| At present,the production field of China's ceramic sanitary ware industry mainly uses robot automatic glaze spraying to apply glaze to the ceramic surface,but the traditional open-loop glaze spray flow control method cannot guarantee the accuracy and stability of its flow control,and it is easy to cause hygiene Defects on the surface of ceramics;in order to ensure the yield,the thickness of the glaze sprayed on the ceramic surface is increased in the process,which is easy to cause problems such as low utilization ratio of the glaze ingredients and high production cost of sanitary ceramics.Compared with the open-loop glaze spraying method,the closed-loop glaze spraying method has obvious advantages,such as high accuracy of glaze flow detection,stable flow rate,and relatively lower cost.Closed-loop glaze spraying technology replaces open-loop glaze spraying technology is an inevitable trend,but China's closed-loop glaze spraying flow control technology is not mature,the main reasons are the following two aspects,one is the quality of glaze mass flow detection equipment technology water products are relatively western The national technology is immature,it is difficult to accurately detect the spraying quality of the glaze per unit time;second,the closed-loop glaze spraying control technology is defective,and the stability during the production process is poor.In this paper,based on the development status of the glaze flow control system in China,based on the Ximeier GR630 spraying robot of the Robot Research Institute of Shandong University of Technology,a set of robot closed-loop glaze spraying systems for the ceramic sanitary ware production industry was developed The Coriolis mass flowmeter of the mass flow rate of the material is studied and analyzed to achieve accurate and stable mass flow control of the ceramic glaze.Not only can it effectively improve the utilization rate of glaze and the quality of ceramic products,but also rely on the ceramic glaze spraying industry to accelerate the localization process of single-tube spiral Coriolis mass flowmeters.The research contents of this article are as follows:(1)The characteristics of the closed-loop glaze spraying system are analyzed,the technical requirements are clarified,and the overall scheme design is carried out on the basis of part of the open-loop control system.The mechanical structure composition and working methods are introduced in detail,and on this basis,Improvements were made,and a control scheme for alternating operation of closed-loop mass flow control and closed-loop control of glaze slurry pressure was proposed.And analyze the single screw pump,which is an important executive component,to ensure the linear output and operating stability of the system,and select the driving equipment,testing equipment and controller according to the design needs of the system.(2)The principle and working method of Coriolis mass flowmeter are analyzed,the material selection of the mechanical part of the sensor,the mechanical design modeling and the improvement of the processing technology are realized,and the small radius bending technology of stainless steel thin-walled seamless steel pipe is realized.The breakthrough has improved the phenomenon of depressions and protrusions generated at the bend before,and achieved the technical index that the diameter shrinkage is less than 0.5mm,reaching the same machining quality as the German industry.The transmitter is researched and developed to realize the preprocessing of the vibration detection signal including filtering,amplification,analog-to-digital conversion,and the self-excited oscillation circuit driving the excitation coil,and a high-precision second-order sig-The Delta ADC modulator realizes 23-bit high-precision analog signal processing and detection,ensuring the accuracy requirements for the closed-loop glaze spray control system.(3)According to the technical performance parameters of the actual driving execution equipment,a mathematical model is established,and a system transfer function is established according to the closed-loop system control scheme;through simulation analysis of the PID control algorithm of the flow control system,when the overshoot is 0,its adjustment Time t> 5s;when the adjustment time t <1.5s,an overshoot of more than 20% is generated.In order to improve these two conditions,the system is improved.When the spray gun stops running,increase the output pipeline glaze slurry The closed-loop control of the pressure ensures that the pressure is consistent with the pressure when the gun is working,thereby improving the stability of the step response of the closed-loop system.(4)According to the overall design requirements of the control system,test and verify the whole system of the control system.The mass flow accuracy of open-loop and closed-loop systems was compared.The error range of the experimental results of closed-loop mass flow control was about 1%.The three control strategies of the closed-loop system were compared and tested.The experiment showed that the pressure stability control when the spray gun stopped intermittently could reduce the overshoot and adjustment time of the system and improve the stability of the system step response.The control system has good performance. |
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