Integrated Optimization of Structure and Control in Ultra-Precision Motion Systems

2019 ◽  
Author(s):  
Jing Wang ◽  
Ming Zhang ◽  
Yu Zhu ◽  
Xin Li ◽  
Leijie Wang
Keyword(s):  
Complex Dynamics ◽  
System Level ◽  
Structural Topology ◽  
Worst Case ◽  
Integrated Optimization ◽  
Motion System ◽  
Material Interpolation ◽  
Ultra Precision ◽  
Precision Motion ◽  
And Control

Abstract Ever-increasing demands for precision and efficiency in ultra-precision motion systems will result in a lightweight and flexible motion system with complex dynamics. In this paper, a systematic approach is proposed where control gains, 3D structural topology and actuator configuration are integrated into optimization to derive a system-level optimal design which possesses a high vibration control performance, and still satisfies multiple design constraints. A material interpolation model with high accuracy is proposed for the integrated optimization, a simple integral equation utilizing R-functions and level-set functions is established to represent complex non-overlapping constraints of actuators. Over-actuation degrees are utilized to actively control the dominant flexible modes. Responses of residual flexible modes are restricted by increasing the coincidence of their nodal areas at actuators (sensors) locations. The objective function is the constructed worst-case vibration energy of the flexible modes. A dual-loop solving strategy combining the genetic algorithm and the modified optimal criteria method is adopted to solve the optimization problem. A fine stage in the wafer stage is designed to prove the effectiveness of the proposed method.

Roll Vibration Analysis of Planar Aerostatic Bearings through a Distributed Spring Model

2011 ◽  
Vol 346 ◽  
pp. 332-338
Author(s):  
Wei Jiang ◽  
Wen Chuan Jia ◽  
Shan Shan Liu ◽  
Yuan Tai Hu ◽  
Hong Ping Hu
Keyword(s):  
Working Conditions ◽  
Spring Model ◽  
Aerostatic Bearing ◽  
Normal Stiffness ◽  
Ultra Precision ◽  
Aerostatic Bearings ◽  
Precision Motion ◽  
And Control ◽  
Distributed Spring Model ◽  
Stiffness Distribution

The aerostatic bearings used in guide ways in ultra precision motion stages can provide both normal stiffness and roll stiffness, which are critical to the dynamic characteristics and control of systems. The normal stiffness has been widely investigated so far, but the roll one has seldom been studied. A new method for analyzing the roll stiffness is proposed, in which the aerostatic bearing is modeled as a set of distributed springs. The stiffness distribution is obtained by using the derivate of the pressure distribution with respect to the air gap. All the distributed springs are then integrated by using the presented transformation and it leads to an equivalent spatial spring which contains both the normal stiffness and the roll stiffness. A planar aerostatic bearing is taken as an example to illustrate the procedure of the calculation. The proposed method can be used to predict the vibration characteristics of various kinds of aerostatic bearings under working conditions.

Design and Control of a Linear Electrostrictive Motor

1999 ◽  
Author(s):  
Min Hu ◽  
Hejun Du ◽  
Shihfu Ling ◽  
Yong Li ◽  
Zhaoying Zhou
Keyword(s):  
Thrust Force ◽  
Electrical Discharge Machining ◽  
Precision Motion Control ◽  
Micro Electrical Discharge Machining ◽  
Ultra Precision ◽  
Precision Motion ◽  
P Type ◽  
And Control ◽  
High Thrust ◽  
Maximum Thrust

Abstract This paper presents a novel linear electrostrictive motor with high resolution and large stroke for ultra-precision motion control. High thrust force is obtained by taking use an electromagnetic clamping mechanism with force magnifying structure in the motor design. An operator alterable P-type iterative learning control algorithm is proposed for the digital control of the motor. A prototype of the motor, which is 60mm in diameter and 120mm in length, is designed, built and tested. Experimental results show that the prototype has a mechanical resolution of 0.02μm, less than 2μm yawing error and maximum thrust force of 30N. Applications of the motor include producing the servo feed motions required in micro electrical discharge machining (micro-EDM) system or as a precision motion device for other micro machining systems.

THE EVALUATION OF SURFACE MORPHOLOGY USING FLEXURE GUIDED NANO-POSITIONING SYSTEM AND ULTRA-PRECISION LATHE

2012 ◽  
Vol 06 ◽  
pp. 172-177
Author(s):  
Nam-Su Kwak ◽  
Jae-Yeol Kim
Keyword(s):  
Surface Morphology ◽  
Piezoelectric Actuator ◽  
Control Method ◽  
Positioning System ◽  
Motion Error ◽  
Precision Stage ◽  
Cnc Lathe ◽  
Single Crystal Diamond ◽  
Ultra Precision ◽  
And Control

In this study, piezoelectric actuator, Flexure guide, Power transmission element and control method and considered for Nano-positioning system apparatus. The main objectives of this thesis were to develop the 3-axis Ultra-precision stages which enable the 3-axis control by the manipulation of the piezoelectric actuator and to enhance the precision of the Ultra-Precision CNC lathe which is responsible for the ductile mode machining of the hardened-brittle material where the machining is based on the single crystal diamond. Ultra-precision CNC lathe is used for machining and motion error of the machine are compensated by using 3-axis Ultra-precision stage. Through the simulation and experiments on ultra-precision positioning, stability and priority on Nano-positioning system with 3-axis ultra-precision stage and control algorithm are secured by using NI Labview. And after applying the system, is to analyze the surface morphology of the mold steel (SKD61)

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