Measuring the Speed of Docking Ship with Total Station

The big modern ships are the largest mobile objects that exist in nowadays world. Their huge mass and length in combination with their limited maneuverability can result in the risk of extreme destructions of the infrastructure, as well as environment, in the case of even minor malfunction of any of its elements. The main danger is the kinetic energy of such a colossus and in these circumstances the accuracy of information on the ship's speed becomes particularly important. This is the reason of a growing interest in various systems designed to support harbor pilots during the maneuvers. The most popular ones are based on laser-measurement of the distance, as the rule, installed as static installation in the quay. This article presents the results of the experiments of vessel’s speed measurements when approaching the quay with use the geodetic total stations in a reflectorless variant.

Measurement of tool wear using a non-contact method, using a laser measuring system

Measurement of tool wear using a non-contact method, using a laser measuring system. This article examined the tools - straight cutters with a contactless method using a laser sensor. The first aspect of the research was to determine the influence of the spindle rotational speed on the accuracy of laser measurement. The second aspect of the research was to establish the correlation between the diameter of the tool measured with a laser micrometer and the wear of the tool measured with the microscope. A good (R2> 0.8) Pearson's correlation was found between the measured tool diameter and it’s wear.

Measurements of the local temperature correlation time in a turbulent flame using coherent anti-Stokes Raman spectroscopy

The feasibility to determine the timescale of pulsations of “instantaneous” local temperatures in a turbulent flame at a microsecond time scale by using coherent anti-Stokes Raman scattering (CARS) spectroscopy is demonstrated for the first time to our knowledge. A laboratory laser measurement complex was utilized, based on two CARS-spectrometers employing synchronized pulse-repetitive lasers with 10 ns pulse duration. The system enabled to record, with high temporal resolution (in one single laser shot) and at a variable delay between two sequential shots following each other in pairs at a repetition rate of 10 Hz, series of CARS spectra of N2 molecules from a probe volume as small as 0.03×0.03×2 mm3. From the spectra, “instantaneous” temperatures at a given delay were derived. The obtained values enabled calculation of the correlation coefficient of temperature pulsations vs the delay. The results are presented for the series of 500 single-shot coupled measurements, at the delays in the range 1 μs – 0 ms, of local gas temperatures in a few points of an open turbulent partially premixed methane-air flame of a model burner with visually distinguishable stability of combustion. The average temperatures were between 1500 K and 1800 K. The measurements allowed temperature correlation times in the selected points of the flame to be derived.

An Offset Laser Measurement Method for the Deviation Analysis of Cylindrical Gears

Generally, in the laser measurement of gears, the laser beam passes through the center of the gear, and the laser displacement sensor reads the spatial distance from the gear involute tooth surface to the laser displacement sensor. However, in this method, the angle between the laser beam and the normal vector of the measured tooth surface is too large, which affects the accuracy of the measurement and the stability of the data. This paper proposes an offset laser measurement method. The laser beam is offset from the center of the gear by a certain distance to form a larger incident angle with the tooth surface, which can effectively address the problem and increase the measurement accuracy. Through a selection of the optimal offset distance, the range of optimal offset measurement positions was obtained and clarified by experiments. We solved the data conversion problem caused by the change in measuring position, and we measured the pitch deviation and helix angle of the gear to confirm the feasibility of this method. According to the theoretical calculation and experimental verification, it was found that this method has the advantages of better measurement accuracy and less fluctuation in measurement data. It is, thus, suitable for precision gear measurement.

Research on Identification of Road Features from Point Cloud Data Using Deep Learning

Laser measurement technology has progressed significantly in recent years, and diverse methods have been developed to measure three-dimensional (3D) objects within environmental spaces in the form of point cloud data. Although such point cloud data are expected to be used in a variety of applications, such data do not possess information on the specific features represented by the points, making it necessary to manually select the target features. Therefore, the identification of road features is essential for the efficient management of point cloud data. As a technology for identifying features from the point cloud data of road spaces, in this research, we propose a method for automatically dividing point cloud data into units of features and identifying features from projected images with added depth information. We experimentally verified that the proposed method accurately identifies and extracts such features.