Research About Air Leak Detection Control System Based On Embedded System

Leakage detecting plays an important role in quality assurance of products and is becoming increasing widely applied. Currently, the research on the new gas leak detection device controller based on the IPC has defects like high cost, poor portability and so on, the embedded system can mend these defects due to the advantages of small size, light weight, low cost, and high reliability. In this paper, the air leak detection control system based on embedded system is researched.This paper firstly introduces the principle of vapour-pressure type leak detection, then volume compensation leak detection is put forward based on the method of differential pressure leak detection. According to the function needs of the volume compensation leak detection, an air leak detection control system based on ARM9 and Linux is designed in this paper, the whole control system is composed of hardware and software system.According to the characteristics and functions of air leak detection system, in this paper, ARM9 processor S3C2440 is used as core controller in hardware system, and the circuit in core controller is designed in detail. According to the overall design requirements, peripheral interface circuits are separately designed like power reset circuit, LCD interface circuit, communication interface circuit and so on, on the other hand hardware about data acquisition module and executive component(relay and stepper motor) are designed in detail, then the design of entire system’s hardware platform is completed. The data acquisition module collects analog signal through the sensor in gas path system, converts it to figure signal and transfers it to microprocessor, then the microprocessor processes data on LCD display and controls the executive component according to the data. The primary work of Software design is to build embedded Linux platform which is suitable for the control system, including:build a cross development environment between host machine and target machine, Bootloader transplantation, Kernel custom transplantation, design and load of stepper motor and data acquisition drive, root file system’s design and transplantation. At last, application software of volume compensate type leak detection device designed by QT/Embedded is used to complete stepper motor’s PID control, relay control, the displaying waveform in differential pressure transducer and displacement sensor and the calculation and display of the leakage and leakage rate in the measured compensation device.The experiment is preformed after the build of the embedded air leak detection platform. Experimental results indicated:this system can well control the air leak detection device, accurately detect the leakage and leakage rate of sealed container and can reach the intended purpose on basis of reducing cost and improving portability of the system.