 0.1 mm. A new simple reference point detection method that use a scale grating edge as an reference point has been proposed. This technique allows significant reduction of nonlinearity errors of the...
Many optical methods of geometrical quantities' measurements need continuous, precise, and high speed determination of positions of light beams interacting with the measured surface. Existing photodetectors, namely chargecoupled devices (CCDs) and position sensitive detectors (PSDs) in many cases do not comply with these demands. We are developing a new device with superior characteristics. It is based on the domain wall motion in a transparent ferromagnet, a so-called orthoferrite. The velocity limit of the domain wall motion in orthoferrite crystals is extremely high: 20 km/s. The device...