Stabilization of Microrobot Motion Characteristics in Liquid Media
Magnetically actuated microrobot in a liquid media is faced with the problem of head-tilting reaction caused by its hydrodynamic structure and its speed while moving horizontally. When the instance microrobot starts a lateral motion, the drag force acting on it increases. Thus, the microrobot is una...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2018-07-01
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| Series: | Micromachines |
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| Online Access: | http://www.mdpi.com/2072-666X/9/7/363 |
| _version_ | 1818958588108865536 |
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| author | Ali Anil Demircali Huseyin Uvet |
| author_facet | Ali Anil Demircali Huseyin Uvet |
| author_sort | Ali Anil Demircali |
| collection | DOAJ |
| description | Magnetically actuated microrobot in a liquid media is faced with the problem of head-tilting reaction caused by its hydrodynamic structure and its speed while moving horizontally. When the instance microrobot starts a lateral motion, the drag force acting on it increases. Thus, the microrobot is unable to move parallel to the surface due to the existence of drag force that cannot be neglected, particularly at high speeds such as >5 mm/s. The effect of it scales exponentially at different speeds and the head-tilting angle of the microrobot changes relative to the reference surface. To the best of our knowledge, there is no prior study on this problem, and no solution has been proposed so far. In this study, we developed and experimented with 3 control models to stabilize microrobot motion characteristics in liquid media to achieve accurate lateral locomotion. The microrobot moves in an untethered manner, and its localization is carried out by a neodymium magnet (grade N48) placed inside its polymer body. This permanent magnet is called a carrier-magnet. The fabricated microrobot is levitated diamagnetically using a pyrolytic graphite placed under it and an external permanent magnet, called a lifter-magnet (grade N48), aligned above it. The lifter-magnet is attached to a servo motor mechanism which can control carrier-magnet orientation along with roll and pitch axes. Controlling the angle of this servo motor, together with the lifter-magnet, allowed us to cope with the head-tilting reaction instantly. Based on the finite element method (FEM), analyses that were designed according to this experimental setup, the equations giving the relation of microrobot speed with servo motor angle along with the microrobot head-tilting angle with servo motor angle, were derived. The control inputs were obtained by COMSOL® (version 5.3, COMSOL Inc., Stockholm, Sweden). Using these derived equations, the rule-based model, laser model, and hybrid model techniques were proposed in this study to decrease the head-tilting angle. Motion control algorithms were applied in di-ionized water medium. According to the results for these 3 control strategies, at higher speeds (>5 mm/s) and 5 mm horizontal motion trajectory, the average head-tilting angle was reduced to 2.7° with the ruled-based model, 1.1° with the laser model, and 0.7° with the hybrid model. |
| first_indexed | 2024-12-20T11:28:08Z |
| format | Article |
| id | doaj.art-19bbc3f3d2974291a88d96307766ac34 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-12-20T11:28:08Z |
| publishDate | 2018-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-19bbc3f3d2974291a88d96307766ac342022-12-21T19:42:18ZengMDPI AGMicromachines2072-666X2018-07-019736310.3390/mi9070363mi9070363Stabilization of Microrobot Motion Characteristics in Liquid MediaAli Anil Demircali0Huseyin Uvet1Department of Mechatronics Engineering, Yildiz Technical University, 34349 Istanbul, TurkeyDepartment of Mechatronics Engineering, Yildiz Technical University, 34349 Istanbul, TurkeyMagnetically actuated microrobot in a liquid media is faced with the problem of head-tilting reaction caused by its hydrodynamic structure and its speed while moving horizontally. When the instance microrobot starts a lateral motion, the drag force acting on it increases. Thus, the microrobot is unable to move parallel to the surface due to the existence of drag force that cannot be neglected, particularly at high speeds such as >5 mm/s. The effect of it scales exponentially at different speeds and the head-tilting angle of the microrobot changes relative to the reference surface. To the best of our knowledge, there is no prior study on this problem, and no solution has been proposed so far. In this study, we developed and experimented with 3 control models to stabilize microrobot motion characteristics in liquid media to achieve accurate lateral locomotion. The microrobot moves in an untethered manner, and its localization is carried out by a neodymium magnet (grade N48) placed inside its polymer body. This permanent magnet is called a carrier-magnet. The fabricated microrobot is levitated diamagnetically using a pyrolytic graphite placed under it and an external permanent magnet, called a lifter-magnet (grade N48), aligned above it. The lifter-magnet is attached to a servo motor mechanism which can control carrier-magnet orientation along with roll and pitch axes. Controlling the angle of this servo motor, together with the lifter-magnet, allowed us to cope with the head-tilting reaction instantly. Based on the finite element method (FEM), analyses that were designed according to this experimental setup, the equations giving the relation of microrobot speed with servo motor angle along with the microrobot head-tilting angle with servo motor angle, were derived. The control inputs were obtained by COMSOL® (version 5.3, COMSOL Inc., Stockholm, Sweden). Using these derived equations, the rule-based model, laser model, and hybrid model techniques were proposed in this study to decrease the head-tilting angle. Motion control algorithms were applied in di-ionized water medium. According to the results for these 3 control strategies, at higher speeds (>5 mm/s) and 5 mm horizontal motion trajectory, the average head-tilting angle was reduced to 2.7° with the ruled-based model, 1.1° with the laser model, and 0.7° with the hybrid model.http://www.mdpi.com/2072-666X/9/7/363microrobotscontrol systemsuntethered manipulationdiamagnetic levitation |
| spellingShingle | Ali Anil Demircali Huseyin Uvet Stabilization of Microrobot Motion Characteristics in Liquid Media Micromachines microrobots control systems untethered manipulation diamagnetic levitation |
| title | Stabilization of Microrobot Motion Characteristics in Liquid Media |
| title_full | Stabilization of Microrobot Motion Characteristics in Liquid Media |
| title_fullStr | Stabilization of Microrobot Motion Characteristics in Liquid Media |
| title_full_unstemmed | Stabilization of Microrobot Motion Characteristics in Liquid Media |
| title_short | Stabilization of Microrobot Motion Characteristics in Liquid Media |
| title_sort | stabilization of microrobot motion characteristics in liquid media |
| topic | microrobots control systems untethered manipulation diamagnetic levitation |
| url | http://www.mdpi.com/2072-666X/9/7/363 |
| work_keys_str_mv | AT alianildemircali stabilizationofmicrorobotmotioncharacteristicsinliquidmedia AT huseyinuvet stabilizationofmicrorobotmotioncharacteristicsinliquidmedia |