The Design Of High Precision Detecting And Eliminating System Of Bottled Liquid Level Based On Dielectric Constant Detection Method

China is a big country of beer and beverage production and consumption.With the improvement of people's consumption level,there is an urgent need to improve the production efficiency and quality of drinks.Therefore,the production of drinks in China is pushed towards the direction of informatization and intelligence.With the continuous improvement of the speed of the automatic drink production line,the detection and elimination of bottled liquid level in the filling line are also changing to the intelligent mode.There are mature liquid level detection and elimination equipment abroad,but the detection accuracy of domestic equipment is still difficult to reach the international advanced level,so it is necessary to develop a high precision online detection and elimination system of bottled liquid level with domestic proprietary rights.In this paper,the technical indicators of the system were firstly determined according to the requirements of the drink production on the chain channel speed and the requirements of the bottled level measurement standard in the quantitative packaging commodity measurement supervision and management method.The detection speed was up to 72000 bottles/hour,and the detection accuracy was 1mm.Then the principle and technology of various liquid level detection are compared and analyzed,and the detection method based on dielectric constant is finally determined.Firstly,a parallel plate capacitor model is established to analyze the influence of dielectric with different dielectric constants on the final liquid level.Then the liquid level signal is collected through the signal receiving module and converted into digital signal after multistage circuit processing.Finally,the digital signal processing algorithm is used to calculate the liquid level value and judge whether the liquid level is qualified,and the unqualified liquid level is removed in real time.The high-precision detection and elimination system of bottled liquid level based on dielectric constant detection method designed in this paper is composed of signal source module,signal receiving module,main controller module and elimination module,which has the characteristics of high precision,high speed and low cost.This system not only considers the influence of liquid temperature,bottle foam and bottle deviation on the final result,but also designs a digital signal processing algorithm which can satisfy the high-speed operation of the chain channel,and USES statistical process control to carry out comprehensive management and scheduling for each link.In view of the serious electromagnetic interference in the workshop,various grounding filtering measures and stainless steel shielding shells are designed.At present,the high-precision detection and elimination system of bottled liquid level based on the dielectric constant detection method has been put into use in several production sites,which can meet the requirements of high-speed and high-precision,as well as the detection requirements of different bottle types and solutes.