Active Wide-Band Vibration Rejection for Semiconductor Manufacturing Robots

2015 ◽  
Author(s):  
Zining Wang ◽  
Cong Wang ◽  
Masayoshi Tomizuka
Keyword(s):  
Semiconductor Manufacturing ◽  
Experimental Validation ◽  
Control Strategies ◽  
Vibration Reduction ◽  
Wide Band ◽  
Controller Synthesis ◽  
Manufacturing Industries ◽  
Tracking Accuracy ◽  
Active Vibration ◽  
Active Vibration Cancellation

Currently, the semiconductor manufacturing industries over the world are upgrading from processing 300mm wafers to processing 450mm wafers. In order to satisfy the requirements of producing and processing 450mm wafers, vibration control of wafer handling tools has to make new breakthroughs. This paper introduces an active wide-band vibration rejection method with a vibrotactile actuator and applies it to a wafer transfer robot. Compared to conventional methods based on motor control of the robot, active vibration cancellation with a separate actuator does not risk compromising the tracking accuracy of wafer transfer motions. A three-step controller synthesis scheme is developed by analyzing and combining the strengths of several control strategies. Experimental validation shows a vibration reduction of more than 40% in energy and 30% in amplitude.

Modified Clipped-LQR Method for Semi-Active Vibration Reduction Systems with Hysteresis

2011 ◽  
Vol 177 ◽  
pp. 10-22 ◽  
Author(s):  
Marek Sibielak ◽  
Waldemar Rączka ◽  
Jarosław Konieczny
Keyword(s):  
Smart Materials ◽  
Degrees Of Freedom ◽  
Model Simulation ◽  
Dynamic Properties ◽  
Vibration Reduction ◽  
Active Suspension ◽  
Controller Synthesis ◽  
Magnetorheological Damper ◽  
Reduction System ◽  
Active Vibration

Smart materials are being applied more and more widely in semi-active vibration reduction systems. Actuators built with their use are characterized by nonlinearities and hysteretic effects. Their omission in mathematical descriptions may lead to deterioration of the vibration reduction systems. For that reason, it is important to take into account these negative phenomena associated with the actuators at the controller synthesis stage. One method for determining the control laws in semi-active vibration reduction systems that is frequently discussed in academic literature is “Clipped-LQR”. The present paper proposes modification of that method to allow inclusion in the controller synthesis of the hysteretic properties and other nonlinearities of an actuator. The method developed was verified by determining the controller for the semi-active suspension of a machine operator’s seat. A magnetorheological damper was used as an actuator. The dynamic properties of the foam covering of the operator’s seat were included in model. Simulation tests were performed on the vibration reduction system and function of vibration transmissibility was determined. The semi-active vibration reduction system tested was compared to a passive system. The considerations presented herein relate to the semi-active suspension of a machine operator’s seat, and the method presented may be applied to other controlled systems with many degrees of freedom.

scholarly journals Classes of Strongly Stabilizing Bandpass Controllers for Flexible Structures

2012 ◽  
Vol 2012 ◽  
pp. 1-11
Author(s):  
Alberto Cavallo ◽  
Giuseppe De Maria ◽  
Ciro Natale ◽  
Salvatore Pirozzi
Keyword(s):  
Control Strategies ◽  
Vibration Reduction ◽  
Flexible Structures ◽  
Linear Matrix ◽  
Design Strategies ◽  
Control Laws ◽  
Practical Applications ◽  
Strong Stabilization ◽  
Inequality Technique ◽  
Active Vibration

This paper proposes different design strategies of robust controllers for high-order plants. The design is tailored on the structure of the equations resulting from modeling flexible structures by using modal coordinates. Moreover, the control laws have some characteristics which make them specially suited for active vibration reduction, such as strong stabilization property and bandpass frequency shape. The approach is also targeted the case of more sensors than actuators, which is very frequent in practical applications. Indeed, actuators are often rather heavy and bulky, while small and light sensors may be placed more freely. In such cases, sensors can be usefully placed in the locations where the primary force fields act on the structure, so as to provide the controller with a direct information on the disturbance effects in terms of structural vibrations. Eventually, this approach may lead to uncolocated control strategies. The design problem is here solved by resorting to a Linear Matrix Inequality technique, which allows also to select the performance weights based on different design requirements, for example, a suitable bandpass frequency shape. Experimental results are presented for a vibration reduction problem of a stiffened aeronautical panel controlled by piezoelectric actuators.

scholarly journals Nonlinear vibrations and time delay control of an extensible slowly rotating beam

2020 ◽  
Author(s):  
Jerzy Warminski ◽  
Lukasz Kloda ◽  
Jaroslaw Latalski ◽  
Andrzej Mitura ◽  
Marcin Kowalczuk
Keyword(s):  
Time Delay ◽  
Control Strategies ◽  
Vibration Reduction ◽  
Least Action ◽  
Active Elements ◽  
Principle Of Least Action ◽  
Second Mode ◽  
Delay Control ◽  
Speed Range ◽  
System With Time Delay

AbstractNonlinear dynamics of a rotating flexible slender beam with embedded active elements is studied in the paper. Mathematical model of the structure considers possible moderate oscillations thus the motion is governed by the extended Euler–Bernoulli model that incorporates a nonlinear curvature and coupled transversal–longitudinal deformations. The Hamilton’s principle of least action is applied to derive a system of nonlinear coupled partial differential equations (PDEs) of motion. The embedded active elements are used to control or reduce beam oscillations for various dynamical conditions and rotational speed range. The control inputs generated by active elements are represented in boundary conditions as non-homogenous terms. Classical linear proportional (P) control and nonlinear cubic (C) control as well as mixed ($$P-C$$ P - C ) control strategies with time delay are analyzed for vibration reduction. Dynamics of the complete system with time delay is determined analytically solving directly the PDEs by the multiple timescale method. Natural and forced vibrations around the first and the second mode resonances demonstrating hardening and softening phenomena are studied. An impact of time delay linear and nonlinear control methods on vibration reduction for different angular speeds is presented.

The Use of Damping Based Semi-Active Control Algorithms in the Mechanical Smart-Spring System

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Wander Gustavo Rocha Vieira ◽  
Fred Nitzsche ◽  
Carlos De Marqui
Keyword(s):  
Active Control ◽  
Control Algorithm ◽  
Control Strategies ◽  
Vibration Reduction ◽  
Flow Analysis ◽  
Coupled Systems ◽  
Control Technique ◽  
Control Algorithms ◽  
Control Techniques ◽  
Spring Mechanism

In recent decades, semi-active control strategies have been investigated for vibration reduction. In general, these techniques provide enhanced control performance when compared to traditional passive techniques and lower energy consumption if compared to active control techniques. In semi-active concepts, vibration attenuation is achieved by modulating inertial, stiffness, or damping properties of a dynamic system. The smart spring is a mechanical device originally employed for the effective modulation of its stiffness through the use of semi-active control strategies. This device has been successfully tested to damp aeroelastic oscillations of fixed and rotary wings. In this paper, the modeling of the smart spring mechanism is presented and two semi-active control algorithms are employed to promote vibration reduction through enhanced damping effects. The first control technique is the smart-spring resetting (SSR), which resembles resetting control techniques developed for vibration reduction of civil structures as well as the piezoelectric synchronized switch damping on short (SSDS) technique. The second control algorithm is referred to as the smart-spring inversion (SSI), which presents some similarities with the synchronized switch damping (SSD) on inductor technique previously presented in the literature of electromechanically coupled systems. The effects of the SSR and SSI control algorithms on the free and forced responses of the smart-spring are investigated in time and frequency domains. An energy flow analysis is also presented in order to explain the enhanced damping behavior when the SSI control algorithm is employed.

Experimental comparison of different automatically tuned control strategies for active vibration control

2021 ◽  
Vol 35 ◽  
pp. 281-297
Author(s):  
R. Kleinwort ◽  
J. Herb ◽  
P. Kapfinger ◽  
M. Sellemond ◽  
C. Weiss ◽  
...  
Keyword(s):  
Vibration Control ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Experimental Comparison ◽  
Active Vibration
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