Collision Detection Algorithm of Belt Grinding of the Blisk Based on Improved Octree Segmentation Method

In the process of belt grinding aero-engine Blisk(Bladed Disk), the abrasive belt can easily interfere with the Blisk, which will damage the valuable Blisk. Therefore, it is indispensable and significant to study the collision detection of belt grinding the Blisk. However, the application of traditional collision detection algorithms in this complicated realistic scene is difficult to obtain satisfactory results. In order to improve the accuracy and efficiency of the collision detection of grinding the Blisk, a collision detection algorithm based on the improved octree segmentation method is proposed in this paper. Firstly, the Oriented Bounding Box (OBB) is applied to establish the collision detection model for the abrasive belt. Secondly, the traditional octree segmentation method is optimized based on the k-means clustering algorithm, and an improved octree segmentation method is presented, in addition, the flow chart of the collision detection algorithm for belt grinding of the Bliskis given. Finally, algorithm verification and experimental verification are carried out based on a certain type of the Blisk. The results suggest that compared with the traditional method, the method in this paper not only promotes the accuracy of collision detection, but also promotes the efficiency of collision detection, and meets the requirements of object collision detection in this tanglesome scene with both accuracy and speed.

Design and Implementation of the Universal Servo Control Algorithm Verification System Based on High-Speed Communication Fieldbus

In recent years, there have been several breakthroughs in the theoretical research of servo control algorithms. However most of these control algorithms remain in the simulation stage. They are difficult to be applied directly to practical platforms or complex industrial sites because of the lack of an experimental system suitable for the verification of their effectiveness. To address this problem, we designed a multi-function servo control algorithm verification experiment system (MVES) within the MATLAB/Simulink theoretical simulation model directly to communicate with the TwinCAT 3 PLC master program to perform different servo control experiments. The MVES supports various Simulink models. However, its and the operation is simple and convenient, which greatly reduces the workload of the algorithm test and has important practical value. Two sets of comparative experiments were used to verify the versatility and superiority of MVES.

Verification of Prognostic Algorithms to Predict Remaining Flying Time for Electric Unmanned Vehicles

This paper addresses the problem of building trust in the online prediction of a eUAV’s remaining available flying time powered by lithium-ion polymer batteries. A series of ground tests are described that make use of an electric unmanned aerial vehicle (eUAV) to verify the performance of remaining flying time predictions. The algorithm verification procedure described is implemented on a fully functional vehicle that is restrained to a platform for repeated run-to-functional-failure (charge depletion) experiments. The vehicle under test is commanded to follow a predefined propeller RPM profile in order to create battery demand profiles similar to those expected during flight. The eUAV is repeatedly operated until the charge stored in powertrain batteries falls below a specified limit threshold. The time at which the limit threshold on battery charge is crossed is then used to measure the accuracy of the remaining flying time prediction. In our earlier work battery aging was not included. In this work we take into account aging of the batteries where the parameters were updated to make predictions. Accuracy requirements are considered for an alarm that warns operators when remaining flying time is estimated to fall below the specified limit threshold.

Review of Kalah Game Research and the Proposition of a Novel Heuristic–Deterministic Algorithm Compared to Tree-Search Solutions and Human Decision-Making

The Kalah game represents the most popular version of probably the oldest board game ever—the Mancala game. From this viewpoint, the art of playing Kalah can contribute to cultural heritage. This paper primarily focuses on a review of Kalah history and on a survey of research made so far for solving and analyzing the Kalah game (and some other related Mancala games). This review concludes that even if strong in-depth tree-search solutions for some types of the game were already published, it is still reasonable to develop less time-consumptive and computationally-demanding playing algorithms and their strategies Therefore, the paper also presents an original heuristic algorithm based on particular deterministic strategies arising from the analysis of the game rules. Standard and modified mini–max tree-search algorithms are introduced as well. A simple C++ application with Qt framework is developed to perform the algorithm verification and comparative experiments. Two sets of benchmark tests are made; namely, a tournament where a mid–experienced amateur human player competes with the three algorithms is introduced first. Then, a round-robin tournament of all the algorithms is presented. It can be deduced that the proposed heuristic algorithm has comparable success to the human player and to low-depth tree-search solutions. Moreover, multiple-case experiments proved that the opening move has a decisive impact on winning or losing. Namely, if the computer plays first, the human opponent cannot beat it. Contrariwise, if it starts to play second, using the heuristic algorithm, it nearly always loses.

Breaking the temporal barrier in air quality monitoring over Europe with Sentinel-4

<p>European UVN satellite missions deliver global measurements for air quality and climate applications from Low Earth Orbit (LEO) satellites since over two decades. Currently we have in the morning data from GOME-2 on the three MetOp satellites and in the early afternoon data from OMI/Aura and TROPOMI/Sentinel-5 Precursor.</p><p>The temporal barrier imposed by LEO satellites, providing only one daily observation, can be broken using Geostationary Equatorial Orbit (GEO) satellites. The Sentinel-4 (S4) mission on-board the MTG-S GEO satellite will focus on monitoring of trace gas column densities and aerosols over Europe with an hourly revisit time, thereby covering the diurnal variation of atmospheric constituents.</p><p>We present the algorithm, verification, and processor work being performed as part of the ESA Sentinel-4 Level 2 (S4-L2) project responsible for developing the operational S4-L2 products: O<sub>3</sub> total and tropospheric column, NO<sub>2</sub> total and tropospheric column, SO<sub>2</sub>, HCHO, CHOCHO columns, aerosol and cloud properties as well as surface reflectance.</p><p> </p>

DETECTION OF SPACECRAFT ORBITS IN MULTI-ELEMENT LAUNCHES WITH LOW SCATTERING SPEED. DISTRIBUTION OF MEASUREMENTS OF ORBITS

The paper considers the structure of the algorithm for detecting the orbits of spacecraft in multi‑element launches with low speed of scattering. These launches are used in recent years for the launching of microsatellites into orbits. In the proposed algorithm, the difficult task of distributing measurements to orbits is solved on the basis of taking into account the features of the relative motion of nearby space objects that form a dense cluster at launch. In particular, it is proposed to use the relative distance between the spacecraft in the direction of the velocity vector as a distribution parameter. Then the problem of detecting orbits is reduced to the distribution of measurements in one‑dimensional space of relative distances. The developed structure of the algorithm can significantly reduce the detection time and the number of calculations compared to the standard algorithm. Verification of the proposed method on the example of analyzing data on the actual launch of the spacecraft confirmed its effectiveness.