Research On Measurement Of Thickness And Temperature Of Robot Spraying Coating

Rapid tooling (RT) has become more and more important for its low manufacturing cost and ability of rapidly responding to the market. Plasma spray metal tooling has obtained a special attention for its advantages of fewer limits on the pattern's size and spraying materials. The key problem here is how to keep formability and coating quality in rapid spray tooling. In most cases, cracking and peeling of coating will often occur when the temperature and thermal stress of coating are non-uniformed during the coating process. Coating temperature and thickness are the most important reasons, so it is necessary to monitor and control them.The coating on ceramic is made of iron,nickel and chrome alloy powder in our lab, so magnetic measurement and eddy current measurement are not fitting. They are used to measure the thickness of the coating on metal parts. Some non-contacting methods(laser and ultrasonic measurement) are not fitting for low precision or limits on environment. The measurement with displacement sensor has advantages of fewer limits on the pattern's size and coating materials, and robot with sensor can freely measure the thickness. The equipment is simple and low cost. So in this paper the measurement of robot with displacement sensor was presented and developed system. And finished some experiments, the measuring precision at fixed point, dispersed points and continuous points are compared by analyzing the measured data from micrometer. The results show that the measurement method can be used to measure relatively thick coating.For temperature detecting, measuring temperature via infrared controlled by PLC on the robot was used to collect data by scanning the surface of the processed parts. Measuring temperature via infrared combined with relevant scanning track can implement serial detecting of coating temperature distribution in robot spray tooling, improved the detecting range and system flexibility. The results of research of relevant experiments show that adopting cycle average value and standard deviation of temperature can easily make good response for phenomenon of temperature wave and crack of coating. So temperature monitor system based on measuring temperature via infrared can assistant to do spraying technics analysis and process diagnosis. It also provide object parameter for adaptive control of coating temperature.Series experimental research shows that the PC with PLC measurement system reached the designed purpose in the main. For introduction of OPC, PC can get data real time to see the processing of spraying in order to keep formability and coating quality in rapid spray tooling.