Adaptivni laserski zapis absolutne pozicijske oznake na jekleno merilno palico

Pogačar, Marko (author), Jezeršek, Matija (mentor), Možina, Janez (comentor)

Raziskave in razvoj merilne palice z laserskim zapisom informacije smo usmerili v ponovljiv, robusten in točen laserski zapis pozicijskih oznak z dobrim amplitudnim odzivom na magnetnem senzorju. Ponovljiv zapis je pomemben zaradi umerjanja magnetnega senzorja na določeno pozicijo, robustnost je pomembna zaradi odpornosti na zunanje motnje, točnost zaradi merjenja v mikronski ločljivosti in dober amplitudni odziv za višjo tipalno razdaljo med senzorjem in merilno palico, kar povečuje tolerance vgradnje takega merilnega sistema v aktuatorske aplikacije. V rezultatih smo primerjali različne tehnike laserskega zapisa, ki vključujejo krmiljenje laserske moči in dva različna režima laserskega zapisa, površinsko in parnično segrevanje. Pokazali smo način povečanja točnosti zapisa pozicijskih oznak z inovativnim pristopom izdelave in zaznavanja predoznak ter ovrednostili vpliv krčenja palice zaradi spremembe mikrostrukture. Najpomembnejši doprinos k znanosti so razviti principi za adaptivno krmiljenje laserskega snopa z namenom ponovljivega zapisa pozicijske informacije v jekleno palico, vrednotenje in analiza dveh režimov segrevanja površine, kjer se parnično segrevanje izkaže za bolj ekonomično, neobčutljivo na zunanje motnje in predvsem kot boljše v smislu doseganja višjih amplitud na magnetnem senzorju. S pomočjo izdelave in zaznavanja predoznak ter upoštevanja dolžinskih skrčkov smo uspeli nadzorovati mesta izdelave pozicijskih oznak pod točnostjo 10 µm.

• Language: Slovenian
• Keywords: lasersko površinsko segrevanje, lasersko parnično, segrevanje, laserski zapis, predoznake, zaznavanje, adaptivno krmiljenje, pozicijske oznake, mikrostrukturne spremembe, pozicijska točnost
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [M. Pogačar]
• Year: 2020
• Number of pages: XXVI, 100 str.
• PID: 20.500.12556/RUL-115215
• UDC: 621.9.048.7:531.716(043.3)
• COBISS.SI-ID: 17210627
• Publication date in RUL: 18.04.2020

Secondary language

• Language: English
• Title: Adaptive laser inscription of absolute position label on steel measuring rod

Abstract

In this work we were focused on research and development of absolute position marks on steel measuring rod which can be used for in-axis positioning measurements where durability and high precision are needed. High speed laser power regulation was made for repeatable laser-based micro-inscription. Two different regimes for laser surface treatment were compared: a surface heating and a deep penetration heating. The first regime is the same as conductive heating and the second is similar to the process of keyhole welding. The experimental results show that both processes can be effectively stabilized by means of controlling the width and depth of the microstructure transformation cross-section, as they are able to compensate for external disturbances, such as higher roughness, and the gradual accumulation of heat. We demonstrated a method to increase the accuracy of location of magnetic micro-inscription by using an innovative pre-position signs which were made and detected by the same laser source. The impact of shrinkage due-to microstructure transformation was evaluated and taken into account. In this way we were able to compensate the thermal expansion and guarantee the absolute location of position marks under the accuracy of 10 µm.

• Keywords: Laser surface heating, Laser deep penetration heating, Laser inscription, Position marks, Pre-position signs, Detection, Adaptive regulation, Feedback control, Microstrocture transformation, Position accuracy