An Real-time Vacuum Detecting System Based Audio Frequency Analyzing Technology

As the spate of food safety problems at home and abroad in recent years, food safety become more and more attention, state quality inspection departments of food safety supervision is becoming more and more big. the quality of the food and beverage enterprises for the production process real-time monitoring is becoming more and more attention. Herbal tea. vegetable protein beverage cans of food and drink after filling in the process of production high temperature vacuum formed after cooling, to ensure the quality of drinks can be a long time. Due to various reasons result in some vacuum substandard product be packing through production line and then sell to the public, these vacuum unqualified products very easy metamorphism and bring food health threat. On cans of food production must therefore be online real-time detection, vacuum and vacuum bad products to be removed.Nowadays, cans of filling production line of vacuum testing equipment market enterprises dominated mainly by the United States and Germany. Not only expensive, but not the friendly operation interface in English to domestic users has brought about many problems. Real-time vacuum detection system to study the effects of domestic independent intellectual property rights is of great significance, not only can satisfy domestic cans of food enterprise demand for online vacuum testing equipment, and can effectively restrain the high price of similar products abroad.From acoustic theory, this paper first analyzes the vacuum (negative pressure) and easy pull cover the inherent vibration frequency, the vacuum property is obtained, the higher the vibration frequency tank cover important conclusions, and this conclusion is verified by experiments. Then make full research system of the actual work environment and working process of the detailed design of the system hardware frame and software interface. Then the system is divided into three parts:DSP real-time audio collection analysis module software and hardware design, high-energy magnetic pulse excitation voice module software and hardware design and PLC man-machine interface design, each module separate test by integration testing, again after the final successful real-time production line of vacuum test system is designed.Reached1000bottles/min in the actual plant environment, high test speed and in continuous test10000cans product, has not been a miscalculation false negatives.This paper mainly do the following work:1. In this paper, from the hardware and software framework for system development provides the correct way of thinking, the implementation of the system is divided into three modules to complete:high-energy magnetic pulse excitation voice module. DSP audio signal collection and analysis module and PLC man-machine interface module.2. Detailed explained the high-energy magnetic pulse module of software and hardware design. Emphatically analyses the capacitance of the inductance of the discharge process produce high-energy magnetic pulse, and high frequency charging and discharging of the hardware and software design.3. Detailed explained the DSP audio signal collection and analysis processing module design. Hardware design emphasizes the microphone audio collection processing and high-speed AD sampling circuit design of the circuit, and briefly introduces the DSP minimum system design. Software focus narrative voice signal processing programming.4. Describe the function of PLC module, the software flow chart of PLC modules was introduced in detail.5. The system integration test made a clear instructions, shows that the developed system has practical value, can solve the current domestic beverage cans of food enterprise demand.