rus
Issue #3-4/2022
V.P.Mikhailov, A.A.Kopylov
RESEARCH OF THE PLATFORM FOR ACTIVE VIBRATION ISOLATION OF THE NANOTECHNOLOGICAL EQUIPMENT
RESEARCH OF THE PLATFORM FOR ACTIVE VIBRATION ISOLATION OF THE NANOTECHNOLOGICAL EQUIPMENT
DOI: 10.22184/1993-8578.2022.15.3-4.232.238
The platform containing dampers based on a magnetorheological (MR) elastomer applied for active vibration isolation of nanotechnological equipment is described. The results of experimental studies of an active damper are presented and amplitude transmission coefficients of vibration displacements in the low-frequency range are determined.
The platform containing dampers based on a magnetorheological (MR) elastomer applied for active vibration isolation of nanotechnological equipment is described. The results of experimental studies of an active damper are presented and amplitude transmission coefficients of vibration displacements in the low-frequency range are determined.
Теги: active and passive vibration isolation damper magnetorheological elastomer vibration amplitude transfer coefficient vibration isolation активная и пассивная виброизоляция виброизоляция демпфер коэффициент передачи амплитуды виброперемещений магнитореологический эластомер
Received: 25.04.2022 | Accepted: 30.04.2022 | DOI: https://doi.org/10.22184/1993-8578.2022.15.3-4.232.238
Original paper
RESEARCH OF THE PLATFORM FOR ACTIVE VIBRATION ISOLATION OF THE NANOTECHNOLOGICAL EQUIPMENT
V.P.Mikhailov1, Doct. of Sci. (Tech), Prof., ORCID: 0000-0003-3638-7932 / mikhailov@bmstu.ru
A.A.Kopylov1, Post-graduate, ORCID: 0000-0001-5528-6518
Abstract. The platform containing dampers based on a magnetorheological (MR) elastomer applied for active vibration isolation of nanotechnological equipment is described. The results of experimental studies of an active damper are presented and amplitude transmission coefficients of vibration displacements in the low-frequency range are determined.
Keywords: magnetorheological elastomer, vibration isolation, active and passive vibration isolation, damper, vibration amplitude transfer coefficient
For citation: V.P. Mikhailov, A.A. Kopylov. Research of platform for active vibration isolation of nanotechnological equipment. NANOINDUSTRY. 2022. V. 15, no. 3–4. PP. 232–238. https://doi.org/10.22184/1993-8578.2022.15.3-4.232.238
INTRODUCTION
To protect the nanotechnology equipment (equipment for micro- and nanolithography, electron microscopes, scanning probe microscopes, etc.) against external vibration disturbances, various types of vibration isolation systems (pneumatic, hydraulic, piezoelectric, etc.) are used, which are classified into passive and active ones [1–3].
Passive systems effectively suppress vibration at frequencies above 50 Hz, but in the low-frequency range they are ineffective because they cannot compensate resonance phenomena. Active vibration isolation systems are used for vibration isolation in the low-frequency range, using the energy of an additional source. Modern systems combining active and passive vibration isolation are most effective [4–9].
DESCRIPTION OF THE PLATFORM AND DAMPER FOR ACTIVE VIBRATION ISOLATION WITH CLOSED-LOOP CONTROL
The active vibration isolation platform (Fig.1) consists of two plates between which there are four units of a passive quasi-zero rigid system based on an elastic suspension with mass correctors, and four active dampers based on magnetorheological (MR) elastomer [10–14].
In order to investigate the active damper, a stand was assembled which general view is shown in Fig.2 and the schematic diagram in Fig.3. The active damper I (Fig.3) contains rigid centre 1, membrane 2 made of MP elastomer, body 3, electromagnetic coil 4, core 5 and damper base 6.
The active damper (item I, Fig.3) operates as follows. Whenever the control current is applied to solenoid coil 4, closed magnetic field is generated in the coil. Axial magnetic field with a given induction is generated between core 5 and membrane 2 made of MP elastomer. The magnetic induction causes the MP elastomer diaphragm 2 to deform axially within the air gap and move rigid centre 1.
Damper base 6 is subject to periodic vibrations with defined characteristics generated by the screw vibration setter. The amplitude of movements generated by the vibration settter is determined by the thread pitch of the screw gear and rotation angle of stepper motor 9. The screw gear contains nut 7 with a pusher and lead screw 8. The displacement amplitude is calculated in advance to ensure the operating stroke of up to 0.5 mm. The vibration frequency is preset and adjusted during the experiment by the Rigol DG1022 signal generator. The principle of setter operation is as follows: stepper motor driver 9 is supplied with voltage and a signal with the required vibration frequency from the Rigol DG1022 signal generator. Stepper motor 9 transmits rotation to screw shaft 8 provided with nut 7. In order to convert rotation of the screw shaft to linear movement, nut 7 is locked against rotation and is rigidly connected to the base of damper 6 thereby ensuring accurate movement of the damper.
The closed-loop automatic control system of the active damper (Fig.3) includes a microcontroller STM32F407VET6 on a debug board, an amplifier unit (UU), an ADC/DAC unit USB-6009ADC for taking readings of the capacitive displacement sensors D1, 2, 3 with a DL6220/ECL2 sensor controller, DAC1 for analog signal transmission to the amplifier unit and a personal computer (PC) for displaying debugging information. The ACS processes readings of the capacitive displacement sensors and outputs the control signal to the amplifier unit and, then, to the electromagnetic damper coil, producing the required displacement. The control program implements the control algorithm according to the PI controller law.
PROCESSING of EXPERIMENTAL RESULTS
An experiment was carried out at 2 Hz frequency. Fig.4 shows a displacement diagram for D1 and D2 which compares a PC-based control system that reduces vibration amplitudes from 150 µm to 20–25 µm and a microprocessor-based control system that reduces vibration amplitudes from 150 µm to 10–15 µm.
Experiments were also carried out in the frequency range from 0.5 to 20 Hz and vibration amplitude transfer coefficient (VATC) was determined as a function of the external disturbance frequency for closed-loop automatic control systems implemented in the personal computer and a microcontroller (Fig.5). The VATC indicates how much of the vibration displacement is transferred from a damper base to a rigid centre of the MP elastomer diaphragm. This parameter is important for evaluating performance of an active damper and this platform as a whole, i.e. for assessing its vibration-isolating properties:
, (1)
where А1 – amplitude transfer coefficient of rigid centre; А0 – amplitude of vibration displacement of a damper base.
The graph in Fig.5 shows a noticeable increase in vibration isolation efficiency in the low frequency range for a closed-loop control system implemented in a microcontroller in comparison with a PC-based control system. The results show that the active damper with a closed-loop control system based on STM32 microcontroller can effectively reduce the vibration displacement amplitude in the range of dangerous for nanotechnology equipment frequencies of 0.5–10 Hz, while the vibration displacement amplitude transfer ratio is in the range of 0.01...0.1.
CONCLUSIONS
To protect nanotechnology equipment from external vibrations, it is advisable to use active dampers and vibration-isolating platforms based on magnetorheological elastomers.
The most effective vibration protection is provided by a system which combines active and passive vibration isolation, in particular an active system based on MR dampers and a passive system based on quasi-zero stiffness elastic suspension with mass correctors.
The STM32 microcontroller based active vibration damper with a closed-loop control system effectively reduces vibrations in the frequency range of 0.5–10Hz with a vibration amplitude transfer coefficient of 0.01...0.1.
PEER REVIEW INFO
Editorial board thanks the anonymous reviewer(s) for their contribution to the peer review of this work. It is also grateful for their consent to publish papers on the journal’s website and SEL eLibrary eLIBRARY.RU. ■
Declaration of Competing Interest. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Original paper
RESEARCH OF THE PLATFORM FOR ACTIVE VIBRATION ISOLATION OF THE NANOTECHNOLOGICAL EQUIPMENT
V.P.Mikhailov1, Doct. of Sci. (Tech), Prof., ORCID: 0000-0003-3638-7932 / mikhailov@bmstu.ru
A.A.Kopylov1, Post-graduate, ORCID: 0000-0001-5528-6518
Abstract. The platform containing dampers based on a magnetorheological (MR) elastomer applied for active vibration isolation of nanotechnological equipment is described. The results of experimental studies of an active damper are presented and amplitude transmission coefficients of vibration displacements in the low-frequency range are determined.
Keywords: magnetorheological elastomer, vibration isolation, active and passive vibration isolation, damper, vibration amplitude transfer coefficient
For citation: V.P. Mikhailov, A.A. Kopylov. Research of platform for active vibration isolation of nanotechnological equipment. NANOINDUSTRY. 2022. V. 15, no. 3–4. PP. 232–238. https://doi.org/10.22184/1993-8578.2022.15.3-4.232.238
INTRODUCTION
To protect the nanotechnology equipment (equipment for micro- and nanolithography, electron microscopes, scanning probe microscopes, etc.) against external vibration disturbances, various types of vibration isolation systems (pneumatic, hydraulic, piezoelectric, etc.) are used, which are classified into passive and active ones [1–3].
Passive systems effectively suppress vibration at frequencies above 50 Hz, but in the low-frequency range they are ineffective because they cannot compensate resonance phenomena. Active vibration isolation systems are used for vibration isolation in the low-frequency range, using the energy of an additional source. Modern systems combining active and passive vibration isolation are most effective [4–9].
DESCRIPTION OF THE PLATFORM AND DAMPER FOR ACTIVE VIBRATION ISOLATION WITH CLOSED-LOOP CONTROL
The active vibration isolation platform (Fig.1) consists of two plates between which there are four units of a passive quasi-zero rigid system based on an elastic suspension with mass correctors, and four active dampers based on magnetorheological (MR) elastomer [10–14].
In order to investigate the active damper, a stand was assembled which general view is shown in Fig.2 and the schematic diagram in Fig.3. The active damper I (Fig.3) contains rigid centre 1, membrane 2 made of MP elastomer, body 3, electromagnetic coil 4, core 5 and damper base 6.
The active damper (item I, Fig.3) operates as follows. Whenever the control current is applied to solenoid coil 4, closed magnetic field is generated in the coil. Axial magnetic field with a given induction is generated between core 5 and membrane 2 made of MP elastomer. The magnetic induction causes the MP elastomer diaphragm 2 to deform axially within the air gap and move rigid centre 1.
Damper base 6 is subject to periodic vibrations with defined characteristics generated by the screw vibration setter. The amplitude of movements generated by the vibration settter is determined by the thread pitch of the screw gear and rotation angle of stepper motor 9. The screw gear contains nut 7 with a pusher and lead screw 8. The displacement amplitude is calculated in advance to ensure the operating stroke of up to 0.5 mm. The vibration frequency is preset and adjusted during the experiment by the Rigol DG1022 signal generator. The principle of setter operation is as follows: stepper motor driver 9 is supplied with voltage and a signal with the required vibration frequency from the Rigol DG1022 signal generator. Stepper motor 9 transmits rotation to screw shaft 8 provided with nut 7. In order to convert rotation of the screw shaft to linear movement, nut 7 is locked against rotation and is rigidly connected to the base of damper 6 thereby ensuring accurate movement of the damper.
The closed-loop automatic control system of the active damper (Fig.3) includes a microcontroller STM32F407VET6 on a debug board, an amplifier unit (UU), an ADC/DAC unit USB-6009ADC for taking readings of the capacitive displacement sensors D1, 2, 3 with a DL6220/ECL2 sensor controller, DAC1 for analog signal transmission to the amplifier unit and a personal computer (PC) for displaying debugging information. The ACS processes readings of the capacitive displacement sensors and outputs the control signal to the amplifier unit and, then, to the electromagnetic damper coil, producing the required displacement. The control program implements the control algorithm according to the PI controller law.
PROCESSING of EXPERIMENTAL RESULTS
An experiment was carried out at 2 Hz frequency. Fig.4 shows a displacement diagram for D1 and D2 which compares a PC-based control system that reduces vibration amplitudes from 150 µm to 20–25 µm and a microprocessor-based control system that reduces vibration amplitudes from 150 µm to 10–15 µm.
Experiments were also carried out in the frequency range from 0.5 to 20 Hz and vibration amplitude transfer coefficient (VATC) was determined as a function of the external disturbance frequency for closed-loop automatic control systems implemented in the personal computer and a microcontroller (Fig.5). The VATC indicates how much of the vibration displacement is transferred from a damper base to a rigid centre of the MP elastomer diaphragm. This parameter is important for evaluating performance of an active damper and this platform as a whole, i.e. for assessing its vibration-isolating properties:
, (1)
where А1 – amplitude transfer coefficient of rigid centre; А0 – amplitude of vibration displacement of a damper base.
The graph in Fig.5 shows a noticeable increase in vibration isolation efficiency in the low frequency range for a closed-loop control system implemented in a microcontroller in comparison with a PC-based control system. The results show that the active damper with a closed-loop control system based on STM32 microcontroller can effectively reduce the vibration displacement amplitude in the range of dangerous for nanotechnology equipment frequencies of 0.5–10 Hz, while the vibration displacement amplitude transfer ratio is in the range of 0.01...0.1.
CONCLUSIONS
To protect nanotechnology equipment from external vibrations, it is advisable to use active dampers and vibration-isolating platforms based on magnetorheological elastomers.
The most effective vibration protection is provided by a system which combines active and passive vibration isolation, in particular an active system based on MR dampers and a passive system based on quasi-zero stiffness elastic suspension with mass correctors.
The STM32 microcontroller based active vibration damper with a closed-loop control system effectively reduces vibrations in the frequency range of 0.5–10Hz with a vibration amplitude transfer coefficient of 0.01...0.1.
PEER REVIEW INFO
Editorial board thanks the anonymous reviewer(s) for their contribution to the peer review of this work. It is also grateful for their consent to publish papers on the journal’s website and SEL eLibrary eLIBRARY.RU. ■
Declaration of Competing Interest. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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