LMS Alternating Current Blocking Method Rhythm Muscle Crowding Soil Erosion Under Observation

Reinforced concrete is an important load-bearing component in buildings.Its structural durability is directly related to the safety of buildings.Corrosion of reinforced concrete will lead to the degradation of the load bearing capacity of the whole structure,which may cause building damage,economic loss and safety accidents.Therefore,the study of the corrosion of reinforced concrete structures has important theoretical significance and practical engineering value.In view of the problems existing in the current corrosion detection technology,such as being unable to unify the parameters,only obtaining partial corrosion information,and the accuracy and accuracy of the measurement results remain to be improved.An improved corrosion detection method of reinforced concrete based on AC impedance method is presented in this thesis.Compared with other detection methods,the AC impedance method can obtain more dynamic information and structure information of the electrode interface,and can analyze the performance change of reinforced concrete microstructure.The measurement of reinforced concrete corrosion by AC impedance method takes the AC sinusoidal signal with a amplitude of 10 mv as the excitation signal,and the detection signal after the reinforced concrete system is the weak signal of microsecurity level.The weak signal is vulnerable to noise,which leads to large error of the measured data and cannot accurately reflect the corrosion state of reinforced concrete system.An LMS adaptive filtering algorithm with variable step length is proposed to solve the problem of weak signal error in measuring corrosion of reinforced concrete.The correspondence between error and step factor is improved.When the error is large,the step size factor is used to improve the convergence speed.When the error size is small,the step size factor is used to reduce the steady-state error.The improved algorithm has better tracking capability for the whole system and improves the signal-to-noise ratio of the weak detection signal in the AC impedance method.Based on this,a corrosion detection system of reinforced concrete based on AC impedance method is designed.The system includes a low frequency to high frequency variable frequency weak excitation signal generating circuit,a weak current into a measurable voltage detection circuit and a current-voltage conversion circuit.The system implements variable step length LMS adaptive filtering process.The information of the real and imaginary parts of the impedance of reinforced concrete can be obtained through the DFT algorithm,and the information of the AC impedance spectrum of reinforced concrete can be obtained.The variable step size LMS adaptive filtering algorithm proposed in this paper is applied to the measurement of reinforced concrete corrosion by AC impedance method.The signal-to-noise ratio of the weak detection signal is obviously improved.The impedance spectrum can be obtained from the measured data,and the corrosion state of the reinforced concrete system and the electrical parameters of the whole system can be obtained from the impedance spectrum,which have been well applied in engineering practice.