Research On Inertial Array Sensor Technology In High-speed Railway Bridge Health Detection

MEMS inertial devices can detect acceleration,angular velocity and other signals in real-time and accurately,and have been widely used in industrial control,structural health monitoring and other fields.As an important part of high-speed railway line,the health status of bridge structure directly affects the comfort and safety of high-speed railway operation process.In the current high-speed railway bridge health detection system,the selected detecting instruments basically have defects such as single detection information,low automation and large error.Therefore,this paper takes the health detection of high-speed railway bridges as the research background,in order to improve the detection accuracy of health detection system for bridge structure information.MEMS inertial devices are used to design array sensors,and related data processing and error analysis techniques are studied.The main work of this paper is as follows:1)In order to realize the optimal detection of bridge structure information,this paper uses the effective independent method to optimize the layout of the sensor measuring points,and realizes the most accurate bridge structure information measured by the least layout points.In view of the problems such as missing and abnormal data in the process of bridge health detection,this paper preprocessed the original data of bridge structure,eliminated the abnormal values according to the pauta criterion,and smoothed the data by using the five-point three-time method.The data after preprocessing greatly reduced the influence of the above factors.In order to obtain accurate angle data,this paper uses the AHRS algorithm to merge the acceleration and angular velocity data,and obtains more accurate angle data through Kalman filtering processing,which can realize the detection of bridge inclination.2)Aiming at the problem of damage analysis of bridge structure response signal,Hilbert-Huang Transform（HHT）method is used to process the signal,and its good processing ability for non-stationary signals is verified by simulation analysis.Four damage detection indexes are constructed and verified by simulation calculation.The results show that the inertial array sensor designed in this paper can identify different damage conditions and positions.However,due to the HHT method will produce modal aliasing problem under strong noise interference,this paper proposes an improved HHT method based on wavelet threshold denoising,and compares its denoising performance with the original method through simulation calculation,which verifies that the improved method can effectively solve the problem of modal aliasing and improve the accuracy of HHT method.3)According to the overall research scheme of inertial array sensor,the design and implementation of its hardware and software are completed.The inertial array sensor will inevitably produce errors under the influence of production,installation,environmental temperature and other factors.In order to ensure the accuracy of its output value,the determination error is calibrated and compensated.After compensation,the output values of accelerometer and gyroscope are closer to the theoretical output value.The sensor test platform was built in the laboratory,and the inertial array sensor was debugged and tested.Through multiple sets of experiments,it was verified that it could meet the requirements of detection equipment in the health detection system of high-speed railway bridges,and it was proved that it could detect the bridge structure information in real-time and reliably.