【作者】 吕承康；

【导师】 朱凌云；

【作者基本信息】 东华大学 ， 电力电子与电力传动， 2007， 硕士

【摘要】 人工合成金刚石技术是利用超高压、高温技术来人工合成金刚石晶体的新兴技术。六面顶压机作为其中的主要生产设备，其质量的优劣和控制精度的高低直接影响着人造金刚石的品质。在六面顶压机的控制系统中，位移控制精度决定了压机的对中性和同步性，影响到金刚石的生长和设备安全；压力和温度控制精度决定了金刚石的质量和产量。近些年来，我国人工合成金刚石技术发展迅速，总产量位居世界前茅，在设备上与国外的差距不大，但由于压机控制技术落后的原因，产品质量普遍较低，缺乏国际竞争力。所以，对六面项压机控制系统的改造尤为迫切。本课题就是在此背景下，对控制系统进行了研究和改进，提出了一些新的方法和见解，主要研究工作及效果如下。1．介绍了金刚石压机的结构组成和工作原理，并分析了目前国内几种压机控制模式的优缺点。针对国内压机控制方法的不足，本文提出了一种新型压机控制模式—基于DSP的智能控制模式。这一方案充分利用DSP的高速处理能力来实现智能算法的大量数据处理，使系统具有很好的控制效果。2．进行控制系统的硬件设计。详细介绍了系统硬件电路的各个模块：信号调理、过零检测、工艺参数显示、工艺参数设置、开关量负载驱动、晶闸管触发以及系统电源。系统通过控制晶闸管的移相角来实现保压和保温控制，与以往的继电器控制系统相比，这一方案使被控变量能很好地跟踪给定的工艺曲线。晶闸管驱动采用全数字方式触发，从而具有了很好的抗干扰性。另外，电压和电流信号均通过信号隔离变压器调整为DSP要求的电压范围，同时也起到了信号隔离的作用。在信号输出端都采用了光电耦合器件，增强了系统抗干扰性。3．进行控制系统的软件设计。为了便于编程调试和代码维护，软件部分采用模块化设计，按照功能划分为八个模块：系统初始化、数据采集及滤波、位移控制、压力控制、温度控制、工艺参数设定、LCD显示、故障处理。根据系统的实时性要求合理分配了系统的中断程序及各自的优先级，并详细分析了各软件模块的控制流程。其中，重点讨论了位移、压力和温度控制，并对保压和保温控制提出了新型的智能控制算法，给出了控制算法的软件实现。4．详细分析了压力和温度控制的特点，基于各自的特点分别提出了混合模糊PID控制和模糊自适应PID控制算法，这些算法能很好地解决保压和保温控制中存在的问题。针对压力和温度系统模型，在MATLAB中进行算法仿真，从实验结果可以得出，新提出的智能算法具有很强的自适应能力，能很好地满足高精度。5．在DSP控制板上进行了实验调试，测试了系统的AD转换精度、过零点检测精度。最后，对本文所做的工作以及实验结论进行了简短的总结。提出了需要继续完善的地方，以作为后续研究工作的参考。更多还原

【Abstract】 Artificial-synthesized diamond is a new technology to produce diamond crystal on the conditions of super-pressure and super-temperature. The six-anvil hydraulic pressure, is the main current equipment for the production, the quality and the control precision of which affect the quality of synthetic diamond. During the synthesizing process, pressure and power precision control the quality and yield of the products. Position precision controls diamond pressure’s symmetry and synchronization, which affects the growth of Artificial-synthesized diamond and the safety of equipment. In recent years, our artificial-synthesized diamond technology develops rapidly and the productivity exceeds any other countries. However, for reason of the inferior control technique, our product quality is still resigned to the middling or low rank, which is short of international competitiveness, so it is critical to reform the control systems now. In such a background, this dissertation is to study and reform the control system of six-anvil hydraulic pressure. During the research, some new ideas and methods were brought forward and the main work and achieved progresses are shown as follows:1. The work principle and structure of the control system in producing artificial diamond are introduced. It is introduced about the universal control mode in our country and considering of the merit and shortcoming of each control mode, a new kind of auto control mode is brought forward—an intelligent control mode on DSP. It makes the best of high speed processing ability of DSP to complete the task of huge of data processing at the time of running intelligent strategy.2. The hardware of control system is designed. The main modules of hardware are introduced in detail, which included signal-sample and filter, zero-check, craftwork parameters-display, craftwork parameters-set up, load-drive, thyristor-drive and power-support. It takes use of transmit time of thyristor to achieve the control of keeping pressure and temperature, so the parameter can track craftwork parameter better than the relay control system. In the control system, two thyristors are sprung through numerical method, so it has a good anti-jamming capability. Another, the signal of position, pressure, voltage and electric current are transmitted to DSP by separated transformer’s adjusting to an appropriate extension, so it has a good anti-jamming capability also. In addition, the optocoupler was used in the fan-out, so the output of system has excellent anti-jamming capability.3. The hardware of control system is designed. Considering of the convenience of program debug and codes maintenance, the software structure is carved up eight main modules, which include: system-initial, data-sample, position-control, pressure-control, temperature-control, craftwork-set up, LCD-display and malfunction-handle. Based on of the system requirement of real time, the interrupt programs and its’ priority are distribute in reason. Also, each flow of software modules is explained in detail, among which, the control of pressure and temperature are emphasize. The intelligent strategies are employed into keeping pressure and temperature.4. The characteristic of pressure control and temperature control are anatomized. Based on the difficulties of the both, a mix fuzzy PID strategy and fuzzy self-adaptive PID strategy are brought forward respectively. Simulations are done with the help of MATLAB, and the experiments results shows that the intelligent strategy has an excellent adaptive capability and an ideal control effect.5. Some important testing experiments were done on the DSP control board, which include AD transform precision test, zero-checking precision test and the method of choosing PID parameters and fuzzy parameters. At last, the dissertation make a summary of the work in the course of system development, points out what the system needs to be improved, and offers the reference for following the development work.更多还原