Research And Realization Of Fault Diagnosis Platform For Analog Circuits Based On Embedded System

Analog circuits are widely used in various of electronic equipments.Compared with digital circuits, analog circuits have higher fault rate.Once the analog circuits get fault may take great damage to the equipment.Therefore study on the fault diagnosis theories for analog circuits has great significance.Because tolerance and nonlinear are widely existent in analog circuits,traditional fault diagnosis methods are difficult to diagnose quickly and accurately.Neural network and other intelligent methods provide an effective way to the fault diagnosis for analog circuits.With the development of Embedded System, embedded technology has been widely used in many fields. If the diagnostic platform can be embedded into electronic devices, the signals can be captured from the circuits board of the device in real time. Fault diagnosis methods used to analyse the signals,the platform will be able to give diagnosis results in real time. This will greatly improve the level of the stability of electronic devices, meanwhile it's a good attempt that if we apply this technology on military electronics.This paper is based on the above ideas to start pre-study.Firstly, BP network was researched deeply.Combined with the fault diagnosis for analog circuits,the design methods of BP network was studied. Then, the BP network was used to ECG amplifier circuit fault diagnosis.MatLab simulation showed that the BP network could classificate failure modes correctly, which verified the feasibility of the article. To the circuits which containe capacitors and inductors, this paper studied how to extract fault features from the circuits under AC excitation.Combined Pspice with MatLab the diagnostic process of specific analog circuit was given.After the research of the BP network, the fault diagnosis system for analog circuits was realiszed on the embedded ARM platform. Combined with the needs of fault diagnosis system for Analog circuits, the overall design block diagram of the hardware platform was given. The cross-compiler and software development environment on the PC were installed.Linux OS was transplanted on the platform and ADC driver was written. A software which could monitor and diagnosis the soft faults of the ECG amplifier circuit was designed.The software obtained good diagnosis rate.An embedded ARM-side client and a PC–side server which realized communication between ARM and PC by net-port were designed based on Linux-Socket.The diagnosis results could be transported and displayed on the PC-side server in real-time . This paper transplanted Qt / E GUI development environment and designed a friendly GUI interface. The innovation of this paper was applied embedded Linux system on fault diagnosis for analog circuits and achieved a real-time monitoring and fault diagnosis system. This paper designed a server and a client base on Linux Socket.The circuit diagnosis results could be sended from the ARM-side client to the PC-side server in real time.The embedded platform of fault diagnosis for analog circuits has good application prospect.