基于VB自动等离子喷焊控制系统研究

【作者】 张明华；

【导师】 陈克选；

【作者基本信息】 兰州理工大学 ， 材料加工工程， 2005， 硕士

【摘要】 本文首先介绍了等离子喷焊技术的特点、发展历史、现状及应用,接着阐述了喷焊技术的发展方向以及PLC和单片机控制器在喷焊过程中的应用,并针对目前国内等离子喷焊设备大多采用硅整流电源、体积大、可靠性差等问题,提出了主电源采用IGBT逆变电源,控制系统采用PC机与单片机联合控制的研究方向。 本文主要介绍了所设计的PC机和单片机联合控制系统的组成结构和控制原理,系统阐述了喷焊主电路、控制系统的串行通信接口电路、参数预置与显示电路、直流电机调速电路、开关量输入输出电路和控制软件,并对系统调试和试验结果进行了详细的分析。 喷焊主电路采用IGBT逆变单电源,高频引弧器与弧焊逆变器具有良好的兼容性。控制系统采用高性能16位单片机80C196KC作为其核心,串行通信接口电路采用电平转换芯片MAX202实现PC机的RS—232C通信标准与单片机的TTL电平的转换,进行参数预置、喷焊命令传送,单片机采用MAX7219实时显示,实现对模拟量、开关量以及喷焊过程的控制。设计了晶闸管电动机(SCR-M)调速电路和PWM调速电路,用于送粉电机、平台移动电机和摆动电机调速系统,喷焊过程中单片机实时采样喷焊参数,并与预置值进行比较,其偏差经单片机PI离散运算后输出相应的控制量,来调节直流电机的转速,从而达到稳定的喷焊过程。根据喷焊工艺动作程序编制系统软件,PC机在Windows环境下通过Visual Basic语言的串行通信控件MSComm与单片机沟通,由PC机控制喷焊参数和喷焊状态,单片机实现喷焊过程的自动控制。 在喷焊控制电路和软件部分都进行了可靠性与抗干扰设计,系统分析了可能影响喷焊过程正常工作的各种干扰及其产生原因,并在原理图设计、PCB制作、信号传输以及程序编制的过程中采取了相应的硬件、软件抗干扰措施。 对喷焊控制系统的各个组成部分进行了调试分析,得到了初步的结果,并给出了在试验过程中记录的数据与相关波形。调试结果表明:所设计的喷焊控制系统及软件合理可行,控制精度高,抗干扰能力强,操作方便,工作稳定可靠,能够实现喷焊过程的自动化。 最后,在本课题设计的基础上,结合目前自动控制理论及应用的发展,提出了采用BP神经网络实现喷焊智能化的设计方案,为以后进一步实现喷焊智能化和提高稳定性提供了一定的基础。更多还原

【Abstract】 Firstly, the characteristics, history, actuality and application of PTAW (Plasma Transferred Arc Welding) are introduced in this paper. The development of PTAW-tech, as well as the application of PLC and microprocessor controllers in PTAW process is set forth. Aimed at the shortcomings of widely application of silicon rectifier domestic, which makes the system more bulky and bad reliability, the project is put forward, in which IGBT inverter is chosen as the main power source and combined controlling system of PC with microprocessor 80C196KC is designed.The build-up configuration and control principle of combined controlling system are introduced in the paper. PTAW main circuit, serial communication circuit, parameters pre-setting and display circuit, speed regulation circuit of DC electromotor, switching values inputting and outputting circuit, as well as control software are explained systematically. Meanwhile, debugging procedures and test results are analyzed in detail.IGBT inverter single power source is adopted in main circuit. High frequency arc-striking equipment has good compatibility with inverter. High performance 16-bit microprocessor 80C196KC is taken as the core of the control system. Electrical level transferred IC MAX202 is adopted in serial communication circuit to achieve the transition between RS-232C (PC) and TIL (microprocessor). And data and orders are transferred between them.MAX7219 is used to drive the LEDs to display in real time. It can realize the control of analogue variables, switching values and the PTAW process. SCR-M and PWM speed regulation circuits are designed to obtain steady running in feeding powder, flat moving and swing of gun. The voltage feedback PI algorithm is used to adjust the speed, which is controlled with closed-loop. Programme is designed according to the process requirements; the parameters and states are transferred between PC and microprocessor through the serial communication controlling component MSComm of Visual Basic under the Windows circumstance to realize the auto-PTAW.Reliability and anti-interference designs are also involved in all PTAW control circuits. Various noises probably appearing in the PTAW process, as well as their mechanism, are analyzed systematically. Subsequently, in order to reduce their bad infections to great extent, some hardware and software measures are adopted while designing schematic chart, PCB board, code transferring and compiling program code.Through online debugging of each component of the system, test data and waveforms are attained and analyzed. The experiment results show that the combined control system has many advantages such as high control precision, strong anti-interference ability, easy operation and reliable performance. It can meet the need of realizing automatic PTAW process.At last, the design project adopting BP neural network is put forward to realize the intelligent PTAW, which is expected to make the whole system more automatic and steadier.更多还原