A novel triple-actuating mechanism of an active air mount for vibration control of precision manufacturing machines: experimental work

Abstract

With the goal of vibration control and isolation in a clean room, we propose a new type of air mount which consists of pneumatic, electromagnetic (EM), and magnetorheological (MR) actuators. The air mount is installed below a semiconductor manufacturing machine to reduce the adverse effects caused by unwanted vibration. The proposed mechanism integrates the forces in a parallel connection of the three actuators. The MR part is designed to operate in an air spring in which the EM part is installed. The control logic is developed with a classical method and a switching mode to avoid operational mismatch among the forces developed. Based on extended microprocessors, a portable, embedded controller is installed to execute both nonlinear logic and digital communication with the peripherals. The pneumatic forces constantly support the heavy weight of an upper structure and maintain the level of the air mount. The MR damper handles the transient response, while the EM controller reduces the resonance response, which is switched mutually with a threshold. Vibration is detected by laser displacement sensors which have submicron resolution. The impact test results of three tons load weight demonstrate practical feasibility by showing that the proposed triple-actuating mechanism can reduce the transient response as well as the resonance in the air mount, resulting in accurate motion of the semiconductor manufacturing machine.

Lateral vibration control of a precise machine using magneto-rheological mounts featuring multiple directional damping effect

“…The hybrid mounts was composed of an air spring and an MR damper for isolation and absorption, respectively. The MR damper can generate 415 N of damping force in resonance conditions, and its working distance was ±5 mm [10,11]. The sealing of MR fluid was a major issue in design because of working distance and nonlinear elasticity.…”

“…When an MR damper is used with an isolator, it is called a hybrid mount. Seong et al proposed an MR damper installed in a hybrid mount system [10], and Kim et al proposed a hybrid mount system by integrating an MR damper with an EM actuator [11]. Most of the hybrid structures have been based on a parallel connections, but Zhu proposed a serial connection of MR damper and an isolator [12].…”

“…Only a few cases are found in multidirectional damping effect for industrial applications. Most studies on MR mount systems have used the stresses generated from the magnetic field in the target direction [11,17]. The present study uses the stresses of MR fluids in another direction to control the plane motions that occur in precision equipment, such as semi-conductor manufacturing machines.…”

Design and damping force characterization of a new magnetorheological damper activated by permanent magnet flux dispersion

“…For the past 20 years, the significant advantages of MR fluids, such as their fast reactivity and easy controllability in terms of high yield stress, have been utilized in various devices including dampers [3], valves [4], brakes [5], clutches [6], mounts [7][8][9], and even medical devices [10]. In particular, it has been reported that MR dampers are applicable to many different industries in terms of a reduction of unwanted vibrations and impact, including in vehicle suspensions (for passenger [11][12][13], military [14], and railway [15] vehicles), landing gear systems [16], seat dampers [17,18], washing machines [19,20], industrial machines [21,22], seismic response reduction structures [23,24], bridge vibration control [25], impact absorbers for gun recoil systems [26], vehicle crash energy absorbers [27,28], pedestrian protection systems in vehicles [29], and shock profile systems [30].…”

A hybrid magnetorheological elastomer-fluid (MRE-F) isolation mount: development and experimental validation

“…A conventional passive-isolation scheme has to make a reasonable compromise between attenuation at high frequency and amplification at resonance due to the intrinsic limitations of fixed stiffness and damping parameters. To cope with this problem, active, semi-active, and hybrid solutions have been sought to develop tunable vibration mounts with variable dynamic characteristics [7][8][9][10][11][12][13][14].…”