Plasma Spraying Multi-Parameter Integrated Control Strategy And Application Research

Plasma spraying is an important technology to obtaining functional coatings on the surface of materials.It is widely used in the fields of surface modification,crack repair and functional coating preparation of mechanical parts,and plays an important role in materials engineering and industrial production.Since the traditional plasma spraying control system is composed of relays and switches,the spraying equipment adopts open-loop control.At the same time,the plasma spraying process has many parameters and the process is complex and changeable,resulting in defects in the control accuracy,response speed,and equipment control of the plasma spraying system.In order to solve the problems of low integration,no self-diagnosis alarm function,no data acquisition function and low gas flow control accuracy of traditional plasma spraying control system,this paper takes embedded controller as the core to carry out in-depth research on plasma spraying multi-parameter integrated control system.By analyzing the working principle and process parameters of plasma spraying,the technical indicators of plasma spraying multi-parameter integrated control system are determined for the plasma spraying process.The plasma spraying integrated control system scheme,control system hardware circuit and plasma spraying special equipment with ARM chip as the control core are designed.Firstly,the control strategy of plasma spraying arc voltage is studied,and the overall structure of plasma spraying arc voltage control is determined.The plasma spraying arc load model of current,voltage and gas flow is established by BP neural network,and the plasma spraying arc model is simulated by MATLAB software.The validity of the arc model is proved by comparing the simulation results with the experimental results.Secondly,according to the plasma spraying voltage control method,a single neuron PID control algorithm is proposed to improve the stability of plasma spraying voltage control.Simulink is used to establish a single neuron PID simulation model to control the spraying voltage.The simulation results show that the single neuron PID control algorithm can effectively improve the control stability of arc voltage.According to the control process and hardware circuit,the integrated control program of plasma spraying is designed.The control program includes communication program,ADC sampling program,single neuron PID program and man-machine interface program.Finally,a multi-parameter integrated control system for plasma spraying was built to test the key functions of plasma spraying.The test results show that the protection alarm function is normal,the current control accuracy reaches 0.1%,the gas flow control accuracy reaches 0.5%,and the powder feeding speed control accuracy reaches 1.6%.The test results of plasma spraying voltage control show that the single neuron PID control algorithm has better dynamic response performance and control accuracy for controlling arc voltage.The application experiment of plasma spraying integration is completed.The experimental results show that the plasma spraying integrated control system can run stably and has high control precision.It solves the problems of poor control accuracy,poor protection measures and low integration of traditional plasma spraying system.