機(jī)械專業(yè)畢業(yè)論文外文翻譯--三軸工作臺(tái)銑床及運(yùn)用先進(jìn)現(xiàn)代控制算法

1、 中文 中文 6512 字出處： 出處：International Journal of Precision Engineering and Manufacturing, 2010, 11(1): 39-47Development of a 3-axis Desktop Milling Machine and a CNC System Using Advanced Modern Control AlgorithmsKim B S, Ro

2、 S K, Park J K1. IntroductionAs new fields such as IT(Information Technology), BT(Bio Technology) and NT(Nano Technology) emerge as a driving force in the industry, the interests in micro-factory system have been growing

3、. The micro-factory is a miniaturized flexiblemanufacturing system which consumes minimal space and energy compared to theconventional one, and it is desired to produce micro/meso size mechanical components necessary for

4、 IT, BT and NT applications. Major technical units contributing to micro mechanical machining systems are,to name a few, high speed spindlesystems, micro high precision feeding systems, control systems to generate coordi

5、nated motions, tooling and chucking systems, frame design and module allocationschemes based upon optimization for high stiffness. Researchers have been trying to put micro technologies together to build micro-factory sy

6、stems which make micro/mesosize precision parts to meet the needs from the manufacturing industry.1In this paper, we present a miniaturized 3-axis milling machine and a dedicated CNC system for the machine. The 3-axis mi

7、lling machine is constructed as one of micro-factory module and designed to produce high precision micro parts. It has a desktop size of 200×300×200 mm3 and is serving as our testbed machine.From finite element

8、 analysis and an impact hammer test, we have verified that ithas a good structural stiffness and high natural frequencies. A high speed air turbine spindle on the horizontal z-axis can run at up to 160,000 rpm. This 3-ax

9、is milling machine was put under real machining tests and it successfully demonstrated its machining capabilities.A CNC system was developed for operation of the 3-axis desktop milling machine. The CNC system includes a

10、G-code interpreter which can process a basicset of G-codes and M-codes in real-time. The CNC system consists of two parts.The one is agraphical user interface which runs under Microsoft Windows, andthe other is a DSP pro

11、gram which interpolates commands and executes a real-time servo control. Two parts communicate each other through a dual port RAM(Random Access Memory). Job assignments for the two parts are discussed in detailin this pa

12、per. To improve the performance of the CNC system for the 3-axis milling machine beyond the traditional PID-type control, different control schemes have been tested including H∞ control, input shaping control, disturbanc

13、e observer and cross-coupled control on the 3-2.1 Static and Dynamic AnalysisFinite element analysis was done to investigate the static and dynamic characteristics of the designed 3-axis milling machine using a finite el

14、ement model as shown in Fig. 3. The computational results showed that the deflection due to its own weight was negligible. When a 10N force was located at the machining position in z-direction, the numerical results show

15、ed that the displacement change at the work table would be about 0.07 ., and the back fame would undergo less than 0.02 . deflection in z-direction. It seems that the 3-axis milling machine has good stiffness due to good

16、 frame design and a pair of small LM guides supporting each x- and y-direction.The modal analysis revealed many important dynamic modes of the 3-axis milling machine. We used the impact hammer test to verify the computed

17、 natural frequencies. The measured natural frequencies do not exactly match the computed ones, but the indicated frequency range from the finite element modal analysis was similar to that from the impact hammer test. Fig

18、. 4 and Table 1 show the measured natural frequencies and corresponding frequency response function of the 3-axis milling machine. It can be seen that the natural frequencies of z-axis stage, which is supposed to be low

19、in stiffness due to its air bearing, locate at a range of 250~390 Hz. The natural frequency of the XY stage shows at about 400 and 710 Hz and, for the back frame, it is around 440 and 640 Hz. It seems that the designed m