Research Dynamic Detection System Of Rolling Speed And Thickness Based On Capacitive Sensor

Hot rolling is the main processing technology of metal plate and strip. During the hot rolling process, the steel is the most common phenomenon which influences the hot strip rolling process. Such as Baosteel 2050 hot rolling production line, in 2012 there were 7 steel accidents, which seriously affect the production efficiency of the production line.Piling up of steel is mainly caused by the change of strip speed when rolling. Piling up of steel production enterprises loss a lot, such as heap big security problem existing in the steel;steel sometimes cause the roller fracture pile; pile of steel will make the whole ingot completely scrapped. At present, some continuous rolling line is used to looper alleviate the problem of steel pile. But sometimes looper had false action, very prone to piling up of steel.In the face of this situation, it is urgent to find a suitable and effective way to solve this situation.In this paper, through the design of capacitance sensor can on-line detection of rolling speed, solves the problems in the process of rolling steel pile. The capacitive sensor has high precision and good real-time performance. Through the sensor of the steel plate thickness and the speed of the accurate real-time detection, real-time adjustment of the roller speed, avoid the production process in the occurrence of steel pile accidents, improve the production efficiency.First of all, the traditional capacitance sensor measuring head has carried on the ANSYS modeling, and the finite element analysis of magnetic field. The results show that the measuring head there are a lot of clutter around magnetic field lines, namely when measuring the influence of edge effect. To this end, the measuring head of capacitance sensor structure optimization, through the outside of the measuring head increase shielding layer, two layers of insulation layer and two layer to eliminate the edge effect and parasitic capacitance on the effects of capacitance sensor measurements.Secondly, the capacitance sensor for on-line measurement of plate thickness, plate up and down vibration in rolling process, which makes the results of the measurement. Therefore,using independent double thickness capacitor structure, thus overcome the due to the plate with jumping up and down the problem of inaccurate measurement results. Through the application of CDC technology, the analog signal can be converted to digital signal directly,which makes the measurement result can be directly displayed on the liquid crystal display.Again, between the two sets of two sets of capacitive thickness measurement device,respectively, to extract the thickness of the thickness of the two sets of thickness measured signal. Using signal cross-correlation principle, the two sets of thickness signals are analyzedby MATLAB software, and the maximum value of the cross-correlation function at a certain time is obtained, and the real-time speed of the plate is calculated. This realizes the real-time measurement of the plate speed.Finally, the simulation platform of Wind River MATRIX is applied to control the speed of the roll of the seventh stands. By measuring the rolling speed of the plate in real time, the speed of the roller can be adjusted in real time, so as to avoid the steel accident caused by the unequal flow of the frame before and after rolling. The simulation results show that the design of the rolling speed real-time control system is feasible, which plays an important role in the technical innovation of hot rolling production line.