【作者】 张永亮；

【导师】 杨兆军；

【作者基本信息】 吉林大学 ， 机械制造及其自动化， 2009， 硕士

【摘要】 各种微孔加工方法中,钻削加工可以获得较好的加工质量和较高的生产效率,但是微孔钻削时钻头极易发生折断,且钻头一旦折断,很难从工件中取出,常以工件的报废而告终。基于主电机电流的微孔钻削在线监控可以提高钻削加工的效率以及自动化程度,本文提出了一个全部由DSP控制的微孔钻削主轴电机电流在线监控系统,该系统由硬件部分和软件部分组成。硬件部分包括自动进给钻床,霍尔电流传感器,TMS320F2812DSP开发板;软件部分是以CCS软件为编程基础,Matlab为开发工具的集成开发系统,且采用了小波变换处理方法,对数据信号的各个频域成分进行了分析,这样有利于我们进一步对各种高、低频信号的具体分析,实现对电压信号的采集、小波滤波、存储、显示、监控。本文研制了以DSP为控制核心的全功能微孔钻削在线监控系统,系统可以不依赖PC机而独立运行。对微钻头钻削折断时主轴电机电流增量极限值的分布规律进行了研究,验证了极限值服从三参数威布尔分布的结论。根据可靠性理论,建立了微孔钻削主轴电机电流在线监测的数学模型,得出在一定可靠度水平下计算监测阈值的公式,获得了以主电机电流增量为监控阈值的一种有效方法,实验验证了DSP全功能微孔钻削在线监控系统的可行性。更多还原

【Abstract】 Microcellular Processing is widely used and take a great proportion in Micro Precision Machining with the precision and miniaturization and integration of modern industrial manufacturing.The high-speed drilling, compared to laser processing, electron beam and electrical discharge machining, take advantages in its low cost, flexible operation, high accuracy hole wall and disadvantages in its easily broken bit and dispersion lifespan. At present, monitoring system, composed of computer, data acquisition cards, single-chip, which controls the microporous process by testing drilling parameters, is the most widely use of Micro-hole Drilling in Online Monitoring. Such monitoring device characters relatively low computational speed, inadequate hardware resources, and relatively simple instruction, unsuitable for a weak, fast digital signal processing and control, all these undoubtedly reduce the real-time system and the utilization of the bit. Therefore, the development trend of on-line monitoring technique is to exploit monitoring system adopting hardware platform with higher speed to treat the weak, fast digital signal.With the sophistication of DSP technology development, DSP digital signal processing have strong advantages than the IPC, single-chip and other systems. In this paper, I set a multi-functional on-line monitoring control system platform that concludes human-computer interaction and human-machine communication cored in DSP TMS320F2812. This system can control sports feeding system and tool wear warning by monitoring the spindle motor current signal and Micro-hole Drilling tool condition. This system integrates DSP technology, power technology, sensor technology, electrical and mechanical control techniques, study the micro-hole drilling full-featured online monitoring system in the following areas: hardware, software, digital signal processing, study the system-curing process, in accordance with the experimental data and reliability theory to determine the threshold monitoring.The hardware system includes: Micro-drilling machine, Hall Current Sensor, TMS320F2812 board control functions, the system power supply, power amplifier and so on. In this paper, I focus on the main function of the system board, design and explain its reset circuit, clock circuit, A / D sampling interface, both inside and outside the extended memory, DSP simulation interface (JTAG), LCD display and keyboard input output control device. The highly integrated DSP platform simplify the monitoring system and improve the monitoring performance.Software system is designed by the integrated development platform based on MATLAB and supplemented by CCS. I graphically design DSP control procedures, and set algorithm model under the integrate exploit environment of the DSP2812 progrmme platform designed by the MATLAB-c2000lib, and simulate monitoring system in Simulink environment. After stimulation, the executable code is got and loaded to the target DSP board which running automatically. and proceed hardware connections, program run and debug consequently by applying Real-Time Workshop. By detecting the function of the entire system and procedures for the operation, confirmed the feasibility of monitoring system. Finally, use the CCS platform develope the LCD display output and keyboard input to control peripheral procedures and software systems to curing dsp chip.Wavelet treatment is adopted to analyze signal. The real-time analysis of the signal using wavelet method is more accurate and reliable. Such more reliable monitoring signal could be got in order to enhance the preciseness and the reliability of the whole system.Test results show that the multi-functional micro-drilling monitoring system based on TMS320F2812 could collect, filter, and compute on the current signal of the spindle motor. This system can also forecast the state of the bits, which has provided a more efficiency way for the on-line monitoring for the drilling process. DSP reduces the difficulty of monitoring methods before with less equipments and higher mobility. Besides, this method improves the monitoring speed, providing the whole system with the feature of real-time.At last, we made the conclusion that the limit of the difference of motor voltages obeys the Weibull distribution, according to the experiments and K-S testing to which the mould of the on-line monitoring was established.In this paper, experiments were made to test the threshold of on-line monitoring system under different reliability level, taking the reliable voltage difference as monitoring threshold. Which can avoid the broken of drill in drilling effectively under expectation. The new system is real-time, reliable and effective.更多还原