Study And Application On Key Technology Used For The Controller Of Micro-Positioning System

Precision manufacturing is a manufacturing method that has a less than 0.1μrn accuracy and a lower than Ra0.025μm roughness. When glass, ceramic and semiconductor are grinded, the cut depth is not more than 0.1μm. There is no craps on the surface of the parts, and the scraps are curl like plastic. But the feed system of the traditional grinding machine has creep unavoidably, low resolution and response speed.This article based on a study of 'Micro-feed system used for precision grinding and its application', presents a close-loop control system used for piezo-driven micro-feed platform, which is an integration of drive, inspect and compensation.Some research has been done including:1. The design of a micro-feed system. Through a compare of all kinds of micro-feed system and piezo-driven methods, the pattern of micro-feed system is designed. The system uses piezo stack as the actuator and flexure hinges as guiding unit The precision grinding machine has a duel feed stage that including rough stage and precision stage. The rough stage achieves the rough grinding and semi-precision grinding, and the precision stage achieves micro-feed with high stiffness, resolution and quick response.2. The dynamic model of the micro-feed system is built. To avoid thenon-linear of the platform's output and other factor during grinding, an open-loop and a close-loop control system are designed and simulated with Matlab. The result proves that the micro-feed system has a high accuracy and a quick response under the open-loop control system.3. A close-loop control system is designed based on the non-linear model of the piezo stack. The system uses MCS-51 series single chip AT89C51 as central processor, an inductance sensor as feed back. The system is a modularization design which has dive module and inspect module. The drive module includes power supplier and D/A. The non-linear model of piezo stack and the control program are presented.4. The data acquisition system is designed. The static and dynamic experiments are made to test the properties of the micro-feed system. The results prove that the control system of piezo-driven system has a 27um stroke, ±0.04um accuracy and a 195N/um stiflhess with a friendly interface, low cost, small volume and agile applicationWANG Haolin (Mechanical Manufacturing & Automation)Supervised by Prof. LI Beizhi...