MEASUREMENT OF THE GEOMETRY OF MANUFACTURED DRILLS USING OPTICAL SCANNING

This article deals with the control of the geometry of manufactured tools. The geometry of the cutting tool has a great influence on the machining process. One of the processes of manufacturing cutting tools is grinding. Grinding cutting tools is a complex process after which it is necessary to check the geometry of the tools. Five solid drilling tools were manufactured for the experiment. The measured parameters were tool diameter, helix angle, point angle, rake angle, relief angle and core diameter of the cutting tools. The geometry of the cutting tools was measured on a non-contact structured 3D scanner ATOS Triple Scan light. The measurement results were evaluated using GOM software. The scanning results were compared with the geometry measurement on an optical measuring device Zoller Genius 3s. It has been found that the use of a non-contact structured 3D scanner is suitable for checking the geometry of cutting tools. Furthermore, the article deals with the roughness arising when grinding a sintered carbide flute.

Novel Algorithm for Mutual Alignment of Railway Track Geometry Measurements

Track geometry measurements are regularly collected to monitor the condition of a railway network. To detect deterioration patterns and enable predictive maintenance, sequential measurement runs must be mutually aligned which has been proven a serious challenge. This paper presents a novel algorithm for mutual alignment of track geometry signal data. It resolves several previously intractable alignment problems: highly segmented data with variable sample rate, spatially correlated and uncorrelated measurement errors, convergence to true locations, and consistency over time. The algorithm adjusts spatial measurement errors by splitting signals in continuous segments. Re-sampled, error-corrected signals are mutually aligned using cross correlation, and this process is repeated until the mutual alignment meets a pre-defined precision threshold. Missing measurement values are handled by imputing an interpolated offset from nearby segments, ensuring that the signals remain continuous. By using weighted average offsets over all aligned signals, the law of large numbers guarantees convergence and consistency. The practical feasibility of the algorithm is demonstrated on empirical track geometry measurement data from the British railway network, owned and operated by Network Rail.

Assessment of track and turnout condition based on geometry measurement and railhead condition data

The paper presents the procedure of track and turnout geometry condition assessment, taking into account also the deterioration of the rail running surface. Track geometry measurements are made using manual tools, microprocessor-based portable instruments, and geometry cars. Methods of collecting track and turnout geometry data are discussed, and an exemplary equipment design features are presented. Maintaining and possible improvement of the technical condition of the permanent way call for regular inspections providing voluminous data requiring detailed analysis. The approach based on track line-speed dependent geometry parameters analysis is explained. Several synthetic track condition assessment coefficients are described, and analysis of the temporal trend of the track and turnout geometry change. Train operation safety is also affected by changes on the running surface of the rails. In addition to the track geometry, the significant reasons for train operation safety are the railhead wear being affected by the type of transport, traffic intensity and maximum allowable axle load. Determining the permanent way condition with the continuous design and maintenance characteristics is possible if measured on the minimum 200-300 m length with the measurement steps of ca 0.5 m. Comments on employing the Artificial Intelligence tools for track and turnout condition analysis are provided. Most of the inspection data collected using various equipment, like track and turnout geometry measurement data and video inspection information, can be analysed automatically by the dedicated software agents. Such an approach yields analysis results equivalent to the standard inspections, except that the trains and self-propelled trolleys can record data at higher speeds, railways staff could achieve.

DYNAMIC OBJECTS GEOMETRY MEASUREMENT BY LASER SCANNING – A CASE STUDY

The objective of the study was to analyse of measurement of moving objects by means of the Total Station (TS) method and Terrestrial Laser Scanning (TLS). The subject of the tests was the “Polinka” gondola cable car over the Odra river in Wrocław. Research covered the basic and control measurements. The results of observations of suspension ropes’ deflection of the cable car in kinematical state were compared for various degrees of loading. During the motion of the gondola, the shape of the pull and supporting rope is subject to constant shifts. TS measurements are restricted solely to registering interim positioning of the points of pull lines (measurement of static objects). Laser scanner measurements may reveal changes in the location of many points (i.e. drive lines, catenaries or carriages) within a unit of time. The tests were designed to show whether it is possible to capture the shifts in geometry of the moving object (mainly by means of the TLS methods - in the course of constant vibrating of lines and during the movement of gondolas). The analyses indicated that it is possible to capture the changes of geometry by means of the TLS method, however, upon strictly specified measurement conditions.

Geometry and Measurement in Quran

The Quran contains the basic principles of science and civilization. These sciences include natural science and mathematics. The study of mathematics covers algebra, statistics, logic, geometry, measurement, and others. This research aimed to examine the verses of the Quran, which contain geometry and measurement concepts. This research employed the descriptive-qualitative method with library research design. This research revealed that the Quran contains five concepts of geometry: three concepts of line and two concepts of angle. Meanwhile, the Quran also contains fourteen concepts of measurement: six units of time, five units of weight, two units of area, and two units of length or distance.

Nonlinear Complementary Filter for Attitude Estimation by Fusing Inertial Sensors and a Camera

Using a standalone camera for pose estimation has been quite a standard task. However, the point correspondence-based algorithms require at least four feature points in the field of view. This paper considers the situation that there are only two feature points. Focusing on the attitude estimation, we propose to fuse a camera with low-cost inertial sensors based on a nonlinear complementary filter design. An implicit geometry measurement model is derived using two feature points in an image. This geometry measurement is fused with the angle rate measurement and vector measurement from inertial sensors using the proposed nonlinear complementary filter with only two parameters to be adjusted. The proposed nonlinear complementary filter is posed directly on the special orthogonal group SO(3). Based on the theory of nonlinear system stability analysis, the proposed filter ensures locally asymptotic stability. A quaternion-based discrete implementation of the filter is also given in this paper for computational efficiency. The proposed algorithm is validated using a smartphone with built-in inertial sensors and a rear camera. The experimental results indicate that the proposed algorithm outperforms all the compared counterparts in estimated accuracy and provides competitive computational complexity.