Development of A Servo Control System for Ultrasonically Assisted Machining
| Autor: | Chien-Heng Tang, 唐健恆 |
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| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 The objective is to design of the vibration displacement device for ultrasonic machining process. A set of piezoelectric vibrators is used as actuator associated with an amplification mechanism to generate desired vibration displacement. Another set of piezoelectric vibrators is used as sensor to measure the vibration displacement simultaneously, which provides the feedback control purposed of adjustment of the driving frequency immediately. The main research topics include the design of longitudinal vibrator made by d33, the amplification mechanism design with exponential shape, the system vibration analysis as well as wave transmission analysis. In experiment, the developed piezoelectric actuator integrated with amplification mechanism is able to provide vibration displacement of 2.29 micrometers under the driving frequency of about 39kHz and can immediately and effectively measure the vibration displacement, So that the piezoelectric longitudinal transducer and the piezoelectric sensor can produce longitudinal vibration and induced velocity. We use the piezoelectric ceramic materials as the actuator and the sensor at the same time, where the actuator provides vibration displacement, and the sensor can be easily combined with the actuator which can instantly measure the output of the vibration displacement for feedback control design purpose. Concerning the wire problem due to rotary operation, a transmission mechanism is implemented between the ultrasonic machining assisted device and the cutter. In practice, vibration displacement of 0.23μm is transmitted to the cutter. Implementation of the entire ultrasonic assisted servo system onto a grinding machine with an operation speed of 10000 rpm to grind glass, for example, can obtain roughness Rave of 0.9353nm measured by Atomic Force Microscopy (AFM), which is much better than the regular operation with roughness Rave of 13.82nm. As expected, the developed system is suitable for the subject of ultrasonically assisted machining purpose to improve the grinding efficiency. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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