In-Process Height Displacement Measurement Using Crossed Line Beams for Process Control of Laser Wire Deposition

We propose the use of the line section method with crossed line beams for the process control of laser wire deposition. This method could be used to measure the height displacement in front of a laser spot when the processing direction changes. In laser processing, especially laser deposition of metal additive manufacturing, the laser process control technique that controls the processing parameters based on the measured height displacement in front of a laser processing spot is indispensable for high-accuracy processing. However, it was impossible to measure the height displacement in front of a processing laser spot in a processing route in which the processing direction changes as the measurement direction of the conventional light-section method comprising the use of a straight-line beam is restricted although the configuration is simple. In this paper, we present an in-process height displacement measurement system of the light-section method using two crossed line beams. This method could be used to measure the height displacement in a ±90° direction by projecting two crossed line beams from the side of a laser processing head with a simple configuration comprising the addition of one line laser to the conventional light-section method. The height displacement can be calculated from the projected position shift of the line beams irrespective of the measurement direction by changing the longitudinal position on the crossed line beams according to the measurement direction. In addition, the configuration of our proposed system is compact because the imaging system is integrated into the processing head. We could measure the height displacement at 2.8–4 mm in front of a laser processing spot according to the measurement direction by reducing the influence of intense thermal radiation. Moreover, we experimentally evaluated the height displacement measurement accuracy for various measurement directions. Finally, we evaluated continuous deposition in an “L” shape wherein the deposition direction was changed while using a laser wire direct energy deposition machine for the laser process control based on the in-process height displacement measurement result. We achieved highly accurate continuous deposition at the position wherein the processing direction changes despite the acceleration and deceleration of the stage by laser process control.

Horizontal CCMs in small-capacity metallurgy

Production of light-section rolled products and wire rods of alloyed steel grades differs by small volume of yearly output and wide range of smelted grades. To organize production of light-section rolled products of alloyed steel grades in small volumes, OJSC “Spetsmash” elaborated concept of small-capacity production, which was implemented at several plants. It was shown that horizontal CCM can be effectively applied in the small-capacity production within complexes of light-section rolled stock of alloyed steels production. At the plant “Ferrotrade” (Beloretsk) when creating a complex for production wire rods of 6.5 mm diameter of austenite class steels and nickel-based alloys, a horizontal CCM was constructed. Production of 60 mm diameter billets by the machine was mastered, which enabled to apply a rolling mini-mill, characterizing by small dimensions and power. The horizontal CCM, constructed in 2016 at the steelmaking shop of CJSC “Izhevsk pilot-mechanical plant”, was equipped by electromagnetic stirrer (EMS). It was noted that EMS was applied for the first time in domestic metallurgy at the industrial CCM of horizontal type. In the process of this CCM mastering, more than 60 heats were casted into billets of 80, 200 and 120 mm diameter. EMS application resulted in improving average point on the central porosity to 1.2—1.8 depending on the stirring modes. In 2018 the OJSC “Spetsmash” for the Research Center “Thermodeform” (Magnitogorsk) constructed an experimental horizontal CCM, designed for casting of billets of 40—60 mm diameter by direct casting of melt from the crucible of 60 kg induction furnace into the metal reservoir 776 of the machine. Development of a project of horizontal CCM for PJSC “PlasmaTek” (Ukraine, Vinnitsy) finished, designed for production of billets of 50 and 60 mm diameter within a complex of equipment for manufacturing welding electrodes not only of alloyed but also of carbon steel grades. The designed productivity of the complex is 12,000 t/year. Basic technical characteristics of the CCM presented. Small-capacity production with horizontal CCMs can be organized as independent objects and within existing steel-works for expanding product range.

A Study of Light Verse Features in Athar Tahirs Selected Poems

The current research examines light section included in Muhammad Athar Tahir's chosen sonnets: "Basant" (The Gift of Possession, 2012, p. 37), "Bison"(Boody Loom, 2006, p. 64), Bulbul (The Last Tea, 2015, p. 85) and "Jikka Gali Evening" (The Gift of Possession, 2012, p. 42). These sonnets are taken from Tahir's three volumes of verse: Body Loom (2006), The Gift of Possession (2012) and The Last Tea (2015). The point of this examination is to advance how a portion of Tahir's sonnets falls into the class of light stanza verse. He incorporates mind, virtuosity and rebellious quality in the light refrain verse. Furthermore, Amis (1978) calls attention of the authors that light section conveys best words in the best request. The discoveries of this examination study avow that Tahir's sonnets can be appraised as light section verse. His verse gives the impression of simplicity and accordingly inspires a well-meaning smile.

3D Measurement of Large Structure by Multiple Cameras and a Ring Laser

This paper presents an effective mobile three-dimensional (3D) measurement system that can obtain measurements from the inside of large structures such as railway vehicles, elevators, and escalators. In the proposed method, images are acquired by moving measurement equipment composed of a ring laser and two cameras. From the acquired images, accurate cross-sectional shapes, which are obtained via a light-section method by each camera, are integrated into a unified coordinate system using pose estimation based on bundle adjustment. We focus on the method of separately extracting the information necessary for the two processes – the light-section method and pose estimation – from the acquired images. The laser areas used for the light-section method are detected by a bandpass color filter. Further, a new block matching technique is introduced to eliminate the influence of the laser light, which causes incorrect detection of corresponding points. Through an experiment, we confirm the validity of the proposed 3D measurement method.

Sensing System for Real-Time Measurement of Seed Spacing, Depth, and Geo-Location of Corn: A Proof-of-Concept Study

Proper seed placement during planting is critical for achieving uniform emergence, which optimizes the crop for maximum yield potential. While uniform plant spacing and seeding depth are often used by corn growers to determine the performance of precision planters, these parameters can be influenced by factors other than machinery, such as seed germination, insects, diseases, and soil properties (e.g., temperature and moisture). Currently, the ideal way to determine planter performance is to manually measure plant spacing and seeding depth. However, this process is both cost- and labor-intensive and prone to human errors. Therefore, this study aimed to develop and test a proof-of-concept sensing and measurement (SAM) system to measure seed spacing and seeding depth and provide the geo-location of each planted seed. The system consisted of a high-speed camera, light section sensor, potentiometer, and survey-grade real-time kinematic (RTK) global positioning system (GPS) unit. Results demonstrated the potential of the proof-of-concept SAM system for measuring seed spacing, seeding depth, and geo-location of corn seeds. Results showed that seed spacing can be calculated using the generated stitched images, achieving a root mean squared error (RMSE) of 0.63 cm and a coefficient of determination (R2) of 0.87 when compared to actual seed spacing measurements. Likewise, 98% of the recorded seeding depths were within the acceptable tolerance of ±10% error. Finally, GPS coordinates were recorded for individual images, which can be used to locate individual seeds and provide detailed information on missing plants (no seeds).HighlightsCalculated seed spacing showed an RMSE of 0.63 cm and an R2 of 0.87.98% of the recorded seeding depth was within the acceptable error of ±10%.GPS coordinates were recorded for individual images. Keywords: High-speed camera, Image mosaic, Light section sensor, Proof of concept, Seeding depth, Seed spacing.