Design Of On-line Filling Level Detection System Based On Capacitive Coupling

In order to ensure the quality of the product,on-line detection of the beverage filling level is an essential part of production.With the increase of production capacity,bottled beverage production lines are currently designed to produce 72,000 bottles/hour.Traditional artificial light inspection methods have been difficult to meet the needs of modern high-speed filling lines,which requires the introduction of on-line automatic detection equipment.In view of the existing problems in the production process of Chinese beverage production enterprises,based on the advanced sensor technology,embedded ARM processor chip and digital signal processing method,the on-line detection system of beverage filling level based on the principle of capacitance coupling 1s designed and implemented in this paper.The system firstly collects the liquid level signal through a capacitive sensor.After the collected signal is processed by a multi-stage circuit,it is converted into a digital signal,and then the liquid level value is calculated through a signal processing algorithl.In order to achieve the trigger detection of the bottle in the rapid production process,the filling level on-line detection system has designed the main controller and is responsible for the system's detection process control.Because there are a large number of electromagnetic interference sources in the production site,in order to improve the electromagnetic compatibility of the system,this paper designed a variety of interference suppression measures on the hardware and software to ensure the stable operation of the system.This paper fir-st analyzes the existing filling level detection scheme,and proposes a detection scheme based on capacitive coupling for the disadvantages of existing schemes.Through the analysis of the equivalent circuit of the system and a large number of experiments,the detection parameters of the sensor are optimized.According to the characteristics of the actual production site,the overall structure of the system was planned and designed,and the hardware circuits and software programs of each subsystem were introduced.Then through a series of experiments,the feasibility of this detection scheme was verified.The system has the characteristics of low cost,high precision,wide application range,convenient installation and debugging.At present,based on the principle of capacitive coupling,the online detection system for beverage filling liquid level has been put into use at several production sites,and has achieved good detection results.