rus
Issue #5/2023
V.P.Mikhailov, A.A.Kopylov
PLATFORM FOR ACTIVE VIBRATION ISOLATION OF NANOTECHNOLOGICAL EQUIPMENT
PLATFORM FOR ACTIVE VIBRATION ISOLATION OF NANOTECHNOLOGICAL EQUIPMENT
DOI: https://doi.org/10.22184/1993-8578.2023.16.5.282.287
The results of mathematical modeling of the active damper automatic control system based on a magnetorheodogical elastomer in the Simulink MATLAB environment are given. The results of experimental studies of the platform are presented and the transmission coefficients of the amplitude of vibration displacements in the low-frequency range are determined.
The results of mathematical modeling of the active damper automatic control system based on a magnetorheodogical elastomer in the Simulink MATLAB environment are given. The results of experimental studies of the platform are presented and the transmission coefficients of the amplitude of vibration displacements in the low-frequency range are determined.
Теги: active vibration isolation automatic control magnetorheological elastomers автоматическое регулирование активная виброизоляция магнитореологические эластомеры
INTRODUCTION
Modern technologies of production and research of micro- and nanostructures (films, bulk structures), have a wide range of methods of formation and control of local surface properties, so it is necessary to carry out work with a resolution of less than 100 nm [1–3]. Such technological and research equipment includes facilities that use ion, electron or X-ray beams for surface processing and analysis (electron microscopes, scanning probe microscopes, equipment for micro- and nanolithography, equipment for nanolocal ion and electron processing, etc.), as well as optical radiation (high-resolution optical microscopes, etc.). At the same time, the most important task of ensuring quality of such equipment operation is the effective protection from external vibration effects in the low frequencies range, at resonance, phenomena are appeared. This is especially important in case of intensive development of nanotechnologies, which are realised mainly through the use of ultrahigh vacuum equipment, the elements of which have low rigidity (thin-walled vacuum chambers, bellows, motion inputs into the vacuum, etc.) and, accordingly, low resonance frequencies.
For this purpose, various types of vibration isolation systems are used, and they can be divided into passive and active [4–8]. Passive systems effectively suppress vibrations at frequencies higher than 40–50 Hz, while in the low-frequency range such systems are ineffective because they cannot compensate for resonance phenomena. For vibration isolation in the low-frequency range, active vibration isolation systems using the energy of an additional source are used. Modern systems combining active and passive vibration isolation are the most effective. Depending on the type of the actuating mechanism, active systems can be divided into the following groups: hydraulic, pneumatic, electromagnetic, piezoelectric, magnetostrictive, magnetorheological and others. [10–14].
MODELLING OF AUTOMATIC CONTROL SYSTEM OF ACTIVE DAMPER
The scientific group of Bauman Moscow State Technical University has developed an active vibration isolation platform based on magnetorheological (MR) elastomers [15]. Modelling of the developed automatic control system (ACS) of the active MR-damper in the Simulink MATLAB software environment has been carried out. While modelling, the system response was analysed under simultaneous action of harmonic vibration disturbances and a stepped control signal with a stepwise movement of the MR-damper by 5 μm. A comparison of three-axis and single-axis MR dampers behaviour under axial displacement was carried out, which showed similar dynamic characteristics with a slight decrease in the axial stiffness of the three-axis damper. At the same time, the vibration displacement amplitude transfer coefficient for both models does not exceed 0.1 in the frequency range of 0.3–100 Hz. Modelling also allowed to choose control algorithms, structure and composition of the control system. The structural scheme of ATS of one control channel of a three-axis MR-damper with PID controller is shown in Fig.1.
PID-controller 1 is built after the signal combiner in series with the ATS links of the MR-damper: electromagnetic coil 2, magnetic core 3, MR-elastomer 4, moving core 5, measuring system 6. Transient process of ATS of three-coordinate MR-damper under the influence of sinusoidal vibration impact with vibration amplitude of 5 µm and frequency of 20 Hz, with input step signal – 5 µm – is shown in Fig.2.
The transient time was no more than 0.2 s, with residual vibrations not compensated by the PID controller. The value of the vibration displacement amplitude transfer coefficient is 0.03...0.05.
EXPERIMENTAL RESULTS
Experiments were performed in the frequency range from 0.3 to 100 Hz, with a maximum vibration disturbance spread of 600 μm. Figure 3 shows the graph of dependence of the vibration displacement amplitude transfer coefficient (VADC) of the platform on the frequency of external disturbances for the mode of active vibration isolation of the MMR-1 metallographic microscope, showing the high efficiency of the system, with the maximum value of the displacement amplitude transfer coefficient in the whole range under study not exceeding 0.071.
This parameter is important for evaluating efficiency of the active damper and the platform as a whole, i.e. for evaluating its vibration-isolating properties: , where А1 – amplitude of the membrane vibration displacements of the rigid centre made of MR-elastomer, on which the protected object is fixed; А0 – amplitude of vibration displacements of the damper base and the platform.
Because of the conducted researches, the developed system high efficiency of automatic control for active vibration isolation platform based on MR-dampers in the extremely low frequencies area at dangerous resonant vibrations of precision equipment occur was proved.
Figure 4 shows the comparative plots of the dependence of VACIS on the frequency of external disturbances for the proposed platform and modern active vibration isolation systems.
The platform based on MR dampers (curve 3) demonstrates higher vibration isolation efficiency in the frequency range of 0.3–3 Hz compared to the piezoelectric system STACIS (curve 1) and in the frequency range of 0.3–20 Hz compared to the platform based on the electromagnetic force actuator DVIA-MB (curve 2).
CONCLUSIONS
The analytical review of modern precision equipment means of protection against vibration effects and methods of their automation allowed to formulate a set of requirements to active vibration isolation systems, including requirements to ensure the transmission coefficient of vibration displacement amplitude not more than 0.1 at low frequencies.
Modelling of the system of automatic regulation of active MR-damper in Simulink MATLAB software environment allowed determining the transient process of damper movement under influence of harmonic vibration effects, to choose the regulator type and calculate their tuning parameters, to increase stability, speed and accuracy of the system.
The experimentally obtained amplitude-frequency characteristic of the platform automatically controlled by means of a microcontroller on the basis of active MR-dampers and elastic suspension with quasi-zero stiffness showed high efficiency of vibration isolation at frequencies of 0.3–100 Hz with the transmission coefficient of vibration displacement amplitude not more than 0.075 and confirmed the modelling results.
PEER REVIEW INFO
Editorial board thanks the anonymous reviewer(s) for their contribution to the peer review of this work. It is
Modern technologies of production and research of micro- and nanostructures (films, bulk structures), have a wide range of methods of formation and control of local surface properties, so it is necessary to carry out work with a resolution of less than 100 nm [1–3]. Such technological and research equipment includes facilities that use ion, electron or X-ray beams for surface processing and analysis (electron microscopes, scanning probe microscopes, equipment for micro- and nanolithography, equipment for nanolocal ion and electron processing, etc.), as well as optical radiation (high-resolution optical microscopes, etc.). At the same time, the most important task of ensuring quality of such equipment operation is the effective protection from external vibration effects in the low frequencies range, at resonance, phenomena are appeared. This is especially important in case of intensive development of nanotechnologies, which are realised mainly through the use of ultrahigh vacuum equipment, the elements of which have low rigidity (thin-walled vacuum chambers, bellows, motion inputs into the vacuum, etc.) and, accordingly, low resonance frequencies.
For this purpose, various types of vibration isolation systems are used, and they can be divided into passive and active [4–8]. Passive systems effectively suppress vibrations at frequencies higher than 40–50 Hz, while in the low-frequency range such systems are ineffective because they cannot compensate for resonance phenomena. For vibration isolation in the low-frequency range, active vibration isolation systems using the energy of an additional source are used. Modern systems combining active and passive vibration isolation are the most effective. Depending on the type of the actuating mechanism, active systems can be divided into the following groups: hydraulic, pneumatic, electromagnetic, piezoelectric, magnetostrictive, magnetorheological and others. [10–14].
MODELLING OF AUTOMATIC CONTROL SYSTEM OF ACTIVE DAMPER
The scientific group of Bauman Moscow State Technical University has developed an active vibration isolation platform based on magnetorheological (MR) elastomers [15]. Modelling of the developed automatic control system (ACS) of the active MR-damper in the Simulink MATLAB software environment has been carried out. While modelling, the system response was analysed under simultaneous action of harmonic vibration disturbances and a stepped control signal with a stepwise movement of the MR-damper by 5 μm. A comparison of three-axis and single-axis MR dampers behaviour under axial displacement was carried out, which showed similar dynamic characteristics with a slight decrease in the axial stiffness of the three-axis damper. At the same time, the vibration displacement amplitude transfer coefficient for both models does not exceed 0.1 in the frequency range of 0.3–100 Hz. Modelling also allowed to choose control algorithms, structure and composition of the control system. The structural scheme of ATS of one control channel of a three-axis MR-damper with PID controller is shown in Fig.1.
PID-controller 1 is built after the signal combiner in series with the ATS links of the MR-damper: electromagnetic coil 2, magnetic core 3, MR-elastomer 4, moving core 5, measuring system 6. Transient process of ATS of three-coordinate MR-damper under the influence of sinusoidal vibration impact with vibration amplitude of 5 µm and frequency of 20 Hz, with input step signal – 5 µm – is shown in Fig.2.
The transient time was no more than 0.2 s, with residual vibrations not compensated by the PID controller. The value of the vibration displacement amplitude transfer coefficient is 0.03...0.05.
EXPERIMENTAL RESULTS
Experiments were performed in the frequency range from 0.3 to 100 Hz, with a maximum vibration disturbance spread of 600 μm. Figure 3 shows the graph of dependence of the vibration displacement amplitude transfer coefficient (VADC) of the platform on the frequency of external disturbances for the mode of active vibration isolation of the MMR-1 metallographic microscope, showing the high efficiency of the system, with the maximum value of the displacement amplitude transfer coefficient in the whole range under study not exceeding 0.071.
This parameter is important for evaluating efficiency of the active damper and the platform as a whole, i.e. for evaluating its vibration-isolating properties: , where А1 – amplitude of the membrane vibration displacements of the rigid centre made of MR-elastomer, on which the protected object is fixed; А0 – amplitude of vibration displacements of the damper base and the platform.
Because of the conducted researches, the developed system high efficiency of automatic control for active vibration isolation platform based on MR-dampers in the extremely low frequencies area at dangerous resonant vibrations of precision equipment occur was proved.
Figure 4 shows the comparative plots of the dependence of VACIS on the frequency of external disturbances for the proposed platform and modern active vibration isolation systems.
The platform based on MR dampers (curve 3) demonstrates higher vibration isolation efficiency in the frequency range of 0.3–3 Hz compared to the piezoelectric system STACIS (curve 1) and in the frequency range of 0.3–20 Hz compared to the platform based on the electromagnetic force actuator DVIA-MB (curve 2).
CONCLUSIONS
The analytical review of modern precision equipment means of protection against vibration effects and methods of their automation allowed to formulate a set of requirements to active vibration isolation systems, including requirements to ensure the transmission coefficient of vibration displacement amplitude not more than 0.1 at low frequencies.
Modelling of the system of automatic regulation of active MR-damper in Simulink MATLAB software environment allowed determining the transient process of damper movement under influence of harmonic vibration effects, to choose the regulator type and calculate their tuning parameters, to increase stability, speed and accuracy of the system.
The experimentally obtained amplitude-frequency characteristic of the platform automatically controlled by means of a microcontroller on the basis of active MR-dampers and elastic suspension with quasi-zero stiffness showed high efficiency of vibration isolation at frequencies of 0.3–100 Hz with the transmission coefficient of vibration displacement amplitude not more than 0.075 and confirmed the modelling results.
PEER REVIEW INFO
Editorial board thanks the anonymous reviewer(s) for their contribution to the peer review of this work. It is
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