Design And Implementation Of Concrete Measuring System Based On IPv6 And Low-power Consumption

The reinforced concrete will be subject to varying degrees of corrosion in a variety of environments,especially in the seawater rich in harmful ions,there's a large quantity of chlorine and sulfate,which will respectively have chemical reaction with steel and concrete,resulting in steel corrosion and concrete cracking.Therefore,the detection of corrosion of the reinforced concrete is important in civil engineering,which can be used as a reference for the detection and protection of concrete corrosion.In the early construction of Qingdao Cross-sea Bridge,and a large number of the sensors were embedded in the concrete pier subjected to the erosion of seawater,thus to measure its internal electrochemical parameters.However,the location of the sensor on the pier and the number of embedded sensors has brought great difficulties to the traditional field measurement.Therefore,for the complex application scenarios of Qingdao Cross-sea Bridge,there's the need to use its embedded sensors to achieve a simple and effective automated measurement,and transmit the data collected to the network through the wireless way.After studying and comparing a variety of the corrosion electrochemical measurement methods and this subject uses AC impedance to measure and analyze corrosion condition of concrete.AC impedance is a method by using small amplitude sinusoidal AC signal for electrochemical testing.The measured AC impedance data is used to analyze its electrochemical characteristics.AC impedance measurement is conducted by using AD5933,and AD5933 is the solution for the high-precision impedance converter system.The internal DDS generates a signal to excite the external complex impedance,ADC collects the response signal,and then the complex impedance value on each frequency point is obtained by the chip DSP for conducting DFT calculation.Data upload is conducted through the wireless sensor network,and the terminal node of the wireless sensor network node collects sensor data,and forms a multi-hop self-organized network,letter to communicate wirelessly.Considering the embedded hardware condition,network protocol and system environment.This subject focuses on two major demands of low power consumption and IP network on the basis of Contiki operating system,and CC25348 controller,thus to combine the concrete parameter measurement with wireless sensor network,designing and implementing a concrete inspection system suitable for Qingdao Cross-sea Bridge.Among them,subnet coordinator and node run the Contiki system,IEEE 802.15.4 protocol standard is used for wireless transmission,the adaptation between IEEE 802.15.4 and IPv6 is achieved through 6LoWPAN,uIPv6 protocol stack is achieved based on the appropriate cut and necessary modification,thus to form a more lightweight IPv6 protocol stack,and the author designs the corresponding routing protocol according to node distribution of Qingdao Cross-sea Bridge.The system gateway operates development board MT7688 development board running WRT,connecting with the IP network,and the connection between router and IP network through the wired way,connecting CC2538 minimum system through the serial port to realize the connection between the smallest system and wireless network.After debugging and improvement,the subject finally set a subnet with wireless sensor network on the piers of Qingdao Cross-sea Bridge,and the data is collected per 6 hours every-day,which is uploaded to the Internet.After a period time of statistics and analysis,the node data is with the missing,but it does not affect the long-term data analysis.It can be seen that this study has completed the detection of Reinforced Concrete Bridge in Qingdao,which has a certain reference to the concrete detection of civil construction such as highway,buildings and others in addition to the great significance of corrosion detection and protection.