Research And Desien Of Gas Tightness Detection System Based On Machine Vision

Airtight container is a kind of common equipment to store gas. such as gas storage tanks and acetylene cylinders. It is widely used in industrial production and daily life. Airtight container of gas leakage especially combustible gas leakage, can be directly caused explosion, fire, and even injury and the personal safety; Therefore the airtight container gas leak detection is an important research topic on public security areas of disaster prevention and mitigation. It is of great significance for preventing unnecessary accident and protecting people’s life and property security.This article introduced the domestic and foreign research present situation and the development trend of air tightness test on small pressure vessels. Aiming at solving shortage of some Pressure Vessel Factory in Jiaxing plugging hole and estimating bubble by artificial, an automatic air tightness test system controlled by PLC was designed. Main research contents and results are summarized as follows:(1) The domestic and foreign research present situation and the development trend of air tightness test on small pressure vessels is studied. Several kind of detection method is analyzed. By discussing deficiencies of original bubble water detection method, automatic detection scheme based on machine vision is proposed.(2) The structure characteristics and process requirements is introduced. A simulation model of gas storage is established by PRO/E. Through detailed designing of mechanical parts like the test platform, tanks supporting frame, transmission device, clamping device and blocking, etc. The overall design of the mechanical system is completed.(3) Through analytical investigation of technological realization to Air tightness measurement and control system, the type and the parameter of cylinder and motor is calculated and selected. As automatic control system developed, we realized the tanks from waiting for inspection station to check station, flooding/water, output location of automatic transmission.(4) The basic principle of the optical flow method is introduced, the bubble image detection method based on optical flow method is discussed. In the following of study of the formation of the image processing system and setting up a platform for image acquisition, research of using high speed camera equipment for the water bubble film and image acquisition and processing of experimental is carried out. Results show that this system can detect the size and centroid location parameters of air bubble, realized the recognition of the leak and leakage. When there are air bubbles, the system can give alarm by PLC, in order to prompt the leakage of pressure vessel. The system has high feasibility.