Study On Construction Of Comprehensive Detection System Based On Embedded System

In recent decades, with the economy in our country is developing rapidly, Bridges, tunnels and other large engineerings increase year by year. Safety accidents occur repeatedly, the problems of safety detection are the main reasons, therefore, the relevant datas should be detected and analyzed reasonably when the engineerings are under construction, the existence of hidden dangers can be founded and removed in time, the safety and quality can be assured in construction.Strain is an important parameter of engineering detection, the methods of strain measurement have attracted much attention, this paper chose vibrating wire sensor which output signal steadily and is detected easily to measure strain, according to the vibrating wire sensor, the paper designed and realized a kind of comprehensive detection system based on embedded system which is applied in the engineering detection field.This paper firstly introduced the classification, structure and principle of the vibrating wire sensor, this paper described why choose the single coil vibrating wire sensor, this paper introduced the mathermatical model of the sensor and the formula of strain, this paper mainly studied the method of exciting and detecting the vibrating wire sensor, this paper designed a new improved method of low voltage frequency sweep vibration, this paper chose the input capture mode to detect the vibrating wire sensor.This paper chose the embedded microprocessor STM32as the core of the construction of comprehensive detection system, according to the characteristics of vibrating wire sensor and the functional requirements of large capacity data storage and wireless sending datas. This paper designed the excitable and amplifying circuit of vibrating wire sensor, the improvement of low voltage frequency sweep excitation signal have been produced through the software program, the circuit of excitation is simplified, the sweep time is shortened effectively. This paper designed the pick up circuit for the detection of week signal of vibrating wire sensor, the pick up circuit includes a band-pass filter, the band-pass filter can eliminate noise interference efficiently and improve the measurement accuracy.This paper designed a simple switch circuit, it can effectively control the vibrating wire sensor to connect the excitation circuit or the pick-up circuit, it also can control the vibrating wire sensor to disconnect the excitation circuit or the pick-up circuit. Besides, according to the requirements of the specific function of detection system, this paper studied large capacity storage module based on SD card, the capacity of system can be extended to32GB, the function of real-time data storage is realized; The system is equipped with the display module of TFTLCD, the datas which are detected and the status of storage or sending can be display in real time; Six kinds of wireless communication technology are analyzed and compared, this paper described why choose WIFI technology and studies the technology of wireless communication based on WIFI, the datas can be transmitted wirelessly in real time. As to software design, this paper chose the modular embedded C language to programme, the structure of program is simplified, the program is easy to transplant and maintain.Finally, this paper verified and tested the function of the construction of comprehensive detection system. The results show that compared with the traditional artificial integrated detector, the comprehensive detection system has many advantages, such as:portability, low-cost, the large capacity data storage,wireless sending datas and so on.