Based On The Vb Automatic Plasma Spray Control System

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.