发布时间：2015-01-23 来源：人大经济论坛

自动化专业论文范文 目 录 第1章 线切割机及张力控制简介1 1.1线切割机简介1 1.2 电火花线切割机张力控制简介及原理2 第2章 直流电机基本原理4 2.1 直流电机的机构与调速原理4 2.2 霍尔效应及其原理7 第3章 硬件及方案的选择9 3.1控制方案的选择9 3.2 键盘的选择11 3.3 显示方式的选择13 3.4 电动机驱动芯片的选择14 3.5 CS3020霍尔组件的介绍17 3.6 总方案的确定18 第4章 硬件系统的论述20 4.1电源部分20 4.2 PWM波形产生部分20 4.3电机驱动部分21 4.4测速显示部分23 第5章 软件系统的论述25 5.1主程序25 5.2 PWM信号发生程序27 5.3测速子程序29 5.4显示子程序31 5.5键盘扫描子程序33 第6章 总结37 参考文献38 致 谢39 摘 要 随着科技的发展，现代制造技术对机床性能的要求越来越高，因此对线切割机提出了更高加工工艺指标，尤其是效率指标，提高机床加工的稳定性、可靠性。而其中控制电极丝在切割中保持恒定的张力控制是至关重要的。这是长期困扰提高丝线切割机加工精度的症结。如果电极丝的振动没有很大的改善，那么加工精度也难以得到可观的提高，并且也不可能实施可以有效提高加工精度的多次切割工艺。 因此本毕业设计就钼丝的张力控制进行了分析和研究，通过单片机控制，运用了直流电机PWM控制原理，对线切割机的直流电机进行了转向，转速的精确控制，进而对钼丝的张力控制进行精确的控制，本设计中运用了能严格满足性能要求而又价格低廉的AT89S51和AT89C2051的单片机片子，以及L298（一种高电压、大电流）电机驱动芯片、LED显示。还运用了寿命长，体积小，方便安装的CS3020霍尔元件作为测速装置。此外本设计附带了红外线遥控扩展功能，具有体积小、功耗低、功能强、成本低等特点，使整个控制系统性能更加完善。至此，可以解决线切割机钼丝张力不平衡的难题。 关键词：高频PWM控制，单片机，直流电机调速，张力控制 Abstract Along with the technical development, the modern technique of manufacture is getting higher and higher to the engine bed performance's request, therefore proposed to the line cutter the higher processing technic index, the efficiency target, enhances the stability which, the reliability particularly the engine bed processes. But the control electrode silk maintains in cutting the constant tensity control is very important. This is the long-term puzzle increases the silk thread cutting machining precision the crux. If electrode silk vibration not very big improvement, then the working accuracy also with difficulty has the considerable enhancement, and is impossible to implement may increase the working accuracy to cut the craft many times effectively. The this graduation project has therefore carried on the analysis and the research on the molybdenum silk's tensity control, through the monolithic integrated circuit control, has utilized the direct current machine PWM control principle, carried on to the line cutter's direct current machine changed, the rotational speed accuracy control, then carried on the precise control to the molybdenum silk's tensity control, in this design utilized has been able to satisfy the performance requirement and the low in price strictly AT89S51 and at89C2051 monolithic integrated circuit flat and thin piece, as well as L298 (one kind of high voltage, big electric current) motor-driven chip, LED demonstration. Also utilized the life to be long, the volume was small, facilitates the installment CS3020 the Hall part achievement to measure the fast installment. In addition this design has supplemented the infrared remote control extended function, has the volume to be small, the power loss is low, the function is strong, the cost low status characteristic, causes the entire control system performance to be more perfect. Hence, may solve the line cutter molybdenum silk tensity not balanced difficult problem. key word: The high frequency PWM control, the monolithic integrated circuit, The direct current machine velocity modulation, the tensity controls